I installed the HKS Catback several months ago and did not notice much of a difference in performance but do love the sound. Will installing a 3" test pipe make a difference? I plan to get a downpipe as well in the near future.

Current Mods:
RMR Intake
MBC
HKS Catback
DynoFlash
Gounding Kit

 

YES. Less restriction = more power. You cant have the FULL effect of less restriction of airflow with the cat in!

 

couldnt have said it better

 

That is what I thought due to the cat and muffler being the most restrictive. I am looking at Ultimate Racing's test pipe. Thanks for the reply.

 

Thats What I bought....great deal for the money, even has the 02 bung.

 

about a 6-9whp differance.Search test pipe or cat delete, plenty of info on this subj.

 

I gained close to 20hp by installing a 2.5 inch UR testpipe. I gained 2mph trap speeds and .2 tenths. With only a dynoflash mail in and test pipe I went 12.6.. I noticed a huge difference installing the test pipe with ll stock exhaust and it sounds great.

 

Butt dyno I assume?

 

I got a B&B test pipe and down pipe. Perfect fit, great workmanship. I'm staying stock and could use the cash for other things..... PM me for a good deal

 

It will definitely make a difference, cats are quite restrictive

 

Ran an 8.8 on th 1/8 mile with a flash and catback. Added the Megan Racing cat delete and ran a 8.5 the next week. Makes a nice improvement, but the fumes get to me.

 

yes , you will notice a difference

 

Yes, you will notice yourself getting headaches on longer drives. Also, fellow motorists will wonder what that smell is. Finally, the odor and increased loudness will together invite more attention from public servants who see you as an emissions ticket goldmine.

Also, worth about 15hp on a stuck turbo and a couple hundred RPM of spool-up.

 

No, you assumed incorrectly. I stated the e.t. and mph difference.

 

You'll def. feel the power from removing the cat.