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Thread: How 2 Drag - Please explain

  1. #1

    Default How 2 Drag - Please explain

    Hey guys, unsure what topic this would really fall under so since im after help with How to drive my car i guess it goes in the "How 2's" section.

    Mods please move it if its not appropriate.

    I have never ever Drag raced a car and need to learn. I want to take my MPS6 to the track for a test n tune before i install my mods and see what i can get it to run. Only i've been told i need to learn how to launch my car. I was given a run down on what i should be doing (apparently) since i don't no im unsure if this info is correct.


    Well here is what i did, and here is what happened:



    Car at a stand still. Rev to 4kRPM and dumpage of clutch.

    Car launches forward with a great roar sending me down the road at a rather fun speed.

    I push clutch in to shift to 2nd at 5.5kRPM and pull foot off clutch and i get no engagement.

    NOTHING.

    I put foot back on clutch and changed into 3rd thinking maybe the revs got to high with my brain failing to complete the number of tasks in order. I thought i prob left my foot on the excellerator. I assumed i did and the car hit the rev limiter which caused it to feel like it was doing nothing.

    I pressed the clutch again and removed foot off accelerator, let the revs drop back down to 2kRPM and it then went into into 3rd gear like normal.

    I tried this again. Launch great, gear shift FAIL. Every time i change into 2nd i get nothing. On the second attempt i removed my foot off the clutch after changing into second to see its just reving out but not propelling me forward anymore. When i put my foot back on the clutch to try and save my poor car i am pretty sure the clutch was half in already with out my foot on it. STICKING MUCH?.

    I am sure a heap of you are shaking your head at how much torture i prob just put my poor baby thru. And im sure i agree. But i would like some advice please.

    Is this a clutch problem or have i been told to do something completly wrong, or am i a completly useless driver, or simply all of the above.

    Figured i would ask you guys cause if anyone can tell me right and help me out it would be fellow MPS owners. Also not sure if turning traction controll off would have saved me from this and the god awful smell that my car emits.

    (P.S i did hear that the MPS6 has clutch issues but im pretty sure its on the 05 model, i have an 07)

    Feed back appreciated!
    Latool- far from normal

  2. #2
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    I know the MPS3 has safety features in place that don't allow you to over-rev it in 1st & 2nd gear, it opens the dupm-gate or something to drop the boost.
    Apparently if you over-ride this, it can start snapping drive-shafts etc...
    So I'm not sure if this is an issue with the MPS6, as it is an AWD and operates slightly differently. I think I recall Shakespeare saying that he didn't think the 6 had that issue.

    I've also been warned that your car's computer registers everything, and excesive driving like this can be retrieved by Mazda...anyone know if this is true?

  3. #3

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    Couple of questions: Did you flick your foot off the pedal or let it out real quick? How long between the two launches you tried? Did the clutch smell?

    I've had the same issue you describe. In my case it was caused by clutch slip overheating the clutch plate resulting in a complete loss of drive. It was in gear but felt like neutral. The solution was to let it cool down.

    The material on the clutch plate is very similar to brake pad material and it can fade in the same way when it gets hot. Perhaps that's what you experienced?

    ---------- Post added at 09:48 AM ---------- Previous post was at 09:46 AM ----------

    Quote Originally Posted by EVILMPS View Post

    I've also been warned that your car's computer registers everything, and excesive driving like this can be retrieved by Mazda...anyone know if this is true?
    Only if a fault is recorded, the operating parameters at the time of the fault are also recorded.

    Gone to Volvo


  4. #4
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    Quote Originally Posted by kmh001 View Post
    Couple of questions: Did you flick your foot off the pedal or let it out real quick? How long between the two launches you tried? Did the clutch smell?

    I've had the same issue you describe. In my case it was caused by clutch slip overheating the clutch plate resulting in a complete loss of drive. It was in gear but felt like neutral. The solution was to let it cool down.

    The material on the clutch plate is very similar to brake pad material and it can fade in the same way when it gets hot. Perhaps that's what you experienced?

    ---------- Post added at 09:48 AM ---------- Previous post was at 09:46 AM ----------



    Only if a fault is recorded, the operating parameters at the time of the fault are also recorded.
    For my sanity, these can be cleared by a dash hawk etc no?
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  5. #5

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    Quote Originally Posted by Jmac View Post
    For my sanity, these can be cleared by a dash hawk etc no?
    Yes and no. There are two levels of fault recording. Most can be cleared by the dashhawk, but there are some fault codes that are beyond the reach of anything but the MMDS.

    Gone to Volvo


  6. #6

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    Quote Originally Posted by kmh001 View Post
    Couple of questions: Did you flick your foot off the pedal or let it out real quick? How long between the two launches you tried? Did the clutch smell?
    1. i let it out really quick, did not flick my foot off.

    2. there was about 3 min between each launch with some driving.

    3. There was a horrid smell. However im not completly convinced it was clutch smell as i have smelt that before when doing hill starts, ect. This smell had a more. . um. . . metalic/electronic smell to it.

    I agree it felt like after the initial launch it had 0 operation. Felt like a safety had kicked in or something, but in the same attempt it only took until i let the revs drop before the clutch engaged again. both times, it only took probably about 5 seconds for the car to be drivable after the launch/fail. And i did not have to stop and start again.

    Its a little puzzling. Im also unsure if starting at 4kRPM is to high or low for the MPS6.
    Latool- far from normal

  7. #7

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    I'm 99% sure your problem was clutch slip. If the smell was acrid it was almost certainly the clutch.

    AWD cars are notoriously hard to launch because there is so much grip. When all that power is unleashed something has to give. 2wd cars slip their tyres which makes it easy, while our weak spot is the clutch and/or the drive train itself. The key to a good launch in the MPS6 is to get the tyres slipping instead of the clutch.

    If there's any clutch slippage at the start, even a few tenths of a second, it may not be able to get a grip and the hotter it gets the more it will slip. Unless you back off quickly to let it hook up you're fighting a loosing battle. It's rare to get consistently good results using that method. To overcome that, when you launch, you really need to snatch the clutch.

    You're in the right ball park with the rpm. I think 4500 to 4800 is the sweet spot for a launch in these cars. What you're trying to do for an effective and safe launch is to get the tyres slipping.

    I'm cringing as I write this, but to avoid clutch slip, you need to slip your foot sideways off the pedal. But that's too extremely dangerous. Slipping your foot off the clutch is a high risk activity, so something between slipping and snatching is required. That's where you have to perfect your technique.

    Remember something has to give, if the clutch doesn't slip and the tyres don't slip, something in the drive train could break.

    Unfortunately there is no easy answer. If you want to launch, you need to choose between a clutch bbq or the risk of something going bang, and base your technique on that.

    BTW make sure the evil axle-snapping DSC is turned off.
    Last edited by kmh001; 15-06-2009 at 11:34 AM.

    Gone to Volvo


  8. #8
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    your car smelled like burnt clutch when we went nebo running the other week.

    2nd gear should engage straight away

  9. #9

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    evil axle-snapping DSC is turned off.

    Your a sport.

    While i was doing these expiriments it was on. While the initial Launch was very successful im going to need to be able to shift out of first to continue my stint down the strip. So it would seem that my only option is to get some tire spin.

    Given that i got none by lifting my foot straight off and that the clutch went smush due to the grip. I can forsee it will be much harder to launch correctly on the drag strip with the sticky road.

    At the end of the day i really want to go and see what my MPS6 can do but if i can't launch it correctly there is little point. Since the car is still under warranty i can't do alot.

    This is very depressing. Unless i start off line like an agressive street light driver im going to hurt my baby and not get to see what it can actually do. NO WIN...

    I thought mps6 could get the power to ground... but thats the problem right. I think i need that MPS3 Switch installed. OMG yes i just said it. oh no cry cry cry.
    Latool- far from normal

  10. #10

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    It is slightly depressing. Since my wife snapped a rear axle in this car I've decided to avoid hard core launches. My nana launches are always biased toward clutch slip because it's a whole lot safer but I've never been able to perfect a technique that is consistent. I think it's another of those MPS6 quirks. But the car is still quick enough that you can gather up a poor launch and romp past most challengers.

  11. #11
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    1st -> 2nd is a different story me thinks.
    I have never had issues with this, mainly with 2nd -> 3rd, aftermarket engine mount helped with that ALOT.

  12. #12

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    k, i dont want to break the axle. I tried the flick foot to the side thing with the clutch but with only 3kRPM and that was a fail, car wanted to launch but not enough power, nearly stalled but recovered and shifted into 2nd with no problems.

    No clutch smell either.

    Does this mean i may be getting closer. lol

    J MAC, under normal driving/hooning off of lights and such i have never had this 1st-2nd issue its just that under the "LAUNCH" properties the car/clutch is not handling it, basically feels like your in Neutral even thou you clearly have it in 2nd gear you get 0 performance out of it.

    However in my normal driving/hooning/ giving it a boot full i have had issues with the 2nd-3rd transition. just seems to get stuck and wont go into 3rd till i decelerate a little. at first i thought i was short on my clutch due to the speed i was trying to do everything... but after being very careful i can reproduce the fault.
    Last edited by Latool; 15-06-2009 at 12:50 PM.
    Latool- far from normal

  13. #13
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    :mod: Just remember always, that if you have OMPSC stickers on your car (or, known that you are part of Oz MPS), we do not condone this kind of behaviour on public roads.

    All for spirited driving, but once again, we don't want to be known in the community as idiots on the road, or have the police watching our every move.

    -OzMPS Club Forum Staff.

  14. #14

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    Quote Originally Posted by Latool View Post
    k, i dont want to break the axle. I tried the flick foot to the side thing with the clutch but with only 3kRPM and that was a fail, car wanted to launch but not enough power, nearly stalled but recovered and shifted into 2nd with no problems.

    No clutch smell either.

    Does this mean i may be getting closer. lol
    Yes, you're on right track. Do that with about 4800 rpm if you're game and you'll learn about good launches and sore necks at the same time.

    Gone to Volvo


  15. #15

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    hmmmmm DAN did i fail to mention this is on DRAG STRIP. lol (most of the time) point taken.



    Friend claims that his wrx could only pull about 5-7 hard launches like this without blowin bits. . but apparently that is their known week point.

    Mazda have this? if so my numbers are limited

  16. #16
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    Quote Originally Posted by Latool View Post

    J MAC, under normal driving/hooning off of lights and such i have never had this 1st-2nd issue its just that under the "LAUNCH" properties the car/clutch is not handling it, basically feels like your in Neutral even thou you clearly have it in 2nd gear you get 0 performance out of it.

    However in my normal driving/hooning/ giving it a boot full i have had issues with the 2nd-3rd transition. just seems to get stuck and wont go into 3rd till i decelerate a little. at first i thought i was short on my clutch due to the speed i was trying to do everything... but after being very careful i can reproduce the fault.
    Of course, all on private roads or at the strip!

    When you have the problem, your foot is off the clutch and the car is not accelerating quickly anymore? - are the revs high? - Id say KMH is correct, most likely clutch slip.

    As for 2nd to 3rd, if you are keen look into a replacement rear motor mount.
    MY16 WRX STi Crystal White Pearl
    -= Rally Armour Flaps - 2XS Muffler Delete =-

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  17. #17
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    Cheers for clarification Latool

  18. #18

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    A clutch bbq is the same as brake fade. There will be gasses and liquids boiling out of the clutch plate which lubricate the friction surfaces. You can select any gear and the engine will just rev up like it's in neutral. In fact selecting a higher gear will exacerbate the problem because it turns faster causing more friction which keeps the heat up.

    I've been thinking about your MPS3 switch idea. It may be possible to step off the clutch, get the front wheels turning then switch on the rear diff to make the launch happen. It would be kinder to the mechanicals by reducing the initial shock, but difficult to achieve and I suspect you'd still loose at least 0.5 second compared to a proper awd launch.

    Gone to Volvo


  19. #19
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    The MPS3 switch idea sounds good to me, though you'd have to be quick with your switching to get this right and where I've placed my switch it's probably a bit far for a quick flick!

    The 4500-4800rpm launch seems to have worked the best when I've tried it and it's a combo of step off/slip off clutch technique - definitely need flat light soled shoes when you try this (EvilMPS I'm referring to the other night - Launch FAIL!) Though I too am afraid of things breaking (diff bolts etc!!) but by heaven, when you do get it right, it usually takes for ever to get the grin off your face (until you get the chiropractors bill for neck alignment)

    Enjoy your experimentation Latool
    R36 - Just like an MPS6 except with a growly V6

  20. #20
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    Quote Originally Posted by Latool View Post
    hmmmmm DAN did i fail to mention this is on DRAG STRIP. lol (most of the time) point taken.
    Easy fix remove your sticker or stickers like I did
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