135i drivers - What does the tach read @ 80 mph?

[Night1]

Just curious. Anyone know? :iono:

[ehnaych]

According to my math at an actual (not indicated) speed of 80mph in a 6MT car:

3rd gear: 5463.59 rpm
4th gear: 4114.98 rpm
5th gear: 3457.97 rpm
6th gear: 3008.43 rpm


~Noel

[Scuderia]

I hope bmw releases a performance LSD. 3000 RPM in 6th gear at 65 MPH would be perfect.

[Dr. No]

According to BMW the gear ratios are the same to the 135i and the 335i, and for the latter, 1,000 rpms in sixth gear corresponds to 48.55 km/h (30.17 mph).

According to this the car will be doing 2,652 rpms for 80 mph and 2,154 rpms for 65 mph.

These are quick calculated figures, I think that it would be best to check it the next time I drive the car in a road. ;-)

[wnta135]

According to my excel spreadsheet (which was quite close for the e36 ///M3:

3rd: 5294
4th: 3989
5th: 3346
6th: 2918

BTW: 7000 RPM in 6th is 192 MPH

[MOTO69JOE]

I dont know the exact number but it was rather low under 3k im sure of that.

[blue-coupe]

3000 RPM seems high to me for such a powerfull car with a six speed. I was hoping that at 85mph (my cruising speed) for something closer to 2000rpm.

Oh well.

[Italteen3]

Originally Posted by wnta135

According to my excel spreadsheet (which was quite close for the e36 ///M3:

3rd: 5294
4th: 3989
5th: 3346
6th: 2918

BTW: 7000 RPM in 6th is 192 MPH

I don't anticipate on driving 192mph anytime soon :biggrin:

[BMWeber]

Originally Posted by blue-coupe

3000 RPM seems high to me for such a powerfull car with a six speed. I was hoping that at 85mph (my cruising speed) for something closer to 2000rpm.

Oh well.

only American cars waist a whole gear just for fuel economy. 2000 rpm at 80 is about what my 2001 camaro SS did.

[ichiban]

it probably only reved to 6 tho.

[BMWeber]

Originally Posted by ichiban

it probably only reved to 6 tho.

very true but that doesn't mean much seeing that 6000 rpm in 6th gear would be equal (after doing the math) approximately 260MPH and 5th would be 175MPH. the camaro was more like a 4spd with 2 overdrives. when you have a car with 350ftlbs of torque and you have to downshift on the highway somethings wrong :wink:

[Russo]

Originally Posted by BMWeber

very true but that doesn't mean much seeing that 6000 rpm in 6th gear would be equal (after doing the math) approximately 260MPH and 5th would be 175MPH. the camaro was more like a 4spd with 2 overdrives. when you have a car with 350ftlbs of torque and you have to downshift on the highway somethings wrong :wink:

we usually do this when someone is camping the left lane and you need to relay a message via the exhaust to remember to stay in the right lane... :biggrin:

[Devon K]

Originally Posted by Russo

we usually do this when someone is camping the left lane and you need to relay a message via the exhaust to remember to stay in the right lane... :biggrin:

With a Honda Fit??

[wnta135]

This should give you the whole picture:

[AwesomeBMW]

Originally Posted by wnta135

This should give you the whole picture:

what a great graph to practice calculus on:biggrin: Clearly the derivative of 1st gear it the highest so it has the greatest acceleration. J/k I hate math

[larryn]

Hmmm. 72mph on the rev limiter in 2nd gear... Anybody else thinking this would be a great autox car? If you're on a tight to average course, leave it in 2nd, on a open course, you have enough torque to leave it in 3rd for longer stretches.

[AwesomeBMW]

I didn't realize there were speed limits of 80 mph in LA:wink:

[PrematureApex]

Originally Posted by larryn

Hmmm. 72mph on the rev limiter in 2nd gear... Anybody else thinking this would be a great autox car? If you're on a tight to average course, leave it in 2nd, on a open course, you have enough torque to leave it in 3rd for longer stretches.

What long course autox's are you at that see 72+ mph?

For the vast majority of SCCA courses, I'm thinking this will be pretty good, if not still on the high side.

I'd like to see a little shorter gearing for the car. And with 4th being so long, and considering the torque of the motor, I think 6th could be substantially taller for the highway.

[larryn]

I run with the CCA that tries to keep under 60, but there are sections where you can hit a bit more. I have run with clubs that are set up for Vipers, and those you are past 80. It's nuts, but fun to do occasionally.

[mikeo]

My E36 M3 had a 3.23 diff and I topped out ~62mph in 2nd. I thought that was almost perfect for SCCA Solo courses. But that car had nowhere near the low end torque of the 135i. Have to wait and see.

[Night1]

Hey guys. Thanks for the great responses, as always. The numbers are right around what I was expecting.

:headbang:

[Gary@TireRack]

Originally Posted by Dr. No

According to BMW the gear ratios are the same to the 135i and the 335i, and for the latter, 1,000 rpms in sixth gear corresponds to 48.55 km/h (30.17 mph).

According to this the car will be doing 2,652 rpms for 80 mph and 2,154 rpms for 65 mph.

These are quick calculated figures, I think that it would be best to check it the next time I drive the car in a road. ;-)

There's a YouTube video that shows 6th gear cruising at about 75mph and the tach appears to be just under 2600. I'd say 2652 at 80 would be about spot on based on this.

I can't link YouTube from work...