Miles in Florida

After the first dyno session that only got 407rwhp, and then 46Xrwhp with open headers, I ordered a Random-Tech x-pipe with hiflow cats, GHL exhaust, and Halltech Stinger intake. The shop installed it all, and tuned again, and got 448rwhp, 433ft-lbs of torque. Pretty low for a 402 .

Mods:
LS2 402
Patriot Stage 3 heads
Comp XE-R 238/244 cam
LS6 intake manifold (stock TB, stock MAF)
Stainless Works 1 3/4" LT headers
Random Tech hi-flow cats and X-Pipe
GHL exhaust
42lb injectors
Halltech Stinger air filter
underdrive pulley
NLP (Next Level Performance) dyno-tune

Blown04Z06

bro i have been waiting to see what happened. at least its not on the low low side like it was. after reading tony mamo's posts. i would say its a combination of intake, heads and cam, although that cam should be the right cam based on tony's comments regarding over cam'n. this isnt a big cam.

the real question is how does the car drive?

lilbuddy1587

iTrader: (1)

Hmmm..

beardWS6

iTrader: (1)

Need to change intake set-up etc. Its choking you. Is this 6sp or auto?

STRIPSTAR

iTrader: (4)

yeah and that cam isnt exactly small either.

Mr Z51

very small cam for that motor. my 408 was a 248/252.

CHRISPY

Fast 90/90 setup will give you at least 20-25RWHP more than you have now.

What is your SCR and DCR?

Cheers
Chris

Cyborg

iTrader: (8)

What's your LSA and CR?

David Gordon

iTrader: (1)

I made 475 with a ls6 intake, I bet it is something else.

Miles in Florida

static compression is 10.9:1 and dynamic compression IIRC is 8.3:1

LSA is 112, and there's 2 degrees advance, so ICL is 110.

kumar75150

cam is too small, headers are too small, intake and TB are stock, heads are probably below average for that size motor

still should make around 465-470 i would think

xaon

iTrader: (12)

is the car an automatic? If so, are you sure they locked up the converter. The numbers will be way low if they did not lock it up.

The cam and headers are fine, there have been plenty of people make 500+ on them.

Intake/TB/MAF are fine as there have been numerous people make 470+ with those. (You would benefit from a FAST 90/90 setup... but it's not choking you off bad enough to account for a 50+ horsepower loss)

There have also been quite a few people make good horsepower with the Patriot Stage 3 heads on 400" motors.

We really need more information on the rest of the car's drivetrain to assess what is truly wrong with your dyno numbers.

Miles in Florida

It's a 6-speed, 99 C5 corvette, with the stock 3.42 rear end. Stock wheels, Kumho non-runflat tires, I aired 'em up to 35psi before taking the car to the dyno shop. I guess flat tires or a slipping clutch could explain it, but I assume NLP would know to look for that.

11SECDWS6

iTrader: (3)

+1 for headers, intake, TB. Also, there's probably alot more left in the tuning.

Was it throwing any codes? Sometimes that can lead to something else like a bad O2 sensor or knock sensor. Both of which can KILL power...

NumberOneSled

iTrader: (1)

What did Norris say?

NEVRLIFT

In case you didn't know, Norris's dyno is very conservative. Even with that those numbers are a little low. You will gain around 20whp with a FAST 90/90 combo.

The cam seems fine for this combination. Not too much, not too little. My uncle's 404ci Z06 has the same exhaust setup as you except for his Borla Stingers. I wonder if he loosing a bit of power because of the headers?

Miles in Florida

He said I should have gotten AFR heads, and that a Fast 90/90 would help. He also said my cam is bigger than he'd recommend. The cam selection along with different heads would have given me a higher dynamic compression ratio.

I agree with him (and all of you) that the intake is a bottle neck, and I could have gotten better heads, and a different cam, but it still seems like my numbers are low for the parts I've got. It's hard to find someone with the exact same setup, but it seems like similar cars have gotten 470+, so perhaps I'm only down 20rwhp right now. That might be explainable by his dyno reading low (as I've heard from several people), but I won't beleive that until I dyno "high" somewhere else. I'll look for a dyno in Denver when the car makes it out here.

- Miles

Miles in Florida

I hope not, I assume Mike would have told me if it was.

11SECDWS6

iTrader: (3)

Well, I made the same wrong assumption with my tuner If the check engine light is on, you may need to scan for codes. I took mine to Autozone and the scanned it for free. That could give you some clues to start with.

11SECDWS6

iTrader: (3)

Also, what kindof converter are you running? locked or unlocked?