esmith972

I've been plagued with a few exhaust issues that I have not been able to fix since day one. To help with the diagnosis, I've recorded some decent audio.

Background of the car: Unknown header, unknown catalytic converter (definately aftermarket, considering there are no hangers to hook onto the rubber grommets hanging down) with a RB muffler. Other than that, it's totally stock.

First thing is when I decelerate with it in gear, it makes a bunch of mini backfires about every half a second until about 2000rpm. Keep in mind, I also get some pretty gnarly backfires when I red line the engine. (they usually echo they are so loud)

Second thing is, the exhaust almost sounds like a chain rattling (obviously not) when the car is under a load. (thank you Mike)

Moving on, audio time. (With a couple of other complaints to boot)

First sound clip is a couple of red line shifts with a nice decel "pat pat pat pat."
Second is the "pat pat pat pat" decel normally driven.
Third is power braking for the weird drone.
Fourth is the loudest backfire recording known to man. Ever.
Fifth is the mic placed under the muffler with 0mph revs.
Last but not least, sixth is the mic under the catalytic converter with 0mph revs.

And the clutch slip is my fault. Usually after I shift, I let out the clutch pretty slow.

http://bioti.us/stuff/rx7problems.mp3

4portgsl

Heres my two cents... I noticed after installing a RB muffler on mine it had little backfires now and then, and they were nice, sounded kinda cool. When i went to the full RB system and weber intake i had no backfires at all(unless i shut it off without letting it idle for 10 seconds or so) Which leads me to believe that the cat may have something to do with it. The RB main muffler is a beautiful piece, so keep that. Try removing that mysterious cat and putting in a RB presilencer like this one http://www.racingbeat.com/resultset....rtNumber=16401 if it will bolt up to your header and that should solve your problems. Nicest sounding exhaust bar none. Good luck with it, hope you get it straightened out!

esmith972

4portgsl, thanks for the advice. But I want to include a little bit more background information. The exhaust had the regular old muffler on it right before I bought it and it was doing the same thing. After I installed the RB, it did it a little worse.

To be honest though, I could care less about the pops, I want to get rid of that ******* metallic noise. That is annoying as ****. And of course my stuck fan clutch. -_-

esmith972

Oh I didn't even totally read what you wrote. Thanks for the head's up.

Considering I have to do emissions for one more year, should I just get a high-flow cat?

PercentSevenC

From the sounds of things, you have two problems. The first is exhaust leaks. That'll be what's causing the afterburn. The second is that whoever installed the cat probably used cheap exhaust piping. On rotaries, especially NA rotaries with headers, using pipe that is too thin can result in that lovely ringing sound and droning under load. Racing Beat sells .120" wall piping. Use this to rectify your problem.

4portgsl

I agree with him^ I forgot to bring leaks into the equation. As for the fan clutch, lose the belt driven fan and get a 16inch s-blade electric one with a temp sensor. Wire it up to the battery for power all the time, that way it can run and cool the car off after you shut it off on a hot day.(VW's do it) I have that setup on mine, throttle response and top end power are much improved, and you don't have to hear that annoying fan everytime you rev it.