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Old 04-04-2014, 11:51 AM   #21 (permalink)
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For me, the shift is smooth when the RPMs are the same as being in gear at that speed. For example when the revs are 2250 in 5th gear, and the RPMs are the same at 2250 as in my previous post, then the shift is quite smooth.

It seems to me that blipping the throttle to 4000 would NOT match the revs.

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Old 04-04-2014, 11:52 AM   #22 (permalink)
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Professional & race drivers don't generally hold the throttle to match rev. They "blip" it.

It takes practice to get it right.

You really need someone to show you. Learning to do this in a discussion thread is like learning to swim by smoke signals.
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Old 04-04-2014, 12:22 PM   #23 (permalink)
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Quote:
Originally Posted by johnlvs2run View Post
My interpretation of instuctions on another thread are as follows:

1) coasting in neutral / foot not on clutch/ engine running;

2a) push clutch all the way in;
b & c not needed, slows car down too much:
b) let the clutch out part way (to spin up the motor);
c) then press it back down;

3) touch the throttle to bring up the engine speed / to match the transmission speed?
(switched order of 3 & 4)

4) shift into the appropriate gear;

5) then release the clutch.

I presume that re-engage in #5 of instructions means release.

Is this all correct?
Fixed your order (in bold)

It is called heel toe downshifting in racing, because you are never coasting while racing. But I use it even if I am just driving on the streets for downshifting and in coasting situations. It really helps in finding 1st gear as you come up to a stop, and helps your synchros last longer!
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Old 04-05-2014, 04:49 AM   #24 (permalink)
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It is part art, part science. You use the science to develop the art. You do basically have to do it to learn it but knowing the theory helps.

Do hold the rpm at the matched speed. A shift is pretty fast, some fraction of a second, so you're not (usually) sitting with the rpm at a particular speed for even seconds - although you could do so if you wanted to.

If you simply "blip" the throttle and then time the shift lever movement to when you pass through the "right" rpm, you might match the rpm at the start of the shift or some point during it but you can never do so all the way through the shift. Because it is very difficult to get the rpm match exactly right anyway, it may make little practical difference. I think it is better to learn the right way - and to understand - from the start.

If you don't have the clutch engaged (in neutral) when the engine revs are matched, the input shaft and new gear speeds aren't being matched, just the engine and wheel speeds. The synchromesh is still working away to do that for you as you make the new gear selection.

A down shift will still be smoother because you aren't sucking energy from the car into the engine rotation. It's also easier on the clutch. It's OK as a valid driving technique but it's not full rev matching.

It is faster than double de-clutching because you don't have to pause and pump the clutch in the middle of the shift. Like I said, it is a valid technique.

If you are starting from a neutral coast situation with the engine running, whether after bump starting or not, there's no valid reason not to rev match before depressing the clutch. And reason to do so.

A comment on accelerator pedal movement: It is quicker to move the gas pedal past the position that would maintain the required rpm and then come back off it as the rpm rises to the desired level.

Last edited by Occasionally6; 04-05-2014 at 05:12 AM..
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Old 04-05-2014, 05:43 AM   #25 (permalink)
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Quote:
Originally Posted by johnlvs2run View Post
It seems to me that blipping the throttle to 4000 would NOT match the revs.
Obviously you don't let the engine hit 4000, but you give the gas a deep jab to quickly get the engine speed up. The point is, hard jab, then off the gas right away. If you do it fast, a passenger sitting next to you will wonder why your feet are making such dramatic stomps so quickly if they're not familiar with stick shift

Here, this might help:


Notice how when he blips, the throttle pedal is basically floored momentarily.

Another:


Notice how fast the blips are; It sounds like a DCT's auto blip, except it's done by a human.

Last edited by serialk11r; 04-05-2014 at 05:49 AM..
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Old 04-05-2014, 11:32 AM   #26 (permalink)
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Thanks much for the detailed comments and interesting videos.

I'm fine shifting from gear to gear. The issue arises after coasting down in neutral, then shifting back into 5th, for example coasting in neutral from 65 to 50, then going back into 5th, so my question is only about shifting from coasting in neutral, back into 5th.

Based on the comments and videos, I need to press & release (blip) the gas, then clutch, then gas. In other words the gas is pressed down, then quickly released as the clutch is pressed, which is then quickly released as the gas is pressed back to 5th gear position.

I want to review and practice these things, then will post back with results.
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Old 04-05-2014, 08:05 PM   #27 (permalink)
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Yea that sounds right. Basically if you're watching the tach, what you do is stomp the gas, press the clutch in and release gas together and the moment it's all the way down you put the shifter in gear, and hopefully the engine was at the right rpm, it'll go over a little, and then by the time you release the clutch it hopefully would've dropped back down to the correct rpm again.
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Old 04-05-2014, 10:32 PM   #28 (permalink)
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Quote:
Originally Posted by johnlvs2run View Post
I'm fine shifting from gear to gear. The issue arises after coasting down in neutral, then shifting back into 5th, for example coasting in neutral from 65 to 50, then going back into 5th, so my question is only about shifting from coasting in neutral, back into 5th.
It blurs into gear shifting because what you are doing is effectively half of a gear shift. The same techniques apply.

Quote:
Based on the comments and videos, I need to press & release (blip) the gas, then clutch, then gas. In other words the gas is pressed down, then quickly released as the clutch is pressed, which is then quickly released as the gas is pressed back to 5th gear position.
Don't lose sight of the end which is to match the engine, gear and shaft speeds.
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Old 04-06-2014, 11:36 PM   #29 (permalink)
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Rhetorical question: what is the engine rpm at 50mph in 5th gear?

That is only how far you need to blip the throttle
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Old 04-09-2014, 11:34 PM   #30 (permalink)
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Thanks to the recent comments, especially the video, the shifting is now smooth.

I took a trip the same day as the video and shifted the same way. This worked quite well from the start and was most effective when the RPMs were heading up or coming down from 300 to 500 above the objective. The faster the shift then the closer they could be.

The issue was that previous RPMs were just not high enough, as the gas pedal has the greatest resistance right in the middle, however I'm adjusting for that with more pressure, while making sure it isn't too high.

Thanks again for the helpfulness.

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