S4 muffler set up

[pamitchell]

Pictures of my S4 muffler set up using a Dynomax Super Turbo muffler 17675. Sourced from Summit Racing. Part no. WLK-17676
I used insulation blanket from Aircraft Spruce to line the muffler pocket under the spare wheel well. I was fortunate that a local San Jose muffler shop was willing to take on the job of bending up the inlet and outlet pipes so it exited straight out the back. The best part was Babe's Mufflers only charged me $80 for an excellent job. I may add a resonator tip if I find the noise excites the neighbours. Sounds glorious.
I'm pleased with the install and the additional ground clearance. Total materials and labour was $150 USD.
Phil

[Frank Howard]

Phil,

I don't mean to put a damper on your post, but it seems to me that the inlet pipe is not bent high enough. As a result, there appears to be approximately 1-1/2" of space between the end of this pipe and the chassis. This part of the pipe is the lowest part of the car and as a result, you have lost 1-1/2" of ground clearance. I can tell you from personal experience that I have bottomed out and ruined the clamp holding the inlet pipe to the main pipe.

See if your local muffler shop can bend the inlet pipe upwards so that it comes as close to the chassis as possible without touching it. Otherwise, it's just a matter of time before you will be bringing it in to see if they can open up a flattened pipe.

The rest of the installation looks great though!

[gjz30075]

Phil, can you post a sound clip?
Thanks,

Greg Z
'72 Sprint

[richboyd]

Phil,

Thanks for the posting and for your creative work. I've thought about designing a similar solution; now you've laid the ground work for me. Your photos go a long way towards answering many question of mine. Thanks again.

What are your thoughts on ground clearance and noise level? Both are topics of interest to all of us (as seen in the first two replies to your post).

Rich Boyd

[elansprint71]

Did all US-spec S4 cars continue with the S3 exhaust system? S4's in the UK had a straight(ish) pipe and an in-line silencer, or twin silencers. Also that indentation in the rear valance disappeared.

Cheers,
Pete.

[Frank Howard]

Did all US-spec S4 cars continue with the S3 exhaust system? S4's in the UK had a straight(ish) pipe and an in-line silencer, or twin silencers. Also that indentation in the rear valance disappeared.

Mine came with an in-line silencer. When I replaced it, Christopher Neil advised me that the correct part for the S4 was the twin silencers however, most preferred the single (and simpler as well as less expensive) in-line silencer as used on the Sprint. The indentation in the rear valance to accomodate a transverse muffler remains in my car even though it never had one.

These are the first pictures I have ever posted. I finally moved into the 21st century.

[pamitchell]

I'll keep the ground clearance in mind when I get back to driving. The car was off the road for 14 months for a leisurely gearbox rebuild, sump leak and rear bushing replacement among other items on my punch list.
I preferred using the tranverse solution as I wanted the muffler tucked up as much as possible. The straight through mufflers that would fit in the center didn't have much sound deadening quality IMHO.
I'm always more conscious of sound levels in a coupe and I used aircraft sound deadening material in the headliner and trunk as well as a coating, Quiet Car, which a viscous, fibrous brush on sound deadener. I also used the aircraft material along the driver foot well, tunnel and flooring. The biggest gain was by insulating and sealing the rear parcel shelf. The car is actually very comfortable to drive on the highway & your hearing is not impaired. What ever weight I've added from sound proofing is offset with a lighter alternator and Odyssey battery.

[bcmc33]

It looks like a very poor fitting S3 system to me.

[Driveline]

Looks great.