Nothing AT ALL to do with weld quality!

There is a major design defect with the muffler. The inlet pipes are too close to the shell periphery. Stainless steel transfers heat poorly and is also fairly weak as a material, so when the inner pipe is 1000 degrees F or more and the outer shell is only 200F-300F or so, the inner pipe is going to break the end cap because the end cap is too small in area there to allow for the heat related dimensional changes.

Also the mufflers are loud and very sharp sounding. The new muffler was as loud as my old muffler with no packing left in it, but with an even harsher tone. I ended up making restrictors by welding large washers with 38mm inside diameters to the tailpipe tips in an effort to cut down the noise. It made it only barely tolerable.

With my repacked old muffler, you cannot hear the exhaust AT ALL when cruising down the road at 4000-4500rpm in top gear. Granted, part of this is how noisy my ring and pinion are, but even in city traffic, you mostly hear intake honk rather than exhaust noise.

 

I couldn't wrote it better, same experience.
The new style didn't work with a bridgy, perhaps with a none ported 12 A making some louder sound show and will give a slightly better flow then the italian style old muffler without the reliability.

Some pictures of the inside of the italian style muffler also not the best welding get optimal flow.

 

....and I installed that muffler on a GSL-SE engine with stock port closing times, just runner modifications, and that is the engine I had all the problems with it.

The bridge port was out of the car between 2017 and a month or two ago. I only ran the stainless muffler for about that month, about a thousand miles, and it did hold up but only because I put about a pound of MIG wire on the back of the muffler to tie the pipe in to the outer shell. This probably is just moving the weak spot somewhere else, when metal wants to expand it WILL expand or die trying.

 

The interesting thing is that I datalogged the same tune, on the bridge port, with both mufflers.
This is with the stainless muffler.


This is with the old perf core muffler after I rebuilt the over axle pipe, using 1 7/8" to 2" twin pipes merging into a 2 1/4" pipe, 16 gauge stainless instead of 1 3/4" to 2 1/4" schedule 40:



WOT is largely UNCHANGED. However the interesting thing is the perf core muffler flows a lot more at part throttle/mid range RPM, as evidenced by the tune leaning out heavily. This is big on a bridgeport because you want the exhaust to be free flowing to keep from getting too much part throttle exhaust reversion. So it's still a win, even if peak flow did not change.

 

is stainless easy to weld, I know aluminum isn't because when forming a bead, you just get a big glob. I use to stick weld mild steel in shipyards with 5p and LH. I think it was 5p

 

Stainless is a bitch because it does not transfer heat very well. At least with a MIG, the margin between getting good penetration and blowing a huge hole in it is razor thin.

Sort of the opposite problem as with aluminum, which wicks away all the heat.

 

i find stainless easier to stick weld than mild steal. 316l rod.

 

I think back then they use to be made in Italy and it was thick wall metal now they suck to be honest I rather buy a vibrant exhaust

 

While I understand this is a first gen post primarily, you guys have me thinking about the quality across all the RB products.

I purchased this second hand RB dual for my FD about a week ago, given the fact that they are on backorder until March 31st if memory serves, and for a whopping price of $250.00. Needless to say, I jumped on it, remembering how great it sounded on my last FD way back when. I can't say how many miles the exhaust has had, how many owners, etc. I realize the pictures aren't that great either. I did take a grinding wheel to the welds to clear the rust off, and part of the pipe, but would you say the quality has changed on this one as well, for those of you that have seen the RB dual?

 

Hi guys, so I just picked up a used full sp exhaust from a local seller for less than half of the price new. Here’s what I can see after washing off the dirt and grime as it was stored outside. The midpipe section shows sign of rust all over so my plan is to paint it with high temperature bbq paint a little later today or tomorrow. My question is, should I paint the headers and muffler too? They seem to be better material quality and show light rust in some spots by the weld areas. Nothing crazy but I’m wondering if it’s best to paint everything now while it’s off the car. I’ll post some pictures soon so you can see what I’m working with after washing it all but here’s what it looked like prior.

 

Nice score. Only paint that last on the exhaust is vht. But even that doesn't last that long. Especially on the header. That ss muffler has a raspy dirt bike sound too it. Not like the deep tone of the old Italian made ones.

 

If you want to paint it use ceramic coating paint….it’ll last a little bit longer…..

 

Hi guys, so here’s the update. I decided to leave the header and muffler alone since it seems to have minimal rust. I plan to use Mother’s polish on it tomorrow. I painted the midpipe section as it had a lot of surface rust on the welds and all over the piping. I had some leftover “racing beat blue” (Ford Blue) rattle can BBQ paint and decided to just paint it that color. I figured you can’t see it and the main goal is to keep the rust from spreading.

 

Here’s the paint I used. I just realized it was their “Engine Enamel” but I have had really good results with this brand. On my previous Turbo car, Forced Performance told me they used this brand’s “BBQ paint” with great results on the turbo exhaust manifolds they sold. Never had an issue the whole time I’ve been using them since. 👌

 

Mother’s polish on the headers and muffler. 👍

 

I think your blue paint will last about 5min. Rotary exhaust way way above 500°f.

 

LOL - I'll keep you updated. I have used the paint on headers and turbo manifolds with good results but as you pointed out - the true test lies with the Rotary Engine Heat. = )

 

I used bbq paint which is good to about 2000F and its still on the midpipe just a bit faded and chalky.

 

I used 2000° ceramic exhaust paint from crust-oleum on my exhaust and it's mostly peeled off the header within a few months.

I've also had a **** poor experience with RB exhausts, previous owner installed an RB header on my car and I had to cut it down + pie cuts to get reasonably tucked under the car and not an inch off the ground. Horrible fitment. And then the cherry on top I bought the RB power pulse muffler for almost 500$ and it sounded AWFUL, HORRIBLE tinny "Ringing" sound. At idle it's the sound of the powerful rotary pulses dinging against the back wall of the muffler. The muffler is double wall except the back wall it seems which is a single sheet of hard stainless that rings like a bell.

Not to mention the internal Y pipe is unequal length which causes fireballs to mostly only shoot out of one of the 2 tips which just peeves me. Also, the muffler did approximately **** all to actually muffle. The car was LOUD AS HELL. Also they could've given at least a little bit of pipe sticking out the back of the muffler to weld to instead of welding practically on the back wall of the damn thing. For 500 ******* dollars you'd think they'd think about some quality of life improvements but I guess not.

I ended up going with a chambered flowmaster 70 series, a 3" magna flow resonator, and 2 cheap Amazon 2" resonators that I repacked with SS brillo pars. I welded those onto the header then into a y pipe that turned it into 3" . The whole muffler is now mild steel because the previous stainless steel rang like a bell.

So anyways 4 mufflers later the car is now tolerable.

 

Finally got around to installing the SP full racing beat exhaust. So here is my experience with it. It substantially opened up the throttle response and acceleration like I expected. The sound is good which I believe is most likely from having dual resonators for each exhaust port. I agree that the new muffler is nothing close to as great as the previous RB "Made in Italy" version that I had on my previous rx7. It did a great job of containing the noise levels from getting Tinny and always sounded deep. I wanted to ask; do you guys think that part of the Tin sound is coming from it hitting up against the heat shielding under the car? I went under the car and noticed it was rubbing against the piping so I got some pliers and pulled it back as much I could. The car still makes that tinny noise when I leave my driveway but not as bad I guess. The issue I am currently having is in the morning is when it comes to turning on the vehicle. It's extremely hard to start the car and keep it idling. I expected this with the removal of the air pump and using the block off plates on the intake manifold. I just didn't expect it to be so bad that it takes 5-10 mins of me pumping the gas peddle to hold idle. I noticed my rpm idle dropped from 850 to about 500-650 where the car constantly wanted to die. I had to make adjustments to the rpm screw and have been playing with the air/fuel mixture screw the last day to try and even out the throttle response and drive ability

 

Crawl under the car with a metallic object and tap on the back wall of the muffler, that'll be the source of the tinny sound.

That's abnormal, do you still have the fast idle hooked up to the plunger?

 

So you put it on with no real changes to the Nikki? It may be running leaner at idle. The mixture may need some richening. Do you still have a choke or did you modify it?

 

U can check for exhaust leaks. Only use the metal Mazda gaskets.anyyhinh else to will burn up. Ever since RB went to the shinny ss mufflers they sound like that. Doesn't do a very good job of quieting down the exhaust either. RB said about a year ago that they redesign the muffler to sound like the older ones. But I have yet to hear of anyone get one. Maybe they need to sell off the old stock of the shitty ones first.

 

I actually moved the exhaust piping back and forth and heard the Tinny sound from the heat shielding. The muffler itself sounds tinny as well on idle and low acceleration from my experience. Yes, I do. Only thing removed was the air pump and attachments to it. I used the two block off plates on the intake manifold after removal of air pump assembly.

 

I don’t have a choke as the previous owner disabled it. I have been playing with the mixture and rpm screw. I Seem to almost have it dialed in but the real test will be in the cold morning tomorrow to see if I have the same starting issue.