Some thoughts on 8's and acceleration... (archive)

Stock, they're not set-up for standing start acceleration like the 540. The stock 8's gearing is immensly tall: 2.65 vs. 3.15 for the 540 Sport. Regardless, they're powerful enough that if you encountered a stock 6spd it should have taken you or if an autobox (99% more likely) it should have been very close.

To set things on a more level playing field you'd have to put the up-to-date BMW "Sport" equipment in the 850. That is, change the final drive ratio to something that launched the car instead of giving it a theoretical 190mph top end for US roads, put in a modern chip, and get rid of the restrictive exhaust. Pretty much what BMW did to create the 540 Sport, 740Sport, etc., but the resulting 8 with V12 torque is ALOT faster.

I installed the same 3.15 posi-rear final drive ratio as your 540 (167mph top speed with 6spd), a Conforti chip and a SuperSprint exhaust. Equipped this way the 850 6spd runs at least 5.6-5.8 sec 0-60's instead of the stock 6.1. Not only does it cruise comfortably at 100+ mph, but is comes off the line like a slingshot with a mean bark from the V12 and both tires spinning ;).

Greg K
1991 850 6spd (See Link)
1988 M5

http://www.mindspring.com/~gkovecses/850.htm

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