So I have a 90 gxl for which I picked up a sweet exhaust for. It's racing beat headers -> straight pipe -> dual borla mufflers. I did use old manifold gasket.

Basically now it sounds like I have exhaust leak coming from the engine bay, however I don't see any smoke. Did anyone else had this experience with RB headers?

 

Sound/noise is relative, when it comes to people's acceptance.

I'd change the gasket for sure.

So you have no cats? Therefore engine--header-mufflers? That will be too loud for some.

 

+1 it is relative to the person with the exhaust. Decibel levels are relative to how far you are from the vehicle. The louder you are, the more attention you attract good and bad.

I personally wouldn't reuse gaskets unless I know the current condition of the gasket. Even then, any slight leak, bend, break, etc. within it would be to replace it.

 

The thing that kills me about headers on a rotary is the chainsaw noise if you aren't running pre-silencers. A good presilencer and some good cans on the back solves that issue.

I would never reuse a header/manifold gasket just for the very fact I would be incredibly pissed if I had to take the **** apart again because the gasket wasn't any good. I have however reused the factory asbestos gaskets before with success (as long as they dont fracture) but the new style metal gaskets are pretty much a one time deal.

 

I have RB header on my n/a with a crappy presilencer and magnaflows on the back, about 3K steady will make you go deaf in the car, so going down the highway (70 mph) friggin sucks

 

Running RB street single collector, to a stockish cat, and factory y-pipe to bosal OE repolacement mufflers. Idles sexy, WOT it is a tad Chainsaw, but to me, far less worse then my buddies old PBX setups on a single slammer civic 1.6l frankenstien.

 

I have the collected RB header to straight pipe to RB catback and there is no chainsaw or raspy tone. Unfortunately I have solid motor mounts (never again on a DD) and they do transmit a lot of noise and vibration through the cabin but with the top down it's a quieter ride and the exhaust has a deep, smooth tone to it. I also have a street ported motor.

 

I have the rb true dual set up. gotta be one of the quietest cars Ive ever own until I open it up

 

There are many opinions in this thread I cannot agree with, I have owned several(7)RX7s and my '87 NA(SP built engine,TRUE DUELS-RB Road race header, dual 3 inch pre-silencers, duel Apexi N1 4") It is extremely loud not just at idol not just at mid RPM not just at wide open throttle it's loud. It's obnoxious if I pass someone on the interstate I'm prone to get flipped off, it's almost hard to drive with out bringing it to the attention of anyone else around you on the road with that said it bothered me at first and I considered restricting the exhaust in order quiet it down but eventually learned to tolerate it I do enjoy the sound I just wish it was a little bit quieter
Good luck

 

I have the true dual setup on my NA car and it is actually very quiet until you get on it. It does however have a presilencer and two mufflers.

 

yeah it really depends on your set ups.

 

You won't necessarily see smoke if you have an Exhaust leak.
The S5 I have right now is running a 2.5 inch RB system,stock cat,downpipe and manifold.
It's a nice sounding car that I am gonna hate to part with.

 

Naturally a header is going to make the car louder... I think so many people modify these cars that they lose touch of the original design. Mazda had so many things in the factory exhaust to quiet the car down; it was nearly silent!
1. Multi-chamber port inserts
2. Cast iron manifold that mixed the exhaust pulses
3. A total of three catalytic converters; the main one having three catalyst matrices!
4. A Y-pipe
5. Small diameter piping with excessive heat shielding
6. Two large-capacity mufflers; again with small diameter piping.
7. Double-wall tail pipes (tips)

I have eliminated all of this on my FC. It is extremely loud. I would not even recommend my exhaust system to somebody with a peripheral port drag car, on the basis that it would violate any near by noise ordinances.

My exhaust:
Racing beat road race header
Uncollected, going to two 2-3/16" pipes that step up to 2-1/4" at the middle of the car. They then go into two straight-through perforated core magnaflow mufflers. 4" o.d., 22" Long. Again, this system is completely uncollected with no presilencer(s) or X pipe.

 

I think you guys have your pipe and pre-silencer/muffler sizes too big. From all I've read a stock or street port n/a doesn't need piping any larger than 3" after the collector yet you guys are running mufflers with cores this big or bigger on a true dual setup. The bigger dia. the core the less effect on reducing the noise level. Too large of piping can actually hurt you and make less power. You could probably make more power and less noise with a different setup.

badsvt1. Replace your mufflers and pre-silencers with ones using a 2" to 2 1/4" core max and it should bring the noise level to a more manageable level.

DaBrkddy. Same thing but throw in some pre-silencers and use 2" pipe throughout.

 

I'm trying to eliminate presilencer(s) from the equation. I'm planning on doing an X-pipe near the rear of the car, and then installing a pair of factory original mufflers with RB double-wall tips. Doesn't seem to me like my pipe diameter is too big... but I dunno.

 

Going by the sizes listed at the bottom of this page they would still be a little big. If your pipe gets too big the velocity of the gasses drops and it hurts performance in a n/a.

Rotary Tech Tips: Exhaust System Configurations

Most exhaust threads I've read seems to point to 2"O.D. for the primaries. My main point I wanted to make was the core sizes of the mufflers were way too big.

I have wondered about an X-pipe as well but the exhaust on a rotary functions different than a piston engine. Seems maybe a proper collector then single pipe a few inches then a Y to split it back out may be better. The merging of the two streams should help some. I wouldn't use the stock mufflers. I had them on my car with RB's header/pre-silencer and above 3k it sounded awful like a bunch of rocks in a can. I imagine it will only be worse without a Pre-silencer

It's kinda pricey but if still too loud you could throw RB's road race pre-silencer in there.
Road Race Presilencer for 86-92 RX-7 - Racing Beat

Here's a quick search to get you started:
RX7Club.com - Search Results

 

Using a Header and stock cans will make the car sound like a Pissed off BEE.
I've never been so embarrassed in all my life to drive a car.
I mean really,it was so closely compared to being seen driving a VW Cabriolet!

 

If you remove the exhaust sleeve diffuser (or use a T2 housing) on the n/a engines it's worse.