Hi All!! I've been reading about the different set-ups between 2.75" v.s. 3" DPs...

I'm gonna be going into Auto-X and I'm not quite sure which diameter DP would be best...

My Mods are gonna be...

264/264 Cams
HKS Hi-Power Cat Back
S-AFC II
Greddy Profec B (@21psi)
AEM Short Ram Intake
RnR I/C Piping

and I'm looking into getting a good cat-delete or high flow cats that would be good for either a 2.75in or a 3in DP...

Thanks for your help

 

The DCSports catless DP is perfect. Perfect fit, power delivery, price, perfect everything. Get yours from NOLIMITMOTORSPORTS.com

 

I went with the HKS DP. You would find a lot of information if you did a search.

 

well all i can find about downpipes in this forum is a bunch of guys arguing which is better..

I'm kinda looking for a suitable downpipe according to my mods..

 

3" is always the suitable downpipe with mods.

 

to answer your ?, i would say go with a HKS 2.75", replace your lower i/c pipe, & replace your O2 turbo outlet. your spool up will be waay faster which you will need coming out of those corners in autox..

 

i went with a cheapie ebay DP. im very happy with the outcome. $90 for a 3" megan racing DP and it bolted on with no problems. when choosing a DP i looked for a unit that had a flex joint in it, due to the engine shifting from torque. the flex joint will relieve stress from the rest of your exhaust, and off your turbo as well. as far as a cat delete, i know guys that run the perrin test pipe all day and can pop "fireballs" using a full TBE. looks cool when jammin up the freeway at night, seeing a short blast of fire come from the muffler.

back to your topic, for autocross, 3" with mods will serve you best. no mods? the HKS has my vote. but isnt putting on a DP considered a "mod"?

 

You have a point. I run the HKS unit and have all the mods you are planing. Also, I am runing 272/264 set-up instead of the 264/264 set-up. The main reason I went with the HKS unit is because it does not sit as close to my TC and I did not have to replace my under support bar. Some of the 3" DP's have clearance problems. Also, I have always used HKS and they build a quality product. It is up to you most people areruning the 3" set-up. Good luck with your decision.

 

as far as clearing your 2 support bars under the car. dont worry. a few washers and your done. but the TC... what year is your EVO? if its an 05, or an MR... you might be in a small bit of trouble, cuz the larger TC and new transmission setup you have comepared to the 03-04's. if you have an 03, or 04 standard EVO VIII, go with who you feel comfortable with. im happy with my choice as i stated earlier. (but you wont catch me with a "megan racing" sticker on my car.... lol

 

I have the Espelir 2.75 inch downpipe. I got mine from Vivid racing.