Engine dynos and dynojets...
07-10-2005, 12:31 AM
#21
Registered User
iTrader: (4)
Join Date: Sep 2002
Location: Who wants a dyno?
Posts: 1,779
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by phunk
A dyno with an eddy current brake allows for less time spent to map a car to precision... but the load applied to the engine is no more realistic then the load of inertia... all the engine see is resistence to accelerate and that is that. A brake dyno allows you to hold a load point... thats it... Think this one thru now... what load is there on the street? Do you have your brakes on when your racing full throttle? I certainly hope not... see there we have it, the street is not a BRAKE load. On the street you are fighting INERTIA to accelerate the car. A BRAKE LOAD is used for TUNING by holding a load point to allow you to accurately tune it. The same thing could be done by using you brakes to hold the car on the street or on an inertia dyno (which would ruin your brakes right away, hence why you dont do it for more than a second or two).
Well as a customer paying upwards of $120/hour to tune I'd think time would be an important factor. Of course as a shop you would want to take as long as possible to maximize profits.
What about the time a driver spends in between idle and full throttle? How about tuning there? I guess if you only interested in peak numbers and not the map area that the vehice spends 95%+ of it's time operating in, partial throttle, partial load conditions, then an inertia dyno is a good thing.
Oh but wait, partial throttle positions can be mapped on an inertia dyno but it will ruin your braking system (per your quote). Sounds like a great way to tune a vehicle. Btw, how quickly does that remote a/f ratio meter react to changes.
Ok how does an inertia dyno w/ 5000lbs interia handle this scenario?
The vehicle has an intermittent loss of power due to faulty injector, coil, plug, spark blow out, bad cell value, poor tune, etc.
Will it show up on the graph? Will you even know it exists?
Nope. A dyno spinning 5,000lbs+, calculating acceleration via counting a flag that swings thru a hall effect sensor has absolutly no chance in hell of catching a momentary power spike.
It will on ours.
http://www.dyno.com.au/usa/ocr/ocr_jason.htm
Direct measurement of power output via a load cell. Our dyno's rotational inertia is less than 250lbs total. BTW, that's real time graphing, something we've had for 15+ years, Dynojet just released their live graphing when, 3 months ago?
Originally Posted by phunk
But in all reality, what most likely happened between your load on/off comparison is that you hit slightly different boost, as engine load will change the boost curve. This is why one particular boost controller setting will make different boost between the street and an inertia dyno... after tuning on an inertia dyno you will need to recalibrate the boost controller to run the boost you just tuned for.
Or maybe you just bought the dynojet because of all the big numbers it spits out.
Big numbers just gives eveyone a warm and fuzzy feeling inside, don't they. "Car drives like crap, throttle response sucks, but hey look @ my numbers!!"
Originally Posted by phunk
How does the turbocharged engine generate boost... or even better yet... why does the boost come on so fast... as fast as it does on the street?
Originally Posted by phunk
Because most brake dynos are setup incorrectly by people who have no idea how to use the machine of their investment, and on a non-tuning full throttle power measurement run the load is not correctly configured and the turbochargers response is not accurate to real world.
Originally Posted by phunk
I have seen some of the dyno graphs of turbocharged Zs on load dynos and their boost curve is WAY off because whoever setup the dyno didnt have it calibrated to properly simulate the road. A dynojet 248, depending on actual weight of the car, gearing, and whta gear its run in, will generate similiar enough load to the street to spool the turbos with a boost profile within a few hundred RPM (or better) as it performs on the street.
Yep you got us eddy current dynos operators here, it does take some intelligence and training to correctly operate the dyno. Not everyone out there should be operating an eddy current dyno that actually lets you change parameters. User definable parameters, frightening stuff there. One has to actually think about what loads to apply, how the engine is going to respond, which method will best simulate real world condition, how to make the customer's car run correctly and safely off the dyno.
Nope, not like a dynojet inertia @ all. Just strap it down and make a pass. 2000lb 120hp honda or 8500lb 880lbft diesel truck. Nope no need to adjust the load those 2 vehicles are going to be subjected to real world. Same load is going to tune them both, yup life is good as an inertia dyno operator.
Thinking hurts.
Last edited by UnderPressure; 07-10-2005 at 01:50 AM.
07-10-2005, 01:07 AM
#22
Registered User
iTrader: (4)
Join Date: Sep 2002
Location: Who wants a dyno?
Posts: 1,779
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by phunk
Mr Q: You can get a good comparison if you do use another dynojet. The dynojets may make it more difficult to accurately tune a car... but you can be assured that another dynojet of the same model you ran on before (most likely the 248) will be a very fair comparison.
DD +-1% worldwide in Shootout Mode. The Shootout accredidation program has not been rolled out here in the US but every DD dyno here has Shootout mode in the software. Some operators choose to use it, some don't.
Originally Posted by phunk
Most Dynojets use inertia as their load (only brand new one are available with eddy current), there are no user defined settings...
Why won't you let you customers have full control over your dyno software? hmm...
Originally Posted by phunk
The inertial mass between one dynojet 248 to another is EXTREMELY close, and it will be very accurate comparison.
Originally Posted by phunk
What you need to find out about your previous runs is if they were done CORRECTED or UNCORRECTED and what type of correction was used. If they WERE in fact corrected numbers then you need to make sure they are accurate corrected numbers... for example some dyno shops will leave their air temp sensors in a poor spot that gets a lot of heat from the car, which will INCREASE the corrected output numbers. The CORRECTED readings are to compensate for baro pressure, air temp, etc. Also for fair comparison you need to be on the same wheel/tire combo with the same tire pressure.
Originally Posted by phunk
Basically what I am getting at is if you meet the proper conditions, you can get an extremely accurate comparison on another dynojet that is the same model... this way you can see your gains or losses... not to mention the dynojet 248 is the most common dyno in the US... you can find one anywhere.
Originally Posted by phunk
Brake dynos are very configurable (which is great for tuning) but unfortunatly you might not even get consistent readings on the SAME dyno from one day to another as they might not be running the same settings as the last time you were on it... if you start using a dyno like that.. make sure and take a note of all the configured settings on the day that you use it... so that when you return (or use another identical dyno somewhere else) you can make sure to have them run it the same way it was before.
Originally Posted by phunk
There is nothing wrong with choosing to use a different dyno now... as like I said before the dynojets that are inertia only (almost all of them) make it more difficult to tune.
Originally Posted by phunk
However, dont believe the ******** from the people posting who have no idea what they are talking about, or no experience with the dynojet, or especially someone who SELLS other dynos, haha. The dynojet 248 is pretty old and obsolete now, but there is certainly nothing wrong with its intended functions.
Everytime I have posted on the subject of dynos I have tried to be as fair and impartial as possible. With your comment you have now opened the flood gates.
I have @ no time hidden the fact that I am an agent for DD. It is listed in my sig for christ sake. I have also been a customer of theirs for the past 4 years. In the past I have worked w/ Superflow, Mustang, and yes Dynojet. I was busines partners w/ the former western USA DJ rep. Dynojet had their time and place, both were over wth 10 years ago. Now they are scrabbling to play catchup w/ the rest of the dyno mfg. They grew complacent because of their bigger numbers are better marketing stratagy. Tuners got better, and dynojet could not match their needs. Look @ DJ's latest offerings, a smaller roller eddy current dyno. Now who does that remind you of? Same w/ Superflow, Mustang, Maha... Sometimes it's just hard being the best.
Oh and if you happen to be @ SEMA this year, come by and see our newest offering, yet again putting everyone else 5 years behind. We will have a dyno setup inside and one outside doing demos. Now, who else does live dyno demos @ SEMA & PRI? Must be those guys who actually take a dyno out onsite to a potential customer and teach them first hand about the dyno w/ no obligation or cost. Actually having the customer drive on the dyno, tune on the dyno, and all in about 3 hours.
Yup just little old us, Dyno Dynamics @ your service.
Last edited by UnderPressure; 07-10-2005 at 01:55 AM.
07-10-2005, 05:08 AM
#23
hey its all good, you dont have to sell me... brake dynos are very useful and my post was not about trying to belittle their function and usefulness. Your focusing on completely the wrong points and just being plain defensive. Especially considering I wasnt even talking to you, or saying negative things about your brake dynos... I was explaining how garys experience made no sense.
But i will spend a little time here and argue back... cause i like to argue...
So the only purpose of a eddy current dyno is to hold steady state, which you claim really serves no purpose other than speeding up the tuning process.
is that not what its intended for? Sounds like that is enough use to make it worth it anyway, no?
Well as a customer paying upwards of $120/hour to tune I'd think time would be an important factor. Of course as a shop you would want to take as long as possible to maximize profits
sounds good... except of course i tuned high paying service customers cars for free most the time back when I owned a dyno. I certinaly never charged more then a couple hundred even on the ones that take forever.
What about the time a driver spends in between idle and full throttle? How about tuning there? I guess if you only interested in peak numbers and not the map area that the vehice spends 95%+ of it's time operating in, partial throttle, partial load conditions, then an inertia dyno is a good thing.
what makes you think that you have to floor it just cause your on an inertia dyno? wtf? I mean come on, you guys really have the lamest arguements here. I do tons of part throttle pulls, very rapidly... within a minutes i can have done 10-20 part throttle drive thru runs datalogging and adjusting maps as i go just tapping the dyno brake over and over. you act like all you can do is strap down and floor it and say oh there it is we are done now.
Oh but wait, partial throttle positions can be mapped on an inertia dyno but it will ruin your braking system (per your quote). Sounds like a great way to tune a vehicle. Btw, how quickly does that remote a/f ratio meter react to changes.
the dyno has its own brake, i never use a cars brakes on the inertia dyno as it will quickly ruin them... that would be a poor decision.
As for the remote A/F meter... that depends on where you put it. If we put it in the tailpipe its a little laggy and the sensitivity to rapid changes goes down. If we are tuning a car with a full standalone where we need better resolution... we just put it in the downpipe... why do you ask?
Ok how does an inertia dyno w/ 5000lbs interia handle this scenario?
The vehicle has an intermittent loss of power due to faulty injector, coil, plug, spark blow out, bad cell value, poor tune, etc.
Will it show up on the graph? Will you even know it exists?
yes, you will see jaggedness in the dyno graph, just as I have several times... not to mention the car will be running like ****. if you need a dyno to tell you that something is wrong with an injector, coil, or your getting spark blow out.... its time to hand the tuning over to someone else. and of course you can tell if the tune is bad on the dyno... when your datalogging A/F along with everything else... and driving around on the dyno... how would you NOT notice???
Nope. A dyno spinning 5,000lbs+, calculating acceleration via counting a flag that swings thru a hall effect sensor has absolutly no chance in hell of catching a momentary power spike.
Wrong.
It will on ours.
http://www.dyno.com.au/usa/ocr/ocr_jason.htm
Direct measurement of power output via a load cell. Our dyno's rotational inertia is less than 250lbs total. BTW, that's real time graphing, something we've had for 15+ years, Dynojet just released their live graphing when, 3 months ago?
Thats a fantastic video... you will see the same results in the graph on an inertia dyno by performing the run in a higher gear... and once again, if you need the dyno to show it... well...
Ok, so your saying after spending the customers money on dyno time, you/customer now have to spend more shop time, re:money, street tuning boost levels as well. This is because the real world load characteristic are diffferent from those the inertia dyno applied during your "tuning" session.So now you have to take the car out on the road and make adjustments via trial and error, wait, wasn't that one of the purpose of buying a dyno to prevent the hazards of street tuning? Cops, traffic, accident, ability to moniter a/f, moniter tangable power losses and gains, etc..
it takes about 1 second, and I usually dont even go with. Its only a couple percent duty cycle. I knock it up a couple percent and say to the customer "if your boost is a half psi low then just turn it up another percent or two and your set". sorry... but its no big deal and i bet that even on your dyno a slight adjustment is required. like it takes so long to turn a ****? sorry but your just pulling them out of your *** now.
Or maybe you just bought the dynojet because of all the big numbers it spits out.
i bought it cause it brings in money, more than your dyno will... equiptment like that is purchased for investment purpose, not bragging rights. It may make tuning take a little longer, but I dont care. Its the standard dyno for comparison in the USA... and nothing is going to change that... and unfortunately for other dyno manufacturers... dynojet now has eddy current dynos available that will pick up where their old inertia dynos left off, and their US legacy will continue as the dyno of choice, regardless of why... people stick with what they know and hear, and for as long as most of these people have been playing with cars... dynojet was the one they were told to use... and now they have updated their lineup with all the great features they were lacking without the eddy current brake.
Big numbers just gives eveyone a warm and fuzzy feeling inside, don't they. "Car drives like crap, throttle response sucks, but hey look @ my numbers!!"
you must have taken your car to a bad tuner in the past, and for this im very sorry... just cause you or someone you knew couldnt use the equiptment for what its worth... dont take it out on the equiptment.
Wait didn't you just say the boost levels had to be retuned after running on a Dynojet? Now you are saying they don't? I'm confused?
??? re-read the sentance. It doesnt say anything about adjustment of boost levels, it says "why does the boost come on so fast... as fast as it does on the street?"
See above, yet again. So inertia dynos are good because you can't change the inertial load. Which you previouslly stated is not indicative of real world conditions. But, by not changing the load of an eddy current dyno to match up w/ real conditions, an eddy current dyno is bad? Do you even know what your trying to say here?
maybe you would know what i was trying to say if you didnt focus on putting words in my mouth to your advantage... matter of fact the only arguements you have are to statements that I never said, but you created. Interesting strategy.
The real question is... do YOU know what your trying to say here? Or are you just asking me?
Ok so for a specific car in a specific gear under a specific condition, the interia dyno "generates similar enough load". Boy that's an awful narrow field of vehicles that dyno is qualified to run.
no... its qualied to run just about any cars. you act like the load on the street is the same in every gear... if you can shift on the street... why cant you shift on the dyno? Put it in the gear of choice that will get you more or less load to aid you in tuning. Sometimes I do tuning pulls in 6th gear to slow everything down and slowly take me thru the load points.
Yep you got us eddy current dynos operators here, it does take some intelligence and training to correctly operate the dyno. Not everyone out there should be operating an eddy current dyno that actually lets you change parameters. User definable parameters, frightening stuff there. One has to actually think about what loads to apply, how the engine is going to respond, which method will best simulate real world condition, how to make the customer's car run correctly and safely off the dyno.
i wasnt trying to get anyone, just trying to eliminate some of the ********. inertia dynos are great for pumping out cars at dyno days and not having to worry about all the BS... and as long as they stick with the same dyno type it will always be a fair comparison.
Nope, not like a dynojet inertia @ all. Just strap it down and make a pass. 2000lb 120hp honda or 8500lb 880lbft diesel truck. Nope no need to adjust the load those 2 vehicles are going to be subjected to real world. Same load is going to tune them both, yup life is good as an inertia dyno operator.
if your not tuning the car... than who gives a ****? they just want to see a graph. on a dyno day my customers get mad if i cant get all 20 of their cars on... sorry, i dont feel like playing with all your settings in that scenario. brake dynos are for tuning, not comparing. thats all i was saying... the rest of this debate is all you.
But i will spend a little time here and argue back... cause i like to argue...
So the only purpose of a eddy current dyno is to hold steady state, which you claim really serves no purpose other than speeding up the tuning process.
is that not what its intended for? Sounds like that is enough use to make it worth it anyway, no?
Well as a customer paying upwards of $120/hour to tune I'd think time would be an important factor. Of course as a shop you would want to take as long as possible to maximize profits
sounds good... except of course i tuned high paying service customers cars for free most the time back when I owned a dyno. I certinaly never charged more then a couple hundred even on the ones that take forever.
What about the time a driver spends in between idle and full throttle? How about tuning there? I guess if you only interested in peak numbers and not the map area that the vehice spends 95%+ of it's time operating in, partial throttle, partial load conditions, then an inertia dyno is a good thing.
what makes you think that you have to floor it just cause your on an inertia dyno? wtf? I mean come on, you guys really have the lamest arguements here. I do tons of part throttle pulls, very rapidly... within a minutes i can have done 10-20 part throttle drive thru runs datalogging and adjusting maps as i go just tapping the dyno brake over and over. you act like all you can do is strap down and floor it and say oh there it is we are done now.
Oh but wait, partial throttle positions can be mapped on an inertia dyno but it will ruin your braking system (per your quote). Sounds like a great way to tune a vehicle. Btw, how quickly does that remote a/f ratio meter react to changes.
the dyno has its own brake, i never use a cars brakes on the inertia dyno as it will quickly ruin them... that would be a poor decision.
As for the remote A/F meter... that depends on where you put it. If we put it in the tailpipe its a little laggy and the sensitivity to rapid changes goes down. If we are tuning a car with a full standalone where we need better resolution... we just put it in the downpipe... why do you ask?
Ok how does an inertia dyno w/ 5000lbs interia handle this scenario?
The vehicle has an intermittent loss of power due to faulty injector, coil, plug, spark blow out, bad cell value, poor tune, etc.
Will it show up on the graph? Will you even know it exists?
yes, you will see jaggedness in the dyno graph, just as I have several times... not to mention the car will be running like ****. if you need a dyno to tell you that something is wrong with an injector, coil, or your getting spark blow out.... its time to hand the tuning over to someone else. and of course you can tell if the tune is bad on the dyno... when your datalogging A/F along with everything else... and driving around on the dyno... how would you NOT notice???
Nope. A dyno spinning 5,000lbs+, calculating acceleration via counting a flag that swings thru a hall effect sensor has absolutly no chance in hell of catching a momentary power spike.
Wrong.
It will on ours.
http://www.dyno.com.au/usa/ocr/ocr_jason.htm
Direct measurement of power output via a load cell. Our dyno's rotational inertia is less than 250lbs total. BTW, that's real time graphing, something we've had for 15+ years, Dynojet just released their live graphing when, 3 months ago?
Thats a fantastic video... you will see the same results in the graph on an inertia dyno by performing the run in a higher gear... and once again, if you need the dyno to show it... well...
Ok, so your saying after spending the customers money on dyno time, you/customer now have to spend more shop time, re:money, street tuning boost levels as well. This is because the real world load characteristic are diffferent from those the inertia dyno applied during your "tuning" session.So now you have to take the car out on the road and make adjustments via trial and error, wait, wasn't that one of the purpose of buying a dyno to prevent the hazards of street tuning? Cops, traffic, accident, ability to moniter a/f, moniter tangable power losses and gains, etc..
it takes about 1 second, and I usually dont even go with. Its only a couple percent duty cycle. I knock it up a couple percent and say to the customer "if your boost is a half psi low then just turn it up another percent or two and your set". sorry... but its no big deal and i bet that even on your dyno a slight adjustment is required. like it takes so long to turn a ****? sorry but your just pulling them out of your *** now.
Or maybe you just bought the dynojet because of all the big numbers it spits out.
i bought it cause it brings in money, more than your dyno will... equiptment like that is purchased for investment purpose, not bragging rights. It may make tuning take a little longer, but I dont care. Its the standard dyno for comparison in the USA... and nothing is going to change that... and unfortunately for other dyno manufacturers... dynojet now has eddy current dynos available that will pick up where their old inertia dynos left off, and their US legacy will continue as the dyno of choice, regardless of why... people stick with what they know and hear, and for as long as most of these people have been playing with cars... dynojet was the one they were told to use... and now they have updated their lineup with all the great features they were lacking without the eddy current brake.
Big numbers just gives eveyone a warm and fuzzy feeling inside, don't they. "Car drives like crap, throttle response sucks, but hey look @ my numbers!!"
you must have taken your car to a bad tuner in the past, and for this im very sorry... just cause you or someone you knew couldnt use the equiptment for what its worth... dont take it out on the equiptment.
Wait didn't you just say the boost levels had to be retuned after running on a Dynojet? Now you are saying they don't? I'm confused?
??? re-read the sentance. It doesnt say anything about adjustment of boost levels, it says "why does the boost come on so fast... as fast as it does on the street?"
See above, yet again. So inertia dynos are good because you can't change the inertial load. Which you previouslly stated is not indicative of real world conditions. But, by not changing the load of an eddy current dyno to match up w/ real conditions, an eddy current dyno is bad? Do you even know what your trying to say here?
maybe you would know what i was trying to say if you didnt focus on putting words in my mouth to your advantage... matter of fact the only arguements you have are to statements that I never said, but you created. Interesting strategy.
The real question is... do YOU know what your trying to say here? Or are you just asking me?
Ok so for a specific car in a specific gear under a specific condition, the interia dyno "generates similar enough load". Boy that's an awful narrow field of vehicles that dyno is qualified to run.
no... its qualied to run just about any cars. you act like the load on the street is the same in every gear... if you can shift on the street... why cant you shift on the dyno? Put it in the gear of choice that will get you more or less load to aid you in tuning. Sometimes I do tuning pulls in 6th gear to slow everything down and slowly take me thru the load points.
Yep you got us eddy current dynos operators here, it does take some intelligence and training to correctly operate the dyno. Not everyone out there should be operating an eddy current dyno that actually lets you change parameters. User definable parameters, frightening stuff there. One has to actually think about what loads to apply, how the engine is going to respond, which method will best simulate real world condition, how to make the customer's car run correctly and safely off the dyno.
i wasnt trying to get anyone, just trying to eliminate some of the ********. inertia dynos are great for pumping out cars at dyno days and not having to worry about all the BS... and as long as they stick with the same dyno type it will always be a fair comparison.
Nope, not like a dynojet inertia @ all. Just strap it down and make a pass. 2000lb 120hp honda or 8500lb 880lbft diesel truck. Nope no need to adjust the load those 2 vehicles are going to be subjected to real world. Same load is going to tune them both, yup life is good as an inertia dyno operator.
if your not tuning the car... than who gives a ****? they just want to see a graph. on a dyno day my customers get mad if i cant get all 20 of their cars on... sorry, i dont feel like playing with all your settings in that scenario. brake dynos are for tuning, not comparing. thats all i was saying... the rest of this debate is all you.
Last edited by phunk; 07-10-2005 at 06:10 AM.
07-10-2005, 05:13 AM
#24
your agueing with the wrong person here.
basically your trying to tell me (Someone who has tuned countless cars on an inertia dyno, and has seen HUNDREDS other tuners cars tuned on an inertia dyno with great success) that it cannot be done.
Sorry, but your not gonna convince me. You dont need to sell me either... if I could have added an eddy current to my Dynojet 248 when I had one, I would have... but I worked around not having it. If your going to buy a dyno these days... you buy one thats eddy current and thats that. If you cant tune without eddy current when its not available... well... sorry but you need to hand over the controls to someone else.
basically your trying to tell me (Someone who has tuned countless cars on an inertia dyno, and has seen HUNDREDS other tuners cars tuned on an inertia dyno with great success) that it cannot be done.
Sorry, but your not gonna convince me. You dont need to sell me either... if I could have added an eddy current to my Dynojet 248 when I had one, I would have... but I worked around not having it. If your going to buy a dyno these days... you buy one thats eddy current and thats that. If you cant tune without eddy current when its not available... well... sorry but you need to hand over the controls to someone else.
07-10-2005, 05:30 AM
#25
The factory spec from Dynojet in '98 was +-3% variance from individual dyno to dyno. So a 200whp car can make 200whp on dynojet #1, 206whp on #2 and 194whp on #3. 12whp difference on just a 200hp car. Factory acceptable. How the hell is a customer that goes to different dynos suposse to tell if they have a gain or loss? Supposedly they have closed up their tolerence range recently due to the market demand.
maybe no one told you that each copy of the dynojet software is specifically calibrated for your dyno and the exact balanced weight of your rollers?
Hey dynojet welcome to the load based dyno party, we've been here 27 years.
you must be so proud. Did you invent the brake dyno yourself? Have a cookie.
Ok let's just assume 1% tolerence from the factory, that still +-50lbs. But then again you are spinning up the equivilant weight of a full size truck. What the hell, we'll let you go on this point.
load is load... did you invent an engine or ECU that knows the difference between load supplied by inertia versus a brake? Didnt think so.
Just because it's the most common doesn't mean it's the best. If so we would all be driving camarys hauling around our 2.5 kids going to our 28k a year job.
never said its the best... inertia dynos are FAR from the best... which is why I said you dont need to sell me. I was just defending some of the more retarded things said. Either way, it doesnt take the BEST for a WOT graph run.
Yup, know your settings. This way an operator can correctly replicate real world conditions. Although any knowledgeable operator should be able to arrive @ the correct setting for your specific vehicle. Yes settings just for you and you alone. Not a global setting to cover all vehicles on the road.
which is what i just said. unfortunatly its not uncommon that brake dyno operators have no idea how to use their investment... I cant even think of how many customers have complained of this to me... and the couple times that I have used them I had to get the manual out myself.
I guess you might be wondering what set off this rant.
I know exactly what set off this rant. You didnt like what I had to say about something you sell, and you didnt like that I basically said that what you say is completely biased. Which it is.
As for the history of dynojet versus your company... history is history and all that matters is what someone is trying to do at the moment they need it done. That involves using what is available immediately. If you can have a eddy current brake, then BY ALL MEANS USE IT. I wont be as offended as you get when someone doesnt.
Of course you will redicule dynojet for catching up with the features you sell... it will be of a big hurt to your company. The dynojet 224xlc with eddy current hasnt even been available for a year yet, and there are already 3 not far from here. Its just the name people know and trust... they may have been behind, but they just caught up, and thats that.
Once again, I never had anything bad to say about your dyno. I am sure its worlds ahead and thats great. What I was doing is expelling all the ******** that the eddy current dyno ***** like to push. You act like an inertia dyno is completely worthless... well sorry its close, but not quite there.
BTW, In interview with several brake dynos, not one of them have told me its no more than a rare occasion that they actually USE a steady state when tuning the car, rather then drive thrus. So talking to shop owners and dyno operators (not dyno salesmen) I have found that the feature is not so imperative... at all.
maybe no one told you that each copy of the dynojet software is specifically calibrated for your dyno and the exact balanced weight of your rollers?
Hey dynojet welcome to the load based dyno party, we've been here 27 years.
you must be so proud. Did you invent the brake dyno yourself? Have a cookie.
Ok let's just assume 1% tolerence from the factory, that still +-50lbs. But then again you are spinning up the equivilant weight of a full size truck. What the hell, we'll let you go on this point.
load is load... did you invent an engine or ECU that knows the difference between load supplied by inertia versus a brake? Didnt think so.
Just because it's the most common doesn't mean it's the best. If so we would all be driving camarys hauling around our 2.5 kids going to our 28k a year job.
never said its the best... inertia dynos are FAR from the best... which is why I said you dont need to sell me. I was just defending some of the more retarded things said. Either way, it doesnt take the BEST for a WOT graph run.
Yup, know your settings. This way an operator can correctly replicate real world conditions. Although any knowledgeable operator should be able to arrive @ the correct setting for your specific vehicle. Yes settings just for you and you alone. Not a global setting to cover all vehicles on the road.
which is what i just said. unfortunatly its not uncommon that brake dyno operators have no idea how to use their investment... I cant even think of how many customers have complained of this to me... and the couple times that I have used them I had to get the manual out myself.
I guess you might be wondering what set off this rant.
I know exactly what set off this rant. You didnt like what I had to say about something you sell, and you didnt like that I basically said that what you say is completely biased. Which it is.
As for the history of dynojet versus your company... history is history and all that matters is what someone is trying to do at the moment they need it done. That involves using what is available immediately. If you can have a eddy current brake, then BY ALL MEANS USE IT. I wont be as offended as you get when someone doesnt.
Of course you will redicule dynojet for catching up with the features you sell... it will be of a big hurt to your company. The dynojet 224xlc with eddy current hasnt even been available for a year yet, and there are already 3 not far from here. Its just the name people know and trust... they may have been behind, but they just caught up, and thats that.
Once again, I never had anything bad to say about your dyno. I am sure its worlds ahead and thats great. What I was doing is expelling all the ******** that the eddy current dyno ***** like to push. You act like an inertia dyno is completely worthless... well sorry its close, but not quite there.
BTW, In interview with several brake dynos, not one of them have told me its no more than a rare occasion that they actually USE a steady state when tuning the car, rather then drive thrus. So talking to shop owners and dyno operators (not dyno salesmen) I have found that the feature is not so imperative... at all.
Last edited by phunk; 07-10-2005 at 05:37 AM.
07-10-2005, 10:15 AM
#26
Registered User
iTrader: (4)
Join Date: Sep 2002
Location: Who wants a dyno?
Posts: 1,779
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by phunk
hey its all good, you dont have to sell me... brake dynos are very useful and my post was not about trying to belittle their function and usefulness. Your focusing on completely the wrong points and just being plain defensive. Especially considering I wasnt even talking to you, or saying negative things about your brake dynos... I was explaining how garys experience made no sense.
But i will spend a little time here and argue back... cause i like to argue...
But i will spend a little time here and argue back... cause i like to argue...
And yes you specifically called me out in your rant to George when you said ignore the ******** from the guys especially the one who sells dynos.
I am not attempting to sell my product here, just educate the community. No one, and I repeat no one on this board is going to read this or anything else I type and go out and purchase a $46,500 machine to put in their home garage. Hopefully after reading our debate they will have a better understanding of what each type of dyno is and is not capable of doing and will make the choice of their tuner accordingly.
So the only purpose of a eddy current dyno is to hold steady state, which you claim really serves no purpose other than speeding up the tuning process.
is that not what its intended for? Sounds like that is enough use to make it worth it anyway, no?
Once again you agree w/ me but then later on disagree over the same point. The point of an eddy current dyno is to hold steady state loads but also to measure those loads in a manner that is more accurate and repeatable than an inertia dyno.
sounds good... except of course i tuned high paying service customers cars for free most the time back when I owned a dyno. I certinaly never charged more then a couple hundred even on the ones that take forever.
Then you are the exception to the rule. Not to many shops can stay in business for very long giving away free time to customers. But then again it was only your high paying customers that got this treatment. Guess you made you money off them elsewhere.
what makes you think that you have to floor it just cause your on an inertia dyno? wtf? I mean come on, you guys really have the lamest arguements here. I do tons of part throttle pulls, very rapidly... within a minutes i can have done 10-20 part throttle drive thru runs datalogging and adjusting maps as i go just tapping the dyno brake over and over. you act like all you can do is strap down and floor it and say oh there it is we are done now.
I never said you had to make a pull full throttle on an inertia dyno. The crux of the problem still remains. You are still sweeping upwards thru the load cells @ a constant rate. You cannot hold the vehicle steady state. Attempting to hold in a cell w/ an inertia dyno is like trying to drive instop & go traffic w/ only 2 speeds full stop & WOT. Sure you might be able to get thru it but it isn't gong to be pretty or easy on the equipment.
Not to mention you are using another piece of equipment, datalogger, to make up for the shortcomings of the dyno. How much extra money was spend on dataloggers?
the dyno has its own brake, i never use a cars brakes on the inertia dyno as it will quickly ruin them... that would be a poor decision.
Yes locomotive brakes. I have had to change a set of pads before. No alot of fun. What would happen if you hit the cars brakes to stop in an emergency?
The rollers brakes still take quite a while to decel the drums from high wheel speeds.As for the remote A/F meter... that depends on where you put it. If we put it in the tailpipe its a little laggy and the sensitivity to rapid changes goes down. If we are tuning a car with a full standalone where we need better resolution... we just put it in the downpipe... why do you ask?
Just another example of DJ's 1970's technology and thinking, thats all.
yes, you will see jaggedness in the dyno graph, just as I have several times... not to mention the car will be running like ****. if you need a dyno to tell you that something is wrong with an injector, coil, or your getting spark blow out.... its time to hand the tuning over to someone else. and of course you can tell if the tune is bad on the dyno... when your datalogging A/F along with everything else... and driving around on the dyno... how would you NOT notice???
How can you tell if the graph is jagged if you have any sort of smoothing applied to the line? You are looking @ a cooked version of the data.
There are instances where momentary and random power losses occur. Here is a first hand example. Was tuning a high hp Supra years ago. Every so often during the session we would have a run come up w/ a neg power spike. It was not consistant or repeatable. Eventually we traced the issue to a faulty injector clip. When the engine bay heat and engine harmonics were just right the clip would momentarly loose contact and drop out 1 cylinder for just a single rpm. Exactly like the the video. On any other dyno we would have never seen this problem until it became a much larger issue. Like the clip failing completely. We replaced the clip and sent customer out to the racetrack that evening.
Nope. A dyno spinning 5,000lbs+, calculating acceleration via counting a flag that swings thru a hall effect sensor has absolutly no chance in hell of catching a momentary power spike.
Wrong.
It will on ours.
http://www.dyno.com.au/usa/ocr/ocr_jason.htm
Direct measurement of power output via a load cell. Our dyno's rotational inertia is less than 250lbs total. BTW, that's real time graphing, something we've had for 15+ years, Dynojet just released their live graphing when, 3 months ago?
Make a video of that same situation and post it up. If need be, I'll send you that inturupt box. Tha laws of physics are against you here. How quickly is an accelerating 5,000lb rotating mass going to react to a partial power loss over a momentary event? I can calculate the answer if you like, but it's not going to be pretty.
Not to mention the way the DJ inertias measure power is by calculating the acceleration of the mass, not a direct force measurement. So on the wild and incorrect assumption that 5,000lbs of accelerating, rotating mass is going to be affected by an near instantanous power loss. It could occur and recorrect itself during the time period in between flag counts.
Thats a fantastic video... you will see the same results in the graph on an inertia dyno by performing the run in a higher gear... and once again, if you need the dyno to show it... well...
How can you tell what is going on w/ DJ's graph w/ smoothing being applied to the graph. All smoothing does is look @ the random scattering of it's sampling point and then linearly interpolates a graphical line. The raw data from the dyno is so bad it is basically unusable. They have to manipulate the data to approach anything that resembles usefull information.
DD smoothing is not available. That's raw data from the load cell being displayed.
i bought it cause it brings in money, more than your dyno will... equiptment like that is purchased for investment purpose, not bragging rights. It may make tuning take a little longer, but I dont care. Its the standard dyno for comparison in the USA... and nothing is going to change that... and unfortunately for other dyno manufacturers... dynojet now has eddy current dynos available that will pick up where their old inertia dynos left off, and their US legacy will continue as the dyno of choice, regardless of why... people stick with what they know and hear, and for as long as most of these people have been playing with cars... dynojet was the one they were told to use... and now they have updated their lineup with all the great features they were lacking without the eddy current brake.
Crack bring in big money too but I'm not going to sell it to my customers. The DJ name does attract customer, no arguement. But that's because the unwashed masses are uninformed about the operation differences about dynos. Have you picked up a magazine lately? Notice how the tuning articles are being done on eddy current dynos, whereas the new product articles, read ads, are still being done on DJ? Care to guess why? Customers are starting to come out of the DJ marketing numbers BS and into the light.
DJ is not going out of business anytime soon. Never said that. Just that the shortcomings of DJ drive away alot of repeat business for them. Alot of shops start w/ DJ because they are industry know and here is the key, cheap. Talk to alot of DJ owners after 2 years and get their opinion. They call me every day looking for alteratives to their "beginner" dyno.
07-10-2005, 10:16 AM
#27
Registered User
iTrader: (4)
Join Date: Sep 2002
Location: Who wants a dyno?
Posts: 1,779
Likes: 0
Received 0 Likes
on
0 Posts
you must have taken your car to a bad tuner in the past, and for this im very sorry... just cause you or someone you knew couldnt use the equiptment for what its worth... dont take it out on the equiptment.
Not taking anything out on equipment just pointing out shortcomings.
There are good and bad tuners out there. The dyno is just a tool. In the right hands a bad dyno can make a good tune. Usually a bad dyno leads to a bad tune.[/b]
No bad tuners lead to bad tunes. A good dyno can make a bad tuner look good. Same as a bad dyno can make a good tuner look good.
maybe you would know what i was trying to say if you didnt focus on putting words in my mouth to your advantage... matter of fact the only arguements you have are to statements that I never said, but you created. Interesting strategy.
How did you not say these things when I have your quote listed there?
no... its qualied to run just about any cars. you act like the load on the street is the same in every gear... if you can shift on the street... why cant you shift on the dyno? Put it in the gear of choice that will get you more or less load to aid you in tuning. Sometimes I do tuning pulls in 6th gear to slow everything down and slowly take me thru the load points.
No every vehicle need it's own specifc load charetristics. What I am getting @ is that 1 specific load does not fit every vehicle. Which we agree upon. W/ an inertia dyno you are limited to the load profile of 5,000lbs of rotating resistance. All changing the gears does is change the mechanical advantage over the rollers inertia. We have not even begun to touch on the fact that the large roller dynos overdrive the wheels carrying out power curves in a false manner.
if your not tuning the car... than who gives a ****? they just want to see a graph. on a dyno day my customers get mad if i cant get all 20 of their cars on... sorry, i dont feel like playing with all your settings in that scenario. brake dynos are for tuning, not comparing. thats all i was saying... the rest of this debate is all you.
See that's the problem right there. It's a numbers game w/ DJ. If your not tuning, ****'em give them a big unrealistic number and send them out the door. Who cares if the number is total BS, take the money and run. All it does is lead to pissing and moaning when their paper hp car get waxed by a car w/ less paper hp from a different dyno.
Last night we had a dyno night up @ CPR in Charlotte. 25 cars in 4.5 hours. Really nice turnout.
On a side note Charles, I'll be in the Chicago area July 23rd w/ the dyno doing a promotion w/ Dunlop. I'd me happy to meet up w/ you so you could take a look @ the dyno first hand. Or @ least hang out and have a beer. I thought about pm'ing you but I didn't have any luck reaching you via PM before.
Not taking anything out on equipment just pointing out shortcomings.
There are good and bad tuners out there. The dyno is just a tool. In the right hands a bad dyno can make a good tune. Usually a bad dyno leads to a bad tune.[/b]
No bad tuners lead to bad tunes. A good dyno can make a bad tuner look good. Same as a bad dyno can make a good tuner look good.
maybe you would know what i was trying to say if you didnt focus on putting words in my mouth to your advantage... matter of fact the only arguements you have are to statements that I never said, but you created. Interesting strategy.
How did you not say these things when I have your quote listed there?
no... its qualied to run just about any cars. you act like the load on the street is the same in every gear... if you can shift on the street... why cant you shift on the dyno? Put it in the gear of choice that will get you more or less load to aid you in tuning. Sometimes I do tuning pulls in 6th gear to slow everything down and slowly take me thru the load points.
No every vehicle need it's own specifc load charetristics. What I am getting @ is that 1 specific load does not fit every vehicle. Which we agree upon. W/ an inertia dyno you are limited to the load profile of 5,000lbs of rotating resistance. All changing the gears does is change the mechanical advantage over the rollers inertia. We have not even begun to touch on the fact that the large roller dynos overdrive the wheels carrying out power curves in a false manner.
if your not tuning the car... than who gives a ****? they just want to see a graph. on a dyno day my customers get mad if i cant get all 20 of their cars on... sorry, i dont feel like playing with all your settings in that scenario. brake dynos are for tuning, not comparing. thats all i was saying... the rest of this debate is all you.
See that's the problem right there. It's a numbers game w/ DJ. If your not tuning, ****'em give them a big unrealistic number and send them out the door. Who cares if the number is total BS, take the money and run. All it does is lead to pissing and moaning when their paper hp car get waxed by a car w/ less paper hp from a different dyno.
Last night we had a dyno night up @ CPR in Charlotte. 25 cars in 4.5 hours. Really nice turnout.
On a side note Charles, I'll be in the Chicago area July 23rd w/ the dyno doing a promotion w/ Dunlop. I'd me happy to meet up w/ you so you could take a look @ the dyno first hand. Or @ least hang out and have a beer. I thought about pm'ing you but I didn't have any luck reaching you via PM before.
07-10-2005, 10:43 AM
#28
Registered User
iTrader: (4)
Join Date: Sep 2002
Location: Who wants a dyno?
Posts: 1,779
Likes: 0
Received 0 Likes
on
0 Posts
The factory spec from Dynojet in '98 was +-3% variance from individual dyno to dyno. So a 200whp car can make 200whp on dynojet #1, 206whp on #2 and 194whp on #3. 12whp difference on just a 200hp car. Factory acceptable. How the hell is a customer that goes to different dynos suposse to tell if they have a gain or loss? Supposedly they have closed up their tolerence range recently due to the market demand.
maybe no one told you that each copy of the dynojet software is specifically calibrated for your dyno and the exact balanced weight of your rollers?
So each dyno is a one-off. Boy that really going to suck when it comes time for something to be replaced. Why couldn't they just make a better product by actually using mfg techniques that enhances repeatablily part to part? I think those techniques were developed about early 1940's during WWII. If they are that unconcerned about the part quality it make you wonder how concerned they are about how accurate their dynos are.
Hey dynojet welcome to the load based dyno party, we've been here 27 years.
you must be so proud. Did you invent the brake dyno yourself? Have a cookie.
Why thank you, chocolate chip please.
Ok let's just assume 1% tolerence from the factory, that still +-50lbs. But then again you are spinning up the equivilant weight of a full size truck. What the hell, we'll let you go on this point.
load is load... did you invent an engine or ECU that knows the difference between load supplied by inertia versus a brake? Didnt think so.
Yes a load is just a force. How the force is applied is what makes or breaks the problem. The inertia dyno cannot hold a load. The inertia dyno cannot simulate a load other than WOT repeatably w/ any degree of accuracy. The inertia dyno drums keep accelerating after peak power is achieved creating a false representation of the engine's output.etc...
never said its the best... inertia dynos are FAR from the best... which is why I said you dont need to sell me. I was just defending some of the more retarded things said. Either way, it doesnt take the BEST for a WOT graph run.
True, @ wot runs are the easiest to achieve. But once again besides drag racers who spends all their time @ wot?
which is what i just said. unfortunatly its not uncommon that brake dyno operators have no idea how to use their investment... I cant even think of how many customers have complained of this to me... and the couple times that I have used them I had to get the manual out myself.
Unfortunatly you cannot control what the dyno operator does once he/she has possesion.
I guess you might be wondering what set off this rant.
I know exactly what set off this rant. You didnt like what I had to say about something you sell, and you didnt like that I basically said that what you say is completely biased. Which it is.
No you called me out specifically, and yes I am bias towards load bearing dynos. After 13+years working w/ dyno I have found what work and what doesn't.
Once again, I never had anything bad to say about your dyno. I am sure its worlds ahead and thats great. What I was doing is expelling all the ******** that the eddy current dyno ***** like to push. You act like an inertia dyno is completely worthless... well sorry its close, but not quite there.
Never said it was worthless, just that they have their time and place. The are cheap, they make big numbers, and simple to use. The problem is that tuners usuall grow out of their beginner phase vey quickly and are held back by the dyno they have chosen. Sometimes they don't even know another option exists.
BTW, In interview with several brake dynos, not one of them have told me its no more than a rare occasion that they actually USE a steady state when tuning the car, rather then drive thrus. So talking to shop owners and dyno operators (not dyno salesmen) I have found that the feature is not so imperative... at all.
Let me guess, large drum eddy current dynos. Basically inertia dynos w/ a retarder attached. So not really what I would consider a load based dyno.
If you'd like to talk to any of our dyno owners and get their opinion I'd be happy to send you the entire list of US shops. This way you can talk to dyno operators as opposed to a salesman.
(awaits round 3 to start)
maybe no one told you that each copy of the dynojet software is specifically calibrated for your dyno and the exact balanced weight of your rollers?
So each dyno is a one-off. Boy that really going to suck when it comes time for something to be replaced. Why couldn't they just make a better product by actually using mfg techniques that enhances repeatablily part to part? I think those techniques were developed about early 1940's during WWII. If they are that unconcerned about the part quality it make you wonder how concerned they are about how accurate their dynos are.
Hey dynojet welcome to the load based dyno party, we've been here 27 years.
you must be so proud. Did you invent the brake dyno yourself? Have a cookie.
Why thank you, chocolate chip please.
Ok let's just assume 1% tolerence from the factory, that still +-50lbs. But then again you are spinning up the equivilant weight of a full size truck. What the hell, we'll let you go on this point.
load is load... did you invent an engine or ECU that knows the difference between load supplied by inertia versus a brake? Didnt think so.
Yes a load is just a force. How the force is applied is what makes or breaks the problem. The inertia dyno cannot hold a load. The inertia dyno cannot simulate a load other than WOT repeatably w/ any degree of accuracy. The inertia dyno drums keep accelerating after peak power is achieved creating a false representation of the engine's output.etc...
never said its the best... inertia dynos are FAR from the best... which is why I said you dont need to sell me. I was just defending some of the more retarded things said. Either way, it doesnt take the BEST for a WOT graph run.
True, @ wot runs are the easiest to achieve. But once again besides drag racers who spends all their time @ wot?
which is what i just said. unfortunatly its not uncommon that brake dyno operators have no idea how to use their investment... I cant even think of how many customers have complained of this to me... and the couple times that I have used them I had to get the manual out myself.
Unfortunatly you cannot control what the dyno operator does once he/she has possesion.
I guess you might be wondering what set off this rant.
I know exactly what set off this rant. You didnt like what I had to say about something you sell, and you didnt like that I basically said that what you say is completely biased. Which it is.
No you called me out specifically, and yes I am bias towards load bearing dynos. After 13+years working w/ dyno I have found what work and what doesn't.
Once again, I never had anything bad to say about your dyno. I am sure its worlds ahead and thats great. What I was doing is expelling all the ******** that the eddy current dyno ***** like to push. You act like an inertia dyno is completely worthless... well sorry its close, but not quite there.
Never said it was worthless, just that they have their time and place. The are cheap, they make big numbers, and simple to use. The problem is that tuners usuall grow out of their beginner phase vey quickly and are held back by the dyno they have chosen. Sometimes they don't even know another option exists.
BTW, In interview with several brake dynos, not one of them have told me its no more than a rare occasion that they actually USE a steady state when tuning the car, rather then drive thrus. So talking to shop owners and dyno operators (not dyno salesmen) I have found that the feature is not so imperative... at all.
Let me guess, large drum eddy current dynos. Basically inertia dynos w/ a retarder attached. So not really what I would consider a load based dyno.
If you'd like to talk to any of our dyno owners and get their opinion I'd be happy to send you the entire list of US shops. This way you can talk to dyno operators as opposed to a salesman.
(awaits round 3 to start)
07-10-2005, 12:45 PM
#29
Round 3.. ding ding ding
im gonna TRY and make this one short and sweet, i dont think anyone else is reading anymore. there are a few parts here where we completely lost each other, and I dont care enough to go deep enough to fix those ones.
The crux of the problem still remains. You are still sweeping upwards thru the load cells @ a constant rate.
hey now i already told you i was sold on the brake... i was just telling you one way to get around it in part throttle tuning situations.
Yes locomotive brakes.
why argue this? if the dyno has brakes, it has brakes... i dont care if they are from a semi truck, locomotive, schwinn, or a rocket ship. They stop the rollers when I push the button.
The rollers brakes still take quite a while to decel the drums from high wheel speeds.
I didnt know dyno manufacturers were competing for the quickest 60-0 times of their rollers???
Just another example of DJ's 1970's technology and thinking, thats all.
ok... i personally havent seen any more advantaged datalogging of wideband before... its always just a horizontal line running versus RPM that displays where you went. Kinda like exactly what is shown on a dyno dynamics graph???
How can you tell if the graph is jagged if you have any sort of smoothing applied to the line?
Easy... you turn smoothing off. Look up any old dyno graph i have ever posted and it always says smoothing:0, I rarely use the feature at all, as it is not realistic.
There are instances where momentary and random power losses occur. Here is a first hand example. Was tuning a high hp Supra years ago
funny, 2 weeks ago i was tuning a twin turbo viper with AEM EMS and an injector clip went bad (a wire was loose is its terminal)... some how on a dynojet 248 inertia dyno we could all clearly see that a 10 cylinder engine was missing a cylinder. Whats also funny is that it was only doing it under part throttle... once we had full throttle runs going on it was firing fine. HOW did we notice it? Easy... because a good tuner doesnt need a dyno to tell him a cylinder isnt firing... we could see it on the dual widebands.
Not to mention the way the DJ inertias measure power is by calculating the acceleration of the mass, not a direct force measurement. So on the wild and incorrect assumption that 5,000lbs of accelerating, rotating mass is going to be affected by an near instantanous power loss. It could occur and recorrect itself during the time period in between flag counts.
If there is an event that occurs and corrects itself THAT quickly... i honestly do not believe you thta you will see it on your dyno either. When the graph is only as wide as a computer moniter, the duration of time spent between one flag and another is going to be smaller in width than a single pixel on a computer moniter.
Now... if you can zoom the graphs with your dyno software... then i will believe it... and if that is the case... thats neat. :thumbsup:, whatever, haha.
im gonna TRY and make this one short and sweet, i dont think anyone else is reading anymore. there are a few parts here where we completely lost each other, and I dont care enough to go deep enough to fix those ones.
The crux of the problem still remains. You are still sweeping upwards thru the load cells @ a constant rate.
hey now i already told you i was sold on the brake... i was just telling you one way to get around it in part throttle tuning situations.
Yes locomotive brakes.
why argue this? if the dyno has brakes, it has brakes... i dont care if they are from a semi truck, locomotive, schwinn, or a rocket ship. They stop the rollers when I push the button.
The rollers brakes still take quite a while to decel the drums from high wheel speeds.
I didnt know dyno manufacturers were competing for the quickest 60-0 times of their rollers???
Just another example of DJ's 1970's technology and thinking, thats all.
ok... i personally havent seen any more advantaged datalogging of wideband before... its always just a horizontal line running versus RPM that displays where you went. Kinda like exactly what is shown on a dyno dynamics graph???
How can you tell if the graph is jagged if you have any sort of smoothing applied to the line?
Easy... you turn smoothing off. Look up any old dyno graph i have ever posted and it always says smoothing:0, I rarely use the feature at all, as it is not realistic.
There are instances where momentary and random power losses occur. Here is a first hand example. Was tuning a high hp Supra years ago
funny, 2 weeks ago i was tuning a twin turbo viper with AEM EMS and an injector clip went bad (a wire was loose is its terminal)... some how on a dynojet 248 inertia dyno we could all clearly see that a 10 cylinder engine was missing a cylinder. Whats also funny is that it was only doing it under part throttle... once we had full throttle runs going on it was firing fine. HOW did we notice it? Easy... because a good tuner doesnt need a dyno to tell him a cylinder isnt firing... we could see it on the dual widebands.
Not to mention the way the DJ inertias measure power is by calculating the acceleration of the mass, not a direct force measurement. So on the wild and incorrect assumption that 5,000lbs of accelerating, rotating mass is going to be affected by an near instantanous power loss. It could occur and recorrect itself during the time period in between flag counts.
If there is an event that occurs and corrects itself THAT quickly... i honestly do not believe you thta you will see it on your dyno either. When the graph is only as wide as a computer moniter, the duration of time spent between one flag and another is going to be smaller in width than a single pixel on a computer moniter.
Now... if you can zoom the graphs with your dyno software... then i will believe it... and if that is the case... thats neat. :thumbsup:, whatever, haha.
07-10-2005, 12:58 PM
#30
OK now, I am not gonna go on with this one... because its not going anymore.
Like said 100 times now, I was sold on the eddy current long ago. I wanted to buy one long ago. BUT, I had to work with what I had purchased years ago, and thats that. I have since sold that dyno and when the time comes that I purchase another one, that one will be a brake dyno.
so whats going on here, is that your arguing with someone who is on your side to begin with. I never put inertia dynos ON TOP of brake dynos... the only thing I think the inertia dyno is better at is comparison runs since there are no user configurations to go wrong.
brake dynos have enough advantages that their owners need to focus on them... not make rediculous claims such as your car will run 1.5 points a/f different at the same load cell on a brake versus inertia dyno. The scare tactics really annoy me.
but one last thing: Let me guess, large drum eddy current dynos. Basically inertia dynos w/ a retarder attached. So not really what I would consider a load based dyno
Well I dont know the brake method that all dynos use... but I have had conversations with a few dynopak owners, and a couple mustang dyno owners. never talked to a guy with a dyno dynamics.
ALSO, I dont blame you for representing your product... I do the same exact thing. I just dont like to see someone who represents one product publicly bashing someone elses product... if yours is so much better, you should have enough sales points to focus on what makes it so good... not what makes theirs so bad.
Like said 100 times now, I was sold on the eddy current long ago. I wanted to buy one long ago. BUT, I had to work with what I had purchased years ago, and thats that. I have since sold that dyno and when the time comes that I purchase another one, that one will be a brake dyno.
so whats going on here, is that your arguing with someone who is on your side to begin with. I never put inertia dynos ON TOP of brake dynos... the only thing I think the inertia dyno is better at is comparison runs since there are no user configurations to go wrong.
brake dynos have enough advantages that their owners need to focus on them... not make rediculous claims such as your car will run 1.5 points a/f different at the same load cell on a brake versus inertia dyno. The scare tactics really annoy me.
but one last thing: Let me guess, large drum eddy current dynos. Basically inertia dynos w/ a retarder attached. So not really what I would consider a load based dyno
Well I dont know the brake method that all dynos use... but I have had conversations with a few dynopak owners, and a couple mustang dyno owners. never talked to a guy with a dyno dynamics.
ALSO, I dont blame you for representing your product... I do the same exact thing. I just dont like to see someone who represents one product publicly bashing someone elses product... if yours is so much better, you should have enough sales points to focus on what makes it so good... not what makes theirs so bad.
Last edited by phunk; 07-10-2005 at 01:02 PM.
07-10-2005, 02:35 PM
#31
Registered User
iTrader: (4)
Join Date: Sep 2002
Location: Who wants a dyno?
Posts: 1,779
Likes: 0
Received 0 Likes
on
0 Posts
We do agree on alot of topics. That is evident. We also have alot of the same experiences w/ dynos.
I have not been bashing DJ for the sake of DJ bashing, simple saying they have their place. I'm not taking over Peter's place on the board. That is exactly the opposite of what I believe in and what I have been doing here. You have touted the advantages or @ least come to the defense of inertia dynos and denounced the "pro-eddy current **** regeim". All I have done is give a rebutal to your arguements. The only time I have brought in new information is to expand upon a topic you brought up.
Yes I'm sure we could sit here and type back and forth for the next few weeks on this topic. So we will just end this here and now.
We agree on somethings, disagree on others. Sky is blue, grass is greens. Peace
p.s. noticed your sig, congrats on stopping smoking. good luck w/ it.
p.p.s. this page length has got to be some sort of record for the forum.
I have not been bashing DJ for the sake of DJ bashing, simple saying they have their place. I'm not taking over Peter's place on the board. That is exactly the opposite of what I believe in and what I have been doing here. You have touted the advantages or @ least come to the defense of inertia dynos and denounced the "pro-eddy current **** regeim". All I have done is give a rebutal to your arguements. The only time I have brought in new information is to expand upon a topic you brought up.
Yes I'm sure we could sit here and type back and forth for the next few weeks on this topic. So we will just end this here and now.
We agree on somethings, disagree on others. Sky is blue, grass is greens. Peace
p.s. noticed your sig, congrats on stopping smoking. good luck w/ it.
p.p.s. this page length has got to be some sort of record for the forum.
Last edited by UnderPressure; 07-10-2005 at 02:37 PM.
Thread
Thread Starter
Forum
Replies
Last Post
liqalu04
Engine & Drivetrain
31
01-02-2022 12:58 PM
ars88
Zs & Gs For Sale
18
04-04-2016 07:52 AM
