Now, we’re no stranger to making S65 exhausts. As a matter of fact, not too long ago we finished up two custom S65 setups for two different customers. One was driven out to Virginia, where a NFL football player had it installed on his daily driver at a shop out there. The other was installed at FMU on a local customer’s car.

In both cases, they received the full FMU exhaust experience – starting with a set of de-catted downpipes (for off-road use only!), the exhaust then moves through a custom X-pipe situated as far forward as possible, then through a flatter and wider section of pipe meant to clear the brace that rests towards the rear of the midsection. From there, the exhaust heads to the rear axle, where it flows through the pass-through resonators and out the exhaust tips. Each customer had different tip preferences, with the local customer opting to cut off the OEM AMG tips and use those for a stealthier experience.

The flatter section retains the same internal area as the rest of the piping, in order to clear the brace without having to modify the brace, or cut down on exhaust flow by necking down the pipe size.

As with every other custom exhaust we build, it’s done entirely by hand, using 304 stainless steel and TIG welding with inert gas back-purging to eliminate oxidization inside the pipe, allowing for a truly laminar flow of exhaust gas. There are V-band clamps between the downpipes and midsection, and between the midsection and rear section.

Here are some pictures of the first exhaust’s construction phase, which we drove out to Virginia shortly after it was finished. Thanks to a local friend of ours for lending us his S65 so that we could ensure correct fitment during fabrication. As you can tell, the requested tips from the first exhaust were a little tricky to fit, but we made it work and the customer was quite pleased:











Here it is completed, just prior to shipping:













And here are some shots from the installation of the second one:







Feel free to shoot us a PM if you have any specific questions!

 

Will downpipes trigger a CEL ?
Or do you add a bung extension on the 2nd oxygen sensor tricking the ecu that exhaust is ok. These cars are really sensitive.

Thanks in advance.

 

greekviking, thanks for the post!

Officially the system is for off-road use only but we have run these with bung extensions. The silver S65 had software deleting the fault, and the gray one was running Renntech software which I believe also deleted the fault.

Thanks again for the response!

 

How much it will cost something like that on a 2004 S 55 ?

 

hotgree, can you e-mail mmarzano@fluidmotorunion.com? We would more than likely need the car here but we can at least provide you with a ball park price!

Thanks

 

Is this available for W221 S65 AMG?

 

I guess it's just another dead thread.

 

Dead thread, but worth posting to ask if anyone has ever installed some exhaust cutouts on a 65. We have them on our V-Wagon and they're delightful for the times you just want to be a bit loud. I'd rather have cutouts than remove parts.

Thanks.