what is double clutching how does it benifit you in a drag and how do you do it

thanks for you help

bruce

 

Double clutching is used to bring the input and output shafts to similar speeds to ease the shift. The idea is on upshifting, to push the clutch in, put in it neutral with the gas off, release the clutch, press the clutch again, then put it in the next gear.

To double clutch a downshift: Put the trans in neutral, release the clutch, rev the motor to the anticipated RPM of the downshift and press the clutch in and then downshift the trans and release the clutch.

This is used by big rigs hauling heavy loads. The amount of force to mesh the gears and the rpm difference is too much for the trans to allow smoothly if this isn't done. In cars and especially performance cars there is no need as we don't weigh in like the rigs and we have synchros that are more than up to the task

 

this sounds like someone believed the fast and the furious..

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1989 Firebird
2.8 v6, t5 swapped in

Ram Hi-po clutch, Cold Air, 1.6 rockers,Lakewood LCA's, Lakewood Lift bars, Wonder Bar, 3" y-pipe, Random Tech Cat, 3" I-pipe, Flowmasters, MSd 6a, MSD Coil, Accel 8.8 wires, Auto Meter Gauges (Water, Clock, Fuel Pressure, and 5" Sport Comp Tach)TB Bypass, 4th Gen Seats

Coming for my v6:
Panhard Bar, 4thgen front seats, Nitrous, Line Lock, Posi, Spohn Torque Arm & Subframe connnectors

"I'd rather run last in a full out race, than to NOT have run at all"

 

It is also used in Formula Fords when your tranny is FUBAR I spend 30 min double clutching, man did it suck! Well I did finish, so it was worth it.

 

You mean someone actually went out and watched it????

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam and intake, World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. 0.030 over 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlock header mufflers, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, LT MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Best 15.1/95.5 @ 5800' Bandimere.

 

Graeme'sFirebird, for your information i did not see that movie, i heard the tearm on a siegnfield rerun when kramar was in the rig with that chick, and thank you all for the information

Bruce

 

It's when you take more than one hit before passing to the next guy.

Sorry, I couldn't resist.



[This message has been edited by whiteroc (edited June 27, 2001).]

 

nah its always been puff-puff-pass

 

Actually, you have to do it in semi's because the tranny's have a different gear style. They use a straight cut gear without syncronizers. Thats also why you can shift them very easily without the clutch. Start out on a hill with a good load and shifting an 18 speed trans = pushing the pedal 36 times just to get up to 60 mph. Of course with 18 speeds you can skip several if you have enough truck.

 

Were are you from???

 

As mentioned above, you only need to "double clutch" with a non-syncro tranny. If you had to "double clutch" in your car, then you need new syncros.

 

I don't know what everbody's deal is on here with the fast and the furious. I saw, I been waiting since last fall to see it, I loved it. I want to see it again. Anybody who doesn't like that movie just sucks.

There is some silly stuff in it, but who cares it's a friggin movie.

------------------
1989 Pontiac Firebird Formula LO3 Auto
-180 degree stat
-Hooker Cat-Back
-velcro t-top bag
-Wonder Bar from my IROC
IAT MOD, 3.3ohm resistor

*****Possible future mods*****
4th gen seats, fiberglass spoiler, new paint

1985 IROC-Z, TPI Auto
-Accel Super Coil
engine and tranny overhauls coming this summer


http://www.geocities.com/krt80/

 

I thought it was having one beer in each hand.

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1989 IROC-Z 5.7L
NOS 150HP kit
ProBuilt 700R4, PI Vigilante 2800 stall lockup
Baer Brakes 12" Sport System

 

Do what I do and just bang 'em like a man.

 

ok you dont have to double clutch a rig. i know i drive one. its how they teach you to drive a rig. supposed to be easier. but as said before i do what is called speed shifting, no clutch exept to take off. and double clutching on hills means disaster. youll never get it back in gear on steep inclines going up or down. you never shift gears on steep inclines. but anyway some of my friends refer to double clutching as, say your racing on street tires and dont want to smoke the tires. you bog it out of the whole then push the clutch back in stomp the gas and let your foot slide of the clutch. also works in second nicely.

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92 z28 170,000 miles 14.20 on goodyear eagles before exhaust only mods k&n and slp 13/4 headers and dual 2 1/2 exhaust
87 trans am 12.20 on motor too many mods to list

 

600 hp Cummins ISX and a RTX20718, There isn't a grade I can't shift on, up, down, with or without the clutch.

Shift a car trans without the clutch and all you are going to do is wear out the syncros prematurely. If it doesn't go smoothly then your looking at excelerated U-joint and rearend gear wear.