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    #16
    Originally posted by elbert View Post

    You can absolutely double clutch a transmission with synchros. It is not necessary to do so, but it does save a slight bit wear on the synchros if done correctly.
    While double clutching on a downshift, you would rev-match.
    Agreed, purpose of double clutching is to more closely match the input shaft's (and thus next gear's) rotational speed to the output shaft's.

    No need to do with a synchronized transmission because the synchros take over that job, but you can still do it if you want.
    2002 Topasblau M3 - Coupe - 6MT - Karbonius CSL Airbox - MSS54HP Conversion - Kassel MAP - SSV1 - HJS - PCS Tune - Beisan - MK60 Swap - ZCP Rack - Nogaros - AutoSolutions - 996 Brembos - Slon - CMP - VinceBar - Koni - Eibach - BlueBus - Journal

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      #17
      What a joke. You're gonna waste time putting the clutch in twice? I've heard it all now. You don't double clutch in modern cars. You blip the throttle to get teh engine speed to match the road speed for the gear you want to go down into. No need for upshifting.
      DD: /// 2011.5 Jerez/bamboo E90 M3 · DCT · Slicktop · Instagram
      /// 2004 Silvergrey M3 · Coupe · 6spd · Slicktop · zero options
      More info: https://nam3forum.com/forums/forum/m...os-supersprint

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        #18
        Originally posted by Tbonem3 View Post
        You blip the throttle to get teh engine speed to match the road speed for the gear you want to go down into. No need for upshifting.
        Blip the rpm to match only works with clutch engaged, which means the clutch pedal must be released, which means you have to push down clutch pedal again to shift to the next gear, which means two times pushing down on clutch.
        Blip the engine with clutch disengaged does nothing to the tranny shifting experience.
        Last edited by sapote; 02-02-2023, 11:11 AM.

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          #19
          Originally posted by mrgizmo04 View Post
          What problem are you having/trying to solve? Are you replacing slave cylinders too frequently? You want a 5 speed? You want taller gears? Why care?

          Sent from my SM-G950U using Tapatalk
          No problem at all, but I feel the 1st gear is quite a high ratio and for this fairly high torque engine (compared to my 1966 Porsche daily driver).

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            #20
            Originally posted by sapote View Post

            Blip the rpm to match only works with clutch engaged, which means the clutch pedal must be released, which means you have to push down clutch pedal again to shift to the next gear, which means two times pushing down on clutch.
            Blip the engine with clutch disengaged does nothing to the tranny shifting experience.
            You haven't heard of heel/toe? it's not about the tranny, it's about engine speed to match the road speed once you go into the lower gear. Is everyone high today?

            Also, you can't "blip" the trottle with clutch engaged. I think that would be obvious.
            DD: /// 2011.5 Jerez/bamboo E90 M3 · DCT · Slicktop · Instagram
            /// 2004 Silvergrey M3 · Coupe · 6spd · Slicktop · zero options
            More info: https://nam3forum.com/forums/forum/m...os-supersprint

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              #21
              Originally posted by Tbonem3 View Post

              You haven't heard of heel/toe? it's not about the tranny, it's about engine speed to match the road speed once you go into the lower gear. Is everyone high today?

              Also, you can't "blip" the trottle with clutch engaged. I think that would be obvious.
              I do toe heel everyday.
              "Also, you can't "blip" the trottle with clutch engaged. I think that would be obvious"
              To be effective, you have to blip the throttle with clutch engaged, in neutral, before shifting into the next lower gear.

              "You haven't heard of heel/toe? it's not about the tranny, it's about engine speed to match the road speed once you go into the lower gear."
              It is not about the engine rpm, but the tranny input shaft speed to match with the output gear of the next lower gear to be engaged. The whole process is to match the synchro slider to the dogteeth of the gear to be engaged, to cut down the delay time that the synchro would take without blipping. I think what you said is for speed shift -- rev the engine to match what will end up its rpm after the gear engaged at clutch released, but this doesn't help to shift the gear.
              Last edited by sapote; 02-02-2023, 01:47 PM.

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                #22
                Tranny thread...

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                  #23
                  Originally posted by elbert View Post

                  You can absolutely double clutch a transmission with synchros. It is not necessary to do so, but it does save a slight bit wear on the synchros if done correctly.
                  While double clutching on a downshift, you would rev-match.
                  I have a habit of double clutch downshift rev-matching 3rd -> 2nd and the resultant feel in the shifter is a whole lot better than if I did not. Rest of the gears, the ratio is much closer so I only rev-match, but this is the largest ratio change I downshift to. I never downshift 2nd -> 1st

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                    #24
                    Originally posted by Tbonem3 View Post
                    Also, you can't "blip" the trottle with clutch engaged. I think that would be obvious.
                    Makes a huge difference in the resistance you feel against when gear lever when theres a large gear ratio differential e.g. 3->2 or 2->1. Above that the difference in ratio is smaller so the synchros do the work no problem.
                    You can physically feel the difference if you rev match into first without lifting the clutch pedal in neutral, there is a lot of resistance getting into gear. If you double clutch and rev match while the clutch is engaged and the trans is in neutral, then clutch in and press into first, if done correctly it will slip into first perfectly because everything is synced and the synchros don't have to work as hard.

                    Is it necessary? No, is it smoother and easier on the gearbox? Yes.

                    "Getting into our getrag's 1st gear is a little easier at a very very slow roll (1 mph) vs dead stop in a lot of cases. If rolling like 2-3 mph,a little gas helps. Don't do it at any speed beyond that imo."
                    You can get the trans into first at speed if you double clutch correctly. The reason you can't change above that is because the gear differential is too large for the synchro to mesh at higher rpms.
                    Last edited by Thoglan; 02-02-2023, 04:12 PM.

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                      #25
                      As about doing double-clutch, most of the time I achieve the same with only doing single-clutch: I shift to neutral by rev match without touching the clutch pedal, then blip the rpm to match the next lower gear, then press the clutch pedal and shift to the lower gear.

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                        #26


                        Originally posted by Tbonem3 View Post

                        Also, you can't "blip" the trottle with clutch engaged. I think that would be obvious.
                        I triple clutch in neutral all the time 😏.

                        Sent from my SM-G950U using Tapatalk

                        Youtube DIYs and more

                        All jobs done as diy - clutch, rod bearings, rear subframe rebush, vanos, headers, cooling, suspension, etc.

                        PM for help in NorCal. Have a lot of specialty tools - vanos, pilot bearing puller, bushing press kit, valve adjustment, fcab, wheel bearing, engine support bar, etc.

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                          #27


                          Originally posted by Tbonem3 View Post

                          Is everyone high today?
                          👀

                          Sent from my SM-G950U using Tapatalk

                          Youtube DIYs and more

                          All jobs done as diy - clutch, rod bearings, rear subframe rebush, vanos, headers, cooling, suspension, etc.

                          PM for help in NorCal. Have a lot of specialty tools - vanos, pilot bearing puller, bushing press kit, valve adjustment, fcab, wheel bearing, engine support bar, etc.

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                            #28
                            Originally posted by mrgizmo04 View Post



                            I triple clutch in neutral all the time 😏.

                            Sent from my SM-G950U using Tapatalk
                            Remove the clutch pedal to save weight

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                              #29
                              Originally posted by Tbonem3 View Post
                              Getting into our getrag's 1st gear is a little easier at a very very slow roll (1 mph) vs dead stop in a lot of cases. If rolling like 2-3 mph,a little gas helps. Don't do it at any speed beyond that imo.
                              thats because youre granny shifting not double clutching like you should. If you double clutch, you can slip right into first even from about 30mph. Significantly easier on the trans for downshifts- i almost always do it if time permits but will heel-toe in a pinch. Not necessary and practically pointless for upshifting though imo
                              Last edited by lemoose; 02-03-2023, 01:59 AM.
                              2002 TiAg M3 Coupe (SMG to 6spd), 2003 Jet Black M5

                              https://www.instagram.com/individual_throttle_buddies/

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                                #30
                                I hear laughter:

                                (SMG corner).

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