i need a decent 3 inch ID muffler
 

for the rx7. i currently have some chrome dual tips on and i think they look kinda ugly so i'm wanting just single tips now.

note: car is a 91 tII with 3inch exhaust, no cats.

For a 3" exhaust with no cats, I would suggest a resonator and a muffler. A single 3" muffler with essentially a straight pipe is going to be way too loud.

I am partial to the Vibrant Performance 3" Ultra-Quiet resonators. They are full stainless and work very well on the rotary to keep noise under control. After that, a quality stainless packed parts store "rice cannon" will be far more tolerable.

While I only have experience with RB duals (which are very quiet) I'm looking at going to a single 3" muffler and am considering these options:

1) RB REV30 - , 304 SS, $170
2) Borla Round: P/N 40085, 5" Dia, 15" long , $148
3) Burns Stainless SM-300-625-17**, 6-1/4" Dia, 17" long, $308.00

None of these choices appear to have tips so i guess you have to decide if you need a shiny barrel at the bumper. this all assumes you've got a precat. If not, you might consider getting a HKS Hi-flow catback for a plug&play solution.

i've heard that you need a certain muffler to hold up to the high exhaust temps of the rotary engines though. is this true?