I was curious if anyone out there has run a 4" exhaust from the turbo back?? Would it help or hinder the performance???

 

I put a 3" pipe muffler and 3"turn down on mine and it takes longer to spool and peak boost is down .5 psi. This is in comparison to a 10" long strait pipe that I was runnin @ 1st. I put a muffler on to tone it down cause I plan on ki;llin my cats. i have been to lazy tho. If I had it to do again I would have went with a 3.5" pipe and used a 4" muffler. I still need to cut my cats and see if I get my boost and spool time back.

 

Going to do just this with a 4" resonator before spring.
I know when I run right off the standard STS pipe from the turbo without a tailpipe it spools quicker, makes more power(sotp)...and is wayy too loud.

 

lol load is niceeee no muffler and no cats and 3.5 piping wit a 6 INCH tip and my truck is lowered

 

I have a 5" tail pipe, works good. No effect on the turbo at all.

 

I have no cats and 3 inch pipe, Of course I dump my exhaust about8 inches after the turbo.....

 

For avsfan and myself, our turbo is near the front of the bed. So we've got probably 5' of exhaust pipe, no muffler, exiting out. Both of us are trying to figure out if a 4" exhaust pipe running that 5' of section would be more power or cause boost creep, etc. Both our wg's vent into the pipe. I tried going to atmosphere with mine once and talk about loud...that was loud.

 

You might try two 3" pipes (flows more than a 4"). At the end of the day, you want 0 backpressure downstream of the turbo if you can get there and stand it

In my new twins build, I'm putting the mufflers in front of the turbo (as I have no cats) and then short pipes out the side. I'm also moving the turbos forward to the front of the bed.

 

Allen runs 4" with a muffler after the turbo

 

I was wondering about that...being in TX, we need a muffler for inspection