TailHappy

According to the skip barber book, one racer said you don't really have to double-clutch if you over-rev on your rev matching (and they were using syncro-less trannies). I guess there's always enough friction to get the gears moving. I had a bad tranny for a while, so it really let me know when I double-clutched and rev-matched correctly. Was great practice, but the credit card sure hurt a while after the new tranny was finally put in!

foko

yeah, truth is double clutching is just so you can rev match the input shaft to the secondary shaft. modern transmissions just don't need this help. since there's no need to completely disengage the clutch on a modern syncro tranny downshift, the primary shaft "spins up" with your blip and you've killed two birds with one clutch....so to speak. it's still necessary to rev match though, to prevent the sudden engine braking from upsetting the car under heavy braking.

barber school "officially" teaches double clutching, but the instructors tell you to forget about it the moment they've stopped talking about it.

happy blipping
fabian

TailHappy

You sure about this? I'm not extremely familiar with trannies so I don't mean to question you other than for the sake of my understanding. However, when my synchros were bad, it would NOT go into gear without a properly matched double-clutch, whether upshifting OR downshifting. And even on my new tranny, you can feel that it goes right into gear a lot easier with a double-clutch....in other words, you can feel that you're not using the synchro as heavily.

Case in point. The most obvious to me is trying to shift from 2nd to 1st while still moving, say 10 or 20 mph.. Do it with just rev-matching, and you can feel the synchro working to spin up the shafts. Then do it with a double-clutch and it'll pop right in.

So bottom line, I can see where double-clutching isn't necessary with synchros, however it sure seems like it's a lot easier on them, and anything that'll make my golden tranny last longer is OK by me!

volley1

If you are double clutching on the upshifts aren't you going to have a slower lap time than if you weren't?

cruiser

Double clutching on upshifts ? You don't need to IMHO... you already have higher rev-speed then it will be in higher gear.

TailHappy

Yeah, just to clarify, I'm talking about double-clutching upshifts on a tranny that was essentially destroyed. Bearings seized, bad synchros, etc. It got me by until I could get it replaced. But my point is that double-clutching made it work, but rev-matching didn't.

You're correct in that normally you'd never double-clutch an upshift, and I don't either now that I have a functioning tranny. However, it still seems easier on everything to double-clutch downshifts when possible.

cruiser

And back to the original topic - what technique of heel-toeing do you recommend for FD with stock steering wheel ? I'll be going to track again in 10days and I want to practice a bit. Sidestepping doesn't work for me, as I move my knee towards the steering wheel because the brake pedal goes too deep to successfully brake and blip throttle.

Maybe I just need some wider gas pedal...

foko

you'll never successfully heeltoe if the pedals are too far mismatched. if the brake pedal is "too deep" than you need to resolve that problem first. a wider gas pedal helps. i personally use the side of my foot for blipping, not the heel....but that's just my preference.

get your pedals adjusted, than use whatever technique works consistenly for u.

good luck
fabian

cruiser

Can the brake pedal height be adjusted ?

Chronos

No one knows anything on that sparco wheel hub thingamabob? Anyone in here bolt a low sitting racing seat?

Necros

Chronos, I didn't understand your question: Are you asking about if you get more room from a Sparco wheel? I do in my Celica, which has a Sparco 383 in it, because it's smaller. MUCH harder to see certain sections of the speedo, though.

Also, I guess I don't understand how rev-matching with the clutch pressed in makes any difference at all. With the engine disconnected from the input(?) shaft, you're not getting any spin-up. I fail to see how anything short of a double-clutching heel-toe provides any benefit.

Hey, look! First post!

DamonB

Keep in mind SYNCHRO transmissions don't need this help. A non-synchro race box (dog box, crash box, etc) will need to be double clutched on the downshifts or you're going to need a lot of gearboxes!

Cheers!

what is a dog box exactly? the teeth on the gears are not helical but rather straight right?

i thought dog boxes don't even need the clutch to be disengage... u just ram it in there.

80-CU.IN.T

I am 6' - 0" 185. Heal toe was a bitch. I had to lean to use my heal on the brake and use the ball of my foot to blip the gas when double clutching on down shift. I have since changed to a Sparco Completion steering wheel and a wide foot small gas pedal adaptor. I also bent my brake pedal a bit. No prob now.

cruiser

Bent brake pedal ?
Can you post some pics ?

I should be getting my new Momo wheel in 2weeks or so. Can't wait!

Which gas pedal adaptor did you use ? I think I'll just get one from Momo also...

DamonB

Typically the teeth are straight as you said but "dog" refers to how the gear is engaged. I can't find a good pic but the dogs inside the gearbox which lock the selected gear to the shaft are much stronger and completely different in design than a synchro. Compared to a synchro tranny a dog box is noisier, harder to shift for "normal" drivers and must be double clutched to downshift. In return the dog box is much stronger, shifts quicker and normally is easier to disassemble for ratio changes.

Chronos

You know what it sounds like when you backwards at about 25mph, right? Immagine that noise ALL the time when you're driving...don't even think about straight gears unless you're not planning to drive your car on the street.

Turbo23

iTrader: (4)

try taking shoes off! The bottom cushion of the shoe gets in the way

cruiser

No way I am driving bare footed

Turbo23

iTrader: (4)

then buy racing shoes, or for cheaper u can prob get yourself a pair of wrestling shoes, they work pretty much the same

cruiser

Don't be silly

I have good shoes for racing with minimum bottom cushion. Its just the fact that I'm a big guy. FD was probably meant for midgets But that won't keep me away

alberto_mg

I have the same problem. Never had this problem in my old FCs or BMW, bu the cockpit on the FD is small. I'm going to get a smaller wheel - either a 350mm Momo or I might try the one of the D shaped Sparco wheels. The Sparco wheel might block some of the gauges though. Need to check that out.

I can still heel-toe with the ***** of my feet on the brake and my heel modulating throttle, but it is annoying especially in a tight turn with my hands hitting my thigh while turning...

cruiser

Alberto, I know where you're coming from. I have same problem, except that I use sidestepping technique for downshifts. I also need to adjust the brake pedal after I change my brake fluid. I think it goes in too deep.

Chronos

Just got my FD back (FINALLY!) and I performed a number of heel-toes tonight. Do you guys get a chirp when you release the clutch after you've blipped? Maybe I'm not blipping hard enough...it is quite a hastle with that steering wheel in the way, and I downshift quite fast.

I'm currently following another thread about installing a racing seat onto the floor of the RX-7 so it sits much lower than the stock seat. I think this is the answer, and it will also give me better visibility out of the windshield as well probably.

DamonB

Done correctly neither the tires or tranny will lurch, that's the whole point.