dingo

1) Is 2.25" good for an exhaust coming out of a stock-port 12a, connected to a racing beat streetable header, no cats? If not 2.25", what would you reccommend and why.

2) Would it honestly be too loud without a muffler?

3) And if I really do need a muffler, what do you guys suggest? I'm trying to do this exhaust as cheap as possible, so possibly the dynomax super-turbo muffler (it's like $30).

I plan on getting a system soon (IE: Next week), and wand some tried-and-true input please.

--Dingo

MosesX605

The rotary is hella loud, and without a muffler, expect to be pulled over by the fuzz on a regular basis. Cheap mufflers tend to get ruined by rotaries, because of strong exhaust pulsations and hotter exhaust temps than is normal for boingers. Some people on the forum have had success with a variety of different brands, but it depends on your tolerance for noise and willingness to replace the muffler after a year or so. 2.25 is plenty big for a stock port, and you could even go to 2 inch if you wanted. If it's good enough for Racing Beat, it should be good enough for us.

My recommendation is to get the RB header and the RB presilencer, and then go to a muffler of your choice, though again, I would recommend the RB muffler. Not only will it last forever, but it sounds so very good. At any rate, the presilencer will help tone down the noise level so that it isn't quite so offensive as straight pipes to a muffler. I went that route on my '82, and even with the stock manifold, I could be heard for almost a kilometer away. My GF would be waiting at the door by the time I pulled up to her house because she could hear me from so far away.

dingo

thanks for the explanations If i were to get someplace to make me a 2" exhaust now and bolt up to the stock header, can I just replace the stock header with a RB header with no problem, or are they different lengths/flange connections

FuLLsMoKe

the RB headers are much longer than the stock manifold (since they bypass the cat) and have different flanges. there are two types of RB headers, streetable (one outlet) and road racing (two outlets) not sure if they are same length.

REVHED

You need to clarify whether you're talking about the primaries or the rest of the system. 2inch primaries flowing into a 2.5inch system and rear muffler is pretty much ideal for most 12A's.