CNB

iTrader: (4)

2000 Corvette FRC M6

Before headers, 333.9 rwhp, 333 rwtq.
After headers, 335.0 rwhp, 343 rwtq.

Mods before longtubes are Vortex air box, LS6 intake, x-pipe, B&B PRT axle back and stock tune. The car dynoed 333.9 rwhp and 333 rwtq. I added Dynatech long tube system, Shaner throttle body, and had the car tuned. 335 rwhp and 343 rwtq. I'll have graphs tomorrow but the a/f was at 13.0. This is much lower then I expected. I'm have no idea what's wrong. O2 sensors seem good according to the tuner, air/fuel is good, and no exhaust leaks. The temperature today is about the same as the last time I dynoed and I used the same dyno. The car feels stronger but the numbers don't show. Does anyone have suggestions?

KB99WS6

iTrader: (6)

well did you have an offroad X-pipe previously? Switching back to a catted system will explain some of it, but even so your gains would still be very low.

KB99WS6

iTrader: (6)

Also, did you use the same dyno?

CNB

iTrader: (4)

I had stock manifolds and stock cats before. I used the same dyno.

KB99WS6

iTrader: (6)

Wow, thats really weird. Your overall numbers arent that bad, it's just the 2hp gain thats way off. The only thing I can think is that something was up with the dyno the first run which caused it to read high. IMO, You should have seen a minimum of a 20rwhp gain between the LT's, TB and tune.

Maybe you were originally around 315rwhp....Thats what i saw a guy with an 01' C5 dyno with just an intake on the car.

Or, you could have a pretty strong runner, but something is now wrong with the car. Might be some little thing like dirty MAF sensors or something messing things up, or maybe your tuner just really sucks and actually made things worse??

dubs6

iTrader: (1)

Car Craft just did a dyno on ls1 manifolds and headers. they showed minimal gains as well from stock corvette manifolds to headers on a stock motor. they picked up about 10hp i think with fbody manifolds though.

CNB

iTrader: (4)

The car does run strong. A couple of my friends and I went to the Ennis racetrack. My friend ran a 12.2 @ 114. On the way home we did a 3rd gear pull and we were dead even. This was before the headers. I'm not saying I would trap 114 but we were even from a 3rd gear pull.

CNB

iTrader: (4)

I understand the factory manifolds flow well but to only gain 1 rwhp is weak.

Beast96Z

iTrader: (21)

Did you check to see if both graphs were SAE and or STD? If one is STD and the other is SAE, that could be your problem. I've seen that happen before. Someone jacks with the dyno computer and changes the correction factor.

CNB

iTrader: (4)

Before header runs are SAE.

Avengeance

iTrader: (4)

How did the curve look overall though? Area under the curve...

CNB

iTrader: (4)

I have the graphs but there is no file extension so I do not know what program to open them with.

WS-Sick

That's odd. Maybe cutouts could free up some extra power.

davered00ss

iTrader: (4)

That does not seem right. You should ATAP the car for codes. The before #'s seem high though.

dubs6

iTrader: (1)

oh yeh tuning helps alot. my friend put on supermax and couldnt pull on me (we were even before) then he got it tuned and pulled a length or two on me.

LG Motorsports

Here is a graph from a Z06 before and after using our LG Pro Long Tube headers. Our headers have a 3" X pipe and 3" rear pipes . We have found better hp gains on C5 cars since the Z06 has a better exhaust system to begin with.

The tune is worth 5 to 9 hp so if your tune was done prior to your installation you might add that to your gain.

thanks
Lou Gigliotti LG Motorsports

Country Boy

iTrader: (24)

If I had a Vette, I would have the LGs without a doubt! They even look good!

Hey, Lou, have you thought having those made in 1 7/8 for the big cube guys, or is there not enough room?

LG Motorsports

Country boy

Here is a graph using the LG Pro Long Tube headers as is with a "Big Cube" engine

I think a 1 7/8" would lift the top some but at the expense of the bottom end of the curve.
and I love torque!

Thanks
LG

LG Motorsports

this graph is a 427 with a blower. So a street driven big block with a Blower can make 680 using these headers. Nice huh.

LG





And here is a Z06 with our headers and G5X-3 cam and AFR 205 heads with stock intake manifold.

LG

CNB

iTrader: (4)

For some reason I could not get my highest pre-header dyno graph but this is close enough. Here is the horsepower/torque graph.
Red is before and blue is after.