Fun with Exhaust

Scott S · Scott S's Garage

I have been on a long time quest for an exhaust that gives both good performance and sound. As you all know I am pretty anal with the "whole package" when it comes to my car (performance and looks). The PO of my car installed the 916 bumpers front and rear. When he did so, he had them blended into the body so they are not removable with out having to repaint the car. This does not allow me to remove or modify a rear valence to get different systems to fit. The car had a Sebring muffler that consists of a 4 into one "header" (it is still bolted to the heat exchangers) and a bolt on muffler that consists of a cherry bomb style muffler. Performance was fine, but is sounded a bit to much like a hot rodded bug for my taste.
This Saturday I spent all morning at a muffler shop. We cleaned/match ported all of the ports of the header section. We then replaced the cherry bomb section with a 2" straight pipe. After many attempts, we were able to get the bends correct to allow a 10" stainless steel Supertrapp to be installed, correctly exiting through the 916 bumper. The sound and adjustability is amazing. With all of the diffuser discs installed it sounds very similar to my 1972 911S - especially when the oil cooler fan kicks on. The low end feels similar to how it was before with a bit more top end. With the discs removed alltogether it's race car loud and revs for days - but not alot of low end. With 1/2 of the discs installed it is almost quiet and pulls great from the low end, running out of steam around 5500 rpms - perfect for around town. I am very pleased. The total cost was 55.00 for the Supertrapp and 80.00 for all of the custom work. I am very pleased - I only wish I had access to a dyno for before and after testing. Just an FYI...

Happy Monday...
Scott S

CHA914 · 05-13-2002, 09:50 AM

I have a KH header with supertrapp....I like the sound too, but I was wondering how many disks are you talking about?

I have currently only run it with 12disks and and open...

I have about 30+ disks so I have alot to play with.

Tony

Va914 · 05-13-2002, 10:14 AM

Good job. It seems like you got a great system with little $$ and alot of brain time.

Photo's and a sketch would be GREAT!!!!

Kerry

DSPTurtle · 05-13-2002, 10:21 AM

Where did you get such a good price on the Supertrapp???

Scott S · Scott S's Garage

I am not sure the amount of disks - just all that it came with.
As far as the cheap trapp, supertrapp must have let the patent expire. I ordered this from Moore Parts Source in San Bernadino (909.883.8891). The Trapp does not say Supertrapp on it anywhere, yet the internals (it is fully rebuildable), the disks, and the end cap are EXACTLY the same. I am pretty sure that the $55.00 included shipping. I found the ad in the most recent Hot VW's magazine. There were several companies selling it. It is available in the short 10" version as well as the regular 18" version. Quite a steal if you ask me!

Brant · 05-13-2002, 12:32 PM

Scott..........

Good job..... I hope to see it soon....
I also recommend safety wiring those 6 (or so) bolts that hold the discs on.... they will eventually come loose and back out.... plus the safety wire just looks cool too....

brant

James Bond · 05-14-2002, 04:23 PM

Any chance one of you guys could get some sounds of your exhaust??? I'm really curious how it sounds. I definitely want one of those exhausts if it sounds similar to a 911 f6!

3D914 · 3D914's Garage

Scott,

How about some pictures of the system - next time your under the car that is!

I'm just starting to rebuild my signal orange 2.0L into a Club Racer, and would like to see how that exhaust fits.

TIA,

Scott S · Scott S's Garage

You got it, prolly not for the next three or so weeks tho'...

airkwld · 05-15-2002, 02:09 PM

Not sure if these will help, pics of KH with SuperTrapp and O2 Sensor. Used the wide style clamp with cutout around sensor.....

Scott S · Scott S's Garage

Okay - This is cheating, but its faster than waiting three weeks. The attached picture is a Sebring exhuast. The only difference between this one and the one on my car is that mine did not have the big canister muffler - mine was a "cherry bomb" style. The down and dirty is simple - I cut the muffler off of the section that attaches to the "header". We bent and welded a section of pipe to replace the muffler/tail pipe section that allowed it to terminate through a shorty (10") stainless super trap, that exits through the existing hole in the 916 bumper. My initial plan was to simply weld flanges on longer style supertrapps, bolting one to each heat exchanger. After several discussions with folks on this list and the Rennlist, the overwelming consensus was that without an appropriate "x" pipe, I would actually have a decrease in power with that plan. I puchased a couple of different junker exhausts (Monza and Anza) and started cutting in an attempt to create an "x" pipe ending in two supertrapps. Finally a light went on - I didn't need duals, and I had a 4 into 1 "header" already on the car. I bit of manipulation, a few swear words, and some welding later, I now have the above described system!

3D914 · 3D914's Garage

Not bad Scott,

Does this mount to the heads like a conventional exhaust?

I was hoping to try using something like the factor put on the 76-914s. There is a short exhaust pipe from the heads with a mounting flange for the header. I really like this approach, as it allows me to remove the headers (when dropping engine) without the risk of pulling out an insert. The header like you're describing would then mount to this short pipe. Any thoughts?

TIA,

Scott S · Scott S's Garage

It is attached to the 1970 - 74/75 style of heat exchanger ( I cant remember the year when they went to the type found on the '76), the type that attach to the heads and then to the "v" shaped exhaust hanger on the transmission...