Close

Results 1 to 12 of 12
  1. #1
    Join Date
    Nov 2011
    Location
    Florida
    Posts
    905
    Rep Points
    795.7
    Mentioned
    113 Post(s)
    Rep Power
    0


    4 out of 4 members liked this post. Yes Reputation No

    BMW DCT 335is - How to Use Launch Control

    I would like to apologise to many whom I promised a video on an official break down of how I use launch control on the BMW DCT 335is.

    It been 1.5 years long over do, so here it is, a crash course, to the point. Hope to see some new 1/4 track times. There is only less than a hand full of us that know how to launch this car that we know off.

    This method is also used by some DCT M3 owners that have the same DCT thats on the 335is and it has been proven to not be harsh on the DCT. I have done over 400+ launches no slippage

    I also tested it out with PTF's E50 tuning which has some crazy torque and there was no no slippage. Hope the 335is owners find it useful


  2. #2
    Join Date
    Jan 2013
    Posts
    68
    Rep Points
    144.5
    Mentioned
    10 Post(s)
    Rep Power
    2


    1 out of 1 members liked this post. Yes Reputation No
    Great video! Thanks for sharing~!
    Instagram: mattyates85
    FB: Matt Yates

    2013 335iS DCT, Alpine/Saddle

    Only JB4/Flash, BMS DP's/DCI/Walbro inline


    Best e/t: 11.57 @120 mph

  3. #3
    Join Date
    Sep 2013
    Location
    SC
    Posts
    361
    Rep Points
    700.1
    Mentioned
    4 Post(s)
    Rep Power
    8


    Yes Reputation No
    Thanks BuraQ! I definitely need to get out and practice. I think part of my problem was that I was letting off the brake as I was applying throttle kind of like the normal left foot/right process you would be used to in letting off the clutch of a manual as you apply gas. I was also applying near full throttle instead of the 1/3 pedal or so. It seems like before you know it first gear is over with and we are into 2nd pretty quickly.

    Thanks again for the video!
    E92 335is DCT

  4. #4
    Join Date
    Apr 2012
    Posts
    36
    Rep Points
    49.2
    Mentioned
    0 Post(s)
    Rep Power
    0


    1 out of 1 members liked this post. Yes Reputation No
    Appreciate the time to explain this so well!

    Do you have to wait a certain amount of time before you can reactive launch control or can you do another one straight away again?

  5. #5
    Join Date
    Mar 2013
    Location
    Israel
    Posts
    57
    Rep Points
    61.7
    Mentioned
    1 Post(s)
    Rep Power
    0


    1 out of 1 members liked this post. Yes Reputation No
    Thank you BuraQ on this very informative post!!
    Funny how on the 135i launch control revs are set to 3500 rpm, and on the 335is it is set to 5000.
    Any chance of programming that to a 135i?
    Maybe the oil pressure is even set higher for the clutch loads?
    135i N55 DCT / JB4 / CP-E 5" DP / BMS CP / CTS Turbo 7" FMIC / KW V3 / M3 Bushings / M3 Front Control Arms / 3.25" SS exhaust / to be continued...

  6. #6
    Join Date
    Feb 2010
    Location
    Miami Beach
    Posts
    1,094
    Rep Points
    513.1
    Mentioned
    10 Post(s)
    Rep Power
    6


    1 out of 1 members liked this post. Yes Reputation No
    good job Click here to enlarge
    Click here to enlarge

  7. #7
    Join Date
    Nov 2011
    Location
    Florida
    Posts
    905
    Rep Points
    795.7
    Mentioned
    113 Post(s)
    Rep Power
    0



    Yes Reputation No
    Click here to enlarge Originally Posted by Ramjet Click here to enlarge
    Appreciate the time to explain this so well!

    Do you have to wait a certain amount of time before you can reactive launch control or can you do another one straight away again?
    You can launch as many times as you like back to back so long as it does not overheat

    I have launched my car 34 times within 5 hours on a single drag strip event, but I am flash only, I dont know how much tolerance it will have with piggybacks. I have heard from others such as @myates lowering boost on the 1st amd 2md gears with the JB4. You will definitely overheat and cause slippage if trying to brake boost multiple times. Stay clear of brake boosting to launch.

    Click here to enlarge Originally Posted by Tamut Click here to enlarge
    Thank you BuraQ on this very informative post!!
    Funny how on the 135i launch control revs are set to 3500 rpm, and on the 335is it is set to 5000.
    Any chance of programming that to a 135i?
    Maybe the oil pressure is even set higher for the clutch loads?
    I dunno. I think there are undefined table(s) that deals directly with this that can be manipulated but no one has been able to define them yet. Perhaps @Josh@Cobb can tell us what their road map is on this ?

    I would assume on the 335is the bar pressures on the clutches are set much higher than on other BMWs that share the same DCT, due to the fact it puts out more torque and then you have the overboost feature.

    Take into consideration though, the LC method in the OP allows you to "feather" the launch to gain more traction thus you have more control over your traction than let the DME control. Too much wheel spin the DME will interviene. I think there is an intervention table in ATR that I can be maniplulated to tolerate more wheel spin before DSC kicks in

  8. #8
    Join Date
    Sep 2013
    Location
    SC
    Posts
    361
    Rep Points
    700.1
    Mentioned
    4 Post(s)
    Rep Power
    8


    Yes Reputation No
    Click here to enlarge Originally Posted by BuraQ Click here to enlarge
    You can launch as many times as you like back to back so long as it does not overheat

    I have launched my car 34 times within 5 hours on a single drag strip event, but I am flash only, I dont know how much tolerance it will have with piggybacks. I have heard from others such as @myates lowering boost on the 1st amd 2md gears with the JB4. You will definitely overheat and cause slippage if trying to brake boost multiple times. Stay clear of brake boosting to launch.



    I dunno. I think there are undefined table(s) that deals directly with this that can be manipulated but no one has been able to define them yet. Perhaps @Josh@Cobb can tell us what their road map is on this ?

    I would assume on the 335is the bar pressures on the clutches are set much higher than on other BMWs that share the same DCT, due to the fact it puts out more torque and then you have the overboost feature.

    Take into consideration though, the LC method in the OP allows you to "feather" the launch to gain more traction thus you have more control over your traction than let the DME control. Too much wheel spin the DME will interviene. I think there is an intervention table in ATR that I can be maniplulated to tolerate more wheel spin before DSC kicks in
    Judging from the logs I have seen from track passes of @myates, I don't think he uses any 1st or 2nd gear boost reduction via the JB4. When I tried using 1st gear reduction the results were worse. I even tried using a reduction to 8 psi 1st gear and launching with the 5k LC and the car just sat there after I let off the brake, like the clutch slipped. Weird. I know you have talked a lot about the mechantronics and bar pressure applied to the clutches and possible issues with piggybacks. I think the backend flashes have helped remedy this some by allowing us to alter the load targets. Still I wonder if a flash only tune is better with the DCT.

    If Cobb were to figure out the launch control and make it user adjustable I'd order a V3 today Click here to enlarge I sent an email to Roman @ ESS awhile back about whether or not they had any plans to work on cracking the non-M DCT and it didn't seem to be something they were interested in or at least hadn't looked into. I had my E46 M3 SMG II for years waiting for an adjustable LC (they were set at 1800 rpm) and it never came, at least not while I owned the car. I am not too optimstic about adjustable LC for the non-M DCT.

    Do you know which table that is in ATR? I would definitely like to play with it in my backend flash tune. I am eager to get out and practice after watching your video but it has been raining so I haven't had the chance. My previous attempts with the 2nd step launch control usually resulted in a huge DSC intervention at the top of first gear to the point where the car bogged. This seemed to happen even when there seems to be little wheel spin or tail sliding out. I logged it and it would show a big throttle closure and boost drop. I really wish the LC could be done with DSC completely off as it would be much easier to modulate wheel spin without the fear of DSC kicking in.

    Thanks again for taking the time to do the video!
    E92 335is DCT

  9. #9
    Join Date
    Feb 2011
    Posts
    1,587
    Rep Points
    2,017.6
    Mentioned
    10 Post(s)
    Rep Power
    21


    Yes Reputation No
    @BuraQ, curious if this is a 335is thing; the brake part of the process (holding the brake pedal while engaging LC) - is that only for this car? Is it required?

    I know on my M3, I do not touch the brake pedal. If I do, the flag turns off (breaks the sequence) - however, I can "touch" the pedal lightly to keep it still, but almost never do. If I press the brake with anymore than say 5 lbs of force, it will not allow a launch. In other words, I just don't touch the pedal.

    Is this not the case with the 335is DSG logic?

  10. #10
    Join Date
    Nov 2011
    Location
    Florida
    Posts
    905
    Rep Points
    795.7
    Mentioned
    113 Post(s)
    Rep Power
    0



    1 out of 1 members liked this post. Yes Reputation No
    Click here to enlarge Originally Posted by musc Click here to enlarge

    Do you know which table that is in ATR?
    "Torque Max Intervention Mode" I got this from another member who tested it but I have not "fully" put it to the test yet. I believe "reducing" the values allows more wheel spin tolerance before the DSC kicks in



    Click here to enlarge Originally Posted by inlineS54B32 Click here to enlarge
    @BuraQ, curious if this is a 335is thing; the brake part of the process (holding the brake pedal while engaging LC) - is that only for this car? Is it required?

    I know on my M3, I do not touch the brake pedal. If I do, the flag turns off (breaks the sequence) - however, I can "touch" the pedal lightly to keep it still, but almost never do. If I press the brake with anymore than say 5 lbs of force, it will not allow a launch. In other words, I just don't touch the pedal.

    Is this not the case with the 335is DSG logic?
    Part of the 335is logic for using LC you must have your foot on the brake(not to be confused with brake boosting), and I believe the same with other N54 and N55 DCT cars


    As far as I am aware of some DCT M3's use this same LC logic from what it "appears" as an "optional" launch, see video below pay attention to the brake light before actual launch



    Unless I am mistaken thats an almost identicle launch that I do....

  11. #11
    Join Date
    Sep 2013
    Location
    SC
    Posts
    361
    Rep Points
    700.1
    Mentioned
    4 Post(s)
    Rep Power
    8


    Yes Reputation No
    With the M3 (E46, E9x) you don't use the brake for LC. Go into S6, sport mode. Hold the shift lever forward. Floor the pedal and to launch you release the gear selector and away you go.
    E92 335is DCT

  12. #12
    Join Date
    Feb 2011
    Posts
    1,587
    Rep Points
    2,017.6
    Mentioned
    10 Post(s)
    Rep Power
    21


    Yes Reputation No
    Click here to enlarge Originally Posted by BuraQ Click here to enlarge
    As far as I am aware of some DCT M3's use this same LC logic from what it "appears" as an "optional" launch, see video below pay attention to the brake light before actual launch
    Correct, you CAN apply the brake (basically, only hard enough to where the light would come on, any harder and the flag turns off) - but cannot really push the brake pedal any harder than what would be required to - say prevent someone from pushing your car while in neutral.

    It sounds like you can literally stand on the pedal in the 335is, which is not the case for the M3, but have no idea why there is a difference. Appreciate the reply.

    Cheers,
    Mike

    EDIT: a better analogy would be - allowing the user to press on the brake pedal just hard enough so that the car does not move when the accelerator is depressed. my M3 will roll slightly forward when the engine spins up to 6k or whatever the launch point is set at. It seems any harder than this, and it will cancel the launch.

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •