I know what double clutch downshifts are (been doing it so long it seems to be the only way I can downshift now). I know that's all about matching revs to be easy on the driveline and to not upset the car as you let the clutch out under heavy braking.

Skip Barber's Driving Faster is at home, but I don't recall seeing the double clutch up shift technique in detail in there either. Any one have a step-by-step to go through this?

Thanks, Matt--

 

Not sure, but I've done it before where I do a normal double-clutch shift, but without the rev spike in between clutches. Unlike downshifting, where you want the revs to be higher, you want the revs to fall a little bit.
I can't tell if it helps or not, I haven't made a habit out of it.

Dan

 

Been watching the "Fast and the Furious" huh... j/k

double clutch upshifts are similar to dc downshifts except you dont blip the throttle. It helps out the synchros if you have them.

 

Do you know of ANY Honda that doesn't have synchros?

Edit: I'd like to try and drive it.


[Modified by LudemanDan, 3:14 PM 7/16/2002]

 

name that movie:

"granny shifting, not double clutching like you should"

 

elgorey, did you have something constructive to add to this??

How about I read a post in the Type R forum about a track day and someone said something about double clutch up-shifts.

What happed to car movies like Lemans and Grand Prix.

Anyways, thank for your comments. I was trying the double clutching in upshifts, but thought maybe I had missed something, more pratice I guess

Does it go something like this: rev the **** out of the motor (its a honda right)
push in clutch, shifter to neutral, push back out
wait for revs to fall the right amount
clutch back in, shifter into next higher gear, clutch
out

Thanks, Matt--

Edit for more friendly content
Thanks, Matt--


[Modified by CW_97_ITR, 3:45 PM 7/16/2002]

 

I was think more along the lines of a formula car with a crash box. But can't think of any Honda (automobile) that does not have them.


[Modified by StageOne, 10:43 AM 7/16/2002]

 

Here is Frank aka GhettoRacer's reply regarding this topic in another thread:

"modern day synchros are quite good, and high performance tranny often have double or even triple cones on the lower gears to take the abuse. there are no performance advantages of performing double clutching when you need to shift quickly, but it does save wear and tear for sure.
when done right you can literally feel the shifter gets "sucked" into the proper gear weather it's on up or down shifts. it's very subtle but you can feel it in the shifter.

i recommend it because it's a good skill to have, and when you drive normally it's boring anyways, you might as well practice it. comes in really handy at the track. after a little practice it is totally second nature. when i need to perform a hot lap i can power shift with the best of them, but if it's just 9/10th lapping why not save the car?"

 

Agreed!

By the way, what is a "crash box"?

 

At first I thought this was a joke but then I realized you were serious . . .


The whole "double-clutch upshift" thing comes from The Fast & The Furious. It is a USELESS technique that was made up by the makers of the movie so that they would sound "tiiiite". If your tranny has synchros there is no need to do it AT ALL. It was probably mentionned in the ITR forum because it is a running joke around here. Double-clutch upshifts go along with "mAaAaAaAd sKiLlZ y0!"

 

My understanding of a "crash box" is a transmission with no synchros, rather, dog clutches engage the gearsets. As a result, the transition can be a bit rough.

Am I correct?

 

I heard the term in racing and refers to cars without synchros in any gear.

"If you have no synchromesh (Crash Box City): You are loafing along in Third gear and want to change to Second gear. When you put in the clutch and change the gear selector from Third to Neutral, the layshaft is going a particular speed that matched Third gear at the present road speed. If you do not change your road speed (your brakes are broke, say), the layshaft is going too slowly to match Second gear. (Sound familiar so far?) As you approach the Second gear selection, the gears go GRAUNCH."

 

THanks for clearing that up for me

 

As Drew said, double clutch shifting is for tractors and antique cars. Absolutely no need on any modern passenger vehicle.

 

double clutch up shifts like F&F..pointless
double clutch downshifts (3rd to 2nd) on a tranny thats already fucked slides in like astro glide y0!

 

If the flywheel is light enough, you actually could need to rev the engine on the upshift, even if it has synchros. I do that when I drive my old Corvette (yes, I know, classic cars are different), but not because of the lack of synchros. I do it because unless you are really trying to rip a shift into the car (which I don't recommend), the RPMs drop pretty far, pretty fast. Sometimes I'll do a complete double clutch and actually come off the clutch during the rev, but it's for fun, not necessity.

If you want to hear what really good double clutching sounds like, watch the chase scene in Bullit. Steve McQueen double clutches the crap out of that Mustang! It sounds amazing!!!


Matt

 

In a non-synchromesh gearbox with straight-cut gears, the shifts are ALL a huge crunch. You don't even need the clutch at all in a good straight-cut tranny but there's nothing subtle or smooth about it.

Absolutely positively never a need to double-declutch upshift under any circumstances ever...how's that? With a good straight-cut tranny, a proficient driver doesnt need the clutch to upshift ever and we used to have heated debates about double-declutching way back in my Jim Russell days and eventually you realize it's a huge waste of time and effort on a race track...in fact I ended up going from 4-1 with one humongous blip in the last 50 feet of the braking zones.

On the street, I fruequently double-declutch downshift but honestly, it's absolutely unnecessary to double-declutch upshift unless the car isn't going into gear for some mechanical problem.

 

Will
-who thinks syncros are 'wear' items and will be replaced when it is time.

 

Actually, McQueen double clutches (on upshifts) his Mustang in Bullitt.

I double clutch my Saab (on upshifts) when the transmission fluid hasn't warmed up.

*leaves to go watch Bullitt, again*

 

whoah, you guys are taking this thread way toooo seriously. anyone wanna tell me how they explain this dumbass technique called double-clutch upshift in that movie? i never saw it, but i keep getting questions on it, id like to know what a motec exhaust is too.

 

They don't explain it. One riceboy street racer says to slower riceboy street racer something along the lines of "you sissy, you need to double clutch upshft, y0!".

 

Not really, my race car has no flywheel at all, just a ring gear, I don't blip on upshifts, and it drops revs VERY fast, I just smash the box up a gear (its a Jerico).

 

Yeah, double-clutch upshifts are used by truck drivers and drivers of old buses. I remember when I was a kid watching the school bus driver double clutching all the upshifts--no synchros in that thing. She did it like it was the most natural thing in the world. It has nothing to do with F&F.

I don't bother double-clutching upshifts, but I do on downshifts, purely for my own enjoyment and fun--which is what it should be all about!

 

slightly off topic, but a lot of people mentioned it:

double clutch downshift = hell-toe braking?

 

not quite. when you are heel-toe downshifting, your foot never lets of the clutch, you just blip the throttle as you downshift.