just as asked

 

most people don't true 2.5" exhausts anyway. 2.5" is better but it has to be custom..exhaust velocity will slow down at the end of the system so it won't be that big of a deal.

 

yeah, probably won't be a huge deal. But, the same diamter all the way through is ideal.

You do know that Greddy makes an Evo TT for the 5th gen, right? Its an Evo2 with Ti tip and I think 70mm piping. Designed for turbos but would also work well with a JRSC or NA build. Should be on greddy.com by now.

If you haven't already purchased all this stuff, you could try a Powercore J-Spec catback - N1-style but I've been told not as loud (similar to Thermal with less drone and probably around the same volume as an Evo). Its 2.5" the whole way with no taper at the cat so it should match up pretty well and it won't bottleneck. Thermal would make you a 2.5" on request, too.

SMSP + 2.5 cat + Evo TT/Powercore/custom Thermal would be an awesome setup.


I'm guessing the measurements are all OD (outer diameter)? Most cats are measured in OD as are most catbacks. Not sure about the SMSP collector. Keep the OD vs. ID in mind if you haven't bought everything yet.

 

what do you need a system this big for? WHat are your engine specs?

 

well right now i have aem cai, dc headers, random tech high flow cat, greddy evo 2 cat back, aem pulleys. I plan on doing more mods all motor in the future so i want a good setup to breath with.

 

i'm pretty sure cats are measured ID. At least thats my experience with carsound.

 

anyone else have a reply on my question for the first post up top?

 

On a close to stock motor it wont hurt it too bad. But when you start going more hardcore with the mods it will def. be a bottleneck taht would hurt your performance.

 

what is a nice sounding muffler for a 2.5 exhaust?

 

I'm running the Kteller rage header with a kteller high flow cat that tapers from the 2.5" down pipe to the 2.25" exhaust. My exhaust is an apexi N1 Cat back. After the install of the header and new cat I found my exhaust became way too loud - more than I could stand anyway. So, I had a magnaflow round muffler put on.

I'm looking to upgrade to a full 2.5" system too. If I do it again I'm definately using a Magnaflow resonator and muffler again. Their piping is consistant all the way through the mufflers and resonator - unlike the bottlenecks of apexi and others. Not to mention the sound is much deeper than the others Magnaflow definately deserves more recognition for their work than they're getting.

The evo TT on the other hand is not available for any cars at the moment - and the piping is 2.7" - a lil better suited for turbo apps.