folsomlarry

The first few years I was racing I just pushed in the clutch, touched the gas pedal and downshifted. A friend of mine who was a professional driver told me to start double clutching to save the gearbox.

When I bought my C-5 I just picked up on the old habit and usually double clutch my downshifts without even thinking about it.

I have read a lot of discussions on various racing formums about heal & toe, braking, etc. No one seems to ever bring up the subject of double clutching. Is this something that only us "old school" drivers do? Just curious.

Larry

FasterIsBetter

IIRC, double clutching is needed in older cars and in some specialty cars like the Formula Fords/Dodge type open wheel racers because they do not have synchromesh transmissions. The double clutch, i.e., letting the clutch out with the gears in neutral and blipping the throttle, causes them to spin up so the downshift will engage without grinding. With a modern full synchromesh transmission like the Vette, double clutching is not required to get the gears spinning so they synchronize. The synchro rings do that for you.

But you should heal-toe and blip the throttle to bring engine rpms up to match the anticipated rev of the engine in the downshifted gear. Otherwise, the engine acts like a brake on the rear wheels and can cause the car to lose traction and the rear end spin out on you.

MilehighZ51

That's how I was taught to heel & toe (double-clutching) twenty years ago. I pretty sure it's still taught that way in racing school.

Cobra4B

^ Nope I never learned how to double clutch. Sounds time consuming to me. Clutch in - car in neutral - clutch out - blip gas - clutch back in - complete shift.

It does save wear on the synchros though... after 60 I finally had to have my gear box re-built because the 3rd gear synchro wore out. However I was downshift way too early and at high rpms because it sounded cool I guess. Now I make sure to slow down more and complete my downsift at the end of the braking zone.

VFrc

When racing it is not necessary to double clutch the downshifts, especially if you are trying to do more then one downshift for a turn. That said, I always double clutch my downshifts on the street as it does save wear and tear on the synchronizers and I do it at the track when I'm only doing one downshift. Will double clutching downshifts extend the synchros forever? No but it does help some and its just as easy to do.

p.s. it’s not an old school thing, I'm 20.

Rogue Leader

Any race manual transmission will not have synchros as they can't handle the rigors of true racing. Most have straight cut gears and sequentials cant have them. I double clutch all the time on my vette and any other stick vehicle I may drive. But then again I race open wheel cars so its kind of ingrained in my head. It makes for a smoother downshift and puts you right in the powerband to roast someone

folsomlarry

My friend who got me doing it was a Formula Atlantic drivers, so as you said you had to double clutch the Hewland box. I just started doing it with my Spitfire and then a couple of other cars I raced and never had gearbox problems. The only time I did not do it was when I was braking later than usual and dropping down a from 4th to 2nd.

I just had not heard anyone talking about it so I was just wondering if drivers were still using this technique. Figured you guys would know.

Larry

danswofford

I quit double clutching with my 02Z. I learned to drive in an Austin Healy 100-4 that didn't have a syncro in first and 2nd and 3rd were worn out. The Vette tranny works well without double clutching. I wouldn't bother. You have to heel and toe just the same however.

MistressMotorsports

On my Vette, I had somewhere over 200 plus hours on the stock transmission without ever a double clutch or a problem. Nothing more than a few fluid changes. I used to practice not even using the clutch in case it went out during a race. If you rev match with the throttle, the synchros are not stressed and little wear occurs. On older cars or cars with race style transmissions, double clutching is beneficial, although I got pretty good at not double clutching a formula ford, again by rev matching well.

Mike