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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/)

SpeedOfLife 10-02-07 12:14 PM

Will I burn out a glass pack?
 
I am making a straight through exhaust on my mostly stock '87 TII, so no cats. I ported the wastegate and I have a 2.5" downpipe and 2.5" y-pipe to cans. My plan is to put a 28" Thrush glass pack in between the y-pipe and downpipe, but will the exhaust heat damage the glass pack? I also want to know if anyone's listened to such a setup, I'm doing this really cheaply, but I really would like to make it sound the best for my money. I don't want it to have that hollow, breathless, rattling sound that I've heard from hollowed cats with all stock components. I'm also considering putting a muffler between the dp and y-pipe, however the current plan is for the glass pack and it's sitting in my garage ready to be welded.

13b4me 10-02-07 12:20 PM

Yes absolutely. Probably within the first 30 minutes of driving. ;)

SpeedOfLife 10-02-07 12:21 PM

Even though there'll be almost no restriction?

micah 10-02-07 12:33 PM

Yes.

SpeedOfLife 10-02-07 12:38 PM

Well crap...

Anyone know how would the car will sound with a muffler in there or should I get a cheap resonator or something instead?

arghx 10-02-07 01:09 PM

dude you will be unhappy with your ghetto exhaust, take it from someone who has gone through several exhaust systems.

buy a good one and you will be satisfied with the performance and sound quality. corksport is a good low restriction exhaust

SpeedOfLife 10-02-07 01:14 PM

well I can't afford much right now so if I'd be better off not wasting time and money with an intermediate muffler and saving for a free flowing presilencer then I would do it, but I just need it quieted down for 3 reasons:
1) cops
2) I don't go deaf
3) my wife will willingly ride in the car again

rotaryracer1 10-02-07 01:22 PM

why dont you just wait and spend some decent cash on a good exhaust set up? fuck doin what you are talkin about that shit is ghetto , you have a T2 not some shitty ricer. Make your car nice and use good parts man, good sound costs good money

PercentSevenC 10-02-07 01:22 PM

Regular glasspacks won't last very long, maybe a week for the good ones.

If you can find some of the old Rotary Engineering glasspacks, they hold up for quite a while and sound very nice. Jeff20B used to have a huge stash of them, but we've been using them on a bunch of rotary projects and he's almost out now. :D

If you're curious, here's some clips of my 13B-powered GLC with two short RE glasspacks (one of them is in good shape, the other is almost dead; I'll replace it with a Magnaflow one of these days):
http://media.putfile.com/13B-streetp...zda-GLC-reving
http://media.putfile.com/13B-streetp...zda-GLC-in-car

Jeff20B's red REPU with a single long RE glasspack (it now has two):
http://media.putfile.com/REPU-with-fresh-engine-rebuild

85rx-7gsl-se 10-02-07 01:29 PM

Go with a Borla.

Houstonderk 10-02-07 01:29 PM

I had my tii with the main cat and got some glasspacks with 3 inch tips on the end and it sounded pretty good. I was going for a deep sound instead of that fart can sound and it worked good. I have heard the glasspacks don't last for some reason though. temp wise.

jackhild59 10-02-07 01:34 PM


Originally Posted by SpeedOfLife (Post 7389603)
I am making a straight through exhaust on my mostly stock '87 TII, so no cats. I ported the wastegate and I have a 2.5" downpipe and 2.5" y-pipe to cans. My plan is to put a 28" Thrush glass pack in between the y-pipe and downpipe, but will the exhaust heat damage the glass pack? I also want to know if anyone's listened to such a setup, I'm doing this really cheaply, but I really would like to make it sound the best for my money. I don't want it to have that hollow, breathless, rattling sound that I've heard from hollowed cats with all stock components. I'm also considering putting a muffler between the dp and y-pipe, however the current plan is for the glass pack and it's sitting in my garage ready to be welded.

Try a 2.5"x14" turbo muffler installed between the dp and y-pipe. They are relatively cheap, freeflowing and tend to have a low tone. I don't think the sound will come out raspy.

http://store.summitracing.com/partde...5&autoview=sku

SpeedOfLife 10-02-07 01:50 PM


Originally Posted by jackhild59 (Post 7389875)
Try a 2.5"x14" turbo muffler installed between the dp and y-pipe. They are relatively cheap, freeflowing and tend to have a low tone. I don't think the sound will come out raspy.

http://store.summitracing.com/partde...5&autoview=sku

that was my initial plan, then GLASSPACK entered my mind and I ran with it. y'know it's cheap enough I might as well try it out.

hopefully I can have this bad boy fabbed up by the end of the week.

Syonyk 10-02-07 01:50 PM

Rule of thumb to determine the suitability of something for RX-7 exhaust:

Will it melt below the melting point of thick stainless steel? If yes, don't use it. Rotaries *eat* cheap exhaust systems for breakfast.

-=Russ=-

t24todd 10-02-07 02:19 PM

^true. i got a magnaflow hi flo cat i can sell ya for cheap...its basically new. mellows out exhaust noise some ..but if your going straight through then i guess no need...let me know

SpeedOfLife 10-02-07 02:22 PM

yeah I want to avoid all serious restrictions, and I'm giving up the air pump for good, so any cat, if I used one, would have to be able to flow without fresh air supplied. I'm not sure if that exists, but I don't care too much to look for one since they're usually just an extra expense in Iowa.

MmSadda 10-02-07 03:37 PM

Yes; you will burn the the shit out of it in days, if not hours or even minutes.

w0ppe 10-02-07 05:13 PM

We got Rotaries, only a few very GOOD items will last
Try Racingbeat!

SpeedOfLife 10-02-07 05:59 PM

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.

Aaron Cake 10-02-07 06:04 PM

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.

SpeedOfLife 10-02-07 06:49 PM

maybe once I have more money to toss at exhaust I'll do it. $60 + shipping on a resonator falls under low priority items right now, but I'll definitely consider those.

t24todd 10-02-07 07:54 PM

well in that case throw the wify some ear plugs were some yourself and go with a test pipe...oh yea throw the car in neutral when by the cops...:lol2:

RDAVEX7 10-02-07 10:11 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.


I dont know jack shit about mufflers but I can tell you this. When I bought my n/a it had 12" or 14" blue glass packs on it. I ran it like that for 5 yrs untill I spend the dough on a complete setup. I have no idea if they were blown or what but it gave a deep throaty sound kinda like a fart cannon but deep. Never had a problem with them rusting through or anything.

I met a guy who said he likes to buy glass packs, run the car so theyre hot, then spray them down with water to purposely blow them out or something. He said they will sound better.

j0rd4n 10-02-07 10:50 PM

if you're thinking of a "well i'll do X for now until i get money" setup, don't waste your time. unless your car is illegal right now (as in you just might get a ticket for noise violation), save your money and do it right. wait until you can get a full system from exhaust header back to the muffler. if you spend the money to put in a system that is half-assed "temporarily," you're just going to have to wait that much longer until you get something that you're really proud of

SpeedOfLife 10-02-07 11:13 PM

Ok think of it this way, guys: IF I continue driving the car as it is, I WILL get fined for noise violation and maybe for not having a cat or mufflers. Probably the only things that's kept me from that issue thus far is the fact that the mufflers are still hung on the car, just not being used. I NEED to quiet it down, and while the car is technically illegal they don't even have emissions stations in Iowa. If they ever do, the car will probably be old enough by then that they still won't care.

Buying this cheap muffler instead of using straight pipe is costing about $15 more, and I'm convinced enough to try it in the aim to keep it from sounding too buzzy. I can also reuse the flanges I'm making when I buy better components, and these flanges cost about $8 in parts and some labor, then about $34 for the muffler and pipes. It'll just have to do.


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