Bad news. My Supertrapp experiment went tits up and damn near melted off
my rear fascia! I'm not sure you caught wind of my thread to go with the
single Supertrapp to see how things would work out but I finished the install
today and after I took the car out and ran it (sounded phenominal) I parked
it and looked at the rear fascia to notice the very underside of it slightly melted.
Not visual from above the car (standing) but up close and underneath, it was
melting from the heat of the exhaust!. Got down closer and freaked! The heat from the discs had begun to bubble the edge of the black rear fascia between it and the plastic suzuka blue rear fender. Not cool.
I only had time to do one accelerometer run and my 1/4-mile dropped by .13 (against the average) so take that for what it's worth. That's a 6hp gain (more or less) from the Tanabe average but eegads! at what cost!
Back to step one with a Spugen single.
I'm wondering how you guys who installed the Trapps managed to get them to work safely. Maybe it's just too close to the lip and I should of extended it more but then it would look stuck out there like a tree limb.

 

Do you have header? cat by-pass pipe?

 

You could get some metalic heat insulator material and clamp it on the the underside of the bumper there. It's too late for me - my J's Racing has already melted small bits of my bumper.

 

Called my local Honda to check on a replacement black rear bumper fascia and they told me it only comes complete with the entire rear bumper. WTF? $288.12 unpainted!
Here's a pic. You can't see this standing up from behind the car but I know it's there. From behind at eye level, it looks normal. Where the paint started bubbling is only visible when you stare at that section from a foot away...otherwise, you can't see that either. Too bad this didn't work out 'cause it sounded insane!

 

Russ,

You installed the discs backwards. That's probably why you had the heat problem. Hopefully you didn't distort the core where the screws go in, because it can distort when the discs go on wrong.

 

I didn't install them, the exhaust guys did and I corrected it right after I took the pic but it didn't change anything. When I started the car you could feel the heat rise so I shut it down. I called Supertrapp and sent them the jpegs. They said the muffler wasn't the right style because I should of bought the one that places the discs within the core of the muffler. This is the only black one which does not have a flare tip on the top to block off the discs' heat. As you can see, it's flush (the end of the muffler). The discs should be INSIDE the muffler, not on the outside. I ordered the wrong one (dumbass). Supertrapp is going to hook me up though. As for distorting the core, the screws are the only thing that goes into the core so it wouldn't have made any difference how the discs were sitting on the outside. The reason the fascia got melted was because the end cap forced the heat upwards. Had I pushed the muffler outboard another three or four inches, I would have spared myself this but it would have looked like crap. Basic lesson. Wrong muffler. The discs need to be on the INSIDE of the muffler. Like one or the other of the ones below I will probably get from Supertrapp. I really want this to work because the sound is fantastic and there is definitely a performance benefit over the twin guns from the Tanabe but it's hard to say if that came from a combination of the weight loss and Supertrapp. How much of one or the other?

 

They make an add-on shield that will fit this muffler. #405-2120. The way your muffler was installed on the car, it should have been fine and the shield probably wouldn't have been needed. The exhaust flows in the direction of the outlets between the discs.

When the discs are installed backwards and the 6 screws are tightened down, there remains a gap between the core end plate and the disc itself since the disc is supported around the outside. This is how that end plate can get distorted.

 

I always thought the discs would restrict flow. Never liked them when they were/still popular on the old Beetles. Not sure how the new ones sound.

 

Adding discs actually opens up the exhaust, making it louder. Each disc has a gap between the next disc; more disc = more gap.

 

Russ - sorry to hear about your car - those pics are horrible

Am I the only one who thinks that Supertrapps belong on Outlaw race cars and not S2Ks? I would probably chuckle if I saw a Supertrapp installed on a civic, and gag if I saw one on an S2K.