KrisD

the only thing i have seen from ACS is a reference to "increased power". i did not baseline dyno my car before changing the exhaust. if any, i believe the HP gains will be minimal and only at the top end of the RPM scale. in order to have what i would consider to be valuable HP/TQ gains, they have to kick in very early (~3000 RPM) and maintain through the duration of the powerband, since BMW has done such an exemplary job of giving us nice, long powerbands.

i will say that the pleasure that comes from the rumble at idle and the growl during acceleration and downshifts surpasses the 5-7HP i *might* have gained. just personal opinion though.

EuroCarFan

Yeah, I'm sure there's an increase but very minimal. I was also checking out Remus exhausts which claim 3%-5% hp increase "...that is not only measureable on the dynometer but noticeable in real world driving as well." - Bavarian Autosport. Hmmmm....

Either way, you're right, the sound and looks of these aftermarket exhausts are probably worth the price of admission.

KrisD

workmanship too, which was what eventually sold me on this one. truth be told - its probably one if not the most expensive after-market muffler-only mod in its class.

EuroCarFan

Yeah, Remus and B&B Tri-Flo are about $700-$800 give or take. I'll probably wait for Dinan to come out with theirs and then weigh my options.

DINAN530i

DINAN as my SA for over ten years at DINAN states will have something at the beginning of the year, price for DINAN exhaust is around 1000.00. I agree Kris the ACS exhaust looks the best and is the most expensive exhaust you can buy as of now. I agree with a 5-10 HP gain, I can tell alittle differnt in my Cars performance maybe cause its a 530i and not the 545 so the sound is better and the rumble is deeper. Sounds more agressive....I am A DINAN guy for life but the ACS exhaust is great and will match my ACS body kit as well. All other Engine Mods for performance will be done thru DINAN..