My friend has a 01 GSR and is looking into a header/exhaust combo. She would like to (key words there) eventually go all out NA on it, but not sure that she will in the future (her money tends to go elsewhere). She doesn't want to get a setup now and have to change it out later for another one. So, she's deciding between a normal header (2" collector) w/ her stock 2" cat and normal 60mm cat-back exhaust -OR- a 2.5" collector header (probably DC JDM), 2.5" cat, and custom 2.5" cat-back. I told her the 2.5" setup would be best when she builds up her motor, but wasn't sure if it would be too much for her otherwise stock (except for intake) GSR now. She has no idea when she'll do more stuff to it (cams, headwork, resleeve block...haha, it's fun to influence friends!), but doesn't want what she gets now to hamper performance now or require changing later. So, is 2.5" all the way thru too much for a stock GSR? Thanks.

 

 

i would try to keep it 2.25 because of back presure concerns, honda's hate not having back presure. But for all out track use a 2.5 is fine.

Just what i have noticed.

 

GSR Stuie: did you try both 2.5 and 2.25 on your car? Or know others who have?..since you said from what you've noticed, it sounds like you have some first hand experience.

thanks guys for the replies.

 

I would say spend the $$$ elsewhere first, springs/shocks, cams/gears, and just get an ITR catback and JDM header. It will take some serious mods before she realizes the gains from 2.5 in all the way through. Just my 2 cents.

 

I have two exhaust and switch between street exhaust and track exhaust. One's 2.25 and the other 2.5. I find the 2.25 is a lot better in the city, more mid range and low range pull, the other (2.5) i don't fell a thing till 8000. But my car is moded different so. But this is the rule of thumb i use, unless your forced you don't need a big dia. pipe.

 

with just a cai and header you wont really need a 2.5 diameter exhaust. but if she plans on doing some work later its better off to get the 2.5, once you put some cams and get some headwork done it will be useful, and it will save her money from having to swap out to one later on.

 

if ur car is lowered the 2.5 is gonna have bad clearance problems ...i know hahaha ..just stick wit 2. and quarter trust me..