Can you say 500 crank / 400+ rwhp? I knew you could…
04-04-2004, 03:56 PM
#41
Registered User
iTrader: (1)
Join Date: Feb 2003
Location: North Carolina
Posts: 689
Likes: 0
Received 0 Likes
on
0 Posts
Ed,
"You can rely on me continuing to point out poor engineering and or tuning into the future, so long as sufficient data is provided to do so. "
Information is always welcome on this site. Instead of us relying on you to point on poor engineering, why don't you give us solutions?
"You can rely on me continuing to point out poor engineering and or tuning into the future, so long as sufficient data is provided to do so. "
Information is always welcome on this site. Instead of us relying on you to point on poor engineering, why don't you give us solutions?
04-04-2004, 05:41 PM
#42
Former Sponsor
iTrader: (564)
Join Date: Feb 2003
Location: Long Island, New York
Posts: 19,266
Likes: 0
Received 5 Likes
on
5 Posts
Ed - you shoud keep in mind that stock Z runs MUCh more base pressure than 43 psi...as such, I see no reason why the stock injectors cannot handle the power the car is putting out
Ed - I think you know your theory, but as is typical with professional engineers (regardless who they work for and whether they could buy or sell other companies), you tend to always look at the equation side of things and not the "real world" state of affairs.
Not every forced induction car will show a "minimum 100 ft/lb gain" at such a low rpm- it's all relative to the car, the VE, the type of blower, the gears, the tires, the wheels, etc etc etc.
Next point - the car was only reved to 6500 from the looks of it. There is no downward trend of torque or HP on the curves, unlike on the stock dyno chart, where torque falls off sharply after 5000 rpm (in typical VQ35 fashion) - the car has a ALOT left on the table in other words
The AFR is substantially richer than it was pre Vortech - which could very well be the reason for the ups and downs of the curve.
Considering this is tuned with a bare knuckles, very simple fuel/timing piggyback, I see nothing wrong with it - put a true standalone on the car, and I would guarantee another 40-50 hp at the wheels and a vastly improved curve...but this is not the car's current setup.
Ed - I think you know your theory, but as is typical with professional engineers (regardless who they work for and whether they could buy or sell other companies), you tend to always look at the equation side of things and not the "real world" state of affairs.
Not every forced induction car will show a "minimum 100 ft/lb gain" at such a low rpm- it's all relative to the car, the VE, the type of blower, the gears, the tires, the wheels, etc etc etc.
Next point - the car was only reved to 6500 from the looks of it. There is no downward trend of torque or HP on the curves, unlike on the stock dyno chart, where torque falls off sharply after 5000 rpm (in typical VQ35 fashion) - the car has a ALOT left on the table in other words
The AFR is substantially richer than it was pre Vortech - which could very well be the reason for the ups and downs of the curve.
Considering this is tuned with a bare knuckles, very simple fuel/timing piggyback, I see nothing wrong with it - put a true standalone on the car, and I would guarantee another 40-50 hp at the wheels and a vastly improved curve...but this is not the car's current setup.
04-04-2004, 05:55 PM
#43
New Member
Join Date: Aug 2003
Location: Boston
Posts: 1,074
Likes: 0
Received 0 Likes
on
0 Posts
Mcduck congrats on making an insane monster with the new go-fast goodies, I know you will be much happier then before and such. Also lets keep this thread on track and quit the flames and give props were its due.
04-04-2004, 06:17 PM
#44
Registered User
Join Date: Sep 2003
Location: Chicago Burbs
Posts: 1,751
Likes: 0
Received 0 Likes
on
0 Posts
congrats on the numbers mcduck,
but the first thing i saw on the graph too was not the loss of Torque, but just the general lack of it all together. I would think with the SC you would be making much more torque than you are there. i know the Z has issues with timing, but in such cases as my mr2, i increased the timing quite a bit in the lower RPM;s to help with the torque numbers.
are you running a constant timing across the RPM range, or if varied, what exactly are you running at each rpm?
i am just trying to maybe help you get those torque numbers up, not being insulting, just raising some questions that are in my mine.
(my old dyno)
but the first thing i saw on the graph too was not the loss of Torque, but just the general lack of it all together. I would think with the SC you would be making much more torque than you are there. i know the Z has issues with timing, but in such cases as my mr2, i increased the timing quite a bit in the lower RPM;s to help with the torque numbers.
are you running a constant timing across the RPM range, or if varied, what exactly are you running at each rpm?
i am just trying to maybe help you get those torque numbers up, not being insulting, just raising some questions that are in my mine.
(my old dyno)
04-04-2004, 08:15 PM
#46
Registered User
I think Turbo Ed's points were all valid (if a little harsh), but many of them are simply part of using a centrifugal S/C (which I guess was his primary point in the first place).
I don't think any of us would argue that a nice turbo kit or roots S/C can get to the peak torque @ much lower RPMs, but they, too, have their drawbacks. The turbo kits are currently at least a couple thousand more than an S/C kit, and the only roots S/C that I know if is the Stillen and that requires changes to the hood and strut bar.
So, given all that, it certainly looks like McDuck has done well with his setup.
Finally, as a fellow engineer, I'd just like to remind Turbo Ed that there is a difference between honesty and tact, and that they are not mutually exclusive. Next time your message might be heard more clearly if you try to incorporate both.
-D'oh!
I don't think any of us would argue that a nice turbo kit or roots S/C can get to the peak torque @ much lower RPMs, but they, too, have their drawbacks. The turbo kits are currently at least a couple thousand more than an S/C kit, and the only roots S/C that I know if is the Stillen and that requires changes to the hood and strut bar.
So, given all that, it certainly looks like McDuck has done well with his setup.
Finally, as a fellow engineer, I'd just like to remind Turbo Ed that there is a difference between honesty and tact, and that they are not mutually exclusive. Next time your message might be heard more clearly if you try to incorporate both.
-D'oh!
04-05-2004, 04:19 AM
#47
Registered User
Join Date: Mar 2004
Location: In the back country
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
gq_model_626
I should have known!!!!!
mcduck
All you have done is repeat the originally posted numbers, which I have already acknowledged. The point is, you are ignoring the RPM where every thing happens. If you wish to continue to do so, there is nothing I can do about it. However, the fact remains, your vehicle is a perfect example of why NOT to use a centrifugal in this application. ( which is probably why NO OE anywhere on the planet does so, in this application, or, come to think of it, in any other).
On top of the basic principle involved, your particular vehicle appears to have serious engine management issues as well. If you choose to ignore them also, again there is little I can do. However, if in discussing the issue, I prevent some other poor soul from making your mistake, well my time has not been all wasted, now has it?
Finally, if you do not believe a well setup twin turbo or screw compressor, running LESS max boost than you, (say 7 psi, with its consequent lower stress on the engine), would not hand you your lunch, then you REALLY do not know what "area under the curve" is!!!!!
Like I said, an apalling forced induction outcome.
I should have known!!!!!
mcduck
All you have done is repeat the originally posted numbers, which I have already acknowledged. The point is, you are ignoring the RPM where every thing happens. If you wish to continue to do so, there is nothing I can do about it. However, the fact remains, your vehicle is a perfect example of why NOT to use a centrifugal in this application. ( which is probably why NO OE anywhere on the planet does so, in this application, or, come to think of it, in any other).
On top of the basic principle involved, your particular vehicle appears to have serious engine management issues as well. If you choose to ignore them also, again there is little I can do. However, if in discussing the issue, I prevent some other poor soul from making your mistake, well my time has not been all wasted, now has it?
Finally, if you do not believe a well setup twin turbo or screw compressor, running LESS max boost than you, (say 7 psi, with its consequent lower stress on the engine), would not hand you your lunch, then you REALLY do not know what "area under the curve" is!!!!!
Like I said, an apalling forced induction outcome.
04-05-2004, 04:47 AM
#48
Registered User
Join Date: Mar 2004
Location: In the back country
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
Zimbo
at the risk of stating the obvious, cost is relative. To outcomes, I mean !! When you say "superchargers", you really mean centrifugals, don't you? Since effectively there is nothing else widely available, at this time.
Let's ignore the "area under the curve" for just a second, and accept none of us are too lazy to down shift. I mean, we are all race drivers, right? We can all downshift faster than anyone can just put their foot down in a car with REAL mid range torque!
So let's just compare peak horsepower numbers, like any layman would. I am prepared to bet any reasonable sum of money that to make 450 flywheel HP at 6,500 RPM, with PROFESSIONAL control of Air/fuel ratio, timing and boost, will COST much the same at the end of the day, whether you use a centrifugal or twin turbos. A screw blower might run a little more.
The difference will be in the load on the engine, ( because of the difference in boost required) and the DRIVEABILITY of the outcome. There, the relative difference will be enormous!!
Thank you for your explanation of the "engine management"(sic) being utilised. It completely substantiates my original "appalling" description! While I accept without question the possible outcome of your outline ( I did originally say that there were other possible explanations than the one I gave), my concern could still be valid. Fundementally, we both could be correct. With such appalling "control" of the basics of engine tuning, who can say for sure no knock was occuring? Even if it was not, your explanation is bad enough, by itself,
Ed
at the risk of stating the obvious, cost is relative. To outcomes, I mean !! When you say "superchargers", you really mean centrifugals, don't you? Since effectively there is nothing else widely available, at this time.
Let's ignore the "area under the curve" for just a second, and accept none of us are too lazy to down shift. I mean, we are all race drivers, right? We can all downshift faster than anyone can just put their foot down in a car with REAL mid range torque!
So let's just compare peak horsepower numbers, like any layman would. I am prepared to bet any reasonable sum of money that to make 450 flywheel HP at 6,500 RPM, with PROFESSIONAL control of Air/fuel ratio, timing and boost, will COST much the same at the end of the day, whether you use a centrifugal or twin turbos. A screw blower might run a little more.
The difference will be in the load on the engine, ( because of the difference in boost required) and the DRIVEABILITY of the outcome. There, the relative difference will be enormous!!
Thank you for your explanation of the "engine management"(sic) being utilised. It completely substantiates my original "appalling" description! While I accept without question the possible outcome of your outline ( I did originally say that there were other possible explanations than the one I gave), my concern could still be valid. Fundementally, we both could be correct. With such appalling "control" of the basics of engine tuning, who can say for sure no knock was occuring? Even if it was not, your explanation is bad enough, by itself,
Ed
04-05-2004, 04:52 AM
#49
Registered User
Join Date: Mar 2004
Location: In the back country
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
Damen,
if you are going to use a supercharger, look for a kit which uses a screw blower. NEVER attempt forced induction without good intercooling. REALLY suss out just how they do their engine management, or just figure on having one of the reprograming companies do it for you and figure the cost into your deal,
all the best
Ed
if you are going to use a supercharger, look for a kit which uses a screw blower. NEVER attempt forced induction without good intercooling. REALLY suss out just how they do their engine management, or just figure on having one of the reprograming companies do it for you and figure the cost into your deal,
all the best
Ed
04-05-2004, 05:18 AM
#51
Registered User
Join Date: Mar 2004
Location: In the back country
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
Z1Performance,
Re my theory, possibly, however, you do not know my background. I was in the REAL world, working with AK Miller and Hugh MacInnes, probably before you were born!! I suspect my practical experience WELL exceeds yours!!
YOU, on the other hand, appear to be a typical workshop operator, who thinks his experience can re invent basic physics!
There is some dispute as to wether the stock dead head fuel system runs 3 or 3.5 bar. However, I do not care if it runs 4.0 bar. The numbers I originally provided are all essentially accurate, so I shall not bother repeating them. In fact, I was a little low on the fuel requirement, as I did not really allow enough for the fuel used to power the parasitic losses. Sorry about that.
You are correct in your self evident statement that not every car will show a 100 ft/lb gain. ( and 3,000 RPM is not "low"). I was not aware that I said it would. However, a well designed forced induction system on a 350Z, running about 7 psi, ( or 25% less than the subject centrifugal), will show substantially BETTER than that!
Your comments about the "engine management"(sic), simply re- inforce Zimbo's, ie the car is equipped with an appalling system.
So much for "practice" versus theory!!
Ed
Re my theory, possibly, however, you do not know my background. I was in the REAL world, working with AK Miller and Hugh MacInnes, probably before you were born!! I suspect my practical experience WELL exceeds yours!!
YOU, on the other hand, appear to be a typical workshop operator, who thinks his experience can re invent basic physics!
There is some dispute as to wether the stock dead head fuel system runs 3 or 3.5 bar. However, I do not care if it runs 4.0 bar. The numbers I originally provided are all essentially accurate, so I shall not bother repeating them. In fact, I was a little low on the fuel requirement, as I did not really allow enough for the fuel used to power the parasitic losses. Sorry about that.
You are correct in your self evident statement that not every car will show a 100 ft/lb gain. ( and 3,000 RPM is not "low"). I was not aware that I said it would. However, a well designed forced induction system on a 350Z, running about 7 psi, ( or 25% less than the subject centrifugal), will show substantially BETTER than that!
Your comments about the "engine management"(sic), simply re- inforce Zimbo's, ie the car is equipped with an appalling system.
So much for "practice" versus theory!!
Ed
04-05-2004, 05:23 AM
#52
Registered User
Join Date: Mar 2004
Location: In the back country
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
Z1Performance,
you are doing the same thing as the car's owner!! IE completely ignoring WHERE the additional 100 ft/lbs of torque is achieved! I am not saying it is completely useless at redline, however, for most people, most of the time, that IS what it effectively IS.
USELESS!!
Ed
you are doing the same thing as the car's owner!! IE completely ignoring WHERE the additional 100 ft/lbs of torque is achieved! I am not saying it is completely useless at redline, however, for most people, most of the time, that IS what it effectively IS.
USELESS!!
Ed
04-05-2004, 05:26 AM
#53
Registered User
iTrader: (4)
Join Date: Aug 2003
Location: NC
Posts: 970
Likes: 0
Received 0 Likes
on
0 Posts
Ed, show me a smoother HP curve from any of the 350Z TT applications that have been published on this board. Also, please explain to me how the timing management of ANY of the existing TT kits betters that of the Vortech, save rewriting the actual ECU (which any Vortech owner could obviously do).
Your argument that centrifugal SCs should "never be used" is akin to be saying that nobody should ever choose a 350Z over a Corvette or that only an idiot would by a black colored car. Different strokes for different folkes. Now bugger off like a good little back woods hermit.
--Steve
Your argument that centrifugal SCs should "never be used" is akin to be saying that nobody should ever choose a 350Z over a Corvette or that only an idiot would by a black colored car. Different strokes for different folkes. Now bugger off like a good little back woods hermit.
--Steve
04-05-2004, 05:26 AM
#54
Registered User
Join Date: Mar 2004
Location: In the back country
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
D'oh,
1) yes, you are correct, that WAS my primary point!
2) You have obviously had to hang around marketing guys even longer than I have and they have got to you!! Shame on you!! Hand in your SAE membership, immmediately!!
regards,
Ed
1) yes, you are correct, that WAS my primary point!
2) You have obviously had to hang around marketing guys even longer than I have and they have got to you!! Shame on you!! Hand in your SAE membership, immmediately!!
regards,
Ed
04-05-2004, 05:42 AM
#55
Registered User
Join Date: Mar 2004
Location: In the back country
Posts: 19
Likes: 0
Received 0 Likes
on
0 Posts
Zimbo,
If you are going to quote me, at least accurately. please. What I said was, centrifugals do not belong on relatively small displacement, high RPM engines. Although, I really should have said, wide RPM operating band engines. They can be made to work acceptably for the street on larger displacement engines, where the relative lack of mid range torque improvement is not such a big issue.
As for the "engine management"(sic) being used, your sole defence of it, is that the two Japanese turbo kits currently on the market, do not have a better one? That's it?!! That simply means no one has done it correctly and the poor innocent consumer gets a false impression of the REAL costs involved. Hey, if this entire thread simply brings that to light, it will have been a real positive,
Ed
If you are going to quote me, at least accurately. please. What I said was, centrifugals do not belong on relatively small displacement, high RPM engines. Although, I really should have said, wide RPM operating band engines. They can be made to work acceptably for the street on larger displacement engines, where the relative lack of mid range torque improvement is not such a big issue.
As for the "engine management"(sic) being used, your sole defence of it, is that the two Japanese turbo kits currently on the market, do not have a better one? That's it?!! That simply means no one has done it correctly and the poor innocent consumer gets a false impression of the REAL costs involved. Hey, if this entire thread simply brings that to light, it will have been a real positive,
Ed
04-05-2004, 05:48 AM
#56
Former Sponsor
iTrader: (564)
Join Date: Feb 2003
Location: Long Island, New York
Posts: 19,266
Likes: 0
Received 5 Likes
on
5 Posts
I'd just like to remind Turbo Ed that there is a difference between honesty and tact, and that they are not mutually exclusive
04-05-2004, 05:59 AM
#57
New Member
Join Date: Apr 2003
Location: Earth
Posts: 5,563
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by Turbo Ed
Hey, if this entire thread simply brings that to light, it will have been a real positive,
Ed
Hey, if this entire thread simply brings that to light, it will have been a real positive,
Ed
You say that Centrifugal SC's should only be put on large displacement engines. Says who? You? I happen to like the power band of my SC'd engine. Isn't that what really matters? I mean it is my car.
04-05-2004, 06:51 AM
#58
Registered User
iTrader: (4)
Join Date: Aug 2003
Location: NC
Posts: 970
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by Turbo Ed
As for the "engine management"(sic) being used, your sole defence of it, is that the two Japanese turbo kits currently on the market, do not have a better one? That's it?!! That simply means no one has done it correctly and the poor innocent consumer gets a false impression of the REAL costs involved. Hey, if this entire thread simply brings that to light, it will have been a real positive.
As for the "engine management"(sic) being used, your sole defence of it, is that the two Japanese turbo kits currently on the market, do not have a better one? That's it?!! That simply means no one has done it correctly and the poor innocent consumer gets a false impression of the REAL costs involved. Hey, if this entire thread simply brings that to light, it will have been a real positive.
Why should I wait until someone puts out a kit that meets your criteria? I have a centrifugal supercharger that works extremely well for my needs on a car I really enjoy.
--Steve
04-05-2004, 06:58 AM
#59
Registered User
Join Date: Dec 2003
Location: clearh2o, FL
Posts: 660
Likes: 0
Received 0 Likes
on
0 Posts
turbo ed-
im a noob here.........
i have a deposit of a 2k4 g35, and a deal already done on the vortech s/c (with int.), to be installed after 1000 miles are run in on the n/a setup...
should i...
1) buy a diff. car
2) buy a diff. enhancement (or induction type)
3) stick with my fx45, and pray for FI
thoughts??
-eS
im a noob here.........
i have a deposit of a 2k4 g35, and a deal already done on the vortech s/c (with int.), to be installed after 1000 miles are run in on the n/a setup...
should i...
1) buy a diff. car
2) buy a diff. enhancement (or induction type)
3) stick with my fx45, and pray for FI
thoughts??
-eS
04-05-2004, 07:07 AM
#60
Registered User
iTrader: (2)
Join Date: May 2003
Location: New Jersey
Posts: 420
Likes: 0
Received 0 Likes
on
0 Posts
If these kits are sooo bad then tell us what should be diffrent.. Give us what you thing a "PERFECT" kit should consist of.. You are putting down cars that are very fast, safe, and fullfilling the needs of most!!! Why are you talking about down low power on a SCer anyways?!?!?!? Boost doesnt kick in until 3500 K then increaces all the way till redline. Which will yield more power up top. Since when is SCer know to make huge torque down low?
Am I the only person here who doesnt know what the hell this guy is trying to tell us? These cars are brand new.. Each day that goes by we find out more and more by trial and error. So of course we dont have all the answers right now but who does? YOU?
Am I the only person here who doesnt know what the hell this guy is trying to tell us? These cars are brand new.. Each day that goes by we find out more and more by trial and error. So of course we dont have all the answers right now but who does? YOU?