i have a 92 civic hatch that is only in its early stages of making power. i have a 60mm skunk 2 catback with 3 inch down pipe. fully built head and sleeved block, the whole 9 yards. i have dual 40mm tial wastegates using a gt35r and i would like to know if this exhaust is going to be too restrictive even though i have 2 Tial 40mm wastegates WITH OPEN DUMP. im only on 12psi right now but will be retuning/turning the boost up in spring.

thanks, Doug

 

12psi on a 35R will definitely be a bit much for a 60mm exhaust. Which engine are you using?

 

its going to be very restrictive. Turbochargers like to breathe, bottlenecking your system wont only prohibit your from making good power, it is also bad for your turbo as well.

 

b18c bored and stroked to a 1.98L

 

definitely get a bigger exhaust. This isnt some D-series running a t25, you're going to need something much bigger

 

I have a setup pretty similar to yours (84.5mm B18C w/ GT3076) and I run a 60mm exhaust. It "feels" pretty restricted in the upper RPM. I installed a cutout in my downpipe and when the cutout is open it feels like it has a TON more up top. It ran so much leaner that I had to build myself secondary fuel-maps for when the cut-out is open. Plan to head to the dyno ASAP for quantitative results.

 

mandrel bend 2.5" will support enough flow up to 300hp ish

running up to 300hp with 3" mandrel bend will help with spool time and give u a louder exhaust note.

i personally would run 3" if i ran anything more than 250hp that is turboed

 

thats funny because i took this exhaust off my old d series.


thanks for the input, i guess its time for a new exhaust