Davemk1 Posted December 17, 2018 Author Posted December 17, 2018 So.....I've had some time to get the Supertrapp set up and tested and I thought it would be worth a report. The muffler can be set up a few ways - first you can use the diffuser discs and an open end cap....or second you can use lots of discs and a closed end cap. It seems obvious that the open cap would flow better but also be louder. I set it up first with the open end cap and all 12 of the diffuser discs and then checked the sound level. My race rules say it can make a max of 100 dB at 50 feet so I set up a dB meter 50' of the road and went by in 2nd gear with WOT at 8000+ rpms. It made 105 dB. Far too loud to meet the rules. It was also annoying and just felt way too loud. Next I put the closed end cap on with all 12 discs. This forces all the gases and sound out at 90° and Supertrapp says 12 discs is the same as "full open" (I was more than a bit skeptical that this could be true given the size of the slots between the discs). I drove by my meter the same way as before and the car felt sluggish and I couldn't tell if the tires where spinning (very cold out and limited grip) or if the power was down. I checked the meter and it said a nice low 96 dB but it felt funny so I reset the meter and tried again this time focusing more on how it felt as the rpms climbed. It felt normal until about 5000ish when it suddenly bogged (it wasn't wheel spin) and then suddenly there was a very loud BANG and the revs shot up very suddenly until it hit the limiter and then I dropped the throttle and could hear the sound of metal grinding on the pavement. I pulled over and found that collector Y pipe had blown right off the headers and only the wire going to the O2 sensor kept it from spinning around and being run over by the rear wheel! I think one can safely say that the claim by Supertrapp that 12 discs is the same as being "full open" is complete and utter BS. There was so much back pressure that it blew the system right off the car. Not so good. The muffler weighed less than the claimed weight and the savings would have been nice but it was way too loud or way too restrictive so I came home and removed it and put on the old system and there was much rejoicing. Anyone want to buy a used Supertrapp? I'll make you a good deal on it! dave 2 1 Quote
Andrew Posted December 17, 2018 Posted December 17, 2018 When I saw your first photos of the silencer, I thought there wasn't a hope in hell of that working.. but for your sake, I was optimistically hoping there was some really clever design involved.. or maybe not. Quote
Davemk1 Posted December 17, 2018 Author Posted December 17, 2018 11 minutes ago, Andrew said: When I saw your first photos of the silencer, I thought there wasn't a hope in hell of that working.. but for your sake, I was optimistically hoping there was some really clever design involved.. or maybe not. You're right - it seems like it should work. I've seen others use them with success so was trying to be open minded. One thing Supertreapp says is that this size is good for 250 hp and that some cars with very high flow (like turbo cars) might be better off going with the larger size. The one I used has 4" discs and the larger size has 5" discs. Doing the rough math tells me that it would flow MUCH better. I suspect that the Honda engine at 8000 rpms flows too much for the system to handle despite the fact that it's within the 250 hp limit and that the 5" system might work well. However - the 5" system weighs much more and the chief thing I was looking for was weight savings and going with the big one wouldn't help me there. Live and learn. dave 2 Quote
Dave Eastwood (Gadgetman) - Club Chairman Posted December 17, 2018 Posted December 17, 2018 Yes, it's starting to look like S2000 Westfields move a serious amount of air, bits breathed in, and of course breathing out through the exhaust system. Quote
AdamR Posted December 17, 2018 Posted December 17, 2018 Sorry to hear it didn't work out Dave, thanks for being guinea pig! 1 Quote
AdamR Posted March 6, 2019 Posted March 6, 2019 On 27/11/2018 at 05:39, AdamR said: That doesn't sound bad to be honest... I've a carbon one (about 6-7", haven't measured it) that comes in at 4.9kg. Bit of a bump with some potentially useful info... this silencer is now 3.12kg with a smaller (2.25" instead if 2.75") perforated tube and the correct amount of Acoustafil in it (rather than their recommended amount which is enough to insulate a whole house ). It's 6" dia and 22" long. All stainless apart from the carbon sleeve, and packing material, obviously! So, looks like you can make a saving Dave 1 Quote
Davemk1 Posted March 6, 2019 Author Posted March 6, 2019 7 hours ago, AdamR said: Bit of a bump with some potentially useful info... this silencer is now 3.12kg with a smaller (2.25" instead if 2.75") perforated tube and the correct amount of Acoustafil in it (rather than their recommended amount which is enough to insulate a whole house ). It's 6" dia and 22" long. All stainless apart from the carbon sleeve, and packing material, obviously! So, looks like you can make a saving Dave Very cool. What brand exhaust is this? And do I have it right that the perforated tube is 2 1/4" ID? dave Quote
Jonsey Posted March 6, 2019 Posted March 6, 2019 On 06/12/2018 at 21:04, Davemk1 said: Well the Supertrapp arrived and I made a bracket for it and bolts it on and all went very well. It sounds great sitting in the driveway but I'm not taking it for a drive today because the temperature is currently 15° F (-9°C) and that's just too cold for it to be any fun. I weighed the old silencer and brackets and of course did the same with the Supertrapp and the total weight loss ended up being 5.2 lbs (2.4kg). Once I've driven it and put it on the dyno and tested it I'll report back. That could be awhile as it's full on winter here but if I can pull it off soon I will. dave these used to be popular on the big four stroke singles such as the xr 600, xt 600 etc , never seen them on cars before , im sure the bike ones used to be tunable by adding or removing the discs from the silencer. Quote
AdamR Posted March 6, 2019 Posted March 6, 2019 4 hours ago, Davemk1 said: Very cool. What brand exhaust is this? And do I have it right that the perforated tube is 2 1/4" ID? dave I actually have no idea sadly. Bought 2nd hand. The perforated tube is 2.25" / 57mm OD Quote
Davemk1 Posted March 7, 2019 Author Posted March 7, 2019 7 hours ago, AdamR said: I actually have no idea sadly. Bought 2nd hand. The perforated tube is 2.25" / 57mm OD Cool - thank you. dave 1 Quote
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