Quiet Muffler

[M5rokit]

I have a 325 ITR with a KromarKraft exhaust system that is making way too much noise at LRP. I've put on the trap with about 11 discs but it is really hurting the engine.
Does anyone out there have advice on a muffler to use that would drop my Db level? I know this depends on header,etc but I need to start somewhere.
Rob

[Knestis]

Get in touch with Cameron at Conover Motor Sports. He did a straight-through custom deal for my Golf that I *thought* was going to be loud but is REALLY nice. For what it's worth, I HATE supertrap mufflers, going back to the late '70s...

KK

[Tristan Smith]

I had issues with sound on the 240sx until I used a Flowmaster Delta series. With the muffler, I used a turn down at the exhaust exit point, and I didn't have any issue after that at any of the tracks I raced at.

[JimLill]

possible quick fix.......... leave in 12 discs and replace end cap with the open one.......

[Greg Gauper]

I've had very good luck with the Borla 'Sportsman' XR-1 series racing muffler on my H-prod.
I am typically in the low 90's for sound.

http://www.borla.com/products/product_multi_detail.aspx?cat=5&type=72&desc=XR-1%26reg%3b+Racing+Exhaust|XR-1%26reg%3b+Sportsman+Racing+Mufflers

[steve s]

you can call active autowerks in miami [305-233-9300]ask for karl he's the owner,
he has a great system .it make just as much power as the kromakraft.it has 2 silencer for quiet tracks and you can remove 1 for 95 db tracks.
i did a lot of dyno work with them testing new stuff on carlos G car. i also believe bimmerworld is selling his exhaust system.
i hope this help!!

[M5rokit]

Thanks everyone! Unfortunately Limerock is 89Db which is so low it makes it very tough. I'll let you all know what we decided on and how it worked.

[erlrich]

One additional trick to consider with whichever muffler you choose is to re-route the exhaust to exit on the side opposite the sound control mic. I redid my exhaust last year to increase the tubing size from 2-1/2" to 3", and while I was at it I routed the exhaust to exit on the right side of the car. With a small (4") diameter bullet muffler - which does almost nothing - I generally record 98-99 db at Summit. I have no doubt if sound control were on the right side of the track I would be flirting with 103. That might be all it takes to turn a 95 db exhaust into an 89 db exhaust.

[tom_sprecher]

I used a plain steel 3" down turn exhaust tip to do the same thing. There are two threaded holes in the tip and one in the muffler. Depending on what side of the track the sound meter is I rotate the tip in the opposite direction and replace the screw.

Never had a problem.

[lateapex911]

Lime Rocks 89db limit is for the "muffled days". SCCA races are much higher....even my car is OK. Sound is generally just after the uphill, drivers right. Turn your tailpipe drivers left and slightly down forlowest readings.

(Isn't it funny how the whole point of dB limits is to not bother the neighbors, but the "workaraound, sue to the meters being INSIDE the track is we turn our exhausts to the outside?? :shrug:)

[robits325is]

Lime Rocks 89db limit is for the "muffled days". SCCA races are much higher....even my car is OK. Sound is generally just after the uphill, drivers right. Turn your tailpipe drivers left and slightly down forlowest readings.

(Isn't it funny how the whole point of dB limits is to not bother the neighbors, but the "workaraound, sue to the meters being INSIDE the track is we turn our exhausts to the outside?? :shrug:)

I always that was ironic too.