Technical question on Cams

I am thinking of upgrading the Cams in my BMW. What is the benefits and cons of such an upgrade? I am anticipating a loss in torque in exchange for high RPM horsepower, ie a shift in the power band up a bit. I should also expect a rougher idle (stock 240, new cams are at 268 degrees), but I am not sure how much (it is a V12, so more naturally balanced...I guess)

At the same time, I am increasing the final drive to 3.15 (from a stock 2.82), which will increase responsiveness off the line and shift the general power band down a little and thus possibly exacerbating the high RPM weakness.

I was hoping to both aid sprints off the line (via the higher ratio) as well as increase power in higher bands (where it is good, but not great) via the Cams.

If I cancel everything out and result in the same performance..that would be rather amusing.

(Not a Ferrari, but you guys are better at this stuff then I)

 

If you are going to put in more cam, going to shorter gears as you are doing is the right thing to do. You always have to be careful about going to too much cam in a car with an automatic but 268 degrees (depending on how they measured it) should not cause problems. I dont know a great deal about the current BMW tuners but if there is a higher stall speed torque converter available it will also give you response off the line as well.
Have fun.

 

If you exchange cams for some with more duration, you won't neccessarily have a rougher idle. This depends on if your v-12 is an independant runner system (one intake runner with one throttle butterfly, per cylinder) a la F355.
An I.R. system runs smooth with large duration cams. Also short stroke engines can take more overlap than undersquare engines. What you want, to keep torque across the rpm band, is more lift.