Let's revisit my Vortech dyno
#1
Let's revisit my Vortech dyno
Hey guys,
my blower will be back from vortech shortly and I want to get 'er back up and running.
Its been a little bit of time since my dyno tune and I am having trouble remembering all the details about the graph. The 370/330 is mine and the other one is a "normal" Vortech graph where you can see steady torque with increasing power to redline. Mine, increases to ~5700. Then the power stays the same but the torque falls WAY off.
Obviously I have problems after 5700 rpms. Its was suggested that I had a boost leak and that the boost leak was causing knocking. Something along the lines of the leak causing the blower to work harder and heat up the air causing knock.
I might have that explanation incorrect though as being my 1st dyno day etc, excitement was high and ears were on low.
But, how can the blower work harder when its directly attached to the motor? Also, wouldnt a boost leak cause a rich condition, the opposite of what would cause knock? I would assume that the timing params are optimal as the tuner knows his stuff. What else could cause knocking at high rpms?? I assume, that if there was alot of knocking above 6000 rpms, the tuning might have backed off timing which would show as a lower torque??
I tried to find dynos of other Vortechs with boost leaks, but was unable to. From what I have read, if it was belt slippage, the boost just levels out. BUT, would you see a -50 ftlb drop in torque? Same question goes for a boost leak, why would there be such a significant drop in torque. If the boost was just bleeding, shouldnt it just hold steady?
I didnt re-gap my new 1 step colder plugs when i installed them, assuming that the stock gap was fine. If a plug was misfiring, how would that show up on the dyno? How would that be seen by the UTEC? I never threw any CEL codes related to misfire, so i dont think thats a problem.
Sorry for the novel, but i wanted to make sure I was detailed as possible.
Thanks!!
my blower will be back from vortech shortly and I want to get 'er back up and running.
Its been a little bit of time since my dyno tune and I am having trouble remembering all the details about the graph. The 370/330 is mine and the other one is a "normal" Vortech graph where you can see steady torque with increasing power to redline. Mine, increases to ~5700. Then the power stays the same but the torque falls WAY off.
Obviously I have problems after 5700 rpms. Its was suggested that I had a boost leak and that the boost leak was causing knocking. Something along the lines of the leak causing the blower to work harder and heat up the air causing knock.
I might have that explanation incorrect though as being my 1st dyno day etc, excitement was high and ears were on low.
But, how can the blower work harder when its directly attached to the motor? Also, wouldnt a boost leak cause a rich condition, the opposite of what would cause knock? I would assume that the timing params are optimal as the tuner knows his stuff. What else could cause knocking at high rpms?? I assume, that if there was alot of knocking above 6000 rpms, the tuning might have backed off timing which would show as a lower torque??
I tried to find dynos of other Vortechs with boost leaks, but was unable to. From what I have read, if it was belt slippage, the boost just levels out. BUT, would you see a -50 ftlb drop in torque? Same question goes for a boost leak, why would there be such a significant drop in torque. If the boost was just bleeding, shouldnt it just hold steady?
I didnt re-gap my new 1 step colder plugs when i installed them, assuming that the stock gap was fine. If a plug was misfiring, how would that show up on the dyno? How would that be seen by the UTEC? I never threw any CEL codes related to misfire, so i dont think thats a problem.
Sorry for the novel, but i wanted to make sure I was detailed as possible.
Thanks!!
Last edited by str8dum1; 01-08-2008 at 05:35 PM.
#3
guess are fine, bc they can be used as starting points. the shop was uninterested in troubleshooting as I did the install myself.
i guess the main question would be, is that dyno representative to what a boost leak would look like in terms of both HP and torque? Thats what I cannot find examples of to compare to.
i guess the main question would be, is that dyno representative to what a boost leak would look like in terms of both HP and torque? Thats what I cannot find examples of to compare to.
#4
Registered User
iTrader: (6)
And it would probably be hard to find an example of a boost leak on a dyno . I believe I told you how to make a pipe with an air compressor fitting to hook up to your IC pipe just before the BOV . Then cap off the exhaust and find the leak if any . There may have been a lot timing pulled up top . There may have been to much fuel added . Your belt maybe slipping up top . Just a lot of guessing
#5
when i searched boost leak, 17 pages popped up, so its not an "uncommon" issue.. Basically everyone just assumed they had a boost leak bc they werent reaching their "expected" boost values.
A quick look at my UTEC tables would show if timing or fuel was added or pulled though right? I just dont want to drive way out to a tuner again, only to have over looked something, hence the general questions.
so you keep the BPV as part of the pressure test?
either way, i'm not looking for someone to fix my car, but more general bits of info about the way the charts should look under difference circumstances.
A quick look at my UTEC tables would show if timing or fuel was added or pulled though right? I just dont want to drive way out to a tuner again, only to have over looked something, hence the general questions.
so you keep the BPV as part of the pressure test?
either way, i'm not looking for someone to fix my car, but more general bits of info about the way the charts should look under difference circumstances.
#6
My350z
iTrader: (48)
hey there, here is an overlay of a few graphs. yours is in the middle. the lowest one is a revup with a 2.87 pulley.
the top one is a graph of your exact same setup that we tuned a few days ago.
this was done here at Performance Factory and made some crazy power!!
im sure you will find something stupid with your setup that makes sense why it doesnt make full power. good luck on figuring it out, shouldnt be hard to do...
thanks!!
the top one is a graph of your exact same setup that we tuned a few days ago.
this was done here at Performance Factory and made some crazy power!!
im sure you will find something stupid with your setup that makes sense why it doesnt make full power. good luck on figuring it out, shouldnt be hard to do...
thanks!!
#7
Thats awesome power. Gotta be one of the top 5 SC dynos. I pm'd you some specific questions about the tune.
DO you have any graphs of belt slip? Does torque nose dive under belt slip as well?
Mechanically i know what i tightened, replaced, moved etc. I can do boost/vacuum checks. But without knowing what was done with tune, like Booger said, it could be any # of other things wrong with the car besides the installation of the blower.
thats what prompted me to repost, to try to pick some brains about "other" things to check that might be assumed info to some, but alternative avenues to recheck nonetheless.
thanks!
DO you have any graphs of belt slip? Does torque nose dive under belt slip as well?
Mechanically i know what i tightened, replaced, moved etc. I can do boost/vacuum checks. But without knowing what was done with tune, like Booger said, it could be any # of other things wrong with the car besides the installation of the blower.
thats what prompted me to repost, to try to pick some brains about "other" things to check that might be assumed info to some, but alternative avenues to recheck nonetheless.
thanks!
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#11
That is what I was told, that the air was heating up and causing knock bc the blower had to work harder. I do recall him saying the car was knocking. We even tried filling the tank with new gas. However getting details on the rpm range it was knocking or how many times was never communicated.
The boost leak was finally settled on as the cause with no further reference to any knocking. So i dont even know if that was an issue in the final tune.
The more I chatted with the turbo guys around here, made me also question this explanation. They wanted me to ask if its normal to see a torque drop during a leak. I can fix that fairly easy with a pressure check and redoing the piping/install Thats why I was wondering about ignition problems, exhaust problems.
My map doesnt look like its pulling timing or fuel at the top (ie the values continue in the same direction as the previous row/column)
I know there's some sort of leak as the power stops rising well before redline. So 1st off that needs to be fixed. I'd just hate to get on the dyno and still have the top end break up. Wastes the tuner's and my time.
Thanks everyone.
The boost leak was finally settled on as the cause with no further reference to any knocking. So i dont even know if that was an issue in the final tune.
The more I chatted with the turbo guys around here, made me also question this explanation. They wanted me to ask if its normal to see a torque drop during a leak. I can fix that fairly easy with a pressure check and redoing the piping/install Thats why I was wondering about ignition problems, exhaust problems.
My map doesnt look like its pulling timing or fuel at the top (ie the values continue in the same direction as the previous row/column)
I know there's some sort of leak as the power stops rising well before redline. So 1st off that needs to be fixed. I'd just hate to get on the dyno and still have the top end break up. Wastes the tuner's and my time.
Thanks everyone.
#12
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Location: columbia md.
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Originally Posted by Audible Mayhem
hey there, here is an overlay of a few graphs. yours is in the middle. the lowest one is a revup with a 2.87 pulley.
the top one is a graph of your exact same setup that we tuned a few days ago.
this was done here at Performance Factory and made some crazy power!!
im sure you will find something stupid with your setup that makes sense why it doesnt make full power. good luck on figuring it out, shouldnt be hard to do...
thanks!!
the top one is a graph of your exact same setup that we tuned a few days ago.
this was done here at Performance Factory and made some crazy power!!
im sure you will find something stupid with your setup that makes sense why it doesnt make full power. good luck on figuring it out, shouldnt be hard to do...
thanks!!
#15
Regular
iTrader: (8)
Originally Posted by str8dum1
as part of the fix, i am using a silicon hose between the MAF and the metal tube. cut the square pieces off completely.
how did you know you had a boost leak if it wasnt detected on the dyno??
how did you know you had a boost leak if it wasnt detected on the dyno??
#19
Registered User
iTrader: (6)
Originally Posted by str8dum1
Interesting, as your experience is complete opposite of what I am seeing/ was told.
I put 1 step colder in before it was dyno'd/ tuned.
Thanks
I put 1 step colder in before it was dyno'd/ tuned.
Thanks
#20
My350z
iTrader: (48)
basically that red set up has a Performance Factory installed system, we did the 2.87 pulley on a non revup. the car has headers, test pipes and a JIC Ti single exhaust. it actually made more power but i had to back the timing down on it due to it starting to knock.
we make sure we take the extra steps to make sure everything is really tight and leak proof. we have seen many many things cause boost leaks and know what to avoid to save the customer time and money.
that car is very very fast...
we make sure we take the extra steps to make sure everything is really tight and leak proof. we have seen many many things cause boost leaks and know what to avoid to save the customer time and money.
that car is very very fast...