Double Clutch & Trail braking
09-26-2002, 06:01 PM
#31
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[quote]Originally posted by Mike in Chi:
<strong>I did a PDE with Hurley Haywood as the instructor. When he was in the passenger seat and I double clutched he said "what are you doing? Don't do that, a blip will suffice on cars with modern synchros."</strong><hr></blockquote>
Sure, you don't *need* to double clutch with modern synchros but you don't have to blip either. Blipping without double clutching is useless. I double clutch most of the time and find that going in and out of gears is much smoother. Even with my brass synchros.
<strong>I did a PDE with Hurley Haywood as the instructor. When he was in the passenger seat and I double clutched he said "what are you doing? Don't do that, a blip will suffice on cars with modern synchros."</strong><hr></blockquote>
Sure, you don't *need* to double clutch with modern synchros but you don't have to blip either. Blipping without double clutching is useless. I double clutch most of the time and find that going in and out of gears is much smoother. Even with my brass synchros.
09-26-2002, 06:14 PM
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DJ
[quote] I think you'll find that the "advanced groups" here are a little more advanced than what you're used to <hr></blockquote>
Quick DJ, hit the edit icon on your post
[quote] I think you'll find that the "advanced groups" here are a little more advanced than what you're used to <hr></blockquote>
Quick DJ, hit the edit icon on your post
09-26-2002, 06:21 PM
#33
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Hi Viken
By double-clutching do you mean:
1. shift into neutral,blip,shift into lower gear
or
2. blip while clutch is depressed during shift to lower gear.
I had been doing #1. Haywood said #2 is fine and accomplishes the same thing.
By double-clutching do you mean:
1. shift into neutral,blip,shift into lower gear
or
2. blip while clutch is depressed during shift to lower gear.
I had been doing #1. Haywood said #2 is fine and accomplishes the same thing.
09-26-2002, 06:27 PM
#34
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[quote]Originally posted by Mike in Chi:
<strong>By double-clutching do you mean:
1. shift into neutral,blip,shift into lower gear
or
2. blip while clutch is depressed during shift to lower gear.</strong><hr></blockquote>
Number 1 above.
[quote]<strong>I had been doing #1. Haywood said #2 is fine and accomplishes the same thing.</strong><hr></blockquote>
I doubt it. When I do #2, I feel absolutely no difference. However, with #1, the shifts are a lot smoother. OTOH, what the hell do I know? I am just another racer wannabe on a high horse.
<strong>By double-clutching do you mean:
1. shift into neutral,blip,shift into lower gear
or
2. blip while clutch is depressed during shift to lower gear.</strong><hr></blockquote>
Number 1 above.
[quote]<strong>I had been doing #1. Haywood said #2 is fine and accomplishes the same thing.</strong><hr></blockquote>
I doubt it. When I do #2, I feel absolutely no difference. However, with #1, the shifts are a lot smoother. OTOH, what the hell do I know? I am just another racer wannabe on a high horse.
09-26-2002, 06:29 PM
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[quote]Originally posted by hn:
<strong>
I used to let the car coast in neutral coming to a turn, braked during the turn, and shift into a gear when exiting. I found this is the easiest way for make a smooth turn (for beginner?) but, of course, could never be in the right gear when exiting.
Now I am learning to shift into a gear with heel and toe technic (usually 2nd), brake to slow down enough so that during the turn I don't have to brake (somtimes lighty accelerate, depends on the speed), and exiting with the car already in 2nd gear. I hope this is the right way (?).
Thx</strong><hr></blockquote>
Although I do not claim to have the experience of Mark or others on the race track, the matter of weight transfer and chassis balance during the turn has been one of the priorities for me to perfect either on the street or track. Since my youth I have been driving manual box cars and with all I have been practicing heal and toe and weight balance while on turn. To me it is a big nono going into a turn without being on a gear.You just have the suspension loading without being able to balance it while you turn. By upshifting you upset the balance even more and on the limit an upset balance might lead to trouble. The main reason for heal and toe is not to upset the balance of the chassis which would be affected by engine braking. The 911 being a different beast than any other car is more difficult to trailbrake because it is more throttle driven and sensitive with all that weight in the back. At my stage on the track I feel that learning how to go into the turn with the chassis being neutral and loading the rear by throttle is a very nice way to be fast and safe.
All the instructors say slow in fast out. So finish up with brakes on straight line, release the brakes before turn in to unload the front and get on the throttle immediately to balance the chassis. Most of the corners I take them with either part throttle or progressively increasing throttle which sometimes it has led to a slight oversteer which is catchable and progressive.
One other thing to help setup before a tight turn which I guess i before learning and applying trailbraking is to brake fast and sharp just before the corner. This way and as you turn in while releasing the brakes the front is still loaded a bit and it helps rotate the rear faster.
I was really amazed to realize of how throttle stabilizes the rear even when you think you should lift which is a very natural reaction.
911's are truly amazing cars to master!
Thanks to all of the great comments and insights.
<strong>
I used to let the car coast in neutral coming to a turn, braked during the turn, and shift into a gear when exiting. I found this is the easiest way for make a smooth turn (for beginner?) but, of course, could never be in the right gear when exiting.
Now I am learning to shift into a gear with heel and toe technic (usually 2nd), brake to slow down enough so that during the turn I don't have to brake (somtimes lighty accelerate, depends on the speed), and exiting with the car already in 2nd gear. I hope this is the right way (?).
Thx</strong><hr></blockquote>
Although I do not claim to have the experience of Mark or others on the race track, the matter of weight transfer and chassis balance during the turn has been one of the priorities for me to perfect either on the street or track. Since my youth I have been driving manual box cars and with all I have been practicing heal and toe and weight balance while on turn. To me it is a big nono going into a turn without being on a gear.You just have the suspension loading without being able to balance it while you turn. By upshifting you upset the balance even more and on the limit an upset balance might lead to trouble. The main reason for heal and toe is not to upset the balance of the chassis which would be affected by engine braking. The 911 being a different beast than any other car is more difficult to trailbrake because it is more throttle driven and sensitive with all that weight in the back. At my stage on the track I feel that learning how to go into the turn with the chassis being neutral and loading the rear by throttle is a very nice way to be fast and safe.
All the instructors say slow in fast out. So finish up with brakes on straight line, release the brakes before turn in to unload the front and get on the throttle immediately to balance the chassis. Most of the corners I take them with either part throttle or progressively increasing throttle which sometimes it has led to a slight oversteer which is catchable and progressive.
One other thing to help setup before a tight turn which I guess i before learning and applying trailbraking is to brake fast and sharp just before the corner. This way and as you turn in while releasing the brakes the front is still loaded a bit and it helps rotate the rear faster.
I was really amazed to realize of how throttle stabilizes the rear even when you think you should lift which is a very natural reaction.
911's are truly amazing cars to master!
Thanks to all of the great comments and insights.
09-26-2002, 06:44 PM
#36
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V
[quote]<strong>I doubt it. When I do #2, I feel absolutely no difference. However, with #1, the shifts are a lot smoother.</strong><hr></blockquote>
Like I said I used to use #1 all the time. So I wondered too about what he said. Then I thought about the car with a sequential gearbox that I used in eight races.
It's impossible to do #1 in it -- it's sequential -- but if you didn't do 2, you at least got a major chirp out of the rear tires, if not a snap spin.
I think #1 is definitely the safest, but the hardest to learn. It seems that #2 suffices fine.
Like you I also find it smoother to use #1 than 2. BuT now I'm in the habit, and rhythm, of the second option after only DEs this year in the 993.
[quote]<strong>OTOH, what the hell do I know? I am just another racer wannabe on a high horse. </strong><hr></blockquote>
I don't know about "wannabe" but wouldn't that be "Prancing" horse?
(or is it a paddle shifter?)
Mike
[quote]<strong>I doubt it. When I do #2, I feel absolutely no difference. However, with #1, the shifts are a lot smoother.</strong><hr></blockquote>
Like I said I used to use #1 all the time. So I wondered too about what he said. Then I thought about the car with a sequential gearbox that I used in eight races.
It's impossible to do #1 in it -- it's sequential -- but if you didn't do 2, you at least got a major chirp out of the rear tires, if not a snap spin.
I think #1 is definitely the safest, but the hardest to learn. It seems that #2 suffices fine.
Like you I also find it smoother to use #1 than 2. BuT now I'm in the habit, and rhythm, of the second option after only DEs this year in the 993.
[quote]<strong>OTOH, what the hell do I know? I am just another racer wannabe on a high horse. </strong><hr></blockquote>
I don't know about "wannabe" but wouldn't that be "Prancing" horse?
(or is it a paddle shifter?)Mike
09-26-2002, 06:50 PM
#37
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[quote]Originally posted by Viken:
<strong>
Sure, you don't *need* to double clutch with modern synchros but you don't have to blip either. Blipping without double clutching is useless. I double clutch most of the time and find that going in and out of gears is much smoother. Even with my brass synchros.</strong><hr></blockquote>
How can blipping be useless??? if you downshift without blipping you feel the jerking motion and engine braking which loads the front suspension. By blipping succesfully you can feel the difference as the car remains neutral, there is not engine braking jerking ,nothing! If you do not match the revs properly blipping is useless...
<img src="confused.gif" border="0">
<strong>
Sure, you don't *need* to double clutch with modern synchros but you don't have to blip either. Blipping without double clutching is useless. I double clutch most of the time and find that going in and out of gears is much smoother. Even with my brass synchros.</strong><hr></blockquote>
How can blipping be useless??? if you downshift without blipping you feel the jerking motion and engine braking which loads the front suspension. By blipping succesfully you can feel the difference as the car remains neutral, there is not engine braking jerking ,nothing! If you do not match the revs properly blipping is useless...
<img src="confused.gif" border="0">
09-26-2002, 06:51 PM
#38
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[quote]Originally posted by Mike in Chi:
<strong>DJ
Isn't that also true when you give a blip while single clutching? -- The speed differential is reduced to zero
</strong><hr></blockquote>
Not at all. Blipping during single-clutching merely reduces the speed differential between the clutch and the flywheel. To be of any benefit at all to the synchros, the clutch must be engaged when you blip (clutch pedal is "out").
<strong> [quote]
I did a PDE with Hurley Haywood as the instructor. When he was in the passenger seat and I double clutched he said "what are you doing? Don't do that, a blip will suffice on cars with modern synchros."
</strong><hr></blockquote>
And, of course, Mr. Haywood is absolutely correct. The difference is that his priorities are different from ours. He is hired to drive the car as quickly as possible. At the end of the race, the transmission will be rebuilt, and he does not have to pay for it.
<strong>DJ
Isn't that also true when you give a blip while single clutching? -- The speed differential is reduced to zero
</strong><hr></blockquote>
Not at all. Blipping during single-clutching merely reduces the speed differential between the clutch and the flywheel. To be of any benefit at all to the synchros, the clutch must be engaged when you blip (clutch pedal is "out").
<strong> [quote]
I did a PDE with Hurley Haywood as the instructor. When he was in the passenger seat and I double clutched he said "what are you doing? Don't do that, a blip will suffice on cars with modern synchros."
</strong><hr></blockquote>
And, of course, Mr. Haywood is absolutely correct. The difference is that his priorities are different from ours. He is hired to drive the car as quickly as possible. At the end of the race, the transmission will be rebuilt, and he does not have to pay for it.
09-26-2002, 06:53 PM
#39
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[quote]Originally posted by Mike in Chi:
<strong>DJ
Quick DJ, hit the edit icon on your post</strong><hr></blockquote>
Why? Did I make a mistake?
<strong>DJ
Quick DJ, hit the edit icon on your post</strong><hr></blockquote>
Why? Did I make a mistake?
09-26-2002, 06:54 PM
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[quote]Originally posted by DJ:
<strong>And, of course, Mr. Haywood is absolutely correct. The difference is that his priorities are different from ours. He is hired to drive the car as quickly as possible. At the end of the race, the transmission will be rebuilt, and he does not have to pay for it.</strong><hr></blockquote>
My original mechanic for my TT supported the TT intro. Haywood was driving the cars, getting 0-60 times, etc. He rebuilt 4 or 5 transmissions in as many days for bent gears support Haywood.
<strong>And, of course, Mr. Haywood is absolutely correct. The difference is that his priorities are different from ours. He is hired to drive the car as quickly as possible. At the end of the race, the transmission will be rebuilt, and he does not have to pay for it.</strong><hr></blockquote>
My original mechanic for my TT supported the TT intro. Haywood was driving the cars, getting 0-60 times, etc. He rebuilt 4 or 5 transmissions in as many days for bent gears support Haywood.
09-26-2002, 06:57 PM
#41
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[quote]Originally posted by Mark D - TT Alumni:
<strong>
My original mechanic for my TT supported the TT intro. Haywood was driving the cars, getting 0-60 times, etc. He rebuilt 4 or 5 transmissions in as many days for bent gears support Haywood.</strong><hr></blockquote>
Q.E.D.
<strong>
My original mechanic for my TT supported the TT intro. Haywood was driving the cars, getting 0-60 times, etc. He rebuilt 4 or 5 transmissions in as many days for bent gears support Haywood.</strong><hr></blockquote>
Q.E.D.
09-26-2002, 07:00 PM
#42
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[quote]Originally posted by DJF1:
<strong>
How can blipping be useless??? if you downshift without blipping you feel the jerking motion and engine braking which loads the front suspension. By blipping succesfully you can feel the difference as the car remains neutral, there is not engine braking jerking ,nothing! If you do not match the revs properly blipping is useless...
</strong><hr></blockquote>
You are correct and if you do that while in a corner, I call that Crashing. Seriously, though, we are confusing a couple of things in this discussion -you can blip to match engine speed to road speed and you can blip to synchronize the internal parts of the transmission. Done right, a double clutch downshift does both.
<strong>
How can blipping be useless??? if you downshift without blipping you feel the jerking motion and engine braking which loads the front suspension. By blipping succesfully you can feel the difference as the car remains neutral, there is not engine braking jerking ,nothing! If you do not match the revs properly blipping is useless...
</strong><hr></blockquote>You are correct and if you do that while in a corner, I call that Crashing. Seriously, though, we are confusing a couple of things in this discussion -you can blip to match engine speed to road speed and you can blip to synchronize the internal parts of the transmission. Done right, a double clutch downshift does both.
09-26-2002, 07:12 PM
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[quote] Why? Did I make a mistake? <hr></blockquote>
Perhaps I misinterpreted your orignal comment. About drivers being more advanced there.
Can you elaborate?
[quote] Blipping during single-clutching merely reduces the speed differential between the clutch and the flywheel. To be of any benefit at all to the synchros, the clutch must be engaged when you blip <hr></blockquote>
Which is why it works with straight cut gears, right? Hey, maybe PDE is nothing more than a PCNA attempt to drive up dealearship margins through transmission rebuilds.
Mark,
I've heard similar stories about him, but also about anyone who tries to drag race a TT.
Mike
Perhaps I misinterpreted your orignal comment. About drivers being more advanced there.
Can you elaborate?
[quote] Blipping during single-clutching merely reduces the speed differential between the clutch and the flywheel. To be of any benefit at all to the synchros, the clutch must be engaged when you blip <hr></blockquote>
Which is why it works with straight cut gears, right? Hey, maybe PDE is nothing more than a PCNA attempt to drive up dealearship margins through transmission rebuilds.
Mark,
I've heard similar stories about him, but also about anyone who tries to drag race a TT.
Mike
09-26-2002, 07:24 PM
#44
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[quote]<strong>Perhaps I misinterpreted your orignal comment. About drivers being more advanced there.
Can you elaborate?
</strong><hr></blockquote>
I was referring to Seth's description of how horrible the drivers were at the DE's he's attended. I was attempting to reassure him that on the West coast, that was not the case.
[quote]Originally posted by Mike in Chi:
<strong>
Which is why it works with straight cut gears, right? </strong><hr></blockquote>
Apparently. I've never been inside a gear box with straight cut gears, so I can only guess how they work.
Can you elaborate?
</strong><hr></blockquote>
I was referring to Seth's description of how horrible the drivers were at the DE's he's attended. I was attempting to reassure him that on the West coast, that was not the case.
[quote]Originally posted by Mike in Chi:
<strong>
Which is why it works with straight cut gears, right? </strong><hr></blockquote>
Apparently. I've never been inside a gear box with straight cut gears, so I can only guess how they work.
09-26-2002, 07:30 PM
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Wow... thanx for all the replies and advices, I really appreciate it.
Greg, thanx for your advice. I will dial in my speed slowly and gradually and I will not rush it.
Mark, DJ: I am hoping that the next time I meet you guys, you can show me how to trail brake in my car. Oh and I also can't wait to get a ride (or more accurately: get my neck sprained) from you guys with your new cars (can I get 3 laps only?).
Seth, I've been given a ride by DJ, Todd and other instructors at Tracquest (Mark's SRF requires a rope and skateboard if I wanna get a ride with him) and I can assure you that they are really fast. Actually I can only manage 3 laps being their passengers because I'll get really sick being in a rollercoaster like that for 30 minutes
I hope that you can join us at one of the Tracquest events, pal.
About double-clutching, I was just curious on when and where on the track it is necessary to do that. Most of the time I am doing heel and toe(not very smoothly yet). I guess the answer from the majority here is that it's not necessary to double clutch on the track
Thanx again all and have a great day..
Greg, thanx for your advice. I will dial in my speed slowly and gradually and I will not rush it.
Mark, DJ: I am hoping that the next time I meet you guys, you can show me how to trail brake in my car. Oh and I also can't wait to get a ride (or more accurately: get my neck sprained) from you guys with your new cars (can I get 3 laps only?).
Seth, I've been given a ride by DJ, Todd and other instructors at Tracquest (Mark's SRF requires a rope and skateboard if I wanna get a ride with him) and I can assure you that they are really fast. Actually I can only manage 3 laps being their passengers because I'll get really sick being in a rollercoaster like that for 30 minutes
I hope that you can join us at one of the Tracquest events, pal.About double-clutching, I was just curious on when and where on the track it is necessary to do that. Most of the time I am doing heel and toe(not very smoothly yet). I guess the answer from the majority here is that it's not necessary to double clutch on the track
Thanx again all and have a great day..