wtknght1

Recently the CRB allowed the C5s to upgrade to headers in class T1. I personally think it was a good idea. There's been a lot of debate regarding just how much extra power headers provide to both a stock vette and one running an already open exhaust.

I'd like to get some feedback from those who added headers to a car that already had an open exhaust (i.e. no cats, no mufflers, etc). I'm looking for actual HP/TQ increase numbers on a relatively stock LS1 or LS6 engine (between 350 and 425 rear wheel hp).

The other issue that came up was the sound level. I have a very strong feeling that adding headers to an open exhaust will send many C5 owners over the 104 db limit. If you have any of that info, it would be helpful.

I don't want to get into any arguments regarding "for" or "against" these mods; I'm just looking for raw, basic data. Thanks!

ryan0

i know that locally, the 103db limit is a 'recommendation'... is it not like that in other divisions?

Olitho

I ran stock headers on Friday with 368, 369 and 371 HP readings from the dyno. That afternoon we installed headers and did a retune and the car went to 414 HP/404 torque. I picked up 3.7 seconds on a roughly 1:50 second track on Saturday.

PushinTheLimit

Wow, thats a huge gain!

rasrboy

Cheese and Rice Oli!!!!! Thats impressive on both parts. Thanks for sharing and will have to let you know what my stuff is when it's done.

Aaron

Olitho

Alright! It just isn't right to let this go on any longer. I am just yanking your chain... mostly Chris Ingle's.

None of us have done headers, yet. I bet we will in the next month or two though. We will report REAL results as soon as we get them.


Oli

rasrboy

That was DIRRRRTY!

RAFTRACER

I wouldn't bet against the hp #'s that you eluded to....the tq # may be alittle far fetched....

drivinhard

and don't forget the 20-25 lbs of weight you'll save, for those trying to make it down to min weight

ryan0

seriously? for someone with 3" straights already?

im still running OEM '01 downpipes, with the dual pup cats and H pipe.. i was only hoping for 30HP... mid-range should definitely get a hand... maybe make up for the giant 3-4 gap.

this could be fun.

Pumba

I did two modifications at the same time on my LS6 that already had a VaraRam air induction system and Corsa mufflers:

1) Crane 1.8:1 aluminum roller rocker arms and springs

2) L.G. Motorsports long-tube 1 3/4 inch headers, random technologies high-flow catalysts, and 3-inch X-pipe, thru the Corsa mufflers.

A chassis dyno run before and after the installation of these parts showed a 44 rwhp improvement.

gkmccready

Was that with a tune, or just with parts?

ryan0

hard to compare.. i think the vararam benefited a lot more from the headers than the stocker will

96CollectorSport

I don't care who you are that's funny right there, you just had every T1 guy chit a little there. That was great!!! We should see some numbers in the next month or so.

Joel

Pumba

The VaraRam has no ram air effect on a chassis dyno.

Bimota Guy

I would expect any good aftermarket airbox to flow better than the stock one on a dyno. No?

Bink

The 1.8 rollers (stock LS6 are 1.7) effectively increased both lift and duration of the cam.

NemesisC5

I'm listening

sperkins

Never had a dyno, but I think I actually lost HP when I installed a full 3" catless Kook's system with straight pipes. I think it's just too much for my stock LS1. My bet is that my HP went down, but my torque improved.

tjZ06

It sounds like you didn't have the car tuned? Throwing mods at LSXs w/o tuning is a waste of $. With a tune it will respond well to the headers.

-TJ