Lotus Elan

Racing Silencer

PostPost by: jkolb » Thu May 13, 2010 5:13 pm

Sanctioning groups in the US are becoming very fussy about noise and I need to find a silencer system that will quiet the car down a bit. I am running a 2 1/4" pipe back from my exhaust header. Car is an S2 and I would like to avoid the original double bend configuration. Engine is producing about 175 hp.


64 26R clone
07 Exige S
Second Gear
Second Gear
Posts: 137
Joined: 13 Sep 2004

PostPost by: Ross Robbins » Thu May 13, 2010 6:51 pm

For some reason the Twin cam registers very badly on the db meters, I think it has something to do with the frequency of the sound produced. I found a Flowmaster that was about 10" long that fit right in the recess under the boot that took out the harshness and brought me down to about 103 db and did not impede the flow or create significant back pressure.It was also light weight. Sounded great too! The only place I ever had trouble was at Laguna Seca as the outlet pointed to the right side of the car and the sound station was track right just as I would accelerate out of turn 5. I had to put on an angled tip that directed the sound to the left to avoid being put on the trailer. Good Luck.
Ross Robbins
Third Gear
Third Gear
Posts: 493
Joined: 03 Apr 2006
Location: Colorado, USA

PostPost by: memini55 » Thu May 20, 2010 10:37 pm


We have been running an S2 in solo and it has large pipe back to a supertrap muffler. The last solo it ran with 94dbA at 50 ft which is quit enough for most events. It also allows one to add or remove disc to change the back preasure. You can also repack if too loud. I know it is old school but so am I, old that is.

User avatar
Third Gear
Third Gear
Posts: 474
Joined: 09 Jan 2004
Location: Mount Vernon, Iowa

PostPost by: crannyr » Fri May 21, 2010 1:44 pm

Jerry, 10 years ago when we were seriously racing in SCCA as a GT2 we used a Borla XR-1 bullit muffler which passed the 105 DB requirements of the time. That with a 200+ H.P. twincam and 8500 rev limit. It had 2.5 in I.D. and it fit under the car (with some mods to the chassis). Hope it helps.

Second Gear
Second Gear
Posts: 137
Joined: 10 Oct 2004
Location: Grafton, MA

Total Online:

Users browsing this forum: No registered users and 5 guests