I lost about 2 pounds of boost with the little MP112 on my 5.3, going from single 3” without cats to single 4” without cats.

 

dual 3" is supporting almost 700whp in my TVS LS1

 

Cool. Sounds like I definitely need more than my single 3”. I imagine I will have to have something custom made.

 

Speed Engineering has a dual 3" system for GMT800's

Maybe they have something for the K series trucks by now too

 

thanks
Speed engineering has a 3” dual connection pipe to x pipe. Exactly what I was looking for something to keep my kooks long tubes.I can piece something together after that. Now I need to try and match the sound level /no drone I have now. I have a giant corsa touring muffler and a borla oval back to back.

 

I've made gains going from single to dual exhaust on N/A applications. That was with more cubes though. I'm in the camp that says there is no such thing as too much exhaust on a blower application. My boosted 408 is running dual 3.5". I'd put dual 3" exhaust under that truck with a H pipe, or no crossover at all. an X pipe is just a restriction in a blower combo IMO.

 

I think that is a very broad generalization. X-pipe construction with length and cross sectional area of the merge heavily influence this dependent on exhaust volume.

 

To explain my reasoning; The theory behind a x pipe is to create a scavenging effect to extract as much of the spent exhaust out the cylinders as possible. In a blown application you're forcing air into the cylinder which will shove the spent exhaust out of the exhaust valve. With that in mind It makes sense to me to make the exhaust as free flowing as possible. I used a X-pipe on all of my past N/A and nitrous builds but decided against it for my blown application. My theory is if the x pipe isnt being used to scavenge exhaust, it is just an unnecessary bottleneck that makes the LS motor raspy as hell. I'm probably wrong

 

in my experience, x-pipes smooth out raspy exhaust tones... way more than h-pipes do.

 

I've had several X-pipe setups over the years and only 1 H Pipe. The H pipe combo is the deepest i've had so far.

This is my dual 3.5 setup with H pipe and 12" bullets.


This is my raspy dual 3" with a X pipe and 12" bullets