LastBlack02SS

iTrader: (21)

Mods are in sig. I'm on a stock block with stock casting heads. I'll post up a dyno graph tomorrow but the car put down 440hp and 456ft/lbs at 6psi. It starts at 8psi but gradually drops off to 6psi at the high end. When i get the eboost2 tapped in to the computer I'll be able to program it per gear and rpm to adjust for the drop in boost. Just got it back from Rick at Synergy and I'm pretty happy.

gametech

iTrader: (1)

I'm curious why the boost drops off. The gt67 will flow enough for a good bit more power than that. I wouldn't expect valve float with the 918 springs, but something just isn't right. Although if this was a dynojet, that might explain it. If the boost drops on the road, however, you are losing power somewhere.

LastBlack02SS

iTrader: (21)

The Eboost2 has to take the boost reference from the turbo and not at the manifold. Although the Eboost2 shows 8psi all the way through, it drops off at the manifold as it gets up high (thats what Rick told me).

gametech

iTrader: (1)

If everything is working right, you're HP peak should be Higher than you're TQ peak. I'm sure the car is a blast to drive, I'm just trying to make sure you aren't leaving some power on the table. And like I said, the #'s could just be a dyno thing, your car may be fine on the road.

SilverSS

iTrader: (30)

Your boost definitly shouldn't drop off like that. Something is wrong. Any leaks in the piping?

Hey GameTech, are you an actual game tech?

LastBlack02SS

iTrader: (21)

I'm almost positive there are no leaks. Besides, wouldn't Rick have picked up on that? Any other possibilities?

gametech

iTrader: (1)

#5
SilverSS
Staging Lane




Join Date: Jun 2005
Location: Houston
Posts: 56
Trader Rating: (2) Your boost definitly shouldn't drop off like that. Something is wrong. Any leaks in the piping?

Hey GameTech, are you an actual game tech?
__________________
I am a technician who works on video games, so I guess. yes, I am really a "gametech".
I still don't quite have a handle on how to do the quotes.

2002ws-6

iTrader: (5)

My numbers are similar and so are our mods. Besides the injector size and my heads are bone stock 241's. I have the same slow boost drop on the dyno, I was on a dynopack dyno. I hit 7.3 psi and finished off just above 6psi. I have checked for leaks and have found none on the cold side, guess i'll be checking the hot side? I did have a problem with my tune. I was in a rush to get it done in time for a race, but didn't have a two bar map sensor. So yes I'm running a 1bar SD tune on a boosted car, for now How much timing where you running? Mine was at 10* because the car was running the low octane timing table, from the 1 bar sd tune.

XpEdItIoUs

iTrader: (44)

Who did you tune?

2002ws-6

iTrader: (5)

pm me and I'll let you know where it was tuned. They where very upfront with how the car would run with a 1 bar SD tune on a boosted car. And they said I'll get a good deal when I go back for a two bar tune.

LastBlack02SS

iTrader: (21)

Mine is with a 2bar sd tune, no maf, done on a dynopack dyno. Any ideas?

2002ws-6

iTrader: (5)

you have your dyno graph? Did you peak at the same RPM as mine both tq and hp. I think with some more timing i'll be able to pull to 6000 rpm. What brand wastegate are you using. I think that some take a little "craking" pressure to first open it then it settles at the lowest psi

Slowhawk

iTrader: (12)

The boost WILL drop if you do not have the wastegate controlled from the intake-not the turbo.

XpEdItIoUs

iTrader: (44)

Will any wastegate have this ability, To be controllled by intake? sorry for the noob question.

LastBlack02SS

iTrader: (21)

Here's my dyno graph

99Fbody99

No,

Its funny watching the arm chair quater backing in here sometimes. The gates referance is not the intake manifold. Its pre intercooler and will see a higher pressure as the core and plumbing with drop pressure traveling across them.
So, in a nutshell, the pressure the gate is seeing and responding to is in fact
8psi and doing exactly what its being asked to do!
The pressure/power drop occurs from the rear to the intake manifold and power/flow requirement go up and friction takes over. If the referance were to be moved to the intake it would then remain manifold constant and increase the boost to compensate for the pressure drops.

Dave

LastBlack02SS

iTrader: (21)

So is the best idea to tap the eboost2 into the computer and have the boost increase at the higher rpms where it drops?

Schantin

iTrader: (6)

Not necessarily. My car put out 426/435 with an STS on 5PSI. The engine and set-up were fine. (though the tune sucked and I've since been re-programming that.)

TS6

iTrader: (41)

How much power did it make before the turbo? I would think you would have been close to 400 rwhp pre turbo, so it doesn't look like you're getting much out of it.

2002ws-6

iTrader: (5)

It looks like alot of cam and bolt on cars reach 400 hp, but they don't get any where near the torque of the STS. My car stock, on a dyno jet made 299hp and 325 ftlbs. I upgraded to the zo6 cam at the same time as the turbo, and so far thats a 125 hp and 140 ftlb gain at 6.5 psi. thats nearly 45% more hp and tq. And these numbers are much earlier in the rpm band all peak #'s by 5000 rpm. Now I just gotta figure out how to pull to a 6000 rpm redline.