ronn1

iTrader: (1)

Ok..as far a double cluching goes but>>>>
If you're comming into a corner very fast and need to downshift...you better at least heeln' toe there or you'll grenade the clutch..I know...been there done that.

thekinn

iTrader: (18)

There are a few things there that don't make sense. ^

Not sure OP.. I'll have to pay attention next time.. seems like clutch in, blip, shift, clutch out... for just normal driving.

ronn1

iTrader: (1)

I'm saying I agree you don't need to actually double clutch when braking into a corner at high speed..just heel and toe as described in #2 by OP. There's a difference, since DC requires shifting into Neutral.

TPete19

iTrader: (15)

Double clutch is the right way to do this.

ronn1

iTrader: (1)

Depends how you look at it...
When I raced my 944 Turbo, I *single clutched* trouble free.

http://www.se-r.net/general/heel_toe.html

Heel/Toe braking is taught both with double clutching and single clutching. Double clutching comes from days gone by when gearboxes were more fragile and synchros didn't last. Using double clutching, as you brake, you press the clutch, take the car out of gear and let out the clutch. You then blip the throttle to bring the input shaft of the gearbox up to the proper speed to mesh with the output shaft (for whatever gear you are selecting). Press the clutch when the revs are matched, select the new gear, let out the clutch. Repeat as necessary.

The modern method is single clutching. This was used by the pros before rev matching was built into racing engine management software. It is also what is taught at racing schools. Using single clutching, as you brake, you press the clutch, blip the throttle to match revs for the next gear, select the gear, and let out the clutch. Repeat as necessary. Single clutching relies on the synchros to mesh the gears

Dr. Venture

iTrader: (19)

lol....everything should happen exactly the same time when "rev" matching. Key is to become that good at it so that it flows with out noticing that you are doing it. Not one after the other in an orderly fashion. The function of rev matching is really to drop and go for speed. Specially going into and out of corners. Basic theory everyone assumes is to drop gears before entering a corner which would slow you down to much for over steer. BUT the best way is to drop the gear while in the turn to accelerate is at its maximum when exiting.

ronn1

iTrader: (1)

You don't wanna use the gearbox as a brake! If you're going too fast for the next lower gear (in the downshift) you're going to grenade the clutch (instead of the tranny!) if you don't have the revs to match the speed of the car at the time of braking.

Noor93y

iTrader: (1)

i do method one strictly out of habit never even considered doing any other way

thekinn

iTrader: (18)

double-post. oops

thekinn

iTrader: (18)

I hope your description is just off.. because you shouldn't be braking or shifting 'in' a high-speed corner.. it should be done before you start turning.. sans trail-braking.

However, you shouldn't be doing anything high-speed on the street and I believe that is all the OP is talking about.

pbn85

iTrader: (2)

Yea I was basically talking about rev matching for the street, no advanced track techniques. I've been having an insanely hard time simultaneously blipping the throttle and down shifting but have an easier time downshifting first and then blipping throttle with the clutch in. Is there any real difference between the two? I feel the first one, that I can't do, is them legit method.

Dr. Venture

iTrader: (19)

did not think it was necessary to explain that one. I figured you were all racer's.

ronn1

iTrader: (1)

Unless I'm missing something in what you saying....

You must blip throttle prior to downshift...
That defeats the purpose of heel and toe...you don't want the downshift ( into lower gear) to absorb the higher speed without having first matched engine revs (Blip throttle) to speed of the car. Otherwise the drivetrain has to absorb the huge difference and the weakest link (Clutch) takes a beating.

pbn85

iTrader: (2)

So you say that the proper technique is: blip throttle, clutch in, down shift, release clutch? Or clutch in, blip throttle, down shift and then release clutch? I just feel everyone has a different way of rev matching (ex: you say NOT to simultaneously blip throttle and down shift while clutch is in). From the replies here it seems like there 3 ways to rev match.

-Trav-

iTrader: (37)

Obviously you need the clutch in first...

Reading some of these responses I can see why youre confused.

Blip the throttle the very instant after you press the clutch pedal, THEN you downshift, quickly. Focus on not letting the revs drop much at all between the time you press the clutch and blip. If the revs fall to fast you either need to shift faster or blip to a higher rpm.

TheVengefulCo

depends what sort of revmatch you want... for just driving normal, clutch in, and blip the gas to the right rpm and let clutch out. if youre tracking or doing the twisties, heel toe and double clutching is the best. in the old days, doubleclutching was used becaused the transmissions had weak or no synchros but on a synchronized transmission like ours, it is used for entering into a corner! And no, double clutching is not some gay move Vin Diesel made up and no it is not used for upshifting like in the movie... thats false. To double clutch, put the clutch in, blip gas, throw in neutral while letting go of the clutch, then do then clutch in again, blip throttle to desired room and move the shifter from neutral to the desired lower gear. this seems like its pointless but when done right its very fast and smooth. i can do it pretty fast now and its pretty easy to figure out. lastly there is the heel toe shift. to do this, clutch in, angle the right foot so the toe is on the break and heel on the gas. apply brake with the toe and blip the throttle with the heel to desired rpm and then let up on the brake. also, if you want to slow down more, add another step in. this can be done by doing the standard heel toe, but while pushing the brake and blipping the throttle repeatedly, you let the clutch up to grab gear and perform a slight engine brake to improve smoothness and also to slow down faster. keep in mind that double clutching and heel toe shifting are for when entering a corner!!!!! i dont want anyone doing this in traffic lmao. These arent that hard to do and after knowing about them for about 2 months ive pretty much mastered them, so really its not hard at all. i basically learned from this vid and ones like it. There is some great footage of the Drift King and other racers doing the heel toe.

<iframe width="420" height="315" src="http://www.youtube.com/embed/VE5M_CHfWR8" frameborder="0" allowfullscreen></iframe>

pbn85

iTrader: (2)

You know, even after all the replies here I found this to be one that clicked. I was never fast to hit the gas as soon as the clutch would go in. I was Always thinking "ok clutch in now blip the gas". In short, I ended up too slow to hit the gas. After reading your reply it clicked and I tried it. It seems that I've got it now. My only issue is nailing the rev match accurately. I seem to be around 100-200 rpm high or low, but I guess its better than being 500 rpm higher with a no rev match down shift.

Thanks all

moflow

I started double clutching my rev matched downshifts about 5 years ago. Now it's pretty much super smooth every time. Unfortunately i recently had my transmission replaced (warranty thank god) so i'm thinking maybe i should knock it off as the evidence would point to it doing more harm than good. Then again this is a 350z we're talking about so the bad transmission could've just been totally unconnected to my driving style.

I used it when approaching corners, or when downshifting before a hill to maintain a lower speed. When done correctly you literally can't feel the gearchange. I double clutch my heel and toes too, but i think that's probably overkill and possibly counterproductive with the time it takes (though i am quite fast.)

Moral of the story is that it probably doesn't really matter that much, though it can be a fun challenge if you're bored.

pbn85

iTrader: (2)

can anyone comment on that?

so you never used rev matching for slow speed city driving? I find that I "have" to rev match on every single down shift now. For instance, if I'm going 20-25mph in 3rd gear and approaching a stop sign, I USED to just slow down enough (around 3-5mph) and knock it in 2nd (without rev matching) to get going again. It felt fine. Now I'm trying to rev match that same exact situation - rev match before going into 2nd gear before approaching the stop sign. Is it really necessary?

RurouniMidnight

iTrader: (3)

Threads like this make me giggle, there is no option 1 or 2 everything about rev matching happens simultaneously there's only one way.