Question about B&M launch control.

Hi I have a B&M launch control kit in my car and it works great for heating up the tires, but I also heard it can be used for "pre-loading" the rear to get a better launch. I have a six speed so I think this could maybe help my launches at the track (which suck right now LOL). Can anyone explain how I would properly do this?

There's no way you can preload with a manual transmission.

You could use it on the start line just to hold the car while your feet are holding down the clutch and on the gas.

You can pre-load the rear end with a manual transmission and line lock (roll control, launch control, etc.) by staging, setting the line lock to hold the car from rolling and letting the clutch out just enough until it starts to engage. This will pre-load the rear end a little. You can give it more gas and let the clutch out a little more if you want more pre-load. However, doing this will wear out your clutch more because it will be slipping while you are waiting for the tree to come down. It takes a lot of practice to get proficient at it, but it can be done.

There's no way you can preload with a manual transmission.

You could use it on the start line just to hold the car while your feet are holding down the clutch and on the gas.


I agree.
You can wire the linelock to engage when the clutch in on the floor and releases when you "pop" the clutch. Not legal for most foot brake bracket races. :rolleyes: This doesn't preload it just keeps you car from rolling out of the beams.

I wouldn't want to drag the clutch to preload the driveline. Slipping the clutch like that will heat it up. A hot clutch isn't a good thing. Maybe in an all out race car that will replace the clutch regulary but not in a street car.

I've seen people use a 2 step operated off the brake switch with an automatic. Brake pedel depressed and the 2 step turns on limiting the amount of rpm the engine will reach. When the brake pedal is released, the 2 step turns off and the engine rpms climb. Just another way to launch at the same rpm every time.

I wouldn't want to drag the clutch to preload the driveline. Slipping the clutch like that will heat it up. A hot clutch isn't a good thing. Maybe in an all out race car that will replace the clutch regulary but not in a street car.
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Exactly, that's why I mentioned that the clutch would wear out faster. I wouldn't want to do it either, but the question was can the launch control be used to pre-load the rear. The answer is, yes it can ;)