[Dylan86]

Originally Posted by F22santiago

Literally showed this to all my coworkers and BMW Geniuses in ALL markets (US,EURO, ASIA) and no one has any idea about this feature

[cxp213]

Thanks for sharing that, Dylan! It doesn't look like a very good launch control, though. Are you sure it's not just limiting your revs and then the clutch delay valve just makes it feel like the clutch is being eased in?

[F22santiago]

Originally Posted by cxp213

Thanks for sharing that, Dylan! It doesn't look like a very good launch control, though. Are you sure it's not just limiting your revs and then the clutch delay valve just makes it feel like the clutch is being eased in?

Im going with this! No word of this ANYWHERE else. Mine lets it go to redline, but I did see older cars hold the revs at 3-4K if you floor it in neutral or with the clutch held in

[XutvJet]

My 2016 M235 6MT has this supposed launch control function. However, I'm far more effective at the launching the car myself without the system. Relying in the system creates an excessive amount of bog, especially if you release the clutch too fast as shown in the video. The launch in that video likely would amount to a dismal 2.2-2.3 60 foot at the drag strip.

Clutch slip is key with launching these cars. Dropping the clutch will result in ether a bog or excessive spin. You must keep the rpms above 3000 when you launch or else you'll risk a bog. When you hear and feel the rear tires tramp and skip a bit, you'll know you got a solid launch.

[Dylan86]

Originally Posted by XutvJet

My 2016 M235 6MT has this supposed launch control function. However, I'm far more effective at the launching the car myself without the system. Relying in the system creates an excessive amount of bog, especially if you release the clutch too fast as shown in the video. The launch in that video likely would amount to a dismal 2.2-2.3 60 foot at the drag strip.

Clutch slip is key with launching these cars. Dropping the clutch will result in ether a bog or excessive spin. You must keep the rpms above 3000 when you launch or else you'll risk a bog. When you hear and feel the rear tires tramp and skip a bit, you'll know you got a solid launch.

The key is to not allow the wheels to spin, when releasing the clutch. In DSC off, especially FBO/meth you won't be able to modulate shit, trust me. The video was not to demonstrate a "good" launch, it was intended to show the LC feature. If you wan't to start nit picking about how "effective" it was, then you're missing the entire point of the video. You can slip it a lot more than I did, here, however I was showing how it simply works with a full clutch drop and the clutch delay valve, it basically gives you the most grip, off the line.

Don't forget I also did this on a busy road, with one hand.. Was simply showing the launch feature. If you wanna swing dick, we can start comparing "best launches" in another thread. I'd be happy to participate with a proper cam setup

[XutvJet]

My intention wasn't to badmouth you. I was calling out the fact you said you were "dropping the clutch" which is never a good idea with a manual with street tires, DRs, or slicks. At best, it creates a bog (like as shown in the idea) or excessive spin. At worst, a sheared axle, input shaft, or ring gear.

You can certainly modulate wheel spin with clutch slippage and throttle control. These cars are and can be quite powerful, but there a more powerful RWD cars out there as well. From years of racing at the strip on street tires and DRs, I learned that launching at a higher rpm and with more slippage resulted in much quicker ETs than launching lower and releasing the clutch really fast. I also learned that rarely can you go full throttle until the upper part of 1st and that allowing the car to roll slightly before letting her rip helped plant the tires and reduce driveline shock.

DSC Off is most certainly the way to go if you have footwork skill and want the best launch possible. There are too nannies in the other modes, even Sport+.

[Dylan86]

Originally Posted by XutvJet

My intention wasn't to badmouth you. I was calling out the fact you said you were "dropping the clutch" which is never a good idea with a manual with street tires, DRs, or slicks. At best, it creates a bog (like as shown in the idea) or excessive spin. At worst, a sheared axle, input shaft, or ring gear.

You can certainly modulate wheel spin with clutch slippage and throttle control. These cars are and can be quite powerful, but there a more powerful RWD cars out there as well. From years of racing at the strip on street tires and DRs, I learned that launching at a higher rpm and with more slippage resulted in much quicker ETs than launching lower and releasing the clutch really fast. I also learned that rarely can you go full throttle until the upper part of 1st and that allowing the car to roll slightly before letting her rip helped plant the tires and reduce driveline shock.

DSC Off is most certainly the way to go if you have footwork skill and want the best launch possible. There are too nannies in the other modes, even Sport+.

All good man, I wasn't taking any of it out of context, just didn't want this to be about the launch itself, because it was fugly as hell, lol.

I agree that DSC off is the best feel, I just haven't experimented much with launching in the grand scheme of things. I find the Sport+ launch fun because I can consistently launch it pretty well (in my opinion lol, not like in the video!). I've done clutch drops with DSC off and the car just smokes up the rear tires, slipped the clutch once too much and spun the clutch, which I really don't want to do again, because that can equate to clutch death. But I could probably spend more time finessing the launch with DSC off, if my goal was a primo 1/4 time.

I can only imagine once I do all of my suspension work this winter, that the launching characteristic will totally change. Coilovers, full bushings, sway bars, etc.. So I may have to re-evaluate my launching style once I do all of that. It'll probably just inherit more wheelspin

[F22santiago]

Originally Posted by XutvJet

My intention wasn't to badmouth you. I was calling out the fact you said you were "dropping the clutch" which is never a good idea with a manual with street tires, DRs, or slicks. At best, it creates a bog (like as shown in the idea) or excessive spin. At worst, a sheared axle, input shaft, or ring gear.

You can certainly modulate wheel spin with clutch slippage and throttle control. These cars are and can be quite powerful, but there a more powerful RWD cars out there as well. From years of racing at the strip on street tires and DRs, I learned that launching at a higher rpm and with more slippage resulted in much quicker ETs than launching lower and releasing the clutch really fast. I also learned that rarely can you go full throttle until the upper part of 1st and that allowing the car to roll slightly before letting her rip helped plant the tires and reduce driveline shock.

DSC Off is most certainly the way to go if you have footwork skill and want the best launch possible. There are too nannies in the other modes, even Sport+.

I should be going this Wednesday again and updating the thread with new timeslips. Temperatures and humidity are going to be much cooler so hoping for 12's. Also, I did not slip the clutch that much and launched pretty low last time, going to try a 3-3.5K slippage now and hoping that helps. I am with you 100% on the not flooring it til the car rolls a little bit and hooks first. On this car especially with JB4 it is hard to find traction even in 2nd

[XutvJet]

Originally Posted by Dylan86

All good man, I wasn't taking any of it out of context, just didn't want this to be about the launch itself, because it was fugly as hell, lol.

I agree that DSC off is the best feel, I just haven't experimented much with launching in the grand scheme of things. I find the Sport+ launch fun because I can consistently launch it pretty well (in my opinion lol, not like in the video!). I've done clutch drops with DSC off and the car just smokes up the rear tires, slipped the clutch once too much and spun the clutch, which I really don't want to do again, because that can equate to clutch death. But I could probably spend more time finessing the launch with DSC off, if my goal was a primo 1/4 time.

I can only imagine once I do all of my suspension work this winter, that the launching characteristic will totally change. Coilovers, full bushings, sway bars, etc.. So I may have to re-evaluate my launching style once I do all of that. It'll probably just inherit more wheelspin

No worries. Agreed with Sport+. It's quite effective on the street for a consistently quick get away and without drawing a ton of attention in terms of tire squeal.

I too am not that caught anymore in the best launch, but I occasionally do it. Unfortunately, to really launch a manual, you have to abuse the clutch. I too got it wrong a few times and smoked it a bit.

What I find most interesting about this 6mt and clutch is that it's a bit difficult to drive smoothly without some thought, but damn does it come into its own when driven in anger.

[XutvJet]

Originally Posted by F22santiago

I should be going this Wednesday again and updating the thread with new timeslips. Temperatures and humidity are going to be much cooler so hoping for 12's. Also, I did not slip the clutch that much and launched pretty low last time, going to try a 3-3.5K slippage now and hoping that helps. I am with you 100% on the not flooring it til the car rolls a little bit and hooks first. On this car especially with JB4 it is hard to find traction even in 2nd

Look forward to seeing the results. Hopefully the track will be decently sticky.

[Dylan86]

Originally Posted by XutvJet

What I find most interesting about this 6mt and clutch is that it's a bit difficult to drive smoothly without some thought, but damn does it come into its own when driven in anger.

So true. I experienced nothing but good feedback and control during threashold braking at the single HPDE event I participated in, this year. The clutch and the gearbox was with me the whole length of the way, never against me. This car definitely shines on the track, not the drag strip, but I think it can hold its ground in both situations, to be honest..

One thing I never considered trying, was the "boost by gear" feature in the JB4. If I lower 1st gear boost to 8-9psi it may be the trick to lunching in "DSC off" with the power levels I have, now. Anxious to try it out, but it's a bit wet here today

[F22santiago]

[IMG][/IMG] So as promised I went again tonight and ran a PR of 12.9 @111.78. The other runs I spun alot (cold weather tires didnt stick as much) and ran 13.1-13.2. I bogged a bit on the 12.9 so I think if i get my 60' down even another .1 to about 2.0 or so I should be even faster. Almost crazy to think I was pulling 1.8-1.9 60' on terrible 17" runflats on my 228i. All the torque of the 40i is much harder to keep controlled in 1st gear

[B58togo]

Awesome trap speed!

[Dylan86]

Great trap speed, indeed!

Your comment regarding the 228i having a better 60' with lower TQ makes me think that the JB4's boost by gear function could really help us 6MT guys out. Been raining non stop, here, or I'd have time to fiddle with it. Soon though!

[F22santiago]

Originally Posted by Dylan86

Great trap speed, indeed!

Your comment regarding the 228i having a better 60' with lower TQ makes me think that the JB4's boost by gear function could really help us 6MT guys out. Been raining non stop, here, or I'd have time to fiddle with it. Soon though!

I agree however, I do not understand what to set it at. I understand how to set it for -3.5 psi or -4 etc per gear. But does anyone have a chart of what stock psi is in each gear? For example, if a car had 6 psi available in 1st I would not want to do -4 psi I would probably reduce 1-2 psi. If a car had 20 psi then -4 wouldnt be bad and so forth.

[Dylan86]

Originally Posted by F22santiago

I agree however, I do not understand what to set it at. I understand how to set it for -3.5 psi or -4 etc per gear. But does anyone have a chart of what stock psi is in each gear? For example, if a car had 6 psi available in 1st I would not want to do -4 psi I would probably reduce 1-2 psi. If a car had 20 psi then -4 wouldnt be bad and so forth.

I don't think the factory tuning limits boost by gear. The most I see on Map0 is 10-12psi spike with a 8-9psi taper and hold. So I was thinking of 8psi for first, 12psi for second and 17psi for third, onward. Should work, theoretically..

[F22santiago]

This is a link of the pass vs a camaro on semi slicks which seems to be suffering from a bad driver mod :

[F22santiago]

Originally Posted by Dylan86

I don't think the factory tuning limits boost by gear. The most I see on Map0 is 10-12psi spike with a 8-9psi taper and hold. So I was thinking of 8psi for first, 12psi for second and 17psi for third, onward. Should work, theoretically..

I dont have the confidence to be messing with it to be honest and then not being able to put it back to default. One thing that does suck however is that we cant lower tire pressure too much. If you do so, the tire pressure light will come on and not allow you to turn off DSC or even do Sport+ :

[Dylan86]

Originally Posted by F22santiago

One thing that does suck however is that we cant lower tire pressure too much. If you do so, the tire pressure light will come on and not allow you to turn off DSC or even do Sport+ :

Thankful us Canadians get FTM, rather than TPMS