I'm building a Locost w/ a large streetported N/A 13B as a race only car. The muffler's basically going to be only a few inches after the collector, so it's going to be seeing some pretty high EGT's. Do any of you guys know a long and round (Preferably 6 or 7" diameter) muffler that will handle this kind of temps? Magnaflow makes a 27" long 6" round, which is the perfect size, but that only uses partial stainless packing and the fiberglass packing around the outside of the muffler will melt. I am even considering buying some perforated tube, sheet metal, and some 321 Stainless Steel shavings from a machine shop to make my own muffler. This guy I know races RX8's, which have lower EGT's, and even their stainless packing burns up after a few sessions, but they were probably using a lower grade, i.e. 304L or 316. thanks.

Steven

 

check out the racing beat turbo back pre silencer, they have generic ones too. that pre silencer is the quietest thing ive heard.

we used the magnaflow, and it also works, but we had it at the rear of the car, so i can't comment on durability

 

Racing Beat makes good stuff, but unfortunately it's not long enough. If someone mad a muffler almost as long as the magnaflow 27" body length x 6" round with all stainless packing then it would work.

Steven.

 

oh but the racing beat is quieter than everything else, and it'll last, cause its built like a tank.

the magnaflow by itself is going to be on the loud side.

 

The racing beat resonator or muffler is not going to be quieter because it's a smaller muffler. the presilencer only has a 4" diameter... not much muffling ability. The Magnalflow will not work because it's not all stainless packing, although the size is perfect. That's why I'm looking for other options... something that's pretty long (over 20" long body) and has a 6 or 7" ROUND body, and uses all stainless packing. Thanks.

 

Do you have the ability to run 2 smaller mufflers? The good thing about the Racing Beat mufflers is that they seem to be tuned for rotary accoustics so they do pretty well at bringing the noise down and not sounding like ***.

 

The reason I don't want to run one after the other b/c that significantly raises the cost of the exhaust system. One longer muffler is only marginally more expensive than a shorter one but if you buy two that's twice the cost. Plus the racing beat mufflers are not round, and oval mufflers don't look as good on a Locost.



If all else fails I'll look into running 2 racing beat mufflers but it just won't look as good as a long round muffler since it runs along the side of the body.

Steven

 

I knew there was a reason you were so set on 1 muffler, haha.

I've had a Borla XR-1 muffler about a foot after the collector on my car for about a year now. It's not a "race car" but i beat the living hell out of it everyday and it's been through a couple autox events and over 30 passes at the strip. I haven't checked out internals but it still sounds like it did new. They have several different sizes that may work so it's worth a look.

 

we ran an ITS fc with both of those mufflers

this http://www.racingbeat.com/resultset....tNumber=16425P is quieter than the magnaflow.

i forget but i think the magnaflow by itself was 110db

racing beat was in the center of the car, magnaflow was at the end.

 

You could take a look at Aero mufflers and resonators...not sure they'd work for what you want though. Thats what Im planning on putting on my 7 though.

 

Do you guys think two of the 2.5" Power Pulse mufflers inline will be too restrictive?

 

Well if you have the skills to make your own muffler, buy the magnaflow, open it up and replace the packing in there with stainless. Also if the mufflers are straight through design the restrictions will be minimal.

 

I wouldn't use the magnaflow shell anyway since it's ferritic 409 and not austenitic 304L stainless. Right now I'm between either 2 Racing Beat Power Pulse Mufflers or building a muffler out of a 304L shell and 316L packing. Is there a warranty on the racing beat mufflers?


for packing I found 316L packing, which will withstand 800 degrees Celsius (1472 deg F) for up to 10 minutes. Each autocross run is only 60 seconds long, so time isn't an issue, but will a rating of 1472 degrees be enough right after the collector?

http://cgi.ebay.com/ws/eBayISAPI.dll...m=310048753815

Thanks.

Steven

 

search rock wool on ausrotary.com

 

https://www.rx7club.com/showthread.p...hlight=muffler