Guys i wanted to know what the best Quad exhaust is for a 545i with a M5 rear bumper? I was thinking of the 4x83mm eisenmann sport, but wanted to know what else you can buy for the same sort of money and quality? And most importantly what sounds the business!

 

Our quad exhaust for the I6 will fit the V8.
Newbie Bimmer has it installed, little resonance, clean, deep and sporty sound, nothing over the top.

Price depends on the tip selection.
http://www.remusexhaustshop.com/530i-remus...37_444_445.html

 

RDsport and custom are other quad options.

 

what do you guys think of the magnaflow exhausts? i have heard good things but i am just worried about the butterfly valve and if they come with them?

 

Magnaflows don't come with the butterfly valve. Anytime you go quad on the non 5 series, the butterfly valve is not present. You can retrofit one, but it would through the middle of the car where your split (x-pipe) occurs. Currently, the split is at the rear, so BMW can locate the butterfly valve on one of the exhaust tip. Magnaflows, especially, the straight-throughs (or any other straight through), will like cause some droning /resonance around the 1500-2100 rpm range. It depends on how loud you want the system to be.

Do you know the funciton of the butterfly valve?

 

I dont know what the function of the butterfl valve is? is it a must to have a butterfly valve?

 

It's to keep the noise down at low throttle usually below 2500 rpm. With after market exhaust, it does not come with a butterfly valve with the exception of eismann - I think.

You can search the forum for "drone" "resonance" and look at SocalMag5's recent upgrade to get an idea for aftermarket exhaust.

 

I have the Magnaflow too and love it, my brother got his used from craigslist but I wanted a valid warranty so I got it here. Magnaflow Exhaust 16833, or you can try one of the sponsors here on the forum, they are allways having sales/specials. Either way its a great exhaust system, sounds great, and very easy to install.