ooticamitica

just powershift with the clutch if you really are that pressed for time otherwise an experienced driver can shift pretty darn fast

94Cobrakid16

true, but sometimes they need to double clutch to shift the rearend when they need the lower gear ratio (if its a 2 speed rear-end) and also if they need to lock the differentials. and im not sure why.

paco_pony

maybe I'm just ignernt...if so them please educate me.

but I understand doubleclutching to be a technique used on down shifts and not something that's similar to powershifting, grannyshifting and the like. so, in essence, it's not a shift technique that would be used at all on a 1/4 strip--just maybe on a road course.

here's my understanding of doubleclutch...moving from 4th to 3rd you'd do the following in very rapid succession. put in clutch and shift from 4th to to neutral (clutch #1). bump the rpms a bit with the gas. put in clutch and shift from neutral to 3rd (clutch # 2, thus the "doubleclutch" name) . the theory being that the double clutch process synchronizes the speed of the flywheel, transmission, driveshaft, etc so there is less wear on transmission/clutch n such. I've also heard that modern manual tranny' s are so efficient that the doubleclutch tecnique is obsolete these days.

and oh by the way, can someone tell what the fug a "grannyshift" is anyway? I've heard the term but have no idea what it actuallly means.

thanks

88stangaruu

its just straight up 1,2,3,4 shifting.

LOUDexhaust

I also think double-clutching is only for downshifting. When you down shift your rpms are going to rise so you get the tranny to rise in rpm also. It would make no sense in upshifting since your rpms are going to drop, so why rev the tranny up?

Bumsdeclaf

double clutching is an old technique that was done back in the very old days when transmissions had no syncros or very stupid ones. most of our cars have a T-5 or T-45 and on these, its pointless. technology has advanced so much that it makes it a waste of time. syncros these days are just that good. what paco_pony discribed sounded more like a cross between heel and toe downshifting and doubleclutching. Heel and toe downshifting is pretty much accelerating and pushing the brakes while the clutch is down at the same time to keep the engine in high RPM's so that the engine is not forced into high RPM's by compression braking. BTW, Trucks usually have 18 gears, most are in the lowend, and they must double clutch because they have sooo much torque that they would tare the syncro's apart

88stangaruu

I mean even in road racing, it still makes no sense to 'take it easy on the trannys' They replace so much, tires, valve springs, etc. after every race, they're probably gonna tear the tranny down anyhow and raplace the clutch. I agree with Bumsdeclaf, ive heard that from my dad also.

PX429

How is double clutching pointless?

Everyone seems to have there own way of doing it. this is mine (and everyone else who street races out here in the OC)

put it in first floor it, shift to second and floor it "right after you shift into second gear don't let go of the gas and pop in the clutch really fast" it puts your car into neutral for a second witch then shoots up your rpms and spins your tires faster. shift to third and do it again. by then the race should be over

OnyxCobra

idk bout you but as long as i dont hear any grinding I'm happy

and can i just say i hate these threads... You do not need to let the clutch out in neutral and rev the engine in order to match the lower gear, you can just push the clutch in and rev it, and let it out in the lower gear, synchros take care of the rest.

92hatchLX

If you had to double clutch they would've told you that when you drive it off the factory floor to keep the transmissions from wearing out and them having to fix a tranny, it's pointless on a T-5.