How to use F8X M3/M4 Launch Control - Facts and Fiction

[Andrew115]

Originally Posted by MaynardZed

Burn outs are cool but "spinning ain't winning". I think most members that have had good 1/4 mile times have not used LC.

on a track you warm the tires first and have a decent prepped surface compared to the street. If you do a decent burnout first LC isn't that bad. It's not Porsche or Audi good but not terrible.

Check the thread you will see good times with LC when done right in the proper place.

[nicknaz]

Originally Posted by MaX PL

if you keep your foot down it fully grabs midway thru 2nd.

The car spun all the way through first and part of second.(sounds like that is what happens for you to)

It was more of a huge burnout than a launch. When I tried Lc in cayman s there was just a chirp and the car cut timing to keep things moving forward. The m3 lc seems like such a fail in comparison. the lc in my z4 was just as bad, but somehow I thought an m car with lsd would be better.

I'll try again but I think modulating the throttle myself will be better.

Edit: I am pretty skeptical of "keeping my foot in it" when the rear is moving around so much. It seems like a recipe for ending up like the c7z that stuffed it into the trees after using Lc....

[Warranty P]

I tried LC and on the street and it worked like a champ...I lowered RPMs to 2500.

[Andrew115]

Originally Posted by nicknaz

The car spun all the way through first and part of second.(sounds like that is what happens for you to)

It was more of a huge burnout than a launch. When I tried Lc in cayman s there was just a chirp and the car cut timing to keep things moving forward. The m3 lc seems like such a fail in comparison. the lc in my z4 was just as bad, but somehow I thought an m car with lsd would be better.

I'll try again but I think modulating the throttle myself will be better.

Edit: I am pretty skeptical of "keeping my foot in it" when the rear is moving around so much. It seems like a recipe for ending up like the c7z that stuffed it into the trees after using Lc....

Find a good road ( flat and wide) lower the launch rpm to 2500ish and give it a go. Stay in the throttle and correct with steering if you have to. Comfort steering works best for me here. Good luck.

[filetitan]

I still have no idea how to use LC...

[nicknaz]

Originally Posted by Andrew115

Find a good road ( flat and wide) lower the launch rpm to 2500ish and give it a go. Stay in the throttle and correct with steering if you have to. Comfort steering works best for me here. Good luck.

Good advice thanks. I'll do 2500rpm for sure.

Looking back, I was in the middle lane of an empty 3 lane road but there was a very gentle curve and slope so it wasn't the best place for keeping my foot it and I backed off (very careful....)

filetitan you need DSC OFF, gearbox in S3 and the car warmed up and driven 6 miles/10 minutes. Brake with left foot, floor throttle with right foot until flag comes up then release brake

[Andrew115]

Originally Posted by nicknaz

Good advice thanks. I'll do 2500rpm for sure.

Looking back, I was in the middle lane of an empty 3 lane road but there was a very gentle curve and slope so it wasn't the best place for keeping my foot it and I backed off (very careful....)

filetitan you need DSC OFF, gearbox in S3 and the car warmed up and driven 6 miles/10 minutes. Brake with left foot, floor throttle with right foot until flag comes up then release brake

Yeah a grade in the road is a major influence sliding the rear end over when using LC. Flat road will keep you from a massive slide. Report back when you try again.

[filetitan]

Originally Posted by nicknaz

Good advice thanks. I'll do 2500rpm for sure.

Looking back, I was in the middle lane of an empty 3 lane road but there was a very gentle curve and slope so it wasn't the best place for keeping my foot it and I backed off (very careful....)

filetitan you need DSC OFF, gearbox in S3 and the car warmed up and driven 6 miles/10 minutes. Brake with left foot, floor throttle with right foot until flag comes up then release brake

Ah! gotcha. I think I tried to launch below 6m/10m mark. Thank you much!

[MaX PL]

yeh now that i think about it, the only times I've had slight traction issues was on a declining road i frequently launch on.
i have always had solid launches on level roads.

[Demxsr]

You can only launch these cars with the traction control turned off right?

Isn't the point of LC for the cars electronics to give you the least wheel spin launch possible? Seems odd.

[babyboss]

LC is useless & scary when u got foot flat & car goin sideways ..

[CanAutM3]

Originally Posted by Demxsr

You can only launch these cars with the traction control turned off right?

Isn't the point of LC for the cars electronics to give you the least wheel spin launch possible? Seems odd.

The point of LC is to do an "optimal" launch on a good traction surface. It is not intended as a "fool proof" system to get off the line quickly. For the the latter, keep in MDM, give a small dab on throttle to engage the clutch and then quickly roll on the throttle. This will allow you the get off the line pretty quickly with little drama.

IMO, LC is more intended for use at the track by folks who know what they are doing behind the wheel. A prior burnout is recomended to clean an warm up the tires.

[CanAutM3]

Originally Posted by babyboss

LC is useless & scary when u got foot flat & car goin sideways ..

I don't call that scary, I call it fun

[9SECDD]

Finally had launch control work well today 3x in a row.

The key was definitely the right surface. Previously did on sub-optimal road, and fish-tailed big-time. Had to let off or would have crashed. Did this probably 6-8 times.

Today went to different road that is relatively new. fresh asphalt, no rocks, level surface. Launch control worked great. I used standard 3k rpm setting. a few chirps and very subtle fish-tailing, but hooked up like a beast by the end of 2nd gear all 3 times without worry like previously. Surface seems to be key.

Been prepping for 1/4 mile track time trial (noob; never done), and have been stressing over whether to trust LC or just mash with MDM mode on. After today, definitely going to use LC. Especially since traction at track should be stellar.

[nicknaz]

Originally Posted by NJ-M4

Been prepping for 1/4 mile track time trial (noob; never done), and have been stressing over whether to trust LC or just mash with MDM mode on. After today, definitely going to use LC. Especially since traction at track should be stellar.

I would start with mashing it in MDM mode (what CanAutM3 advised) to test out the traction

Don't assume that the drag strip will be an "optimal" surface. There isn't a lot of room to save the car if it turns out LC clutch dump gets the car loose

[turbo8765]

Originally Posted by CanAutM3

The point of LC is to do an "optimal" launch on a good traction surface. It is not intended as a "fool proof" system to get off the line quickly. For the the latter, keep in MDM, give a small dab on throttle to engage the clutch and then quickly roll on the throttle. This will allow you the get off the line pretty quickly with little drama.

IMO, LC is more intended for use at the track by folks who know what they are doing behind the wheel. A prior burnout is recomended to clean an warm up the tires.

BMW LC is more of a burnout mode than an LC. The point of a real LC is to make the most of the avail grip. That and consistency.

LC should be dynamic and should adjust power output and or brake application in real time. The BMW LC seems to merely rev and dump the clutch. If there is an active process it's poorly calibrated.

I believe the BMW LC may work well with DRs or ET streets, although the axles may not.

Street tires should not be warmed by doing a burnout.

[CanAutM3]

Originally Posted by turbo8765

BMW LC is more of a burnout mode than an LC. The point of a real LC is to make the most of the avail grip. That and consistency.

LC should be dynamic and should adjust power output and or brake application in real time. The BMW LC seems to merely rev and dump the clutch. If there is an active process it's poorly calibrated.

I believe the BMW LC may work well with DRs or ET streets, although the axles may not.

Street tires should not be warmed by doing a burnout.

I agree, the LC is far from being sofisticated.

For a true burnout, simply mash the throttle with DSC off.

I have had the best success with LC by doing a quick burnout to clean and warm the tires. Others had the same. Not sure why you say we shouldn't...

Anyway, I do not really care about launching from rest. I just doodled with LC out of curiosity. I am more into going around a track .

[nicknaz]

Originally Posted by turbo8765

LC should be dynamic and should adjust power output and or brake application in real time. The BMW LC seems to merely rev and dump the clutch. If there is an active process it's poorly calibrated.

Agreed.

On 987.2 Cayman S PDK, the car launches from redline and you can hear the exhaust backfiring as the timing is pulled. There is a chirp then a forward motion

The smoky burnout our cars can do is cool though

[YasM3]

LC=Clutch dump @ desired RPM. That is all. Its not complicated or sophisticated. It is just performing a clutch dump.

On the street with poor prep, improper tire temps, improper ground temps and poor surfaces you will just do a smokey rolling burnout.

At the drag strip with a properly prepped track, correct heating of the tires (varies depending on what tire) it will hook, stick and work as intended.

It acts the same as if you had a 6mt, revved to 3k and dumped the clutch. That is all it is doing. Period.

Its designed for the car to launch where it makes TQ. Leaving off idle and just stabbing the throttle is not a good way to launch as you are not in the powerband yet. 2500-3000RPMs is a much better starting point

[Defense]

I ran a best 60' time of 2.12 without launch control. I ran a 1.8 60' time by launching at 2600 rpm with launch control. To put it in perspective, I ran a 1.8 60' in a mustang with slicks by dumping the clutch at 5500 RPMs. In the end, it made the difference between an 11.7 and a 12.2 second quarter mile. The difficult part is warming/cleaning the tires off with a light spin or two before attempting to activate it. I don't believe the 6 mile pre activation talk. It will activate immediately after the engine is warm. Regardless, It does not activate reliably after you spin the tires a bit in first and stop. I've seen guys pull it of on YouTube, but I've had big problems with it. In short, my experience has been that you have to skip the tire cleaning burnout to activate it. Which, with the pss2s in summer is like racing on nut covered candy apples on the rears since they pick up every dot of dust, dirt, grass, or rocks in normal driving. Still super impressed with the 1.8 sec 60' time the car could accomplish with stock rubber. Almost unheard of without Drs or awd.

[YasM3]

Originally Posted by Defense

I ran a best 60' time of 2.12 without launch control. I ran a 1.8 60' time by launching at 2600 rpm with launch control. To put it in perspective, I ran a 1.8 60' in a mustang with slicks by dumping the clutch at 5500 RPMs. In the end, it made the difference between an 11.7 and a 12.2 second quarter mile. The difficult part is warming/cleaning the tires off with a light spin or two before attempting to activate it. I don't believe the 6 mile pre activation talk. It will activate immediately after the engine is warm. Regardless, It does not activate reliably after you spin the tires a bit in first and stop. I've seen guys pull it of on YouTube, but I've had big problems with it. In short, my experience has been that you have to skip the tire cleaning burnout to activate it. Which, with the pss2s in summer is like racing on nut covered candy apples on the rears since they pick up every dot of dust, dirt, grass, or rocks in normal driving. Still super impressed with the 1.8 sec 60' time the car could accomplish with stock rubber. Almost unheard of without Drs or awd.

Yea, it should have been made easier to be able to do a burnout and then use launch control right after. Not being able to heat/clean the tires before launching is a big negative for sure. Especially if you are going to be using a drag radial. It kind of sucks if you are at the track, you do a burnout, your LC may or may not work and make you look like an idiot

What year mustang? Also a 1.8 on slicks? Sounds like you need a bit more seat time ;-)

[stroids88]

Search on YouTube for M3 F80 Launch Control. Pretty good 2 minute videos.
Shows DSC off, Trans (DCT) in 3, and foot on brake, other on gas, can regulate down rpm's with cruise control speed lever and launch at lower rpm than 3000 which works better for me with less burnout but spooled up turbos.
Did a couple practice runs the other nite in prep for RaceLegal tomorrow nite.
Hope that helps.