Car currently has a 4" exhaust because the previous owner got the piping for cheap I guess. Its a bit loud if you can imagine, even after adding a muffler. I was thinking about making a really quiet 3" system using Kteller piping or similar, a couple large resonators and the biggest magnaflow muffler I can fit. If the design of all these components is straight through, will I be losing much power? The car currently makes over 500whp on pump and Id like to keep it that way.

 

It shouldn't kill power to much You will know if it richens up. I have kteller with magnaflow round muffler in middle and magnaflow oval muffler in rear. It's pretty quiet untill the wg opens.

 

4" is just absolute overkill, 3" is the max you would ever need on a turbo setup and its good probably till up to about 35psi

 

psi means nothing, its good to a certain amount of hp or exhaust flow really. But 3" will support more hp than your making. The 4" acts like an open DP so it may richen up a lose a couple hp but nothign really major

 

you do realize the amount of air volume you move into the engine determines what size exhaust you need for the volume of air moving out of the engine correct? It has nothing to do with power. HP for an exhaust size is just a rough estimate of previously known requirements for other setups.

 

you do realize 35 psi from a sc61 isnt the same volume of air movement as 35 psi from a gt4202 right? Again PSI means nothing its really how much cfm the 3" piping can flow and for his 500whp its fine.

 

and yet if i said that in another thread i would be wrong, and everyone would tell me psi is psi regardless of CFM, god i hate you ****in people you know that

 

there is manifold pressure and there is air volume. some people just interperate it differently and purposly try to be dicks to make people look bad. 35 psi in the manifold is 35 psi in the manifold but the turbo size determines how many cm of air is contained within the manifold which is the volume measurement and really only way to meaure that would be on a MAF system not a MAP system. I get what your saying though ive seen people depbate that for weeks on here its retarded

 

well i feel a little better that at least you understand what i mean

 

I know the 4" is absolute overkill that's why Im asking lol. Its just nice being able to know that my exhaust is never the restriction.

 

we hate you too, just fyi

 

there are cars making 800 horsepower on this thread that i have personally found (maybe even more power) having the smaller 3" exhaust would improve the efficiency of your setup in the entire power band in my opinion...

 

I plan on doing this exact thing. From what I have read if you want quiet you are going to need two 18" resonators and a Vibrant Stealth muffler at the end or a Magnaflow. Just make sure the mufflers are true 3" on the inside and you shouldn't lose much power at all and will pick up some throttle response out of boost.

 

X2. 4" is just overkill unless your trying to make 800-1000 imo. Hell there are plenty of people making 500 on a damn 2.5" exhaust with the waste gate feeding into the exhaust! Go with a 3" and a round muffler in the middle and an oval muffler in the rear.

 

Just because someone somewhere makes 1,000whp with 2.5" exhaust doesn't make it a good idea or set it in stone.

 

LT defiantly keep the 4" exhaust to where it can go back on if you want. Going to the 3" you might get surprised....3" is a lot smaller than 4" and it might make a bigger change than you want. I'm guessing you can't put mufflers on the 4" because of clearance.

 

im in for results... id like to see the changes

 

I have a vibrant muffler that I just put on and it actually got louder lol. Im guessing the pipe is so big the waves are just bouncing around aimlessly

 

Really I never knew.


I'm running the same setup as Turbo-Ls on my integra. It sounds good and isn't to loud.
Lightining Teg you'll be fine dropping down to 3" -which is a lot smaller then 4"- By 1" just incase you're wondering. lol people
As mentioned 10X already you won't suffer a power loss that's noticeable.

 

Nice I was hoping someone had proof of this. Can you link to the comparison between 3" and 4"? Can't wait to see the before and after dyno pulls (mainly power curve). Was there a before and after at the dragstrip? That'd be nice too.

 

i think your gona be hard pressed to find comparisons to a 4" exhaust anywhere on here, because 4" is just completely unnecessary for 98% of applications, even in a turbo situation.

 

exactly 4" is really for sfwd cars that run at tracks that require an exhaust on the car and have the open dp effect for hp production on huge turbos

 

Wat is the best exhaust for a turbo ls

 

anything 3" with flow through mufflers

 

Wat exhaust u runnin on yerz