Prepare for dyno tune

**mugen24** · 15-10-2007 09:40 PM

I will have a dyno tune very soon.

For my car(B16A4) now has a 4-1 S-S header + 92 civic si original cat + 2.25' cat back system + xforce twinloop muffler.

do i better need change to a 2.25' high flow cat to gain some more power from dynotune? big difference?
If i dont change the cat, how bad will it force?

**misteR_bilzz** · 15-10-2007 09:44 PM

if your planning on gettin a hi flow cat in the near future and its on hand now get it tunned with it on. it make the most of the mod.

**mugen24** · 15-10-2007 09:58 PM

havent got it on hand. if i need it for sure, i will go to a local shop and get it install b4 dyno. just want to know how important is it for the exhaust system, performance and dyno result.....

**barefootbonzai** · 15-10-2007 10:08 PM

get an 2.5" system all the way through for best results. that's 2.5" cat and 2.5" mandrel bend, any exhaust shop should be able to do it for you.

but if you're tight on cash, i would change to a better cat, cause if's the stock SI cat, it's only 2".

**mugen24** · 15-10-2007 10:19 PM

the thing is my system for now is 2.25' throughout. can i still put a 2.5' cat in? stock R34 cat will do? or just go to a local shop for a 2.25' hi flow cat?
barefootbonzai, plz give me some good exhaust shop.....how is right price exhausts on moss street?

**b18c_crx** · 15-10-2007 10:21 PM

any exhaust place should be all the same man maybe the price will be different

**EKVTIR-T** · 15-10-2007 10:24 PM

What size is the header outlet?

**mugen24** · 15-10-2007 10:28 PM

im not sure, i think is 2.25'. if it's 2.25, can i put in a 2.5' cat?

**EKVTIR-T** · 15-10-2007 10:32 PM

Originally Posted by mugen24

im not sure, i think is 2.25'. if it's 2.25, can i put in a 2.5' cat?

It's possible but find out the collector/outlet size and go from there.
If it's a decent 4-1 header it should be 2.5.
If it is,may as well do the rest in 2.5 as others have said.
Straight thru b pipe muffler and the twin loop.Will be nice