Hi, I recently rebuilt the 22re in my 1994 truck and now I'm shopping for an exhaust. My engine is fully rebuilt and bored but otherwise stock, but the truck hasn't had a tail pipe since I got it, just a turn down on the original muffler. Through searches i've seen 2.25 is the reccommended size, I was wondering if i would have any noticable gain from building a stainless 2.25" exhaust and replacing the cat as well if it is plugged, or if you would reccommend the stock 1 3/4" for a replacement. I can buy this exhaust http://www.summitracing.com/parts/wl...a/model/pickup locally for $120, and though it is aluminized steel and wouldnt last nearly as long as stainless, it would be a direct fit. What do you think?

 

i would go with 2-2.25" to open up the flow a little bit. any more and there's too much reduction in back pressure, which is needed for low-end torque - this is why tri-y headers are said to be better (and it's the stock setup) than the 4-1 headers. if you're always full throttle high rpms then the larger exhaust will help with power at speed. either way, a new free'er flowing CAT is probably a good idea since it's a major restriction point in the stock setup, as is the "Y" in the down pipe from the header. i don't think you'll see any significant gains from a larger exhaust until you pair it with a few other things, like the free-flow CAT, new header, etc etc.

personally, if i had the choice, i would go with the 2.25" over stock just because i know it will flow better. i haven't done my current truck yet, but on an old 22ret I had, I went to 2" exhaust and noticed better cruising power on hwy - i would assume 2.25 would be slightly better.

 

I noticed a gain when I first went 2 1/4 cat back. With my stock collection pipe

 

I noticed a good gain when I put on a magna flow hi flow cat and 2.25in exhaust on my tired 22re