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  1. #1
    Radar Fanatic
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    Default Double clutch and rev-matching heel-toeing.

    Does anyone anywhere do this? Maybe racing old cars? I am trying to learn because I have some issue that after $3,000 I still have not solved that makes it hard to shift gears. If I double-clutch its much much simpler/smoother. However, I also like to rev-match when I am in a hurry and downshifting. So now I find myself trying to double clutch and then rev-match when disengaging the clutch once in gear, all while breaking heavily. I can try to force it into gear but it seems hard on whatever it is thats not funcionting properly and takes nearly as long any how as trying to force it in. I have just noticed that its a lot of work and also makes it more challenging to trailbrake while doing it all.

  2. #2
    Good Citizen
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    Default Re: Double clutch and rev-matching heel-toeing.

    Downshifting without rev-matching will create more wear and tear on your syncros than not doing so. I rev match before throwing into gear on virtually all downshifts. I don't double clutch and I have not been able to physically heal-toe and don't really see the need to unless I auto-cross or race my car.

    You could have a problem with your syncros. Are you talking about bike riding? If so, then I have no idea.

  3. #3
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    Default Re: Double clutch and rev-matching heel-toeing.

    Quote Originally Posted by Progress View Post
    Downshifting without rev-matching will create more wear and tear on your syncros than not doing so. I rev match before throwing into gear on virtually all downshifts. I don't double clutch and I have not been able to physically heal-toe and don't really see the need to unless I auto-cross or race my car.

    You could have a problem with your syncros. Are you talking about bike riding? If so, then I have no idea.

    Sorry for any confusion. Talking about the car... but honestly, how could I heel-toe a bike? Also, just to let you know, the way I heel-toe is actually through the use of the side of my foot... you have to have wide feet/shoes and close pedals for this to work. I hate driving a stick shift with the pedals spaced to far to heel-toe with the side of foot method.

    Rev-matching, not double clutching shouldn't "avoid" wear on the syncros at all (as I understand it) because you are already in gear when you rev the engine and let the clutch out. Actually, double clutching would save the syncros (which in my case may or may not be bad already) because it matches the gear speeds manually rather than through the use of the syncros. The reason you rev-match when disengaging the clutch is to make it smoother, whether you are racing or not, but when racing its to keep you from engine braking which may or may not cause you to lose traction, but will at least slow you down abruptly, which you don't need.

  4. #4
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    Default Re: Double clutch and rev-matching heel-toeing.

    I almost always double clutch/rev match my downshifts, less wear and tear on the synchros.

  5. #5
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    Default Re: Double clutch and rev-matching heel-toeing.

    ^ Do you double clutch and rev-match (two separate things in sequence)?

    Double clutch is when you push the clutch pedal, take out of gear, lift clutch pedal, blip, push clutch and insert into gear once the revs-match, and then let out clutch. Now, I also "rev-match" after that by blipping once more after putting in gear before letting out the clutch the second time. Most people that "rev-match" are racing or spirited driving and they don't do the double-clutch part where they match revs with clutch out before putting in gear, just when they let out the clutch. Most people that double-clutch are truck drivers and they don't bother with the second rev-match when letting out the clutch with it finally in the new gear.

  6. #6
    Experienced
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    Default Re: Double clutch and rev-matching heel-toeing.

    Typically I just double clutch. Rev mathicng itself doesn't do anything for snychro life since the clutch is pushed in, the engine isn't changing the input shaft speed. I was incorrectly using the term "rev match" in the sense that while double clutching I'm matching the revs.

  7. #7

    Default Re: Double clutch and rev-matching heel-toeing.

    Quote Originally Posted by 9500ier View Post
    ^ Do you double clutch and rev-match (two separate things in sequence)?

    Double clutch is when you push the clutch pedal, take out of gear, lift clutch pedal, blip, push clutch and insert into gear once the revs-match, and then let out clutch. Now, I also "rev-match" after that by blipping once more after putting in gear before letting out the clutch the second time. Most people that "rev-match" are racing or spirited driving and they don't do the double-clutch part where they match revs with clutch out before putting in gear, just when they let out the clutch. Most people that double-clutch are truck drivers and they don't bother with the second rev-match when letting out the clutch with it finally in the new gear.

    I always double clutch/heel toe/rev match on down shifts. If I'm not in a hurry I'll typically double clutch on my 1st/2nd and 2nd/3rd up shift. It is a skill, and it takes a long time to truly master, however once you do it is like art. When you double clutch you are in effect doing the syncro's job greatly reducing wear. As some one who has been around/rebuilt my fair share of old racing and street tranny's I can tell you it makes a HUGE difference. Once you open the case and look at the clusters/syncro's you can pretty clearly tell which is which by the wear.

    In regards to your above post, you only need to blip once while you are in neutral with the clutch out. I'm not sure why you are blipping twice. Your first one should be large enough to match correctly. I hate to ask this, since it is imperative you are smooth, but perhaps you are shifting a little slow? The process should be brisk, not necessarily fast. Most people don't even notice the fact I am double clutching, unless I point it out. Oddly enough a double clutch h/t downshift requires a shorter blip than a single h/t downshift. Your blip should be exact, I give myself a 100rpm leeway for when I come off the clutch, which for all intents and purposes is a perfect match.
    Last edited by Donut Patrol; 10-17-2009 at 04:03 PM.
    ".....in honour of the last American hero to whom speed means freedom of the soul. The question is not when's he gonna stop, but who is gonna stop him...."

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  8. #8
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    Default Re: Double clutch and rev-matching heel-toeing.

    Two things. Firstly, my timing is still not great so yes, I am slow... you could say. Secondly, when you say blip, you mean hit the gas one time for a second right? If so, how can it match when you shift and when you let the clutch out?? The revs will be falling, so at least one will not "match" perfectly. I guess its not a huge deal if you are fast enough, but just saying. I am noticing now though (for my slow self), I can just maintain the proper RPMs, and operate the clutch and shifter, which matches perfectly... however, it sounds funny. I will try to do it faster though...

  9. #9
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    Default Re: Double clutch and rev-matching heel-toeing.

    I do it a lot like this guy but he is shifting and letting out the clutch a lot quicker than me... one motion almost. I need to try that I guess. I think I need to just go for it... rather than trying to baby it into gear...

    [ame=http://www.youtube.com/watch?v=NWuM3NHrqbA&feature=related]YouTube - heel and toe double declutch downshifting[/ame]

  10. #10
    Yoda of Radar
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    Default Re: Double clutch and rev-matching heel-toeing.

    I smell another Fast And Furious quote thread coming on.

    "Buy the BEST and screw the rest." - fire65

    "im intrested to see how well you do.i never seen a car JTG before would be a first for me.." - radarrob

 

 

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