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-   -   Will I burn out a glass pack? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/will-i-burn-out-glass-pack-693589/)

fastrotaries 10-02-07 11:27 PM

borla is really the way to go. ansa and even magnaflow make some quality products, recently vibranperformance has been putting out quality stuff. Good luck, and remember you get what you pay for.

13bturbofc 10-05-07 09:11 PM

hey hows that FCD workin out for ya

jackhild59 10-05-07 09:17 PM


Originally Posted by SpeedOfLife (Post 7390718)
well, for now I'll be trying a cheap 2.5" inlet by 2.5" outlet, 14" long muffler. what will happen when the glass melts though? will it be expelled or will it collect in the bottom? flames? I don't mind if the glass melts out, I just don't want the structure destroyed because that's the whole point of the muffler in this case: baffles.

Is this muffler a glass pack? Just curious. Anyway glass packing is best at muting the high frequencies.

As the glass packing melts out, the high frequencies will become more and more dominant. The raspy harsh tones will overpower the low tones and your ears will begin to bleed.

Your wife will not ride in this car as female ears are much more sensitive and delicate.

jackhild59 10-05-07 09:19 PM

Look, when I bought my S5 vert it had a Rotary Performance Bonez Superflow Cat. This is basically 2.5" downpipe with a high-flow cat and a 'resilencer' that is basically a glass pack design packed with stainless steel. The exhaust system then went into the 'Y' and out straight pipes. Nothing else. Man, it would make your Heart Sing and your ears ring! I put in 2-2.5" 14" turbo mufflers into the oem spots. They were basic galvanized steel turbo mufflers from a local muff shop. They sound great with the presilencer and the cat. Deep and low toned, they currently have about 20,000 miles on them with no burnout or any other problems even though the exhaust behind the cat is a lot hotter than in front of the cat.

I cannot believe that you will have any durability issues with a true turbo muffler used as a resonator. Turbo muffler design is high flow and low back pressure. BTW, you will see 'Turbo Mufflers" that have glass packing. This is not a true turbo muffler and is unlikely to either perform or last like a true turbo design.

You do not need an uber-expensive muffler for a budget exhaust as long as you stay away from anything that is glass packed.

SpeedOfLife 10-05-07 09:40 PM


Originally Posted by 13bturbofc (Post 7392114)
hey hows that FCD workin out for ya

Actually I've decided not to use it so I sold it to someone else. I've found that even with just the downpipe I only creep up to about 7-8 psi floored in 4th around ~110mph. I figure with exhaust finished I'll be hard pressed to creep like that even in 5th WOT. However, I am curious, at what psi of intake pressure does the stock ECU cut rear rotor fuel?

As for this 'turbo muffler' I got, it's a cheap Thrush turbo muffler and I think it does have glass in it. I don't think anyone has answered my question about what my exhaust temps will do to glass packing, what happens? Will it clog? Burn? Cause any exhaust leaks? I'm not worried it the glass leaves the exhaust as long as it does so without harm to the car or stalling the motor.

Aaron Cake 10-06-07 10:58 AM

The "turbo" style mufflers are only good for a few miles. Some may last a little longer, some may last minutes.

The significant EGTs melt the fiberglass packing, then it blows out.

SpeedOfLife 10-06-07 12:03 PM


Originally Posted by Aaron Cake (Post 7393309)
The "turbo" style mufflers are only good for a few miles. Some may last a little longer, some may last minutes.

The significant EGTs melt the fiberglass packing, then it blows out.

I'm still confused. By 'blows out' do you just mean the packing leaves the exhaust or that the muffler will burst and create a big leak? An unpacked yet sealed muffler would still silence more than a straight pipe of the same length.

Aaron Cake 10-06-07 01:49 PM

The packing itself blows out of the muffler outlet.

SpeedOfLife 10-06-07 03:34 PM

It'll do then. Thanks, guys! I'll try to get some video of before and after, though at the rate crap is falling from the sky I may not be able to finish the exhaust for yet another week. Or two.

micah 10-06-07 03:37 PM

You should take a video of it so we can post it when people ask this question. :)

X-JaVeN-X 10-06-07 03:51 PM

yea...under the section of what not to do to your car.

my opinion is if you can't afford to spend $60 on your car for a better setup...then you don't need a rotary....but whatever.

jackhild59 10-06-07 04:11 PM

1 Attachment(s)

Originally Posted by SpeedOfLife (Post 7393468)
I'm still confused. By 'blows out' do you just mean the packing leaves the exhaust or that the muffler will burst and create a big leak? An unpacked yet sealed muffler would still silence more than a straight pipe of the same length.


The glass will melt. Then it depends on the temperatures. The glass will either sag to the lowest part of the muffler and stay in useless but harmless slug of glass. But if the exhaust is a little higher temp, the glass will liquefy and be 'blown' out the back of the muffler in little droplets. These will reform into small glass beads and will basically be dispersed in the exhaust setup that you are describing. If however you used a glass packed muffler in front of another muffler or a catalytic converter, the little beads would potentially clog the next unit in the system creating back-pressure or component failure.


Originally Posted by Aaron Cake (Post 7393309)
The "turbo" style mufflers are only good for a few miles. Some may last a little longer, some may last minutes.

The significant EGTs melt the fiberglass packing, then it blows out.


A true turbo design muffler has no packing of any kind, nor does it need packing. The word Turbo is often used as a marketing term to describe any kind of muffler the marketer deems as suitable to sell to someone that wants to drive fast.

A poorly designed turbo muffler sucks and proper turbo muffler works well. Cherry bomb turbo mufflers have a poor rep and Walker Dynomax has a great rep. These reps are based both on flow bench and dyno testing. Funny cause the dynomax has fiberglass packing and the cherrybomb does not.:)

A proper turbo muffler has 3 tubes and two baffles. The inlet and the outlet cannot be along the same line. In between the baffles, the tubes are perforated, like a glass pack. The inlet goes through the end, through the first baffle then teminates at the far baffle. The exit does the same from the opposite direction. The intermediate tube extends only from baffle to baffle. Properly designed and sized, this design is reversible in flow, cuts the high freq sounds, is pretty quiet at low rpms/flow and gets fairly loud when you get up into higher rpms/flows.

I think it is a great design for real life, including avoiding police attention/getting 'civilized' women to ride with us.

Good luck and I hope everything works out with your car.

SpeedOfLife 10-06-07 04:28 PM

^^^ what you pictured there is exactly how my 'turbo' muffler is designed. not that it won't melt out any glass, but that's ok. if I didn't mention it before, I will now: I won't have any cats on the system, only pipes and mufflers :D

BrettLinton7 10-06-07 04:29 PM

the po of my car removed everything from the exhaust except the mufflers and put a glasspack in. Of course it's melted by now, so when people ask, I'm just like 'yeah, it's got a straight pipe :lol:

Fault Bucket 10-12-07 09:21 PM


Originally Posted by Aaron Cake (Post 7390735)
There are a bunch of cheap yet high quality resonators on the market. I have one from Vibrant Performance ( http://www.vibrantperformance.com ) on my car and I'm quite happy with it. The key is to get a unit that is stainless packed.

Hey Aaron - I was looking at Vibrant's stuff and contacted them about their Ultra-quiet resonator...they didn't recommend using it with a rotary (because of the heat). How long have you been running yours? No degradation yet?

Thanks.

Aaron Cake 10-13-07 10:36 AM

I've put a few thousand miles on the Vibrant resonator this summer and it seems fine. I can't see how there would be heat issues since it's all stainless.


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