Author Topic: Please look at this video (Read 6246 times)

shellback · « **on:** March 24, 2007, 11:10:52 PM »

I believe its been around for some time, but I wanted to repost since I enjoyed it very much, and I also have some questions about the car.

1) What type of shifter/transmission is on that car? Please note the way the driver shifts.

2) What is that high pitch sound that increases as the car accelerates?

Thank you.

Update: Sorry!
http://www.youtube.com/watch?v=eSJ-HzNWJGM

nickmpower · « **Reply #1 on:** March 24, 2007, 11:26:44 PM »

i see no video but its probably a sequential and the wine is gear wine from straight cut gears

Awgy · « **Reply #2 on:** March 24, 2007, 11:37:37 PM »

All i can say is that it drove my dog nuckin futs!

Definitely a sequential tranny.

1991318is · « **Reply #3 on:** March 25, 2007, 12:22:07 PM »

its a sequential manual gearbox w/ straight cut gears. Normal gears in the tranny are cut around a 45 degree angle, so they are quieter, but if you cut them at less of an angle they are louder and stronger.

nickmpower · « **Reply #4 on:** March 25, 2007, 12:45:23 PM »

yes, i got it before he even posted the vid!

cecotto · « **Reply #5 on:** March 25, 2007, 02:20:09 PM »

Quote from: shellback;22142

I believe its been around for some time, but I wanted to repost since I enjoyed it very much, and I also have some questions about the car.

1) What type of shifter/transmission is on that car? Please note the way the driver shifts.

2) What is that high pitch sound that increases as the car accelerates?

Thank you.

Update: Sorry!
http://www.youtube.com/watch?v=eSJ-HzNWJGM

It wasen't mentioned... But the engine is a S42, the motorsport variant of the M42.

(EDIT: Actually if its an early model it could also be a 2 liter s14)

shellback · « **Reply #6 on:** March 25, 2007, 02:28:19 PM »

Thanks folks. I learned a lot today.
http://auto.howstuffworks.com/sequential-gearbox.htm/printable

I assume these are $$$?

Awgy · « **Reply #7 on:** March 25, 2007, 10:25:53 PM »

I dont know how much for our cars, but for my 240sx, it was $12,k. So I imagine its a pretty crazy price for the e30 or any car.

1991318is · « **Reply #8 on:** March 25, 2007, 11:56:45 PM »

I've honestly never heard of any except for the motorsports ones and the e36 and e46 ones

shellback · « **Reply #9 on:** March 26, 2007, 05:49:06 AM »

Anyone interested in a group buy?

D. Clay · « **Reply #10 on:** March 26, 2007, 03:47:24 PM »

It's probably the spur gears making that sound as it is synched with car speed rather than RPM. Quick change transmissions with individual ratios for each gear also have a set of spur gears in the rear. These usually go from 15% overdrive to 15% underdrive, are straight cut, and eliminate the need for differential changes.

1991318is · « **Reply #11 on:** March 27, 2007, 01:59:16 PM »

Quote from: D. Clay;22244

It's probably the spur gears making that sound as it is synched with car speed rather than RPM. Quick change transmissions with individual ratios for each gear also have a set of spur gears in the rear. These usually go from 15% overdrive to 15% underdrive, are straight cut, and eliminate the need for differential changes.

I'm almost positive it is the gears themselves, as they are straight cut. I dunno much about the spur gear, but I do know that the gears are stronger when cut straight so they cut them straight because of the power the motor is taking.

D. Clay · « **Reply #12 on:** March 27, 2007, 04:27:21 PM »

The gearsets and spur gears are all straight cut. The spur gears are just an extra set to scream on top off first through however many they have. The old Frankland quick change rear ends (I'm dating myself here) had the spur gears in the back of the differential behind the ring and pinion. With these a stock car or Indy cars could run on everything from short ovals to super speedways without ever changing the ring and pinion. Some of GT2, 3, and 4 cars use the mini stock version which is about three quarter scale.

cecotto · « **Reply #13 on:** March 27, 2007, 05:25:47 PM »

Quote from: D. Clay;22302

The gearsets and spur gears are all straight cut. The spur gears are just an extra set to scream on top off first through however many they have. The old Frankland quick change rear ends (I'm dating myself here) had the spur gears in the back of the differential behind the ring and pinion. With these a stock car or Indy cars could run on everything from short ovals to super speedways without ever changing the ring and pinion. Some of GT2, 3, and 4 cars use the mini stock version which is about three quarter scale.

My understanding of these spur gears are that they give a cost effective way of "simulating" having a wide range of differential gearings. By means of an extra gearing placed between the gearbox and the differential.

The thing with differentials are that they are very expensive, and rebuilding them takes special tools and skills. And for a racecar extra cost of locking or limited slip units makes having a selection of diffs at hand almost impossible for the average amateur racer. However i personally doubt that BMW ever used these extra gear-sets to cut costs as the cars competed in the most competitive class of it's era.

Apart from being cost effectice, they have the disadvantage of extra transmission loss. And when everything in the car has been optimized at no expence. I simply dont see this technology being utillized in a racecar like this.

D. Clay · « **Reply #14 on:** March 28, 2007, 11:28:31 PM »

Correct on no spur gears in the BMW sequential trans. I read the WTCC rules - not sure if they apply - and homologation is a requirement. The trans ratios must be the same as the homologated production model. However there are a limited number of approved differential ratios that are allowed all competitiors. The 2007 BMW 320si has gone back to a conventional gearbox because the sequential unit put them over minimum weight by about 40 pounds.
The video does sound like a Hewland STA or Weissman gearbox.