Your shop is giving you bad info. The 3.64 is too steep, unless you have serious race rubber & spend your time trying to beat $10K Camaros in 0-60 sprints from stoplights. Significant gains will not be realized over 30 MPH with deeper gears. You will not be able to hook up with such deep gears combined with the Getrag 4.xx first gear ratio. If you want to play stoplight drags, the M5 is the wrong car. Such duty can break the tubular aluminum rear subframe due to wheelhop.Carbo said:What about going to a 3.64 ratio?
Has anyone done this? My shop says I might not be satisfied with the 3.45 and the 3.64 will give me even more (15% more revs. over the stock 3.15).
The Quaife sounds like the way to go with 40% LSD and fresh clutchs.
It creates more torque multiplication, but basic Physics say that torque does not do work! The power at the wheels is the same. This is why a chassis dyno does not care what gear you are in or what diff ratio you have. With gears that are numerically higher, the engine applies more force to the pavement at a LOWER VELOCITY. What this means is the car will accelerate harder, but you'll be going SLOWER at the same RPM. Basically...the car feels like it's stronger when your going slower. The sensation of acceleration in the same gear is remarkable.MEnthusiast said:Doesnt the higher gearing create more power at the rear wheels? If so, why wouldn't it improve times (shifts excluded)?
Maybe reading Eleven's recent drag racing thread would help. He ran mid 12's with 3.15's and a couple minor mods. I read another thread here where an M5 owner ran high 13's with Dinan 3.45's. I'm not suggesting your car will slow down with deeper gears, but I have yet to see a 3.45 car with repeatable track data showing improvements that go beyond a buttometer.Carbo said:LSCMAN:
Makes sense to me. Thanks for the explanation.
The 3.64 is definitely out. Now I need to rethink the whole idea. It is a lot of money.
I know this has been answered already (and correctly, by the way), but here's another perspective.MEnthusiast said:Doesnt the higher gearing create more power at the rear wheels?