Cut catback pipe at taper?

[EVIL_EVO_VIII]

I recently purchased the HKS Hi-power catback which i wish i never did after finding out that it is not a true 3'' catback :wall: . Read some threads about how the pipe gets smaller towards the end to meet to the stock cat. Well, i am a power freak and if im loosing hp in that pipe taper, then im debating if i should cut the end and weld a 3'' inch pipe and flange.Does anyone know what it tappers to? What i want to know, am i loosing a lot oh hp b/c of this? And how it will affect performance when i add a 3'' test pipe and downpipe? Need advise please!!! Also is the reasonator in the catback also restraining from more power?

[PrimeAi]

I had a hyper on my gsx, which is the same tapering affect. Mine tapered down to just above two inches over the course of 2.5'. I went to an exhaust shop to see what they would charge to cut that section off and put in a 3" pipe, and the price was pretty high, 125$ I think. I have a stock downpipe and cat, when this occured, and I switched to a thermal b/c the hks was ****ing melting my bumper. The performance difference between the two was about nill, except for a _slightly_ faster spool up. I just got power maybe 250rpm earlier. Plus the thermal was stainless, and the HKS was a rusted and busted.

This could all be different on an EVO, but I doubt it. I personally don't approve of HKS exhaust systems, if you can return it, I recommend doing so. If its a hassle, past the deadline, or a 20% restocking or something, I wouldn't bother. You probably aren't losing that much power from it. When you upgrade your DP or cat you will run into problems though.

[BYESTI]

Cut your losses, sell it. The headache isnt worth the agravation. Plus the price to cut and weld is crazy. I called Gato, he said $150.00. Just wait till your tax return check and buy a full turbo back system if you want the most from an exhaust system.