OK guys I'm about to drop my new motor back into my car and once I get my suspension set up and my new rear in I should be getting around 450 horse to the wheeles. I had Hooker Super Comp longtubes and hated the clearence issues.I now have SLP's
1 3/4 primaries with single cat Y pipe.Do I connect the Y pipe to a
Flowmaster American Thunder catback that I all ready have and I will not be running a converter ,so Y pipe into 3in all the way back to the muffler with dual 3 out or do I cut the Y pipe where the two 2 1/2 pipes come together and run duall 2 1/2 pipes back down the factory rout (I know duall 2 1/2 will fit) and end with Dynomax Bullets and turndowns at the axle. My cross member has
had a hump made into it that dual 2 1/2 pipes will fit up into so the exhaust will be tucked up close to the body.I just need advise on which setup to run with the amount of power I'm makeing.Noise isn't a concern and looks aren't important since it will be close to the body and nobody will be able to see it anyway.
Thanks Guys

 

Anybody!!!!

 

if you actually are pushing out 450 hp, then you would want at least 3" duals. both setups mentioned use too small of pipes for 450 hp. what have you done to your car to achieve 450 hp? did you dyno test it or are you just guessing?

 

.30 over forged flat top 350.Forged crank,Eagel rods.Edelbrock Performer RPM heads,Victor Jr. intake,Holley 750 Dbl. Pmpr. with
Proform main body,billet metering blocks,Comp Extreme Energy 294 cam,Roller rockers,MSD wires, Pro Billet Dist.,6al ign,Blaster 3 coil,Turbo 350 BUILT,manual valve body,TCI 3500-stall nitrous converter and in the very near future 9in. with 410 gears.Car weighs in with driver at 2836lbs.The HP figure came from a computer HP calculater.The heads have been gone thru with some mods.porting etc.

 

With your mods and given that you already have the SLPs and apparently intend to use them, I'd go with the 2-1/2" duals. I think IMHO that the duals will serve you better in this case. And with those headers, 3" duals won't gain you a thing.

 

Kinda iffy on the 450 hp, if you did have that much hp, dual 2 and 1/2 would be kinda restrictive Id think. For that kind of power, I would just dump the exhaust out the sides and call it good with no mufflers at all.

If I HAD to choose between 3" and dual 2 1/2" for 450 hp, invariably I would chose the dual 2 1/2", but I would run no muffler, or a turbo-style glass pack.

I usually don't drive my camaro enough to justify getting an exhaust, dumping out the side seems most efficent to me

 

The Dynomax Bullets I'ed be running are a glass pack type,strait thru muffler.A car thats a trailer queen that see's only track time
would be fine running pipes out the side without mufflers but I'ed like to put a couple thousand miles a year on the car driveing it on the street.I want to be able to jump in my car and drive it on a 100mile trip without worring about ripping my exhaust off from pot holes,speed bumps etc.I'll probably only get 400horses to the rear wheeles before I hit it with a 200 horse shot of juice and then traction is going to be my biggest obsticle.
I was just reading a old copy of Chevy High Performance and it gave the following.Up to 400 HP 2 1/4 duals.
400-500 HP 2 1/2 minimum and 500+HP dual 3in.but it never gave any info on single pipe sizes

 

dont those headers have 3" collectors and 1 3/4" primaries....wouldnt you gain something by using 3" duals instead of 2 1/2" duals with those headers?

flowmaster says youd want no smaller than dual 3" for 400 hp. theres a whole chart and everything, but i dont feel like typing it all out . how old is this copy....maybe outdated info? or maybe referring to the inlet diameter of a pipe?

 

If you're pushing 450 RWHP, then definately go 3'' duals.

I was considering 2.5'' duals for a motor pushing close to 400 HP at the crank.

 

FatHippo I was mistaken it is in May 2003 issue of Chevy High Performance,page42.I just have to many subscriptions to car mags.The SLP's have 1 3/4 primaries and 2 1/2 collectors so with 2 1/2 being the smallest area from the headers it wouldn't matter if it had 4in duals it still is only going to flow 2 1/2.

 

Hey you could always go with my exhaust with either a flowmaster or spintech. Just figured, I'd drop another option to ya. Oh yeah, the 4 inch system is equal to 3inch duals.

 

Mufflex makes a Y pipe for SLP shortys?How much?I'ed consider it but I'ed have to sell my American Thunder catback to recoup some money first to put toward exhaust.Im working on a budget.

 

No, they don't make a y-pipe for shorties, only the long tubes.