HellRaiser

iTrader: (9)

Got the car tuned on the dyno yesterday. I picked a perfect day to do it, 100 degrees outside and the humidity was though the roof.

I wish I had more time on the dyno to play with the Eboost, maybe get it to spool up the turbo a little sooner but I didn't get a chance for that.

Also I think theres something wrong with the RPM's reading on my car and the dyno's because I was watching my tach (stock one) and would let off close to 6k but when we pulled up the dyno you can see me letting off around 4700rpms.

Anyways the car made lots of runs and they were all about the same.
10psi
AFR was mid 11's
0 knock
532rwhp
595rwtq

rozzyroz

ok, couple questions for ya... what all do you have done to run 10psi, and what happened to the torque under the curve? (im a noob to FI) and is this the manifold kit?

HellRaiser

iTrader: (9)

You have to have the fuelsystem setup for it, I run dual walbros,-8 feed line,rails,FPR at the rails, and 60# injectors.

Not to sure what you mean by "torque under the curve"

Yes its the manifold kit.

rozzyroz

thanks for the reply. i was talking about your torque down low. most dyno sheets i see of even stock ls1's dont get below 300lbft of torque until about 2.5k rpm, and if they do its not by much. is the turbo that much of a restriction at lower rps? or is that because of the rpm on the dyno being off? its probably the way im reading it.

you have a very powerful setup.

HellRaiser

iTrader: (9)

yeah not to sure on that. Hopefully someone here will know. The runs were started at 2000rpms in 4th gear. I think I can get the torque up some by play with the Eboost, maybe get the turbo to spool up alittle faster and that would raise the torque down low.

rozzyroz

i should have just read your sig!

HellRaiser

iTrader: (9)

I might be able to get more torque down low to if I open the exhaust up. I run 3" all the way back to a GMMG catback. Maybe I should do a 4" with a turndown before the rear..

ddnspider

iTrader: (26)

i think you need to get the rpms figured out....if your tach is wrong then youre not even peaking power wise casue youre stopping b4 500rpms

EightBall

The graph looks like it should to me

You say you let off near 6000, and that's what the graph shows. It looks to me that your car is gettin choked past 4500 RPM and the power is just falling right off. I've seen that in a lot of FI dyno graphs.

EDIT: although, something must be wrong, your HP and TQ curves never meet.

HellRaiser

iTrader: (9)

That could be to. You think the stock heads, stock intake, stock TB could be whats wrong? Also the fact I run full exhaust prolly don't help it much.

Also now that I think about it my overboost is set at 9.5psi. So I might of been hitting that and then the boost would get cut in half there for dropping HP. I forgot to change it while I was on the dyno.

EightBall

If your boost was electronically cut in half at those RPMs, it would most likely account for the drop off. A stock motor will fall off a little anyway, but not that much. Still confused about the curves not meeting though

HellRaiser

iTrader: (9)

Yes I think once it hit 9.5 maybe peaked 10psi it dropped down to 4-5psi which would make the curve look like that I would guess.

ddnspider

iTrader: (26)

id definitely think the stock intake and heads are hurting you a tad....what cam do you have?and you sure the 918's are strong enough for 10#s?

Country Boy

iTrader: (24)

Yeah, something isnt right... Its goes straight up and straight back down.

Jax

iTrader: (2)

Found that odd myself (they should cross @ 5250 RPM)... Why would that happen?

30th t/a

iTrader: (51)

do you have the stock cam still? also, is your bottom end forged? do you have just a single 3" y pipe going back to gmmg?

BubaGumpShrimp

iTrader: (1)

i call bs on that graph. Hp and Tq always cross each other at 5,252 rpm. If they dont its a bs graph... Im not saying your full of it, im saying whoever you took it too didnt set it up right, which is another reason why the tq looks low at first and it drops off real fast.

30th t/a

iTrader: (51)

yea your right........but only when the rwhp column and torque column are the same which they are not in this case. the rwhp goes to 550 and the rwtq goes to 650.

HellRaiser

iTrader: (9)

Stock cam, stock everything but 918 springs. I am sure the drop off is a result of boost going to 9.5psi and then dropping to 4psi because of the over boost function.

As for the curves not crossing I have no ideal whats up with that. I know I made a bunch of runs, could they mix/matched the runs maybe? Like those are 2 seperate runs? I know at one point the car was closer to 540hp and like 570tq but they add some more fuel at the last run and the power was down alittle and tq went up. I will have to call them and ask about it.

HellRaiser

iTrader: (9)

good point. Maybe it never got a chance to cross? I really think I fucked up with the eboost. I never got to set it and it was still set for overboost at 9.5psi from before when I was running 7psi.