I just had some stainless works longtubes installed and a 2 1/4" dual exhaust fabbed up with a pair of 2 1/2" dynomax ultra flo's. I went with 2 1/4" because they fit without any issues and i figured this setup would outflow what i had before. I was running Dyno don shorties to y pipe and 3 1/2" single pipe to flowmaster muffler. My question is, did i make a mistake going 2 1/4" instead of 2 1/2" for the pipes. Dual 2 1/4" should outflow single 3 1/2" right? Anyway, the car sounds better than before and seems to rev quicker. Also, the exhaust fits perfectly with no scraping or rubbing.

 

I'll try to post pics. They are not mandrel bent tubes, so i know it's not the best flowing system, but i figure the long tubes along with dual 2 1/4" should be better than single 3 1/2" to flowmaster setup.

 

here goes.

 

 

Looks sweet man!

capt68

 

It's open to debate, but 2 1/4 crush bent pipe is necking down to 2" maybe even 1 3/4" in the bends. One large pipe generally flows better then two small pipes. If you went from a mandrel bent 3.5" to dual crush bent 2.25", I would imagine you probably sacrificed some flow, and added dead weight, for the ability to say "My car has dual exhaust".