How long is it going to take me to learn to launch RWD style?

[damian]

Originally Posted by onehots2k

None!!! Too bad I like them both!!

Me too.

[71GS455]

Originally Posted by damian

It took a long time to learn how to properly launch a turbo AWD car. Jumping into a 135i, I'm guessing I'm going to just sit there spinning my wheels unitl i get used to the difference. Any tips?

Although and old thread, I did find it interesting to read.

Although I wouldn't compare anything else about the 135i to the 5.0 Mustangs that I've had, I think the launch may be similar.

Assuming that you're running on street tires and not a drag-specific tire, and launching with a manual, you're going to have to deal with the potential for wheelspin. Plus with limited sidewalls, there isn't much to absorb the twisting motion and it's likely even worse than the Mustangs.

What I did back when I ran Mustangs in the same ET range, on street tires, was to try and find that happy place between throttle and clutch that kept the nose up. There are two reasons it doesn't stay up: 1) not getting enough power to the ground and 2) putting too much power to the ground resulting in wheelspin. You need to use a combination of throttle and clutch to modulate this and it's going to take practice and feel of the car to find out where that is.

In the Mustangs, I'd come off the line at between 1/2 and 3/4 throttle with a fast release of the clutch (not dumping it!!!). When I felt the car had traction and the clutch was completely engaged, I'd go WOT. I never bothered powershifting (full throttle gas while doing the clutch sidestep with the shifter yank in one move), instead I'd speedshift and still come off the gas with the clutch/shift portion as a powershift. But I also had a shifter with positive stops that kept me from bending shift forks from going to far.

I'm guessing the 135i will be similar in the launch technique and it may take more gas and more clutch in combination. But you don't really know until you try. I guess the next question is how much is a clutch replacement!?

But if you're going to drag race it seriously - or try to win some bracket rounds, you're going to want a tire specifically for drag racing. There are plenty of drag radials out there that will take the traction element out of the launch, where the question becomes how much gas does it take to keep from bogging?

[stefan]

Old thread.. I'm resurrecting it. I'm that bored.. I finally got to the point where I read literally every new post.

I'm just going to weigh in on this.. I don't think you can approach launching from a mathematical point of view. You just have to bond with the car over time, learn it, and just feel it. It took me a long time to perfectly launch my E36 but this came through just.. learning the car, really. I think by approaching this in a robotic manner, you won't get that great of results.

Of course I'm assuming you're going just for fun, at lights and what not. The guys on these boards have awesome ideas if you are going to want to seriously become good at it for competition.

[john970]

Originally Posted by stefan

Old thread.. I'm resurrecting it. I'm that bored.. I finally got to the point where I read literally every new post.

I've been doing that for 5 months. I need a new hobby.

[nellison33]

Old thread, but you guys are funny. At least it caught my attention. Anyway, it seems like all these people have different ideas of what launching a car would take. To me it is really simple, or the 135 manual is just that easy. Few simple rules I was taught by old race car driver.(i learned stick on my 135)

-Learn where your clutch catches generally, you do this all day while driving so it shouldn't be hard

-I have been taught to let the clutch out slow and steady, no matter how fast/hard you stomp on the gas.

-Your Tires keep you on the road for best grip, so dont give too much gas to spin the tires. The less wheel spin=more acceleration=faster launch.

The best part about the 135 is because of the 1400rpm/300ft/lb. This lets you have a very full range of RPM's to get more speed in each gear. I like to catch between 1500-2000rpm to save on gas, plus more rpm to work with in each gear.

The main point of avoiding wheel spin is so you can get moving and have the rest of your RPM's to work with. Your Tires spin beause your most likely at a high RPM and at a very low speed. If your launching from a rolling start, you have better traction throughout first gear.

I dont have much driving or racing experience, but I have the pleasure of driving different cars that will break traction in 2nd gear doing 40+ mph. Just think about what your doing in 1st gear to maximize grip.

So what I m really trying to say is just go out there and practice. Have Fun!!

[ennislaw]

Originally Posted by stefan

Old thread.. I'm resurrecting it. I'm that bored.. I finally got to the point where I read literally every new post....

It's easy to forget that new folks are joining and, before making a purchase, are lurking and not posting a lot of new questions or threads. Please don't think that just because it's been hashed out before that a new discussion will not bring out new ideas or more recent developments. I can attest that just searching threads and posts isn't as revealing as actually being involved in a new "discussion", even though parts of the thread may be "old hat" to established members. Thanks!

[SpeedballTrix]

Wow, ancient thread, lol.
But since it's already roaming around town in search of brains, Ill throw it a bit.

1 hour.

That's just to learn how to do it, not do it well.
In one hour of solid practice you should be able to launch pretty close to optimal. That should be about 20 launches.

After that, to learn how to get that last 20% to optimal where you can rip off 1.6s 60 foots instead of 2s will take quite a while.
You'll need to be able to do 1.8s to 60' 100% of the time before you can get 1.6s 20% of the time. Then just keep doing it. Over and over again.
You'll probably have to do over 100 full-on hardcore drag launches before you can consistently get 1.7 and 1.6 second 60 foot times. After that it'll be all about reducing your reaction time, which is best done off the racetrack, where you dont have to kill clutches to see results =P

I'm betting since it's been a year and half since the original post that the OP has learned pretty well?
Might be interesting to see =P

[kc_skyrider]

Originally Posted by grant

Make sure you turn off the traction control before trying to launch, otherwise the car will apply brakes and retard spark and it will bog down.

Make sure you buy an aftermarket LSD, so at least you will have 2 wheel drive instead of 1.

Practice a few times - dropping the clutch from around 3k revs and adjust revs for best results.

Prepare to buy a new clutch...

Please look at my thread under N54 and Drive train modes. No LSD... Explain...

[BMW86]

the 135i is easy to launch. it's very easy to get 300hp down i've been happy so far. no mods yet. completely stock.