Aluminum Flywheel

dsobering47 · Sep 22, 2003

I know I ask a lot of dumb questions, so I will ask another one: What are the main pros and cons of buying a performance flywheel. Particularly, the flywheel available from Bavarian Autosport, for a 1987 325is.

Thanks [thumb]

frolf · Sep 22, 2003

ahhhh, fly wheels q's. the fly wheel is mass for the engine to rotate before the power is past your tranny, so the lighter the better. if you have a light flywheel, there is less mass for the crank to turn, so your engine doesn't work as hard. also it provides more throttle control. my buddy has a super super super lightweight flywheel, and although its hard to execute good double clutches when i'm used to my OEM flywheel, i can definately see how you can be more accurate with a light flywheel.

brahtw8 · Sep 22, 2003

The lighter weight will give you a few extra hp, as the engine has to spend less power turning it.

The only noticeable difference will be how the rpms drop when you press in the clutch. The lower rotational mass will cause the rpms to drop much more quickly than they do with the current flywheel.

AFAIK, the primary drawback is a rougher idle, but I don't think its enough of a problem to avoid the flywheel. A lot of people think it is a great modification.

dsobering47 · Sep 22, 2003

i could never figure out what double clutching is.........what is it? [paranoid]

brahtw8 · Sep 22, 2003

It just means that you use the clutch once to get out of the gear, pause in neutral, let your foot off the clutch, push the clutch in, engage the next gear, and let out the clutch.

It is typically used as part of the heel and toe downshift, where you match the revs to the road speed in the lower gear. Do a forum search on heel and toe, as I don't have time to write a book on it right now.

Try this one:

http://www.bmwboard.com/forum/showthread.php?s=&threadid=1872&highlight=heel+and+toe

dsobering47 · Sep 22, 2003

i know heel/toe......i just rev it up when the clutch is pushed in, is this bad compared to putting in neutral and matching the revs?

thanks [thumb]

brahtw8 · Sep 22, 2003

dsobering47 said:

Not if done correctly. You may get a little more wear on the clutch by revving it with the clutch in, but I don't think it makes a significant difference given that you would be engaging the clutch at the higher rpm whether you rev in neutral or rev in the new gear.

You save wear and tear on the synchros if you match the rpms before you engage the next gear (or avoid grinding the gears if you have a non-synchromesh gearbox). Some professional drivers don't pause in neutral when they downshift. For them its more about timing than anything else.

BTW, you didn't mention braking in reference to heel and toe. Are you sure you know what it is? Double clutching is considered to be a part of heel and toe, or more properly described as "heel and toe double-clutch downshifting".

If you aren't thinking about having the left ball of your right foot on the brake while you blip the throttle with the right ball of your right foot, to match revs to the lower gear, then you don't know heel and toe.

dsobering47 · Sep 23, 2003

yes, i do believe i know heel-toe.... i personnally have my right foot below the brake pedal, and press the brake, then rotate my foot so that the right side is on the gas pedal and the left side is on the brake. [thumb]

Dinan55 · Sep 23, 2003

It's harder to get up hills and your engine loses inertia. What is the heel-toe method I never got that.. I drive a manual too but I never really figured out what the “heel-toe” method is and what it’s for.

brahtw8 · Sep 23, 2003

Remember your friend, the search:

http://www.bmwboard.com/forum/showthread.php?s=&threadid=1872&highlight=heel+and+toe

Essentially, it is a way to blip the throttle while braking and downshifting so that you match the revs in the lower gear when it is engaged. This keeps the car stable when you are braking hard into a corner, and gets you in the proper gear for the corner. It also helps with timing when you are racing.

It is a part of "heel and toe double-clutch downshifting"

Spidey · Sep 24, 2003

This VIDEO --> has a cam on the drivers feet. You can get a good idea of how it should flow. [thumb]

Aluminum Flywheel

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