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      11-15-2011, 04:25 PM   #1
D_o_S
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Double clutching yes or no?

Hi,

I have a question regarding double clutching:

Now, as far as I understand it, you want to have the car balanced - "set" - at all times, especially through a turn. With double clutch, this does not seem possible:

When driving on the street, I will brake lightly (transferring weight to the front) with my right foot
Now I push the clutch in, and move the shifter from say 4th gear to neutral, move the clutch out
Now, in order to "blip" the throttle, I must take my foot off the brake (hence transferring weight back to the rear, relatively) and press the accelerator
Then, I can push the clutch in, slide in 3rd gear, and release the clutch
After this is over, I can continue braking - hence transferring the weight back to the front again

Even though this procedure doesn't take long, and the "balance disturbance" is ideally in a straight line, I am still concerned.

Any opinions?
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      11-15-2011, 04:39 PM   #2
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with modern day synchros, there's NO need to double clutch. just rev match.

in regards to turns, you can heel toe BEFORE you enter the turn. you shouldn't be fiddling with pedals during the turn. get in the right gear and as you open up the wheel get on the gas.
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      11-16-2011, 08:11 AM   #3
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Originally Posted by D_o_S View Post
Now, in order to "blip" the throttle, I must take my foot off the brake (hence transferring weight back to the rear, relatively) and press the accelerator
Since you're posting in a track forum, the answer is you need to start learning heel-toe today.

About double-clutching, if I downshift from high speed into 2nd without double-clutching, I feel pretty strong resistance in the gearbox. I've been told that forcing the shifter past that resistance wears the synchros more quickly. In any case, it feels much better if I do double-clutch, and since I'm braking simultaneously anyway, there is no downside.

As for other gears, I don't think I ever feel resistance downshifting into 4th or 3rd in this car, but I did sometimes double-clutch into 3rd in my last car, which was a Mazda RX-8. And I rarely downshift into 1st, but if I do, in a parking lot or something, I always double-clutch.
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      11-16-2011, 08:53 AM   #4
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Rev matching FTW. I don't and won't double clutch on a modern car.
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      11-16-2011, 01:50 PM   #5
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^^^
What he said!!!
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      11-19-2011, 12:44 PM   #6
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Ok, fine,

so I will only rev match. My question now is, is it OK to revmatch while you're braking? Unfortunately, I cannot heel-toe with the stock pedals (too much of a height difference in them, small feet with racing shoes).

The way I see it now:

1) Approaching a turn in say 3rd at 150 km/h
2) Start braking, till like 100 km/h, downshift to 2nd rev matching (means stopping braking for a bit)
3) Continue braking till 60 km/h, take the turn, accelerate...

Or, is it better to leave the revmatch downshift till later, like 70 km/h?
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      11-19-2011, 01:33 PM   #7
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It's difficult to properly rev match if you can't heel/toe as you don't want to be shifting as you're turning into the apex. I'd suggest braking and then just shifting without rev matching - as long as your speed is low enough to not upset the car when you engage the clutch. Otherwise you'll be shifting down at a very high engine RPM for the lower gear, which is not good for the car balance or engine.
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      11-19-2011, 01:37 PM   #8
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Either heel-toe or granny shift. Granny shift means hold the clutch pedal down until you're off the brake and on the gas.

But heel-toe is the right way, and I promise you can do it.
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      11-28-2011, 12:18 AM   #9
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Quote:
Originally Posted by GaryS View Post
Either heel-toe or granny shift. Granny shift means hold the clutch pedal down until you're off the brake and on the gas.

But heel-toe is the right way, and I promise you can do it.
Granny shifting is scary as fuck when you brake for an 80mph turn, lol. CHIRP --> off track.
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      12-01-2011, 04:46 AM   #10
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Quote:
Originally Posted by D_o_S View Post
Ok, fine,

so I will only rev match. My question now is, is it OK to revmatch while you're braking? Unfortunately, I cannot heel-toe with the stock pedals (too much of a height difference in them, small feet with racing shoes).

The way I see it now:

1) Approaching a turn in say 3rd at 150 km/h
2) Start braking, till like 100 km/h, downshift to 2nd rev matching (means stopping braking for a bit)
3) Continue braking till 60 km/h, take the turn, accelerate...

Or, is it better to leave the revmatch downshift till later, like 70 km/h?
Based off your information, it's pretty difficult to give advice on "is it better to leave the revmatch downshift till later, like 70 km/h?"

Ideally, you want to brake then rev match so you're in the gear you want to be in, at the point in the powerband you want to be in.

Ideally, you want to heel toe and trail brake.
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      01-27-2012, 09:46 PM   #11
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I had the same problem but figured I just use the side of my foot and not the heal. As long as you can blip the throttle before the turn holding the brake, down shift and lift off the clutch u good to go. You have to get a feel for it not to upset the balance of the car. It took me a while to get used to it, so practice practice practice. I practice every day I drive the car. Ya every day. After a while I don't even think about it just comes naturally. Check this video out from the MASTER. I have watched this video about ...... shit lost count.
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      01-29-2012, 02:43 PM   #12
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^ +1 on Labreda's comment. I double clutch/heel & toe picking up milk for wife, going to work, and of course at the track. I use ~every~ turn as an opportunity, and it makes mundane street driving tolerable. BTW, it can be difficult to go into 2nd and especially 1st if you don't double clutch.
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      01-30-2012, 12:31 PM   #13
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This is a pretty good article to get started on heel/toe.

http://www.motoringfile.com/2005/07/...g_made_simple/
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      01-30-2012, 10:02 PM   #14
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Granny shifting, not double-clutching like you should.




Sorry about that.
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      02-16-2012, 01:33 AM   #15
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Don't feel like going to sleep yet and happened across this thread, so just some points of clarification for those new to heel/toe:

Rev matching with double clutching
Disengage clutch
Shift into neutral
Re-engage clutch
Blip throttle
Disengage clutch
Shift into lower gear
Re-engage clutch

Rev matching without double clutching
Disengage clutch (and keep it like that)
Blip throttle
Shift into lower gear
Re-engage clutch

For those driving '80s manual transmissions, double clutching is a must. For modern transmissions, optional.

If you're just starting out, 4th gear into 3rd gear ~30-35 mph is good practice. When the shift just slips into gear, then you know you did a good blip. However, you can still mess it up with re-engaging the clutch poorly.

Practice making quick smooth shifts and it will make rev matching easier to learn; if you're riding the clutch, you're kind of defeating the point of heel/toe, which is to get on the power faster coming out of a turn without upsetting the drive train or causing unnecessary wear.
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      02-16-2012, 07:55 AM   #16
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^^I think you need to rebuild your gearbox. I have no need for double clutching my 86 Corolla Heel / toe I love to do no matter where I am going as the pedals are positioned perfectly and the engine is so fast on the revs! Perhaps I should give it a try in the bimmer even if it is a diesel...
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      02-16-2012, 11:53 PM   #17
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Quote:
Originally Posted by RWD Jan View Post
^^I think you need to rebuild your gearbox. I have no need for double clutching my 86 Corolla Heel / toe I love to do no matter where I am going as the pedals are positioned perfectly and the engine is so fast on the revs! Perhaps I should give it a try in the bimmer even if it is a diesel...
Yeah, most likely. I would if I still had either of them. Are you running a TRD close gear ratio or the stock gearing? My 335i is plenty fast, but still no where near as fun as an 86. The 4AG really is such a rev happy engine. I think I spent more time above 4k rpm than below it! Turbos have better torque than NA, but there is a night and day difference in terms of throttle response. For diesels I just do a "no lift" shift, i.e. just keep you foot slightly on the gas rather than taking it off completely.
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      02-17-2012, 05:43 AM   #18
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Quote:
Originally Posted by Figure807 View Post
Yeah, most likely. I would if I still had either of them. Are you running a TRD close gear ratio or the stock gearing? My 335i is plenty fast, but still no where near as fun as an 86. The 4AG really is such a rev happy engine. I think I spent more time above 4k rpm than below it! Turbos have better torque than NA, but there is a night and day difference in terms of throttle response. For diesels I just do a "no lift" shift, i.e. just keep you foot slightly on the gas rather than taking it off completely.
For now everything is stock but we are working on swapping in an AZ6 (Lexus IS200) gearbox This I hope will help a lot since the ratios aren't anywhere near great stock. This and my stock 20V blacktop will be a lot of fun I hope
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      04-04-2012, 05:08 PM   #19
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hahahaha this question brings me back to the days where i thought the fast and the furious was badass.

anyways after reading through through thread I just want to clarify things for myself and for terminology's sake.

When ever I rev match in my car if for say I am 6th gear on the free way going 80mph (around 3000rpm) and I want to start pushing it, I down shift into 3rd and rev it to around 5500rpm before i release the clutch. That to me has always been rev matching.

When I heel/toe im essentially rev matching while breaking (before the corner) so that im in that sweet spot to power out of the corner.

Correct me if i'm wrong on this. I know i've simplified things a bit but that's how i'd put it in layman's terms.

I think for proper heel toe you need to practice rev matching so you have a feel for how your gas pedal reacts to you. you're gain more control over your car and you'll begin to understand how much gas you need to give it when to start trying to heel/toe. Thats how I learned (freeways are the best place to learn to rev match in my opinion).
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      04-06-2012, 05:52 PM   #20
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When I heel/toe im essentially rev matching while breaking (before the corner) so that im in that sweet spot to power out of the corner.
Yes. You probably mean the same thing, but to make clear, it's

1. brake
2. clutch in
3. downshift
4. blip throttle
5. clutch out
7. off brake and turn in
8. throttle
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      04-06-2012, 05:56 PM   #21
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Quote:
Originally Posted by GaryS View Post
Yes. You probably mean the same thing, but to make clear, it's

1. brake
2. clutch in
3. downshift
4. blip throttle
5. clutch out
7. off brake and turn in
8. throttle
+1
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