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shifting vastly improved

My shifter handle started spinning around and I determined that the epoxy that actually holds two parts together had failed. Anyway, it was the nudge I needed to install the short shift kit and bushings I had bought maybe 8 years ago to install "someday".

What a difference! I changed the ball cup under the stick, which didn't look too bad, the ring bushing on the shift rod, which also didn't look too bad, and pressed out the pin on the rear coupler and changed those as well. As I was adjusting the shifter, it was immediately apparent that things were much mechanical feeling, and there was more of a positive snick when I changed into a gear.

Test drive was awesome too, finding first is much easier. (I was the only one who could successfully find first on the car.) It is still almost impossible to engage first when the car is moving, though. I want to check the clutch adjustment next to rule that out. Is the 86 930 four speed adjustment the same as the 915 procedure in Wayne's 101 book?
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Old 04-04-2010, 09:17 PM
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Engaging first while rolling above say 5mph can be tough, but Ive found on many cars, including the 930, if Im below 5mph the shift lever will slide right in.
Old 04-05-2010, 12:30 AM
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Dai Dai is offline
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Try double clutch into first while moving. I find this works every time.
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1981 black 930 with full 1st gen Gemballa bumpers kit. RUF classic wheels. Modification include: Mode Inc. (Bob Holcombe) full bay intercooler, headers, turbo, and muffler. 360RWHP.
Old 04-05-2010, 11:28 AM
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Try double clutch into first while moving. I find this works every time.
Ok, since there's no such thing as a dumb question - - could someone explain how to "double clutch into first..." thanks
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Old 04-05-2010, 04:57 PM
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Here is how double clutch works. First, you step on the clutch, shift from 2nd to neutral. Then, let the clutch pedal up with shifter in neutral, rev the engine to much higher rpm. Quickly, step on the clutch, put the car into first and engage the clutch in first gear. This requires much practice before you get a hang of it. First few tries, make sure you rev the engine in neutral with clutch pedal up position at very high rpm (about 6000rpm) because you are very fast in engaging the car into first gear before the rpm slowed down too much. Double clutch works great when down shifting from any gear.

I hope this is clear. Perhaps someone will chime in if I missed anything.
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Old 04-05-2010, 06:15 PM
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Quote:
Originally Posted by Dai View Post
Here is how double clutch works. First, you step on the clutch, shift from 2nd to neutral. Then, let the clutch pedal up with shifter in neutral, rev the engine to much higher rpm. Quickly, step on the clutch, put the car into first and engage the clutch in first gear. This requires much practice before you get a hang of it. First few tries, make sure you rev the engine in neutral with clutch pedal up position at very high rpm (about 6000rpm) because you are very fast in engaging the car into first gear before the rpm slowed down too much. Double clutch works great when down shifting from any gear.

I hope this is clear. Perhaps someone will chime in if I missed anything.
Ok, I get the picture... I'll make sure I'm not going too fast, so no need for the 6k rpm right away... thanks
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Old 04-08-2010, 03:46 PM
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"double clutch" is something i do on very large very old trucks. are these porsche transmissions "tired" ? just curious. jp
Old 04-08-2010, 03:52 PM
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heel toe is a double clutch technique (combines the brake also "toe") something all pcar drivers should know how to do - track or street...
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Old 04-08-2010, 07:48 PM
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I think of "heel and toe" as engine/trans spin speed matching to facilitate downshifting, without removing all pressure from brake pedal. double depression/release of the clutch is, to me, "double clutching", and is used when driving junk.

Last edited by johnnywishbone; 04-09-2010 at 08:23 AM.. Reason: missing word
Old 04-09-2010, 08:19 AM
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Originally Posted by johnnywishbone View Post
I think of "heel and toe" as engine/trans spin speed matching to facilitate downshifting, without removing all pressure from brake pedal. double depression/release of the clutch is, to me, "double clutching", and is used when driving junk.
Thanks, I figured so -- I won't be "double clutching" my ride...
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Old 04-09-2010, 08:31 AM
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I never ever downshift any manual transmission without match rev double clutching because thats how I learned 35 years ago on my first manual transmission car... a '72 BMW 2002 with completely worn out synchros and output shaft to driveshaft/guibo flange course splines.

It feels wrong to me to use the synchros to spin up the transmission mainshaft, gearsets and clutch disc because I learned by double clutching and it's by far the smoothest way to downshift.

You are doing the transmission a huge favor by match rev double clutching because if you match the revs perfectly you are not using the synchro and brake band rings and there is no jerk when letting out the clutch in the gear you downshifted to. Just totally smooth.

If the engine rpm you'll be in when you downshift to the lower gear is say 4500rpms DO NOT rev engine to 6000 rpms while letting out the clutch in nuetral.
If you do you will be reving everything to an rpm higher than you'll be in and there will be a forward jerk when you let out the clutch.
Thats all wrong and if you are real near to or at the limits of adhesion entering a corner while braking and downshifting, the jerk from not spinning up the engine to the correct rpm about 200 rpms higher than it will be in before engaging the next lower gear OR you spin up the engine and transmission to an rpm way higher than it will be in when you engage the lower gear you'll loose traction at the rear wheels from the upsetting jerk in the suspension, tires, and weight transfer and you will loose control of the car.
If not at the limits of adhesion the car can probably be saved from a spin by staying on the throttle and keeping the weight transfer on the rear wheels.

On a real cold winter day I used to double clutch on upshifts to 2nd gear in that 2002 because the transmission oil was so cold and thick it would slow down the gearset during the short pause while passing through nuetral and because the synchros were shot it would grind unless I spun up the gearset to an rpm 100-200rpms higher than than it will be when quickly engaging the next gear.

It takes alot of practice to get good and smooth at it and then the next challenge is to learn to heel and toe double clutch downshift.
On a 911 you have to either lower the brake pedal with the adjustable linkage rod or modify the gas pedal to be thicker or higher because the brake pedal is way to high from the factory to heel and toe with the gas pedal.
It's a real simple and safe adjustment if you don't lower the pedal too low and make the linkage rod come close to going over center, but some people prefer an adjustable gas pedal or add a section of wood or laminate one or 2 more gas pedals on top of the one installed to make it thicker.

The comparison to a truck is good because a healthy 930 transmission shifts more like a truck than any car I've ever driven.
Not complaining though.. with a Weltmeister short shift kit brazed onto the bottom part of a modified shifter, new shifter and shift rod bushings, and way tighter than stock shift home made shift coupler bushings it feels pretty damn good.
Old 04-09-2010, 12:22 PM
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RESEARCHED "DOUBLE CLUTCH". IT SEEMS I WAS MISINFORMED. I DON'T DO IT, DON'T NEED TO. THAT DOESN'T MEAN OTHERS CANNOT BENEFIT FROM THE TECHNIQUE. JP

Masturbating with one hand while intentionally cutting off oxygen to the brain with the other hand for the purpose of sexual gratification. See also Auto Erotic Asphyxiation.fficeffice" />>>
"He died double clutching in a Bangkok hotel closet.">>
> >
> >
A double clutch (also called a double declutch) is a driving procedure primarily used for vehicles with an unsynchronized manual transmission.
Old 04-09-2010, 02:29 PM
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Quote:
Originally Posted by johnnywishbone View Post
RESEARCHED "DOUBLE CLUTCH". IT SEEMS I WAS MISINFORMED. I DON'T DO IT, DON'T NEED TO. THAT DOESN'T MEAN OTHERS CANNOT BENEFIT FROM THE TECHNIQUE. JP

Masturbating with one hand while intentionally cutting off oxygen to the brain with the other hand for the purpose of sexual gratification. See also Auto Erotic Asphyxiation.fficeffice" />>>
"He died double clutching in a Bangkok hotel closet.">>
> >
> >
A double clutch (also called a double declutch) is a driving procedure primarily used for vehicles with an unsynchronized manual transmission.
LOL - I almost spit out my drink - glad the kids can't read yet, they came over to ask me why i was laughing so hard. This is the kind of stuff that belongs in the FG forums...

Spot on with the Heel Toe comments although i disagree with JF on the porsche pedal being too high. I personally prefer the brake high, you just have to get used to the positions of the pedals. I just installed the later 930 brakes on my car (76's have S brakes) with a 23mm mc, the pedal is way low, but it is very easy to HT, I personally don't like having so much travel in the brake pedal, but to each his own. I say, learn to adapt on all cars, you don't always have the opportunity to adjust, so best to be ready for any situation.

BTW matching revs (i believe) was the original intent of the OP from 2nd to 1st, so I added the brake - i dont' get to drive my 930 much, so when i do i'm either on the gas or the brake, not too many situations where i'm going from 2nd to 1st without being on the brake.
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Last edited by infraredcalvin; 04-09-2010 at 06:36 PM..
Old 04-09-2010, 06:31 PM
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Quote:
Originally Posted by johnnywishbone View Post
RESEARCHED "DOUBLE CLUTCH". IT SEEMS I WAS MISINFORMED. I DON'T DO IT, DON'T NEED TO. THAT DOESN'T MEAN OTHERS CANNOT BENEFIT FROM THE TECHNIQUE. JP

Masturbating with one hand while intentionally cutting off oxygen to the brain with the other hand for the purpose of sexual gratification. See also Auto Erotic Asphyxiation.fficeffice" />>>
"He died double clutching in a Bangkok hotel closet.">>
> >
> >
A double clutch (also called a double declutch) is a driving procedure primarily used for vehicles with an unsynchronized manual transmission.
Now that was seriously funny - - grasshopper!!
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Old 04-09-2010, 06:45 PM
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"Now that was seriously funny - - grasshopper!!"

that was a copy/paste. i have never had an original thought in my entire life. jp
Old 04-10-2010, 05:17 PM
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JFairman put it much more elegant than me. When I first practice the double clutch technique, I had to rev the engine much higher than the speed that I needed to match because if I don't do that, the rpm slowed down too much because it took me much time to complete the double clutch. I am much better at it now so I can bring much closer to the rpm that I have to match for down shifting. Thank you JF for giving us a much more detailed explanation.
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Old 04-10-2010, 06:11 PM
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double clutch technique

I was looking at some you tube videos of vintage Porsche races and I heard almost every driver using the double clutch technique when downshifting in a slow speed curve, I'm going to try this because I got the same problem when shifting to first gear when doing less than 5 MPH.
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Old 04-30-2014, 03:41 PM
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Quote:
Originally Posted by johnnywishbone View Post
RESEARCHED "DOUBLE CLUTCH". IT SEEMS I WAS MISINFORMED. I DON'T DO IT, DON'T NEED TO. THAT DOESN'T MEAN OTHERS CANNOT BENEFIT FROM THE TECHNIQUE. JP

Masturbating with one hand while intentionally cutting off oxygen to the brain with the other hand for the purpose of sexual gratification. See also Auto Erotic Asphyxiation.fficeffice" />>>
"He died double clutching in a Bangkok hotel closet.">>
> >
> >
A double clutch (also called a double declutch) is a driving procedure primarily used for vehicles with an unsynchronized manual transmission.
LMAO on that!
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Old 05-04-2014, 08:22 AM
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