Triple-cone synchros / double-clutching
 

The specs says the RX8 has triple-cone synchromesh on 1st, 2nd and 3rd gears. I searched on the web and couldn't find much info about it. Sounds like to me it's a synchromesh with triple the size(surface area) of a standard one such that it syncs the gears easier/faster (and maybe last longer) when a person shifts between those gears (without double-clutching). Is it correct? or does it actually consist of 3 separate cones doing the syncs all at once?

my 2nd question is, with this triple-cone thing, the whole gear becomes heavier, would it be harder/longer to manually rev-up the gear (heavier->bigger inertia) when a person tries to down-shift with doing double-clutch to match the gear speed manually?

I'm new to Rx8. mine has only 3000km. I have problem doing double-clutching with it. Other upshifting is not very smooth either. Would it be better when the tranny gets more 'run-in' or i just have to live with it?

please help! Thanx in adv.
-jas

The triple cones are for durability. They won't make it any more difficult to double-clutch. In fact, if you're double-clutching properly, the syncros don't even do any work.

I don't know your driving experience, so first make sure that you're double-clutching properly and making a good rev match. You may have to cater your driving style to the car a bit, but its a pretty easy car to drive if you know what you're doing.

good luck

double-clutching = 2x waste of time

thats your opinion...i think double clutching gives a much smoother downshift...

double clutching is not a usefull technique with modern cars, nor is it necessary.

Heel and toe however is what you want to be doing.

Double-clutching may be useless but I always double-clutch when I go into first gear.

Team is right and rev-matching=smooth downshifts. Double clutching hasn't been necessary since the 50s and if you need to do it these days your tranny is broken.

Double clutching may not be necessary, but it's good practice on downshifts. Much easier on all the parts than just shoving it into the lower gear. Personally, I find downshifts to be faster with double clutching.

Heel and toe isn't really necessary in normal driving. It is for performance driving. I remember reading in Jack Brabham's autobiography that he never heel-toed off the race track, since the violence level of driving where you needed it was just inappropriate on public roads.

I heel-toe for the fun of it, even though it's rarely necessary.

Ken

Thx RX8SpdDmn. Maybe I need more time to get used with it. (I used to drive with 5-speed manual) I've been trying hard to find a good rev match and the "feel" from it for months. Just wondering if I just got a not so good tranny since upshift is not smooth either and I saw so many other posts about bad tranny. (mine was end of 2007, not sure if Mazda got all those problems fixed)

For the rest, I don't want this becoming another double-clutching debate thread. :) I've been double-clutching my downshifts for 10+years and I know what i'm doing. It depends wheather it's a waste of time. It's a waste of time when you're going from 6th to 5th or 5th to 4th. But you'll find it harder/longer to shift from 3rd to 2nd due to the bigger rev-diff. between the 2 gears. From 2nd to 1st, it's impossible if you're not double-clutching. Other times I'll find double-clutching actually faster all together than single-clutching are when I skip gears. I usually go find 4th to 2nd, 5th to 3rd, 6th to 4th and 4th to 2nd.

And when you do it right, you'll fall in love with that feel of Zero Insertion Force (Imagine going from 4th to 2nd with your little finger and you still dont feel any resistant at all). :)

I get that feeling with rev matching and a single clutch proceedure.

Synchro's were invented to end double clutching.

I would not be downshifting into first period. What is the need?

My syncros were going out and double clutching didn't do anything for me...

If it was truely your syncros, then you weren't double-clutching right.

If you're braking and downshifting and the double-clutch takes you .01 second longer to execute, who cares?? You're BRAKING. There's no time to be gained by doing it quickly, because engine braking does nothing anyway. Whenever I take students for a ride on the track, IF they realize I'm doing it, its ONLY because they see my left leg do the double-pump. Its seamless and fast.

Brian Till (SPEED commentator and former Indycar driver) and Tommy Byrne (tested for Formula1) were both riding with me the past couple days at Mid-Ohio and neither ever noticed me double-clutching.

you're not the bionic man, it's not humanly possible to double clutch in 0.01 sec :rolleyes:

whatever. the additional time it takes to double-clutch downshift over single-clutching in a typical street car is negligible. :rolleyes:

With some practice.

I don't know why else the gears were grinding in the car, but I assumed it was the syncros. Oh well, gotta new tranny.

Double clutching is an unnecessary distraction in a synchro trans vehicle for most drivers. If you also drive another vehicle that has a dog gear trans then it doesn't hurt to stay in practice. A bad synchro is still going to hose you on the upshift. Otherwise a toe & heal rev match blip is more than adequate.

I can't argue with that.