Exhaust setup for an 84 SE
 

Man I hate to beat this one to death but I searched 2 nights on this forum and haven't found the answer I'm looking for--so I'll ask.

Here is what I'm looking at doing:

> Racing Beat header #16013 from Mazdatrix = $182 (wanted a Mindtrain but out of production).

> A custom made spool piece ~$25.

> Rotory Performance Bonez 2" hi flow cat for an 81-83 #EX800414 = $225.

> Existing stock rear connection pipe, no cost.

> Power pulse muffler from Mazdatrix #16432 = $237.

Thats $669 + flanges, gaskets, bolts, and shipping--call it $750, not bad.

The cat back stuff is a no brainer.

The big questions I have are with the Racing Beat header with the Bonez cat. Has anyone tried this setup before?

I'm using the 81-83 cat because it's much shorter than the 84-85 unit. The 84-85 cat connects to the stock manifold and won't fit properly with a header. The guy at Rotary Performance assured me the units are basically the same except for the length of the nozzle conection that goes up to the stock manifold.

Second, why the Bonez cat? It's $220 cheaper than the Mazdatrix unit and includes a presilencer. For a cat $445 is outrageous--yea I know the stockers are more.

Does anyone know the flange to flange distance for the 81-83 Bonez cat? I asked the guy at Rotary Performance and he wouldn't measure it for me.

Haven't bought anything yet and thougt I'd run this by you guys. Any questions or comments are welcome.:D

Is the "custom spool piece" for your 5th and 6th ports?

~T.J.

Spool piece
 

Good question TJ.

No, I was thinking the cat and header wouldn't match up exactly with the rear connection pipe and a spool piece would be needed.

Doesn't the 5th and 6th ports work off a tee line coming from the cat split air pipe? It's either that line or some internal engine passage in the exhaust port? Surely someone can answer this one. I've had a 12a for 14 years and this 13b is new to me. Either way, the Bonez cat has the connection for the split air pipe.

Scott

yeah the 5 and 6 port they work by a tee in the split air pipe, if you remove that they dony work