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      05-05-2009, 10:04 PM   #23
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i find that the throttle response is not 100% consistent. the electronics must sense some subtle not-so-obvious difference and not allow the throttle to come up the same every single time. other instructors/drivers have made this comment when driving my car for a session or two.

Also, if you try to rev it once and you don't get enough throttle blip...good luck trying to get it to blip right away again without having to mash it down more than you want to (assuming you even have enough time to attempt another blip). it most often refuses to sufficiently respond to the additional blip.

I have found that waiting until the last possible moment to press the clutch pedal and initiating the blip/shift helps keep the tranny and engine at similar enough speeds to make the blip/shift smoother. when i get early to the clutch it can cause problems.
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      05-06-2009, 12:44 PM   #24
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Quote:
Originally Posted by Z4Kevo View Post
i find that the throttle response is not 100% consistent.
Typical of ALL newer BMWs with electronic drive-by-wire. Actually the MZ4 Coupe has the most consistent throttle response of all the drive-by-wire BMWs built to date.

You should drive an E9X and see what "inconsistent" throttle feels like. MASSIVE throttle delay.
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      02-21-2010, 10:34 PM   #25
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FWIW, I too roll my foot over. I use one half on the brake and the other half on the gas, similar to the method JRagan has come to adopt.
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      02-22-2010, 02:28 AM   #26
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This is me driving below. Just view the first ten seconds. Unless you want to see us monkeying around on the track.

Found that using the ball of my heel works very well. All in all, practice, practice, practice. I never got it right and always blamed the car, until one of my friends who's a better driver could nail 4-3-2 on my car very very smoothly. Only THEN i started to get it right.

Throttle is always very precise.

[u2b]<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/au_1HFpUJRo&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/au_1HFpUJRo&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/u2b]

Quote:
Originally Posted by jragan View Post
I, personally, am having a hard time blip-ing on downshift with the stock pedals. I can't see there's any way for me to heel-toe and it looks like the only thing I could do is along the lines of a side-step. What "maneuver" have you guys found that works best for you?
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      02-22-2010, 07:50 AM   #27
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Quote:
Originally Posted by Z4Kevo View Post
I have found that waiting until the last possible moment to press the clutch pedal and initiating the blip/shift helps keep the tranny and engine at similar enough speeds to make the blip/shift smoother. when i get early to the clutch it can cause problems.
You should have your clutch depressed at the moment of braking. If you don't release the engine from the drivetrain you not only be braking to reduce the motion of the car but also your engine as well. Some might think that "engine braking" would help the car decclerate faster but it does the exact opposite.
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      02-22-2010, 08:46 AM   #28
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I used the alternative method as well, practice every day on my commute to work, trips to the grocery store, etc. It's quite funny how many people will try to race you thinking you're "reving" at them but I just ignore it. I've also found it a lot easier to learn with sport mode off, but have things figured out where I can also manage with it on now as well.
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      02-24-2010, 02:55 PM   #29
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Quote:
Originally Posted by zeroselect View Post
You should have your clutch depressed at the moment of braking. If you don't release the engine from the drivetrain you not only be braking to reduce the motion of the car but also your engine as well. Some might think that "engine braking" would help the car decclerate faster but it does the exact opposite.
i've never heard this bit of advice before-- just the opposite, really, which is to keep the car engaged in gear as much as possible.

what you say is true, of course, since the engine just adds to the momentum (and inertia) of the moving car while in gear.

i'd guess it would be harder (for me) to properly rev-match if the rpms are allowed to fall all the way to idle by disengaging the clutch as soon as the brakes are applied.
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      02-24-2010, 03:33 PM   #30
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Quote:
Originally Posted by zeroselect View Post
You should have your clutch depressed at the moment of braking. If you don't release the engine from the drivetrain you not only be braking to reduce the motion of the car but also your engine as well. Some might think that "engine braking" would help the car decclerate faster but it does the exact opposite.
About 1 million racers data acquisition and physics disagrees with you.

Quote:
Originally Posted by R32 View Post
i've never heard this bit of advice before-- just the opposite, really, which is to keep the car engaged in gear as much as possible.
Go to 7k and kick in the clutch, then go to 7k and just take your foot off the gas, pretty clear what the difference is.

Friction and pumping > inertia in this case, especially in an 11.5:1 engine.
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      02-25-2010, 12:21 AM   #31
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Quote:
Originally Posted by zeroselect View Post
You should have your clutch depressed at the moment of braking. If you don't release the engine from the drivetrain you not only be braking to reduce the motion of the car but also your engine as well. Some might think that "engine braking" would help the car decclerate faster but it does the exact opposite.
I agree you should not engine-brake since that is what brakes are for, but depressing the clutch while braking is only necessary if you are changing into a different gear.
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      02-25-2010, 09:40 AM   #32
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Quote:
Originally Posted by RussRamz View Post
I agree you should not engine-brake since that is what brakes are for, but depressing the clutch while braking is only necessary if you are changing into a different gear.
I've always felt that the car wants to rotate more when I end up braking at really low revs or with the clutch in.
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      02-25-2010, 03:10 PM   #33
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Quote:
Originally Posted by O-cha View Post
I've always felt that the car wants to rotate more when I end up braking at really low revs or with the clutch in.
I've found similar as well.
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      02-25-2010, 04:01 PM   #34
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Quote:
Originally Posted by zeroselect View Post
You should have your clutch depressed at the moment of braking. If you don't release the engine from the drivetrain you not only be braking to reduce the motion of the car but also your engine as well. Some might think that "engine braking" would help the car decclerate faster but it does the exact opposite.
Please tell me you are not serious?
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      02-26-2010, 12:59 AM   #35
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Quote:
Originally Posted by O-cha View Post
I've always felt that the car wants to rotate more when I end up braking at really low revs or with the clutch in.
Do I understand you are depressing the clutch in the corner in order to rotate the car? I use trailing-throttle-oversteer to rotate through corners and have tuned the suspension in order to accomplish this. The only time I am on the clutch is changing gears. Balancing the car through the corner modulating the throttle is my driving style. One of many fundamentals I was taught by a pro race driver was to put the car into the proper gear BEFORE entering a corner--this includes clutch depression. I'm not saying what you are doing is necessarily wrong, just not what I learned and not my style. I would think using trailing-throttle oversteer would rotate the car more than simply depressing the clutch.
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      02-26-2010, 01:26 AM   #36
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Quote:
Originally Posted by RussRamz View Post
Do I understand you are depressing the clutch in the corner in order to rotate the car? I use trailing-throttle-oversteer to rotate through corners and have tuned the suspension in order to accomplish this. The only time I am on the clutch is changing gears. Balancing the car through the corner modulating the throttle is my driving style. One of many fundamentals I was taught by a pro race driver was to put the car into the proper gear BEFORE entering a corner--this includes clutch depression. I'm not saying what you are doing is necessarily wrong, just not what I learned and not my style. I would think using trailing-throttle oversteer would rotate the car more than simply depressing the clutch.
No, you're way off base. I am simply saying hat if you brake really hard out of gear, the car wants to rotate more, like in a straight line. Loss of engine braking does that since the brake bias effectively changes as a result.


Same idea as if you go through a corner that you could be in 2nd gear for in 3rd, you will push like crazy because the weight isn't being put on the front wheels from the engine braking.
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      02-26-2010, 01:31 AM   #37
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Quote:
Originally Posted by RussRamz View Post
I use trailing-throttle-oversteer to rotate through corners and have tuned the suspension in order to accomplish this. The only time I am on the clutch is changing gears. Balancing the car through the corner modulating the throttle is my driving style. One of many fundamentals I was taught by a pro race driver was to put the car into the proper gear BEFORE entering a corner--this includes clutch depression. I would think using trailing-throttle oversteer would rotate the car more than simply depressing the clutch.

I agree

That is how I do as well, and work's perfectly for me. I start using that after driving a oldsmobile for sometime, and that car was horrible, so using this method I always had way more control.

please don't ask me what I was doing driving a oldsmobile
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      02-26-2010, 01:35 AM   #38
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Quote:
Originally Posted by O-cha View Post
No, you're way off base. I am simply saying hat if you brake really hard out of gear, the car wants to rotate more, like in a straight line. Loss of engine braking does that since the brake bias effectively changes as a result.


Same idea as if you go through a corner that you could be in 2nd gear for in 3rd, you will push like crazy because the weight isn't being put on the front wheels from the engine braking.
I agree with that as well, but really depends on your suspension setup. I always had my suspension done for my way of driving.

(off topic: Illinois sucks about people to work on race or sport cars)
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      02-26-2010, 01:41 AM   #39
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Quote:
Originally Posted by O-cha View Post
No, you're way off base. I am simply saying hat if you brake really hard out of gear, the car wants to rotate more, like in a straight line. Loss of engine braking does that since the brake bias effectively changes as a result.


Same idea as if you go through a corner that you could be in 2nd gear for in 3rd, you will push like crazy because the weight isn't being put on the front wheels from the engine braking.

(I believe he does that as well) I do, using the brakes will shift the weight to the front, and that is the moment that shifting to a lower gear and giving gas you gain control of the car, and with some oversteer the turn is complete.

but this need to be a smooth.
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      03-01-2010, 11:46 AM   #40
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Quote:
Originally Posted by R32 View Post
i've never heard this bit of advice before-- just the opposite, really, which is to keep the car engaged in gear as much as possible.

what you say is true, of course, since the engine just adds to the momentum (and inertia) of the moving car while in gear.

i'd guess it would be harder (for me) to properly rev-match if the rpms are allowed to fall all the way to idle by disengaging the clutch as soon as the brakes are applied.
This should be only done if your changing down a gear. If you don't need to change down gear you will not be brake enough anyways to have the engines interia be a problem.
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      03-01-2010, 11:47 AM   #41
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Quote:
Originally Posted by O-cha View Post
About 1 million racers data acquisition and physics disagrees with you.



Go to 7k and kick in the clutch, then go to 7k and just take your foot off the gas, pretty clear what the difference is.

Friction and pumping > inertia in this case, especially in an 11.5:1 engine.
I would like to see the "1 million" of data that racers have.

If someone is still going to school ask your physics teacher.

Also don't forget that "engine braking" will put more stress on your engine.
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      03-01-2010, 12:18 PM   #42
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Quote:
Originally Posted by zeroselect View Post
I would like to see the "1 million" of data that racers have.

If someone is still going to school ask your physics teacher.

Also don't forget that "engine braking" will put more stress on your engine.
if thats your theory how would you explain automatics? they engine brake

Watch some races....they dont sit on the clutch when they brake in corners, they use the engine/brakes.
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      03-01-2010, 04:10 PM   #43
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Quote:
Originally Posted by zeroselect View Post
I would like to see the "1 million" of data that racers have.

If someone is still going to school ask your physics teacher.

Also don't forget that "engine braking" will put more stress on your engine.
This kids a joke....
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      03-01-2010, 04:37 PM   #44
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Quote:
Originally Posted by Crimson92 View Post
if thats your theory how would you explain automatics? they engine brake

Watch some races....they dont sit on the clutch when they brake in corners, they use the engine/brakes.
Most current race cars use sequential dog-gear style transmissions which only hammer O-cha's point further. The clutch is used to get the car moving, but between gear shifts up and down only a momentary release of the gas is required to prevent torque transfer from gear to gear. The engine remains loaded except for a brief second for gear changes.
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