joshbot007

Ok,

So now that the car running well Im starting to mess with the features and settings in my hydra and one of those being launch control. Let me first say that I am running 250whp with a FM clutch, 5speed, and torsion (6speed and 6speed rear soon to come) but that is beside the point. The point or what kind of information Im trying to obtain is how realistically hard is launch control on the drive train. Yes It is obviously harder on the transmission to do clutch drops or quick clutch engagements from 4k or so in first but how bad is it really? I would imagine that this clutch drop in first with only 4 or 5 psi built up is way less torque then at the same rpm under WOT and full spool but I would also imagine that this "shock" that the driveline receives is not very good for it and even launching in a NA car would cause similar stresses. I am not as concerned about clutch life nearly as much as I am transmission or rear end. Im also not trying to do this at every stop light just every once and awhile for the fun of it but would seize usage if people find themselves blowing trans after just a few launches. So what are peoples experiences/knowledge with this? Do some of you do it all the time with no issues or is it something that should be avoided like the plague? Perhaps someone with a better understanding of transmission and driveline internals would be able to explain the stresses introduced during a launch better then I can fathom in my head.

Thanks,
Josh

Bronson M

iTrader: (1)

I use it extensively on every auto x start, how hard it is on components depends on how you launch. Leave at 4k and feather the clutch..... . Won't be bad at all, I have over 100 launches on my 00' with a 6 speed and had probably 200 on my 95'with a 5 speed. If you launch at 6k plus and simply drop the clutch with a strong clutch it'll probably give up fairly quickly.

joshbot007

Thanks for the reply. Yes I would imagine that feathering or letting the clutch out at a rate that would take away the initial shock would be optimal and even introduce minimal stress to the trans but I also feel mastering this and discovering at what rate to let it out is a trial and error process that takes practice to get a good feel for it. Any suggestions or ideas of how to best release the clutch? I know this would be very hard to explain via text without seeing it

Bronson M

iTrader: (1)

You're exactly right, technique varies wildly with the surface you're racing on. You have to think of launch control as nothing more than a lower rev limiter cause that's actually what it is. I mean you can retard the timing and get a little boost but when a stock motor can spin the stickiest 225's it's not needed.

I've been on slick asphalt that needed a 4k launch with the throttle at half and clutch release was around a full second.

I've also had some sticky pavement that would take a 5500 rpm launch at full throttle.

This is all on a mostly stock BP4W, I know when I get it right the rpms hang at my launch RPM before sagging to 3500 rpm. If the RPM's flare up or you get axle hop get out of it, you'll only break stuff or go slower.

Here's a video of a good launch, you'll notice I had to try twice to get the launch control to kick in since I was trying to use a half throttle launch.

joshbot007

Great video and thanks for the info! Next wam day im gonna mess with the settings a bit more as i dont have lc working exactly how i want it then im gonna try some launches like yours. Wuth that being said i would still like to hear from others about their experiences with launch controll and breaking/not breaking things

ridethecliche

iTrader: (2)

That celebration at the end tho

Bronson M

iTrader: (1)

Lol, I thought I had won FTD but ended up loosing by like .003 of a second.... That tail wag on the first right hand sweeper killed it for me