Exhaust shopping. Any Recommendation?

Hugh, I have an Eisenmann Sport on my CSi. I like the sound, but as it was on the car when I bought it I cannot comment on how it compares with the stock exhaust. I know a number of guys on Roadfly have done similar upgrades, so you could check there too.

Good luck

From what I've read, most all aftermarket exhausts either reduce HP or don't add any except the Supersprint. The Dinan is supposed to add 10 at redline and little or nothing below 5000 rpm, but their system is just a stock setup with the baffles cut out and some chrome tips welded on. They have the nerve to charge upwards of $2,200. U.s. for this. LOL. The SuperSprint is supposed to add 5HP roughly down in the lower midrange and builds to 29HP (if I'm remembering it right) near redline. The stock system seems dificult to beat.

I am thinking this is a mixture issue, as higher flow often reduces power in one area and gaines it in another, but higher flow should never reduce power everywhere unless the mixture isn't being corrected as I suspect is the case here.

I recently posted a question / speculation on this very topic under modifications.

I had the Supersprint on my last 850i (1992) and liked it very much. Nice burble at idle but quiet at 700 RPM and above.

I'm shopping for a system now for my '91. Best price I've seen is $1290. u.s. on the SuperSprint.

I recently spoke with the guys at Eisenman. They do 3 types of exhaust for the 850, the first (street I think) is about as quiet as stock and adds 0 HP, the second is sport (I think) and adds something like 2-3 Hp, and the third is race, and adds something in the neighborhood of 5-8 if I remember right.

Basically you won't "feel" any difference with anyone of them, unless your mind fools you because of the sound. They say their exhausts usually save 25-30% weight over stock. Price was $1500 ish, (didn't take notes as I wasn't seriously interested after the Hp estimates).

Best price here in North America that I have found is http://www.evosport.com they are at $645 a side or $1290. u.s. bmpd.com (BMP Design) is $20 more per side. I have not checked out of the USA.

Hugh, congrats on buying the car, that means we will hear more from you

Good luck and succes on the exhaust,

Do you have some pictures ?

Hi,
I'm also interest to replace exhaust pipes on my 850 1998, i'm particulary sensitive with the exhaust song and look.

Do you have any pictures of new exhausts, to see how it look like ?

Thanks !

Amethyst from Paris

For a look at exhaust, click on my avatar pic to go to my photo gallery. The second picture shows my last car (a 1992 850i) with the Supersprint exhaust.

Supersprint seems to make the most power, costs about $1300 U.s., and off idle is nearly silent, however it has a great burble at idle.

There are chips to alter the timing and fuel mixture of the engines, Jim Comforti's being the best, but no one tunes cars on a dyno by altering the WOT or part throttle mixture that I know of. I have myself been wondering about adjustable vacuum refrenced fuel pressure regulators to do this very thing. Part throttle on most cars is closed loop with the O2 sensor, and open loop using pre-programmed maps for Wide Open Throttle. Adjusting fuel pressure a couple of pounds should do it. You can view the thread under modifications, "exhaust/fuel mixture".

As far as supercharging, there are companies that do it, their prices seem to be about 18,000.00 Euros for the Kit and 35,000.00 Euros installed. Not an option for a car of this value. For the price of the kit alone, you could buy a late 80's, low miles 944 turbo, put a cat replacement pipe, mass flow sensor / chips from Autothority, and be in the 360 Hp area. Low to mid 4 sec range in the 1/4 mile, and save the 8 series for what it was intended, (which by the way is not as a sports car).

Glad to have you here, have fun with the 8's.