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Thread: Re-dynoed my car

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Posts: 11-20 of 28
2009-11-07 20:38:11
Originally Posted by BenFenner
I would expect a little more power for that turbo at that boost level and a whole lot less peak torque. Although the boost spike at 4k rpm seems to explain the high torque number, and the falling boost might explain the lower than normal peak output. 252 WHP at 13 psi isn't too bad, but at 16 psi that's not right.

The dyno could be a bit off. How does it feel?
I see you ran a 14.07 at 101 mph. That seems to mesh with the 250 WHP readings right guys?

Well I ran a 13.4 @ 102mph with the mods below, and the car is not tuned at all. My setup is SR20VE, T25 @ 7lbs, 370, 4bar, G20 open diff trans.

All in a 91 G20.

The trap MPH seems kinda low.
2009-11-08 00:57:42
If everything is in order I'd say look for boost/vacuum leaks. Its not that far off but with 14-16psi you should have more. I'd say you should be at the ragged edge of those 370s.

Maybe you have a tired motor on your hands.What's the history of it?
2009-11-08 01:12:30
Got it from tiger last year, I've put 7k miles on it maybe? Was mint as hell when I opened it up and got it. All silvery goodness. Still looks good in it. My Duty cycle is 90-91%. Don't see why it's that bad at 4 bar?

What do you guys rate your boost at? After the spike falls or where it falls to? Because this could be on 13psi... But I don't know why I'm making more tq. then hp.

Also the only other mod I have on this motor is an exhaust. Me and Vadim went over this last night, and that can only add a minimual amount of power. Now if I had a 91 cam, velocity stack, pulleys, thermoblock spacers. I could be around 275... Get some real cams and those add on's, Easy 300hp.

Anyone have a dyno sheet with a gti-r t28 on 16lbs. No other mods?
2009-11-08 01:32:46
My GTiR setup did 260 on 10lb but it was a UK motor... higher compression and bigger cams.

If the injectors are at 90% first off I would not be comfortable running like that; secondly I'd also expect another 20 more whp or more. When I put down 260 my 370/4-bar setup was at 75% duty cycle. Ran 14.0 @106.x w/ 2.4 or 2.5 60'

I don't know but if I were in your position I'd have my guys doing some data-logging for me. I'd be suspecting a boost leak and or a weak motor. Have you ever comp tested or leaked it down? I'm assuming the turbo is low-mile or new.
2009-11-08 01:38:56
did compression when i got it, was fine. no blow by. I have sti's going in this weekend and i am recirculating my bov also. Maybe my fuel pressure dropped or something.

Does your boost drop down at higher rpms? like the video i posted of mine? maybe my turbo is starting to take a crap?

and what am i gonna data log? i can do some runs on the street.
2009-11-08 01:53:31
Dunno what to data log. A few of my monkeys always do that stuff for me. Seriously.

My boost wavers at high rpm. We think its from the wastegate flapping but it just goes from 10-11psi. Could be a lot of things.

Its probably something else though. Maybe you need to fine tune for the Z32 MAFS. Its a big MAFS for a 250-300whp setup. Give a ride to one of the local gurus when you have a chance.
2009-11-08 03:43:03
Originally Posted by LikeTheMovies
What do you guys rate your boost at? After the spike falls or where it falls to?
If there is a spike in boost, I don't include that.

Originally Posted by LikeTheMovies
Because this could be on 13psi... But I don't know why I'm making more tq. then hp.
You're making more torque than HP because at torque peak you're running 18 psi and at power peak you're running 13 psi.

I too think maybe a boost leak is the culprit.
One other thing I realized. Where are you reading boost from? The manifold? The cold side of the charge pipes? The hot side? Right from the compressor?
2009-11-08 04:30:26
It does seem a little low. I did 259whp on a t25/t28 @ 14psi (trailing off to 12psi). Do you have cams?
2009-11-08 09:56:08
No, stock w10 cams which are lowports pretty much.

It's reading off the intake manifold for the boost gauge.

MAF is also at 4.2v
2009-11-09 04:35:03
man you need some cams! I bet just cams alone will get you where you want to be for that boost level. My old DET with S3 and JWT tune put out 290whp on 18psi. That turbo was way over-done at this altitude.

when the disco went on it made 270whp on 14psi. The boost spike programmed in from the AVC-R made 330wtq though, so it really felt incredible. When the boost went up to 18psi like the old T28 I am guessing it was putting out 340whp, but I never dynod when I swapped turbos.

But the S3 cams made the biggest diff. S4 cams are just awesome! If I built another DET those would be the cams I would use. 15whp increase on the top end, and 30+whp in the midrange.
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