is there a simple alternative to the RB presilencer? 150ish sounds a little much for a 12 inch pipe....


is there anyone who has fitted glass packs for it?

 

Glass packs burn up in short times.

Try a muffler with straight through design that is packed with steel wool.

EDIT: perhaps what cory simpson used.

 

Define "burnout"

I have a Thrush glasspack behind my header and its still holding up good, its been on for a few monthes now.

 

did you have the pack made custom or did it come with the correct flanges and length?

 

Went to Oreilly and got the shortest glasspack they had that was slightly smaller than the Y-pipe diameter, and jam that bitch between the Y-pipe and header. It sounds alot easier than it really was though.

 

Burnout

You look at your exhaust and peices of the glass pack are falling out.


Perhaps yours is one of the good ones.

 

Thrush has been making glasspacks forever, and i made sure that mine didnt have the fins in it, but the holes rather.

 

BTW the paint burned off with 10 minutes.

 

The WOT exhaust temp at the header outlet is hotter than the melting point of glass.

I'll bet it's a little louder now than when it was new..

 

Damn... I did not know that. But its still holding up ok, but it probably is alittle louder now but since its such a gradual transition I havent noticed any change.

But at $20 a glasspack, thats a pretty good deal even if you have to replace it every 6 months.

 

I would think that a borla XR-1 would hold up pretty good, nice welds and steel packing.

 

To some people the cost would not be the only deciding factor but also possibly the effort and work required to change it every 6 months.

 

Oh definately understood, but if you want to go the cheap route you're going to have to put some work into it yourself.

 

Anyone know where I can get some perforated pipe, so I can turn a catalytic converter into a presilencer? Thak 1 2½ Inlet/Outlet Cat, weld in a length of perforated pipe, pack with stainless steel and viola! Pass visual inspection, quiet down the exhaust, and not have to worry about my exhaust heat destroying the internals.

 

Or you could just use the stock main cat w/o the precats. Someone tried replacing their RB presilencer with their main cat and said that they may have lost a hair of top end but gained some midrange power. I can't remember who it was but they had a full exhaust other than the stock cat.

On another note, how do glass packs hold up way back in the exhaust train, before the mufflers? Ie. welding them inline between the y pipe and rear canisters? I would think the heat would be less back there after the main cat. Opinions?

 

Have yall see the one corksport is working on?? looks pretty nice they put like plates in a spiral motion in a glass pack looking muffler.

From Corksport.com Currently under development by our R&D team. Increases performance and/or eliminates a worn/clogged. Integrated muffler design made to not give you all the extra sound that straight-through mid-pipes do. Specially engineered spiral baffles divide the exhaust flow into two separate paths, significantly reducing noise levels with minimal backpressure. The all-steel construction makes them durable. Variations of the muffler design may occur.

 

There design

 

Someone (either Mazdaspeed7 or Jimmy325i) threw one of those mufflers on his car...

the temp blew the welds from the baffles in under a month.

 

No he didnt they havent made that silencer yet. its still under construction. That may not even be exacly what it looks like. Im sure it will hold up Corksport is making it specificaly for a Rx-7

 

That picture is of a "Spiralflow" muffler. That's what they used. If CS makes one that can hold up, it should do really well, but I'd still bet that the baffles will blow out. RX's are just murder on baffles.

 

jimmi325i's was made by Moreso or some name like that. Obviously not a rotary performance exhaust name, more like a Summit racing name.

 

i didn't read everything here.

but Magnaflow Center in Center out is the way to go. 50-100 bucks and is steel mesh packed so it won't get burnt out.

www.magnaflow.com
for specs

www.jegs.com
for buying or www.hottexhaust.com

 

moroso, if that's what you're talking about makes many things for rotaries including huge oil sumps

 

I dont know about yall but a universal sinencer im pretty sure was in no way made for a rotary. if i where to go with a silencer i would go with one that was specifivaly made for a rotary so you dont burn it up or blow it out. But that corksport siencer isnt really a spiral its like baffles put in a spirla shape. it just breaks the exhaust into 2 paths. i think the spiral motion they put it in was to reduce restriction so the exhaust doesnt get caugh up.

 

My moroso lasted about a month before rattling. it didn't crack the welds, it cracked the fins in half. (yep, in HALF)

The empty glass pack is actually the way to go for cheap and consistent sound. It burns out as soon as you get on the freeway, but the expansion area around the center tube acts much like a gun silencer.

The edelbrock RPM 409 SS lifetime warranty mufflers are also crap. 1800 degree ceramic lasted one trip on the freeway as well. (less than 100 miles till she was rattling)

I doubt a spiral design muffler will ever work in a rotary simply because the failure will occur from expansion and contraction with repeated heat cycling. Maybe someone will figure out a way to pull it off. I loved the sound before it broke.