LethalTT

Put the car on the dyno and makes no power past 5500 it actually falls flat on its face. Spent ll this money on new motor fuel supercharger ....everything to make this kind of power. The AFR was at 11.4 on E85. Here are the specs and graph any help would be greatly appreciated. Suppose to make 17-20PSI 900-1000RWHP not this ****.

2008 Corvette Z51

Engine: 408 9:5:1 compressiondragon sayer crank ultra bllet rods
Procharger F1C w/ 8 rib
Overdrive crank pulley ATI
58x tooth reluctor
4 inch S/C pulley
Dewitts Radiator
A&A "Big" intercooler upgrade
205lb Fuel Injector Clinic Injectors
Fuel innovations triple pump setup
Holley fuel rails
RPM Level 6 Trans
Monster triple disc
Kooks headers
1 7/8 runners with a 3 inch connector
S pipe jet coated Full Zo6 exhaust
Custom grind Comp Cam specs 227/245@50 115 LSA 637 lift
Brian Tooley 660" Lift Platinum Spring Kit with Titanium Retainers SK001
Rollmaster LS3 Double-Roller Adjustable Timing Set - 4X Cam Gear
LS7 lifters
Stock LS3 heads with LS9 head gaskets.

E85

turbotuner20v

Did you degree the cam or just stick it in?

Storx

It could easily be a sensor like the MAF, anyway to log the MAF values to make sure its not saturated... because fuel and timing are cut when MAF values show wrong.. causing it fall on its face..

Gabbiani

Got a log? And/or tune to post?
It's not belt slip. Boost keeps climbing.
Hate to say valve float but it does fall on it's *** hard.
What kind of timing is in it? The spot at 4300 could be a knock or a miss.

Don't get discouraged. It's the first time out with a lot of new parts. At least it didn't blow up. Boosted motors are not very forgiving. Everything has to gel to make power.

LethalTT

I hope it's not valve float. I'm being told it isn't the tune. The shop doing the tune didn't install the cam. They checked preload and compression. They can't figure out what it is either. Everything came out good there. I'm lost and don't get it. Should I keep it off the dyno? What should be the next step.

turbotuner20v

Who spec'd and installed the cam? Do they have any thoughts?

RPOWU8

Should be making more boost than this. Check hose connections and line that goes to BOV is connected to the right connection. Your only gaining 2PSI from 5000 to 6600?. On my Ti Trim A@A I make 5psi @ 5000rpm, and 13 at 6600 rpm.

DJ

LethalTT

He left me high and dry on the build so new shop finished it up, and now that we're at the dyno stage things have hit a wall.

LethalTT

Comp cam said the cam should pull through 7000rpm and engine builder said that it isn't his motor....but would you to expect anything else from an engine builder? He said same motor with stock heads and small cam made 650 all motor.

5 Liter Eater

Seems like a boost leak if that pulley setup is supposed to make upwards of 17#. Doesn't necessarily explain why it's falling off though. Definitely doesn't look like valve float.

turbotuner20v

I agree that boost seems to plateau, but I would think that with a constant boost level it would still produce a normal powerband. If it was a boost leak it might be down on power overall, but it wouldn't dive to 400whp by 6,800 rpm.

Given that the tuner says its ok, all we can do is take his word for that and assume the sensors all work ok and it's some kind of hardware problem.

My thought is that the cam timing is way off and it's bleeding boost as well as totally killing the powerband

turbotuner20v

I assume you're not running cats?

ZBADESTZ@Straightline

My car did this when the cats burned up and clog the exhaust
up

turbotuner20v

I'm sure it's reading lambda and displaying in gas AFR

0.780 lambda should = 7.613 AFR on E85, and 11.466 AFR on gas

RPOWU8

Sorry I remebered that after my post. Good point.

DJ

LethalTT

Roger that...no cats are on the car it's also speed density tuned. ZR1 3 bar MAP sensor also.

narfdanarf

Are there any flex pipes in the exhaust...we had a flex pipe implode once. It was a double walled flex and the inner wall expanded more than the outer causing it to expand inwards....the more we turned the boost up, the less power the car made...took off the exhaust and we picked up 150hp lol.

Frans96ss

Is there a reason you have #205 Injectors ? Not saying that's the cause but that's a HUGE injector for your setup. Also it looks like the car gets some knock around 4k by the dip in the graph and possibly carried all the way out

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NotStock

That is a very odd dyno sheet and numbers for a car with that set-up. I don't have an answer for you but I see you're in San Antonio. You might want to get the car to Corey at Henderson Performance Technology in New Braufels. He's been tuning my car for years and is phenomenal. Keep us posted as I'm curious to see what the problem turns out to be.

LethalTT

went with them because everyone runs out of fuel on the big builds and I wanted room to grow. Carlyle ran them on his old setup with 1000 and it was fine. I bought them from him. Plus E85 was a big issue needing 40% more fuel. I have room if I want to add some nitrous or go twins later. Doesn't look like I'll be doing it anytime soon though.....