[yaoji]

......
sorry for my bad english,
i was trying to say if we actually drive for 50 miles on the road, is it gonna show 60 miles on the mile counter (or trip counter? whatever the name is for that thiing).

[///Matt]

no, no problems there. The mileage is calculated by wheel rotations, so it'll still be accurate. =)

[ck1129]

hey, about the throttle body, our cars dont need them lol. we use valvetronic, we dont have throttle bodies. thats what the master technitian at my dealership told me anyways. he said that he has no clue why dinan came out with it, and that it would take away hp if put on.

[///Matt]

We have throttle bodies, they're just basically useless on a valvetronic car. the only reason they're ON the car is for emergency power limitation (IE closing the throttle valve to prevent wheel slip) and to keep a minimal amount of vacuum in the intake manifold.

He can't know that it would take away HP. In theory, this thing should add HP because it's giving a wider mouth to the intake manifold, but it's just not working in practicality.

Once again, I hope that you are regurgitating information incorrectly, and that there's not a "master technician" out there who thinks the E90 doesn't have a throttle body.

[ck1129]

We'll i dont recall him saying we dont have them, but im positive he said we dont need them lol

[clubspec330i]

Please be aware of M3's higher redline. When I had my M3, it was between 3.91 or 4.1, same price for either one of course. Most of us, including myself, went 4.10 - $1610 installed. Also, remember that M3 diff is LSD.

If you were to put open diff 4.10, if you can find one, in E90 330MT, the 1st gear will be almost useless. 3.91 is probably the most you want to go for open diff, while 3.64 is probably better for everyday car.

[Got-BMW?]

Originally Posted by ksfrogman

Yes, I've known that for awhile.

Going from 3.15 to 3.64 is a 15% change, and 500 rpm difference at speed. The shorter the gearing, the more the shifting. The 3.64 seemed the best compromise, since this car is my daily commuter and I had to consider what my engine speed would at freeway cruising speed (65-85 mph). I didn't want to be cruising at 90 mph above 4000 rpm.

If we had solid lifters and a redline of 8000 rpm, then it might make sense to numerically higher on the differential gearing.

You might recall this gearing worksheet I used to plug in my individual values.

Can you make at chart like this for the 328i E90/92? I was just curious what the Topspeed would be based on the factory gearing with the limiter removed....

I can't wait to read/see your results with the new throttle body....

[ksfrogman]

Originally Posted by Got-BMW?

Can you make at chart like this for the 328i E90/92? I was just curious what the Topspeed would be based on the factory gearing with the limiter removed....

I can't wait to read/see your results with the new throttle body....

Sure, let me know which wheels and tires you have. Are they OEM? I need your tire size for the calculations.

[Got-BMW?]

Originally Posted by ksfrogman

Sure, let me know which wheels and tires you have. Are they OEM? I need your tire size for the calculations.

I have the OEM Sport Package with 17" and I believe 225 front/255 rear but I don't know the circ. of them. I hope that helps....

Thanks a bunch...

[ksfrogman]

Originally Posted by Got-BMW?

I have the OEM Sport Package with 17" and I believe 225 front/255 rear but I don't know the circ. of them. I hope that helps....

Thanks a bunch...

Okay, the E92 328i uses the same differentials as the outgoing E90 325i. The 6MT uses the 3.23 gearing, and the steptronic, the 3.73 gearing.

Assuming the rear tires are 255/40-17, and entering in the 6MT transmission gear ratios for the 328i, you can see how the stock 6MT gearing compares with what would happen if you replaced your differential with the steptronic diff. (similar to what I did).

[Got-BMW?]

Thank you very much!

[E90 ANdy]

So is it possible to slap on a E90 M3 differential on our e90? would the LSD help out for track use? also.. would it make for quicker accelerations for the steptronic? just some questions to throw out there?

[smellthebeans]

Yes any limited slip will help put power to ground especially in a turn.

Lower (taller) gear ratios...for example moving from a 3.10 ratio to a 4.10 as a rule will make you quicker off the line to 60....

It will also lower your top speed, & increase fuel consumption.

[N0OS3]

Originally Posted by ksfrogman

330xi:
3.64 in the steptronic
3.23 in the manual

325xi:
3.91 in the steptronic
3.38 in the manual

330i:
3.64 in the steptronic
3.15 in the manual

325i:
3.73 in the steptronic
3.23 in the manual

So.... in Lamens Terms; if i threw a 3.15 in my 325i Steptronic, i'll get more power to the wheels, faster acceleration? But my redline would come slower?

would 3.23 be ideal then (somewhere in the middle of 3.64 - 3.15?) 3.73 seems like too much shaft turn for a one wheel rotation... TurnerMotorsports uses 3.65:1 in all over their racing BMWs... i guess that's somewhat of a "somewhere in the middle"