RX7_Racing2001

somone please explain the DC method.

jimmyv13

The clutch is depressed to pull the tranny out of one gear and depressed again to put it in another gear.

rico05

Stop watchin the Fast and the Furious, that stuff will rot yo brain boy!

CincySpeedFreak

what is the benefit of doing that? Wouldnt it be easier and faster to just push it once?

Scott 89t2

wow, you have all your engine internals! thats a cool mod...

ronarndt

RX7_Racing2001- Most of the people on the forum are not old enough to remember when you *had* to double clutch to shift . The transmissions used on most cars since the 1950's are synchromesh transmisions. There is an extra set of gears used to "synchronize" the speed of the lower gear with the upper gear being shifted into, and more important- if you are downshifting- to speed up the lower gear to the approximate speed of the upper gear. Otherwise, you would get the grinding of trying to force two pieces of steel going at different speeds to go together. You can get the gears to go the same speed by double clutching. When you up shift, if you depress the clutch, momentarily place the shifter in neutral and release the clutch, the mainshaft in the transmission will slow everything down so that you can depress the clutch and slip into the next higher gear at the low rpm end of its range. Even in non-synchromesh transmissions you can usually "ram" it into the next higher gear, but you can't go the other way to downshift. Here, you must take it out of the higher gear, put in neutral, let up on clutch pedal and quickly blip the gas to speed up the gears, depress the clutch then quickly shift into the lower gear at its upper rpm range. Often if trucks do this and miss on the first try, they can't repeat it quickly enough to get in *any* gear. Then they are in neutral and have only the brakes to slow the truck. If they have a heavy load and a steep hill- well you get the picture. Only advantage in modern transmissions is to probably reduce some wear on the synchros, but most people would consider it a PIA to do this all the time. A good race driver may want to do this if his synchros are starting to go during a race so he does not get a lot of metal fragments loose in the tranny. Some of the stronger race transmissions did not have synchros, not sure if this is still the case with trannys used today. Not sure what other advantage there would be, since it takes longer to double clutch each shift. Also- some regular passenger car transmissions did not have syncros on first gear, so if you wanted to go 2nd to 1st, you had to double clutch, or allow the car to come to a stop and then shift.

Scott 89t2

I do it all the time for down shifting. while apoaching corners etc. it's much smother and lets you get back onto the gas faster. it also prevents locking the back wheels up while downshifting into a high rpm range. I think it is faster to double clutch then just downshift normaly. becuase in DCing you don't need to slip the clutch at all. in a straight down shift it takes a while to release the clutch slowly to not make the whole car buck or lock the back wheels.

I just wish I could learn to heel toe. but the dam pedals are to far apart that is even more usefull then double clutching. although very simalar. as it's just a double clutching while breaking at the same time. (using all 3 pedals at the same time)

iluvrx7z

my sycros are dead going to second....must double clutch every time it works though. i just don't let the clutch out completely...i just give it a LITTLE blip inbetween first and second. after practice...works ever time!

Dan

Snrub

iTrader: (1)

How do you start on a hill?

dcamcoTII

I always heel toe, I actually found the pedal setup great for this.

Node

iTrader: (1)

Only real use double clutching is to us is downshifting I thought. No jump in power, smoother, etc.
I want to learn heel toe too, but my dads truck doesn't seem up to the fast cornering lol. But I try to double clutch on downshifts when I remember

Node

iTrader: (1)

http://www.triumphspitfire.com/Healtoe.html

chris_stampe

Hey,
what is heel toe shifting, and how do you do it. also what are the benifits of it?
thanks,
Chris

Scott 89t2

e-brake

or just release brake and roll back a bit before getting on the gas.

Pacey3182

I'm old enough to remember when you had to double clutch. With modern transmisions, probably just adds exta wear to the throughout bearing.

Pacey3182

Throw out bearing. ( I'm brain dead!)

Pacey3182

Heel toe "shifting" is really heel-toe braking. That is when you brake with the left side of the ball of your right foot and roll the right side of the ball of our foot onto the gas pedal to keep your RPMs up to downshift.

Pacey3182

You do this going into a turn.

ronarndt

Pacey3182- Here I thought *I* was about the only old fart on this forum. I keep hoping that driving a fast car will somehow turn back the clock. So far no luck- guess I need more mods to make the car go even faster. I learned to double clutch on a 1941 Chevy dump truck. *There* was a vehicle where it was a necessity. The brakes were so poor that if you had a full load on the truck, missing a downshift was a real hair raising experience.
Ron A.

Node

iTrader: (1)

like i posted
http://www.triumphspitfire.com/Healtoe.html

Pacey3182

Hey ronarndt,


Glad to meet a felow old fart. I learned to double clutch on an Austin Healy bug-eye Sprite. Should have taken my fathers advice regarding British Leyland cars. Buy two of 'em, 'cause one of 'em is going to be in the shop.

ronarndt

Pacey3182- I am amazed how many RX-7 owners used to own British sports cars- assuming they are old enough to have been driving whe the Triumphs, MGs, AHs, etc. were around. I know what you mean about one to drive and one for a parts car. The British never seemed to get the reliability factor built into their cars. My most foolish British car was a 1961 MG Midget Mark I that I bought as a basket case. I spent almost a year rebuilding almost everything on it and repairing the rust and when I was done, it was still a POS.

RX7_Racing2001

hahaha!

RX7_Racing2001

hahaha! hey node your damn pic is making me dizzy

Pacey3182

Hey ronarndt,

Know what you mean, I've owned several Triumph, MG, AH POSs. Used to refer to Lucas electroncs as "The Prince of Darkness!" Morgans are still built on a wooden chassis, now that's progress!!