545isheff

Sorry if i am about to offend the technical specialists here (and please note I love my car and would only modify it properly), however, has anyone used an M5 exhaust on a 545i... I am pondering a dual system and wondered if I could use the center pipes/box and attach different back boxes... or is it just not worth the effort and get a proper system that is right for the car?

Ps. I just summing up costs and wondered if a DIY job could be done
Pps. I may have just answered my own question

madbmw

It would be gret if all the cars were the same, but the M5 trunk design is different than regular 5 series. You would not be able to put the M5 exhaust on the right side due to the battery box and the spare tire. Not enough room for it.. I am planning on changing the trunk of my car sometime.. Parts are about 1100-1500 plus what ever the body shop charges,usually around 500-1000 for the job.

sirch

Great questions here. I'm assuming your going to do a header to tip upgrade? Material cost is the usually the highest cost of custom projects. I've found the collectors for the headers in stainless steel for $50 each, which can range as high as $250 each. Stainless pipe can be bought affordably at Woolf Aircraft for the bends and straight pipe.

545isheff

Thanks for the reply. I was thinking more from the CATs back and using the M5 dual pipe from the CATs to the rear of the car, and then adding some custom backboxes. I think it would work in theory, however the main issues are pipe diameters and then what backboxes to use... it won't be that simple though as the M5 pipes at the rear probably won't match up to the boxes once cut.

I just wanted to see if I could avoid the ?900 plus for a custom job or the ?1500 for the rdsport set up (both CAT back).

My main objective is to enhance performance (be it little) and weight save from the standard box (which I think is still possible going to dual from the single) - I'm not fussed about having an exhaust that deafens the neighbours