S50 vs. M50 with gear advantage

[02stu]

How close would an m50 with a 4.10 rear end come to an s50 with the standard 3.25 rear end?

m50 hp 190
s50 hp 240

so the s50 has 240/190= 1.26 time the hp an m50 has.

4.10/3.25= 1.26 gear advantage with a 4.10

So does this mean a m50 with a 4.10 diff. is as quick as an s50 with a 3.25 diff.?

[02stu]

The same idea seems to work if you look at a 318is and a 325is.

325is
168 hp
3.73 final drive
0-60 7.5

318is
134 hp
4.10 final drive
0-60 8.8

325is hp advantage
168/134=1.25

318is gear advantage
4.10/3.73=1.09

So the 325is still has an advantage of
1.25-1.09=.16

So the 325is should have a 0-60 time 16% quicker, if the power curve on the 318is doesn't effect it to much.

8.8/7.5=1.17

so a 325is is 17% quicker

[PiercedE30]

it all comes down to how decent the driver is also, but throwing all other variables out the window...........i don't see why they wouldn't be equal given their own advantages, other than the short gears on the m50 causing it to have to shift more.

[EtaSport]

I just ran my roomate's e30 for giggles.
his car- 89 w/m50 vanos, fan delete, no PS, e36 exhaust, s52 flywheel, 3.73 lsd

my car- 87 w/m50 vanos, headers w/modified e30 exhaust, s50 flywheel, 3.25 lsd.

he lost, no it wasnt that close.

[mazur]

That is actually how it should realistically work out. But you will have to shift earlier and more often, so I'm not sure how much that will affect overall accleration compared to a car which just has more power.

I'm not exactly sure how dynometers exactly measure power, but will shorter gearing affect measured output?

[EtaSport]

Yea, my friend and i can shift decently quick and he has more wheel spin, but neither of us drive that well to make our test accurate. However I've seen many times that my car can pull better holeshots for some reason.

the higher (numerical) rear, the more torque is at the rear wheels with the expense of speed. the lower (numerical) rear, the less torque is at the rear wheels but you have more speed.