I looking for recommendations for a cat-back system. I've searched the archives and didn't come up with much on cat-back-only results.

I'm going to autocross my ITR car in stock class, so it won't have any other engine mods. The top priority is mid-range power, then weight. I don't expect much, but 3-4 hp, with no losses elsewhere in the rpm-range, would be worth it to me.

Are there any gains to be had over the stock system? Should I just replace the muffler?

Also, I'd appreciate any links to dyno results comparing stock to cat-back.

Thanks,
Brian Fitzpatrick
'01 PY ITR

 

https://honda-tech.com/zerothread?id=139319

https://honda-tech.com/zerothread?id=100306

https://honda-tech.com/zerothread?id=110314

https://honda-tech.com/zerothread?id=107971

https://honda-tech.com/zerothread?id=96621

You need some practice with the search function then. 200 results for "cat-back", 203 results for "cat-back exhaust". Make sure you select the "archived" button on the right.

There are gains to be had over the stock system, but usually not with just an axle-back (muffler). If you combined that with larger diameter piping from the cat, that'd be another story. It also depends on what you're looking for, is it max power, sound, driveability, etc. Buddy Club Spec II would probably give you some of the highest power yields, but it's also one of the loudest ones out there.

 

I got 15whp/11tq from my setup:

https://honda-tech.com/zerothread?id=659143

Talk to Mike @ IPSracing.com, probably wont have any in until late Jan.

 

I did find a bunch of stuff in the archives, but I didn't find much useful info regarding just a cat-back. It seems like a header and cat is worth quite a bit, but I can't touch those.

So, assuming stock header and cat, are there gains to be made with a cat-back system without hurting mid-range torque?

There are things I'd like in an exhaust, and the stock one fits those criteria well, but I'll give up some things for a few hp.

Brian

 

A cat-back alone isnt going to do much but add sound, you need to eliminate the first big bottlenecks that are the header and stock catalytic.

 

RsR Ex Mag Gt2, Jdm Itr cat, Jdm DC 4-1 header

http://www.rs-r.com/exmag_gt2.htm

Awesome midrange and top end gains

Sounds really good too.

 

w/ my jdm itr 4-1 to 2.5" smsp cat to t1r catback i noticed nice gains on the butt dyno , but just doing a catback isnt going to net you much of a gain

 

Apex N1. I noticed good gains from idle up as soon as I put it on.

 

JIC