c5z headers & intake dyno results
 

Already posted this over on LS1Tech but figured it would be useful here as well...
Had my car tuned last week after getting the long tubes and the intake installed. Overall I'm very happy with the numbers considering the conditions and the conservative tune, the car feels and sounds amazing. Shout out to Powertech Performance in St. Pete. If any of you guys are in the Pinellas/St. Pete/Tampa area I highly recommend you check them out. Joe (owner & tuner) is an awesome guy and the LS platform is his expertise. He walked me through the tune while it was on the dyno and explained what changes he was making as he went along.

Car: 04 c5 z06, 40k miles

Mods: American Racing 1 3/4" long tubes, off-road x-pipe no cats connected to stock Ti axle-backs. Vararam B2 intake w/ power duct.

Conditions: 92F outside/114F in dyno room, 85% humidity, approx 15ft above sea level.

Stock Baseline: 351hp & 329tq

Final Pull: 388hp & 370tq at only 20 degrees of timing.

Is this with or without a tune?

Final numbers are after tune

Solid numbers. I think my 01z only made like 377 with those mods.

Well this is shown in STD so SAE numbers would likely be around 377

37 Hp and 41 Tq gains for headers and intake is spectacular. Congrats.

Nice job OP. Few more mods and you can crack 400 with the stock cam easy.

Thanks. Although I kind of wish I would have just gone with 1 7/8" to squeeze out the last few ponies.

Really? Maybe a Fast 92 w/ ls2 tb and more timing? I think if I went with 1 7/8" long tubes instead + the fast 92 combo I could crack 400 in STD reading. Unfortunately we couldn't push timing past 20 degrees without seeing some slight knock. Tuner believes its most likely due to the 114+ temp and 85+ humidity holding it back but many others seem to be able to throw 26 degrees or more at their engine with zero issues in similar conditions. It bothers me and I'm wondering if there is some underlying issue causing the low timing knock.

I'm making 442/395 with the stock cam and heads on my 03Z06.

Are you running a catch can?

Very nice. My 03Z 60k miles with the same exact setup, except my x-pipe is catted, made 392. I love how much harder it pulls in upper rpm's with long tubes, and the sound is glorious.

1 7/8 versus 1 3/4 wouldn't make much difference, maybe 2 to 3 hp. I think if you had your heads ported you would easily break 400 hp.

No catch can yet but it is certainly on the to-do list. Although, I doubt that I am getting enough blow-by to cause knock at such low timing and I don't seem to be burning much oil between changes. I read your thread and no offense but those numbers simply defy logic, I consider your results to be an extreme outlier and not gospel. Not hating, just my honest opinion. Other than that it's an awesome set up and I'm sure it gets down.

Sweet, and yes it pulls much harder through all rpm

Yeah definitely but I wont be doing heads for long time. Cam is next on the list for power mods.

Nice results!

Thanks. That's the response most people give me. It's a legit build and the track has backed it up. It traps what most cam only cars do on here.

Is that flywheel or rear wheel horsepower?

rwhp.

There is no way you are making 442rwhp on a stock cam and heads unless your boosted or spraying nitrous.