xfactor_pitbulls

iTrader: (16)

It doesnt dissolve anything. I have customers all the time that see dramatic difference in exhuast setups. 7-8whp just from taking duals from before the axle to the back of the car. ORY setups yielding 15whp when they put on cutouts. These are stock cube setups. There is power left on the table. When guys can take a mufflex setup with a high flowing muffler and gain something to cutouts on stock cubes, then a 408 will for sure. I think we are talking about 20whp on this car.

Brandon

JL ws-6

iTrader: (50)

I hear what you are saying... but I can tell you this, they unbolted the Y on his car, so it was open headers to see what that would get them, and it was a 2 hp increase, going from an ORY and a LM to open headers... making the point I was trying to make that the power differnence is so small going from a ory and a Lm to something with a cutout vs the gains that he will most likly see by swapping the intake, that I'd worry about the intake before the exhaust. doing soemthign with teh exhaust in his case, probably good for 5 hp I'd figure. Changing the intakse stup, probably more like 20. I'd go for a 20 hp increase before I worried about a 5 hp increase, that could be the weather that day.

Of all the catback setups out there, the LM has got to be the best flowing that there is, better then a mufflex setup with a muffler, better then any of them. It is the loudest, which means the least restrictive period. Changing that isn't gonna get you very far I'm sure of it.

xfactor_pitbulls

iTrader: (16)

I understand where you are coming from, but we are talking to different things. Yes a LM flows well, but it does not flow as much air compared to 3" duals or a 4" mufflex. A LM is loud because it doesnt have a muffler, it has a resonator. I agree on the intake as well, but they will both show gains. Is the 383 stroke or bore? Makes a difference.

11SECDWS6

iTrader: (3)

What transmission are you using? An M6? If your using an auto, what converter do you have?

ArcticZ28

iTrader: (14)

I've got an M6 with stock gears, soon to be 3.73's.

JL ws-6

iTrader: (50)

383's a stroke motor. If it was a bore motor, I'd see how it's hitting the #'s that it is.

I know that 2 3 inch pipes are gonna flow more then a single 3 inch pipe, I just don't think the power levels we're talking about are being choked with the single pipe.

I'm in the process of a buildup myself, if someone wants to prove me wrong and fab a dual 3 inch setup for my car to disprove what I'm saying, I'd be all for it... and would be happy to pay for it after it's done if it makes more power, I just don't think it will, not enough to justify spending a grand on a header back exhaust setup that runs to the back of the car.

11SECDWS6

iTrader: (3)

I would think with an M6 you'd hit 500 easy with ported heads and a FAST 90/90. I would investigate using some different castings though as someone else pointed out instead of investing alot of money in those. You know your going to want them sooner or later. Might as well do it now and save the money.

ArcticZ28

iTrader: (14)

Nah, won't be getting aftermarket heads at any point. These are my last expenditure for the engine, other than 90/90. This is a daily driver so it needs to stay streetable. I've just been looking for the 500 mark for a while so this is basically my last hurrah as far as power goes. Then this car will become show and I can move on to my next high hp daily driver project

Camaro99SS

iTrader: (4)

Thunder Racing got 451rwhp out of a 99 T/A with stock heads and shortblock, LS6, ported tb, and a 12 bolt rear with a T-Rex cam. The dyno graph and a 1/4 tun are both posted under the T-Rex cam. http://www.thunderracing.com/catalog...&vid=3&pcid=51

With a good dyno tune, I can't see 500rwhp being out of reach with well worked LS1 castings even on a rebuilt 346 CI motor with 11:1+ compression.

Jason

TopFlite

ArticZ, your car sounds killer in that old video clip you posted up after you got the 408 back! Where do you plan to put the second cutout? My only one is just under the rear passenger seat.

ArcticZ28

iTrader: (14)

Thanks, it sounds badass b/c it's a really crappy vid and masks the insane rasp. My two cutouts will most likely be post-cat in the y-pipe once I get the cats back in for emissions down the road.