How many miles on your clutch??
10-02-2002, 01:11 PM
#16
Race Director
I am in the middle installing my 3rd clutch for my Turbo.
Now at 117k
Original replaced at about 60k by Orginal owner.
It was replaced the dealer with factory sachs unit. I am replacing it now (at 117k) since I had problem with springs. The entire secondary plate & springs came off. Otherwise the clutch surface was still good.
I have tracked car the car a few times an am running stock power.
I think the clutch disks will last a good long time with stock power and proper use. Problem is that other stuff tends to break before the disk wears out.
Now at 117k
Original replaced at about 60k by Orginal owner.
It was replaced the dealer with factory sachs unit. I am replacing it now (at 117k) since I had problem with springs. The entire secondary plate & springs came off. Otherwise the clutch surface was still good.
I have tracked car the car a few times an am running stock power.
I think the clutch disks will last a good long time with stock power and proper use. Problem is that other stuff tends to break before the disk wears out.
10-02-2002, 01:18 PM
#17
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[quote]Originally posted by M758:
<strong>I think the clutch disks will last a good long time with stock power and proper use. Problem is that other stuff tends to break before the disk wears out.</strong><hr></blockquote>
I had to have my spring-centered clutch replaced at 50k miles because of broken springs. Except for that, the clutch would have lasted to at least 100k based on the disk wear.
<strong>I think the clutch disks will last a good long time with stock power and proper use. Problem is that other stuff tends to break before the disk wears out.</strong><hr></blockquote>
I had to have my spring-centered clutch replaced at 50k miles because of broken springs. Except for that, the clutch would have lasted to at least 100k based on the disk wear.
10-02-2002, 10:55 PM
#18
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Just replaced mine at 58K. Bought the car 3.5 yrs ago at 42K, so don't know how it was treated most of the clutch's life.
This may sound dumb, but could someone (Ollie?) describe the technique for maximum clutch wear? I've driven lots of sticks over the years, but I don't even know how I learned to handle a clutch, and maybe I actually don't know!
This may sound dumb, but could someone (Ollie?) describe the technique for maximum clutch wear? I've driven lots of sticks over the years, but I don't even know how I learned to handle a clutch, and maybe I actually don't know!
10-03-2002, 01:14 AM
#19
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300K on my '83 na. Drive it every day for work. Same clutch with lots of life yet. Still got the same set of brake shoes too after 9 years. Yes, I baby it. But my son soon won't 
I'll just have him pay for new parts
TurboTime
I'll just have him pay for new parts
TurboTime
10-03-2002, 01:54 AM
#20
[quote] This may sound dumb, but could someone (Ollie?) describe the technique for maximum clutch wear? I've driven lots of sticks over the years, but I don't even know how I learned to handle a clutch, and maybe I actually don't know! <hr></blockquote>
This is quite though question.I must say i can't give an answer.Have driven cars 25 years (only sticks, tested autotrans several times), so it's like bicycle; you learn it and can do it the rest of your life.It's much harder to learn to drive stick if you have driven autotrans most of the time.I mentioned earlier i haven't own an autotrans car.That was a false.I used to own '57 Chevy Bel Air convertible.It has a (High Tec) two speed Powerglide autotransmission
This is quite though question.I must say i can't give an answer.Have driven cars 25 years (only sticks, tested autotrans several times), so it's like bicycle; you learn it and can do it the rest of your life.It's much harder to learn to drive stick if you have driven autotrans most of the time.I mentioned earlier i haven't own an autotrans car.That was a false.I used to own '57 Chevy Bel Air convertible.It has a (High Tec) two speed Powerglide autotransmission
10-03-2002, 09:00 AM
#21
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[quote]...could someone (Ollie?) describe the technique for maximum clutch wear? <hr></blockquote>MAX clutch wear is easy: act as if on a drag strip
Minimum clutch wear is more difficult, but lets give it a try:
Lets start at standstil:
-engage FIRST gear and use the lowest RPM to get it going (some 2200 would do for a turbo, NA can be a bit less)
-Let the clutch come in gently and slowly open the throttle to maintain the RPM.
- when clutch is engaged in full, revv up to max 3500 RPM, disengage and shift to second gear.
- Make sure you match RPM with driving speed and drop clutch (You will either bang your head or hurt your back if you are wrong here, anyway, you will know!)
- revv up to about 4000 RPM and change to 3th.
Go through all gears you need to get at the speed you want, staying out of the RPM band where the turbo cuts in / out, while trying to minimise the chiver you get when mis-matching the RPM. (Just pretend you are transporting a lot of eggs and dont want the mess of them breaking.
Guide line: the clutch wears fastest when the power transfer is biggest, so keep the revvs low and speed up by opening the throttle.
Clutch also wears when slipping, make this time as short as you can.
An amaizing amount of people think the clutch is also suitable for speed ajustments, this is only true for a very limited time span: the clutch life.
Also: a lot of people beleve that taking off in 2th gear will either save material or fuel.
This is not the case since the torque required to get the car moving is now found at an higher RPM level. (gear box converts torque!!), consequently the clutch need to slop more & longer, burning off more friction material.
I hope this helps, it is as Olli says: second nature.
Kinda like a feeling you develop over the years.
I dont have to watch the clock to know what RPM the engine does anymore and hardly look at the dash when shifting.
I have the inversion of your problem:
Automatics: difficult to get some acceleration out of them.
Found out that if you step on the brake and revv up to say 3200, then release brake, than floor it, it kind of moves as what I am used to...
Ford (standard detroit iron, 3 liter V6), AVIS car, Abuse?
TakeCare
Minimum clutch wear is more difficult, but lets give it a try:
Lets start at standstil:
-engage FIRST gear and use the lowest RPM to get it going (some 2200 would do for a turbo, NA can be a bit less)
-Let the clutch come in gently and slowly open the throttle to maintain the RPM.
- when clutch is engaged in full, revv up to max 3500 RPM, disengage and shift to second gear.
- Make sure you match RPM with driving speed and drop clutch (You will either bang your head or hurt your back if you are wrong here, anyway, you will know!)
- revv up to about 4000 RPM and change to 3th.
Go through all gears you need to get at the speed you want, staying out of the RPM band where the turbo cuts in / out, while trying to minimise the chiver you get when mis-matching the RPM. (Just pretend you are transporting a lot of eggs and dont want the mess of them breaking.
Guide line: the clutch wears fastest when the power transfer is biggest, so keep the revvs low and speed up by opening the throttle.
Clutch also wears when slipping, make this time as short as you can.
An amaizing amount of people think the clutch is also suitable for speed ajustments, this is only true for a very limited time span: the clutch life.
Also: a lot of people beleve that taking off in 2th gear will either save material or fuel.
This is not the case since the torque required to get the car moving is now found at an higher RPM level. (gear box converts torque!!), consequently the clutch need to slop more & longer, burning off more friction material.
I hope this helps, it is as Olli says: second nature.
Kinda like a feeling you develop over the years.
I dont have to watch the clock to know what RPM the engine does anymore and hardly look at the dash when shifting.
I have the inversion of your problem:
Automatics: difficult to get some acceleration out of them.
Found out that if you step on the brake and revv up to say 3200, then release brake, than floor it, it kind of moves as what I am used to...
Ford (standard detroit iron, 3 liter V6), AVIS car, Abuse?
TakeCare
10-03-2002, 03:32 PM
#22
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Make sure you match RPM with driving speed and drop clutch (You will either bang your head or hurt your back if you are wrong here, anyway, you will know!)
OK, this is where I get confused. What EXACTLY do you mean by matching the RPM with the driving speed??
Thank you for explaining this...
OK, this is where I get confused. What EXACTLY do you mean by matching the RPM with the driving speed??
Thank you for explaining this...
10-03-2002, 07:01 PM
#23
Race Director
"What EXACTLY do you mean by matching the RPM with the driving speed??"
It's actually easier than it sounds really. The idea is that different gears will coincide with different engine-RPMs for the same road-speed. So for example in 951 with a 1st-to-2nd gear shift: 1st-gear@4000rpm = 25mph = 2nd-gear@2350rpm. So to 'match-revs' when shifting from 1st to 2nd at 25mph, you would use the following sequence:
1. accelerate in 1st
2. ease off gas to get steady-state 25mph@4000rpm in 1st
3. step in clutch (don't change gas-pedal), if you did step#2 just right, you'll notice that the RPMs will stay right at 4000rpm and not change when you step in the clutch.
4. pull lever out of gear and leave in neutral position
5. 2nd, lower revs just enough to come down to 2350rpm. This matches the input-shaft of the tranny to the same speed as the output shaft that's being driven by the wheels.
6. Make sure your speed is still 25mph and your engine-speed is 2350rpm (gotta do steps#3-4 quickly. Push lever into 2nd gear.
7. Let go of clutch pedal and you'll notice that the RPMs don't change, you don't feel the car jerk and you've successfully 'matched revs' during the shift.
8. step on gas and accelerate. go back to step #2 for the next gear shifts.
For example:
2nd-gear@4000rpm = ~40mph = 3rd-gear@2700rpm
3rd-gear@4000rpm = ~60mph = 4th-gear@3000rpm
4th-gear@4000rpm = ~85mph = 5th-gear@3200rpm
With practice, you won't have to do so much math in your head or memorize gear charts. The crucial steps are #2-5 where you simplify your gas-pedal footwork. Most people are taught to let off the gas completely when they step in the clutch, then step on the gas again as they let off the clutch. But this is tough on the clutch and the synchros because they have to use friction to rev-up or slow-down the engine to match the road speed.
Rather than making a two-step gas-pedal process, make it one. Rather than letting off completely, then back on again. Just let off just enough to bring the revs down the appropriate RPM for the next gear. That is 4000->2350rpm in the 1st-to-2nd shift, 4000->2700rpm for 2nd-to-3rd shift, etc. You can actually shift faster this way because you've removed a wasted motion. Also the shifts are smoother with less jerking because the RPMs are matched.
Finally, when you get really good at steps 2-5 above, you can shift without using the clutch at all !!! The tranny on the 951 seems pretty finicky, or perhaps it the remote-linkage all the way to the back, but it's not as smooth as the tranny on my Supra. With that thing, I could do full stoplight drag-race full-throttle runs from 1st to 4th gear and not have to touch the clutch at all after the initial launch.
You can do that by removing steps #3 & 7 completely!
It's actually easier than it sounds really. The idea is that different gears will coincide with different engine-RPMs for the same road-speed. So for example in 951 with a 1st-to-2nd gear shift: 1st-gear@4000rpm = 25mph = 2nd-gear@2350rpm. So to 'match-revs' when shifting from 1st to 2nd at 25mph, you would use the following sequence:
1. accelerate in 1st
2. ease off gas to get steady-state 25mph@4000rpm in 1st
3. step in clutch (don't change gas-pedal), if you did step#2 just right, you'll notice that the RPMs will stay right at 4000rpm and not change when you step in the clutch.
4. pull lever out of gear and leave in neutral position
5. 2nd, lower revs just enough to come down to 2350rpm. This matches the input-shaft of the tranny to the same speed as the output shaft that's being driven by the wheels.
6. Make sure your speed is still 25mph and your engine-speed is 2350rpm (gotta do steps#3-4 quickly. Push lever into 2nd gear.
7. Let go of clutch pedal and you'll notice that the RPMs don't change, you don't feel the car jerk and you've successfully 'matched revs' during the shift.
8. step on gas and accelerate. go back to step #2 for the next gear shifts.
For example:
2nd-gear@4000rpm = ~40mph = 3rd-gear@2700rpm
3rd-gear@4000rpm = ~60mph = 4th-gear@3000rpm
4th-gear@4000rpm = ~85mph = 5th-gear@3200rpm
With practice, you won't have to do so much math in your head or memorize gear charts. The crucial steps are #2-5 where you simplify your gas-pedal footwork. Most people are taught to let off the gas completely when they step in the clutch, then step on the gas again as they let off the clutch. But this is tough on the clutch and the synchros because they have to use friction to rev-up or slow-down the engine to match the road speed.
Rather than making a two-step gas-pedal process, make it one. Rather than letting off completely, then back on again. Just let off just enough to bring the revs down the appropriate RPM for the next gear. That is 4000->2350rpm in the 1st-to-2nd shift, 4000->2700rpm for 2nd-to-3rd shift, etc. You can actually shift faster this way because you've removed a wasted motion. Also the shifts are smoother with less jerking because the RPMs are matched.
Finally, when you get really good at steps 2-5 above, you can shift without using the clutch at all !!! The tranny on the 951 seems pretty finicky, or perhaps it the remote-linkage all the way to the back, but it's not as smooth as the tranny on my Supra. With that thing, I could do full stoplight drag-race full-throttle runs from 1st to 4th gear and not have to touch the clutch at all after the initial launch.
You can do that by removing steps #3 & 7 completely!
10-03-2002, 07:27 PM
#24
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[quote]Originally posted by Danno:
[QB]Finally, when you get really good at steps 2-5 above, you can shift without using the clutch at all !!![QB]<hr></blockquote>
Providing you don't hear any grinding, is this bad for your tranny/synchros?
[QB]Finally, when you get really good at steps 2-5 above, you can shift without using the clutch at all !!![QB]<hr></blockquote>
Providing you don't hear any grinding, is this bad for your tranny/synchros?
10-04-2002, 02:25 PM
#25
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Synchromeshes will synchronize the input shaft to the gears. if the engine with the clutch engaged (not pressed down) matches the gear speed then the synchros cannot be hurt because they are not used.
for those people feeling a little more adventurous here's how to double declutch on an up shift without synchros (you can also do this on a car with synchromesh):
1) declutch (push in clutch pedal), pull out of gear, let off throttle enough to match the engine speed in the gear you will be shifting to
2) clutch (let out clutch pedal)
3) declutch, put car into gear
4) clutch
this is similar to the explanations above, except in this example you are double declutching (what most people call double clutching). The reason for letting the clutch out and then pushing it back in is because this will allow the input shaft in the transmission to match up with the engine speed; in the examples above the synchros were doing the work here. to double declutch on a downshift a similar method is followed:
1) declutch (push in clutch pedal), pull out of gear
2) clutch (let out clutch pedal)
3) tap the throttle to match the lower gear's engine rpm's
3) declutch, put car into gear
4) clutch
The reason to wait till you've clutched before giving it throttle is to avoid burning the clutch... if you're downshifting and you're new rpm is 3000 it wont make much of a difference; if it's 7000 you'll burn some clutch if you don’t follow this method.
anyway, with practice, you can shift faster using this method then you can relying on the synchromesh to match input shaft and drive train speed (this is what happens when you feel that "hump" while you are shifting into a gear).
this is fine for the transmission, if done right.
for those people feeling a little more adventurous here's how to double declutch on an up shift without synchros (you can also do this on a car with synchromesh):
1) declutch (push in clutch pedal), pull out of gear, let off throttle enough to match the engine speed in the gear you will be shifting to
2) clutch (let out clutch pedal)
3) declutch, put car into gear
4) clutch
this is similar to the explanations above, except in this example you are double declutching (what most people call double clutching). The reason for letting the clutch out and then pushing it back in is because this will allow the input shaft in the transmission to match up with the engine speed; in the examples above the synchros were doing the work here. to double declutch on a downshift a similar method is followed:
1) declutch (push in clutch pedal), pull out of gear
2) clutch (let out clutch pedal)
3) tap the throttle to match the lower gear's engine rpm's
3) declutch, put car into gear
4) clutch
The reason to wait till you've clutched before giving it throttle is to avoid burning the clutch... if you're downshifting and you're new rpm is 3000 it wont make much of a difference; if it's 7000 you'll burn some clutch if you don’t follow this method.
anyway, with practice, you can shift faster using this method then you can relying on the synchromesh to match input shaft and drive train speed (this is what happens when you feel that "hump" while you are shifting into a gear).
this is fine for the transmission, if done right.
