10-06-2017, 10:22 AM | #45 |
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10-06-2017, 11:29 AM | #46 |
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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?
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10-06-2017, 12:52 PM | #47 |
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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
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10-06-2017, 02:48 PM | #48 |
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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. |
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10-06-2017, 03:37 PM | #49 | |
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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 |
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10-06-2017, 04:09 PM | #50 |
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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+. |
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10-06-2017, 04:27 PM | #51 | |
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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 |
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10-06-2017, 04:28 PM | #52 | |
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10-06-2017, 11:44 PM | #53 | |
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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. |
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10-06-2017, 11:44 PM | #54 | |
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10-07-2017, 11:47 AM | #55 | |
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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 |
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10-19-2017, 12:25 AM | #56 |
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[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
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10-19-2017, 05:15 PM | #57 |
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Awesome trap speed!
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2017 M240i/ ZF8 Pure Drivetrain Solutions Stage 1 & torque converter/xHP/ DAW Ultra Flow/ DS2/ Nostrum injectors/ E40 Doug Newton tuned/ ER DP/ Remus axle back/ BMS intake/ FTP CP/ M Perf LSD
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10-19-2017, 05:51 PM | #58 |
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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!
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10-19-2017, 06:06 PM | #59 |
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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.
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10-19-2017, 07:05 PM | #60 | |
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10-20-2017, 10:53 AM | #62 | ||
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10-20-2017, 11:27 AM | #63 |
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Thankful us Canadians get FTM, rather than TPMS
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