Anakhoresis

iTrader: (1)

The title only partially explains out what I'm looking for. Specifically, I'm looking for a bolt-on exhaust replacement that will delete the catalytic convertors but isn't limited by what transmission you have. I've looked at the Racing Beat stuff, but they are for either automatic or manual transmissions. I'm guessing this is because they're mounted in different spots.

The RX-7 I have is a 1986 GXL 2+2, zero mods of any kind. I can tell the catalytic converters are stuffed, and I'm getting (more) terrible (than usual for an unmodded RX-7) gas mileage, and hoping to bump the number up a bit since it has just recently become my unexpected daily driver. It's currently an automatic but I very much want to convert it to manual in the near future, but due to the unexpectedness of it becoming my daily driver, increasing gas mileage a little bit would be very welcome.

Does anyone know of any bolt-on exhaust setups for an RX-7 to remove the catalytic converters that won't matter if I have an automatic or manual? Or do I pretty much have to convert first then do exhaust?

Also, on the note of conversion, there's a few write-ups out there, but from what I can tell from searching, they're fairly old and not a lot seem to agree with each other. I was wondering if anyone had any up to date information on any conclusions about transmission swaps for RX-7s? I like the idea of the converter mounts that someone had made (I like it for overall simplicity), but if I remember correctly halfway through the thread they said they changed the way they had done it because of strength issues but weren't really specific on how they changed it.

And lastly on conversion, if I didn't want to swap the back end, would a standard NA manual driveshaft connect to the rear differential properly without modification? For now I'm not going on a quest for large amounts of power so keeping the NA rear end would be cost effective.

That's all I can think of for now, I'm sure I'll have more questions later!

Thanks in advance,
-Ernesto

RotaryRocket88

iTrader: (7)

I think RB is the only place that actually lists a different model NA downpipe for automatics. If there is any difference, it would probably be clearance around the front of the auto transmission. I know for a fact that the downpipe that's listed for convertibles just has a slightly different bend to clear the extra subframe brace under the transmission bell housing. Everything from main cat (presilencer in RB's case) back is going to be interchangeable between all FCs. In other words, if you want the downpipe/silencer combo listed here: http://www.racingbeat.com/RX7-1986-1...omponents.html, buy the auto version to get a downpipe that will fit your car now. You can call RB to confirm that there will be no issue with a manual transmission (the auto should be wider). If you want a header/silencer combo, call to confirm that there will be no clearance issue with an auto transmission.

Rear ends are the same externally regardless of transmission. The ring and pinion will be 3.9 on autos, but 4.1 on some manuals.