I'm getting the exhaust setup done on my car by a local shop in the upcoming week and I've been trying to do some research on what size piping I should go with. The car was previously fitted with a 2.5 inch downpipe and 3 inch catback, and with my new turbo, I have to redo the downpipe.

I've been trying to find out more information about a 4 inch downpipe and/or exhaust combo, but I can't seem to find any clear information. Some people say that it helps the turbo spool faster, some people say that a 4 inch exhaust doesn't make any more power than a 3 inch exhaust. No clear answers though.

Can anyone tell me anything that is concrete information? My car is outfitted with a T4 60-1 with all the supporting mods basically, I just want to be able to get as close to 400whp on pump gas as possible and every little thing would be helpful.

Thanks

 

The less backpressure the better.

3" is standard on a forced induction car.

4" turboback really isnt practical unless you are looking to make some insane high numbers. There are people making 400-500-600hp thru a 3" turboback..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B00STFREAK &raquo;</TD></TR><TR><TD CLASS="quote">The less backpressure the better.

3" is standard on a forced induction car.

4" turboback really isnt practical unless you are looking to make some insane high numbers. There are people making 400-500-600hp thru a 3" turboback..</TD></TR></TABLE>

what he said!!

 

bigger is better. I noticed on spool time on my setup

https://honda-tech.com/zerothread?id=1309873

 

I think the cost out draws the gain on whp here, I think you would be ok running a 3" and sacraficing that 20-30whp gain, if its even that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Adi Radoncic &raquo;</TD></TR><TR><TD CLASS="quote">I think the cost out draws the gain on whp here, I think you would be ok running a 3" and sacraficing that 20-30whp gain, if its even that.</TD></TR></TABLE>

for small setup, its not even worth it

If u r looking for insane power levels then go for it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbocivic94 &raquo;</TD></TR><TR><TD CLASS="quote">

for small setup, its not even worth it

If u r looking for insane power levels then go for it</TD></TR></TABLE>

I'm not really looking for insane power, but I want to be able to hit as much as possible on the stock engine, and with the turbo being so large I'd like to help spool times if at all possible.

Taking into consideration I know some welders, I could buy most the things I need from BurnsStainless and have the downpipe itself welded together for less than I would pay for one from a company. (I.E. Protech charges $440 for a 3.0 inch, + 100 in v-band style)

Would you guys say it would be worth it then?

 

I still say No. But it sounds like you really want to do it so do it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Adi Radoncic &raquo;</TD></TR><TR><TD CLASS="quote">I still say No. But it sounds like you really want to do it so do it.</TD></TR></TABLE>

Just trying to save money/ make a little more power. I think I'll be going wit ha 3 inch job though, thanks for all the opinions