I notice (think) f1 driver shift gear w/o clutch (before the electroinc
controlled gearbox era).
What’s the technique behind? Is it possible to do that with a street car?
TIA
Vincent
vc…@hk.super.net
19
Apr
Manual gear shift w/o clutch??
posted by admin in Uncategorized and have Comments (8)
8 Responses to “Manual gear shift w/o clutch??”
I notice (think) f1 driver shift gear w/o clutch (before the electroinc
controlled gearbox era).
What’s the technique behind? Is it possible to do that with a street car?
TIA
Vincent
vc…@hk.super.net
It is quite possible to shift w/o the clutch on a street car.
Upshift: let off gas, pull stick into neutral, keep applying light
pressure on stick as revs drop, should hit the next gear perfectly once
the revs match.
Downshift: Same basic technique, only blip the throttle while the
tranny is in neutral to bring the revs up. Don’t apply pressure to the
stick until the revs start dropping or your car will jerk and you’ll be
really embarrassed.
So, give it a try! I’ve gotten rather good at it, since I had to
Oh,
drive my mom’s car like that all summer to save its dying clutch
well, that’s about all for today…
Nate
In article <8iOmZVO00iV4I1C…@andrew.cmu.edu>, "Nathan J. Nagel"
<nn…@andrew.cmu.edu> wrote:
> It is quite possible to shift w/o the clutch on a street car.
Might add that its much easier to do on a race car than on your
daily beater. Race gears are flat cut as opposed to the bevel cut
in your beater.
Bob Benson
bob_ben…@qmail.ssc.gov
In article <34b4s5$…@hk.super.net>, vc…@hk.super.net (Mr Vincent Chow)
writes:
I don’t know about F1, but clutchless shifting can be done. I once drove
my Mercedes 240D from MA to VA that way when the clutch slave cylinder
failed.
Put the car in first and engage the starter (engine warm)
The car will start and begine moving
Accelerate till time to shift then use the throttle to match engine speed
to rear wheels. You want to reduce the torque (stress) on the drive train
so that you can pull it out of first into neutral.
When in neutral, match engine speed to rear wheels for second gear (lower
RPM than first). The idea is to get the second gear gears moving at the
same speed so you can gently pull the lever into second. A tach might
help, but I do it by ear. It takes practice. You do not need (want) to
force the gear change. By the time I arrived home in VA I had it down
like an F1 driver–well almost.
This is kinda of the same concept as double clutching. Maybe try that
first to get a feel for matching gear speeds. Good luck.
Mr Vincent Chow (vc…@hk.super.net) wrote:
: I notice (think) f1 driver shift gear w/o clutch (before the electroinc
: controlled gearbox era).
: What’s the technique behind? Is it possible to do that with a street car?
In an earlier issue of Car and Driver Magazine (1990 or earlier, I think),
senior editor Patrick Bedard clearly outlined his experience in shifting
manual transmission cars without using the clutch. Twice, it was by
necessity – the clutches in question having failed utterly – so he
shifted by matching engine and road speeds in such a manner that the
shift lever moved from gear to gear without fuss or muss.
For while, my parents’ 1972 Super Beetle had a very vague clutch pedal
also. What a coincidence that the magazine article to appear at the same
time! By following the directions (which I have now forgotten), I was
actually able to get the car around town without clutching. Mind you, I
would not condone doing this with a new Nissan 300 Turbo or anything!
Nhat-Viet Phi
nhatv…@nucleus.com
Calgary, Alberta
In article <34koiu$…@search01.news.aol.com>, ebr…@aol.com (EBrady) writes…
>In article <34b4s5$…@hk.super.net>, vc…@hk.super.net (Mr Vincent Chow)
>writes:
>I don’t know about F1, but clutchless shifting can be done. I once drove
>my Mercedes 240D from MA to VA that way when the clutch slave cylinder
>failed.
There are a couple of companies that make clutchless manual transmissions.
One that comes to mind is G-force. For those familiar with American
hotrods, the G-Force transmission is externally identical to the Richmond
Gear/ Doug Nash 5-speed, which in turn is loosely based on the Chrysler
hemi-4-speed.
The G-force trans utilizes "lugs" on the side of the gears rather than
syncros. The transmission comes in three flavours:
1) Semi-clutchless – requires the clutch to unload the gears to get out of
gear but not to get into the gear.
2) Partially fully clutchless – made for street machines no clutch required
at all from 1-2 and 2-3 shifts. This one has been shown to hold up behind
1100 ft-lbs of torque of a Pro-Stock drag racer. You cannot decelerate in
1st and 2nd gear – kinda like an over running clutch.
3) Fully clutchless – clutchless upshifting in all gears – probably only
practical for all-out-drag racing. This one will also withstand 1100 ft-
lbs of torque.
These transmissions can be had for about $4500. Don’t forget to factor in
the cost of all the parts you will break. Last but not least it is only
available for GM, Ford, and Chrysler rear wheel drive applications.
Everything else would require adapters etc.
Too expensive? Well there is away to make a transmission "slick shifted"
This entails removing the syncros and filing down every other tooth on the
engagement faces. This will give much more slop between the gears but will
allow better / faster engagement. You cannot shift this slowely. The
shifter must be moved deliberatly into the next gear. This could be very
rough on shifter levers. In the Mopar chassis manual the quote is "WHEN"
your transmission breaks send it to DougNash (who don’t do trannies anymore
as far as I know) and have them repair and strengthen it.
Dirk
Nhat-Viet Phi (nhatv…@nucleus.com) wrote:
: | For while, my parents’ 1972 Super Beetle had a very vague clutch pedal
: | also. What a coincidence that the magazine article to appear at the same
: | time! By following the directions (which I have now forgotten), I was
: | actually able to get the car around town without clutching. Mind you, I
: | would not condone doing this with a new Nissan 300 Turbo or anything!
After reading the original article and a few followups, I decided to try for
myself shifting w/o the clutch (is there a more elegant name?).
My initial tries (and continued attempts) met with almost immediate success.
I did this in a 1991 Mazda B2200 pickup – I found it’s harder to shift
smoothly from 1-2 than it is from 2-3, etc. This makes sense – to get the car
out of gear you sort of have to drift off the gas to remove strain on the
transmission, and to do that in first in this truck is silly because you’re
only in it for a few seconds anyway. So I clutch my way to second.
I started off doing it from third to fourth on a straight, relatively
remote road (not out of my way, but an alternate route). Flat also helps..
I watched the tach a little, and pulled it out of third into neutral, let the
revs drop a little, and it went pretty easily into fourth. There’s usually a
clunk as it gets in gear, but no jerk or anything. I suppose this isn’t so
good for the gearbox, but I have fun doing this.
Going from fourth to third is also pretty easy – just blip the throttle once
you’re in neutral, and push it into third (not too hard, of course).
My questions, though: is this in any way bad for the transmission (assuming
you’re not screwing up and making the gears crunch)? I’d assume it is, but
I’d be pleasantly surprised to hear it’s not.
Since I’m not a star mechanic, what do the synchros do while I’m shifting
without the clutch? Do they only work when the clutch is engaged, so I’m
not stressing them? Or am I completely off base?
Anyway, it was interesting learning to do this..
How would you start off w/o a clutch? (I’ve started my engine w/o the
starter motor, but I mean start moving from a dead stop) Dare I mention
reverse?
David
EBrady (ebr…@aol.com) wrote:
: In article <34b4s5$…@hk.super.net>, vc…@hk.super.net (Mr Vincent Chow)
: writes:
: I don’t know about F1, but clutchless shifting can be done. I once drove
: my Mercedes 240D from MA to VA that way when the clutch slave cylinder
: failed.
: Put the car in first and engage the starter (engine warm)
: The car will start and begine moving
: Accelerate till time to shift then use the throttle to match engine speed
: to rear wheels. You want to reduce the torque (stress) on the drive train
: so that you can pull it out of first into neutral.
: When in neutral, match engine speed to rear wheels for second gear (lower
: RPM than first). The idea is to get the second gear gears moving at the
: same speed so you can gently pull the lever into second. A tach might
: help, but I do it by ear. It takes practice. You do not need (want) to
: force the gear change. By the time I arrived home in VA I had it down
: like an F1 driver–well almost.
: This is kinda of the same concept as double clutching. Maybe try that
: first to get a feel for matching gear speeds. Good luck.
What you accomplished can only be done in a car with a syncromesh
transmission, and probably isn’t the best idea. I used to do it in my old
VW when I didn’t feel like pushing in the clutch.
F1 has a nicer arrangement, with the shifters as levers attached to the
steering wheel and a hydraulic system to actuate the gearchanges. Saab
has a new system coming out, called the Sensonic, that senses changes in
engis speed and actuates the clutch for you! You can get the Tiptronic in
some Porsches, but it’s basically an automatic with a fancy manual shift
mode. Also, Alpina, the european BMW tuner will sell you what is
basically an M5 with their pushbutton shifting system (up and down arrows
on the steering wheel), which is basically the standard ZF five-speed
with a custom shifting program. Hitting redline will cause the trans to
shift itself, however.
–
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