Question about downshifting/braking
+ Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 15 of 17

This is a discussion on Question about downshifting/braking within the New Member Hangout forums, part of the Community - Meet other Enthusiasts category; Hi everyone, I'm a long-time reader, but new poster. Anyways, here's my question (and yes I've looked around before asking ...

  1. #1
    Registered User monduConstruct's Avatar
    Join Date
    Aug 2005
    Posts
    130

    Question Question about downshifting/braking

    Hi everyone, I'm a long-time reader, but new poster. Anyways, here's my question (and yes I've looked around before asking it).

    I just picked up my '05 WRX a few weeks ago and am more than in love with the thing. I park it outside of my window at work to stare at it all day!

    On to the question:

    Since I learned to drive manual transmission 9 years ago, I have always done the following coming into a turn that I am not stopping at: got on the brake some, pushed in the clutch, downshifted, and then let off the clutch while still on the brake (giving it no gas), letting the engine smooth out the deceleration around the corner.

    Recently I was driving with a friend of mine who knows a hell of a lot more about cars than I do, he's a mechanical engineer afterall, and he said that it was completely incorrect to do that type of downshifting without rev-matching. Now as I understand it, if I could successfully heel-toe, this would not be an issue, but I'm just too clumsy to make that an everyday driving technique.

    So. Could I please get some experienced opinions on:
    1.) Is downshifting in the manner I described above really that bad for the car?
    2.) Am I technically supposed to use the brakes all the way up to the turn harder than normal, let off the brakes just as I enter the turn, downshift while off the brakes and using gas to rev-match some, then use the brakes to further slow down around the turn after I've downshifted (with gas)? (this seems retarded to essentially stop decelerating and momentarily accelerate).
    3.) If both 1 and 2 are incorrect, what is the proper shifting/braking technique for slowing down around a corner (especially a downhill turn).

    Thanks for any opinions/advice!

  2. Remove Advertisements
    ClubWRX.net
    Advertisements
     

  3. #2
    Moderator YBNormal07's Avatar
    Join Date
    Jul 2003
    Location
    PA
    Posts
    6,245
    I Support ClubWRX
    Using a combination of foot braking and engine breaking as you've described does not hurt the car and is perfectly acceptable. Granted, it is not the smoothest nor the fastest way, but it isn't going to hurt anything unless you are at excessively high revs when commencing your engine braking. If you could rev match, it would be better of course. I use a similar method as what you described when I am on a road course, but that is mainly due to a preference and not being smooth at heel and toeing (much like yourself).

    #2 is absolutely wrong. Assuming this was meant to be used as the "fastest" way to enter and exit a corner, parts are correct, and parts are wrong. The most efficient (and usually the fastest) is: As you come up to the corner/curve, select your starting brake point, get on the brakes and stay on them until you have set the car up to enter the curve such that no further steering corrections will be needed once the car is committed. While on the brakes, push in the clutch and select the gear that will either allow you to maintain your speed through or accelerate through or out of the curve. Since you will soon be needing power to gain acceleration out of the curve, obviously your revs will need to be matched to your selected gear, if if possible, while braking, putting in the clutch, and selecting your gear (all while approaching your corner entrance), blip the throttle to bring your revs up. This is where heal and toeing come into play (in a modern car). It's not totally necessary to rev match, especially if you are going to use the engine deceleration in conjunction with your braking, but it is much smoother, and smoother is usually faster. If you are quick with your feet, you can easily get the revs matched immediately after disengaging the brake and clutch.

    The key though is to have all of your braking done prior to entering the corner, as additional braking (foot or engine) will upset the car's balance and line, thus causing you to correct with throttle or steering, which will impact your exit speed. With experience, braking during the turn is sometimes used to help the car to rotate and get it pointed where you can make more use of the entry speed you gained by trail braking.

    Heel and toeing is great, but it's too complicated for myself to use, as my times have been comparable using it vs not using it. When you are at +140 MPH entering a hair pin, it becomes very hard to focus on the footwork when you are feeling your way around. But I'm sure others are better at it than I am so don't take my word for it. It is also a "holdover" method of driving a car from when flywheels are so light that you have to heel and toe (and rev match...inherant with heel and toeing) in order for the car not to bog or die. Modern cars with their heavier flywheels are much less susceptable to stalling when off throttle, and our revs don't need to be as high to keep the flywheel momentum up where it is generating HP.

    So summary: Curve coming up. Clutch in, on the brakes (hard), while selecting lower gear. Wait for the curve entry. Blip throttle to rev match, Let off brake, Let off clutch. Modulate throttle to maintain or increase speed. These are not all individual steps, but a smooth
    tEh PriUs=teH faSTah!@@!
    08 Audi S5 Black Diamond edition
    SOLD: 05 SWP Legacy GT Limited 5MT, 13.3ish@105 (stage 2) crappy stock clutch
    SOLD: 04 MPS/SW WRX Sti. 12.971 @ 103.97 (stock)
    278 AWHP/283 AWT, Catback exhaust
    306 AWHP/341 AWT, Stage 2
    (Scott) Moderator-STi, Drag Racing, Car Purchasing, and Tutorial Forums

  4. #3
    Registered User monduConstruct's Avatar
    Join Date
    Aug 2005
    Posts
    130
    Thanks a ton for the response, I have a few questions though,

    1.) When you say "blip" the throttle, how do you do this if not heel-toeing?
    2.) Is this style of braking/downshifting applicable in everday street driving or is this more specific to the race track?


    Again, thanks, greatly appreciate the help!

  5. #4
    Registered User SouthFL_9-2x's Avatar
    Join Date
    Sep 2005
    Posts
    104
    For regular, street driving, there is no need to do this. Our tranny's synchro's allow us to get by without rev matching. But, if you wish to know.........

    Heel/toe, THRESHOLD BRAKING, as taught by Skip Barber (each school has its own method- I attended 5 days of Skip, so I pass on what I learned in the following):

    Sample 3rd to 2nd (applies to all gears) Heel/Toe/Brake (done while threshold braking).

    -3rd gear engaged.
    -Brake hard with the left side of your right foot (using the ball/toes of your foot).
    -Clutch in *while braking*
    -Shift to neutral *while braking*
    -Clutch out *while braking*
    -Blip the throttle (yaanga!) with the right side of your foot (you can just roll your foot over), all while maintaining brake pressure. It helps to angle your right knee inward, towards your left leg.
    -Clutch in *while braking*
    -Shift to 2nd *while braking*
    -Clutch out *while braking*

    Repeat process to step down from gear to gear.

    The entire reason for this whole mess is to keep the input shaft of the tranny rotating at a high rpm to match the engine speed of your downshift. This is not so important with today's synchro trannies, but the process is still beneficial in stabilizing the entire driveline under hard braking. It's essential for the shifter to in neutral when doing the rev match (if the clutch pedal is pressed the input shaft won't turn).
    Last edited by SouthFL_9-2x; 09-20-2005 at 09:57 AM.
    2005 SAAB 9-2x - Stage II

  6. #5
    Registered User SouthFL_9-2x's Avatar
    Join Date
    Sep 2005
    Posts
    104
    Quote Originally Posted by YBNormal07
    Using a combination of foot braking and engine breaking as you've described does not hurt the car and is perfectly acceptable. Granted, it is not the smoothest nor the fastest way, but it isn't going to hurt anything unless you are at excessively high revs when commencing your engine braking. If you could rev match, it would be better of course. I use a similar method as what you described when I am on a road course, but that is mainly due to a preference and not being smooth at heel and toeing (much like yourself).

    #2 is absolutely wrong. Assuming this was meant to be used as the "fastest" way to enter and exit a corner, parts are correct, and parts are wrong. The most efficient (and usually the fastest) is: As you come up to the corner/curve, select your starting brake point, get on the brakes and stay on them until you have set the car up to enter the curve such that no further steering corrections will be needed once the car is committed. While on the brakes, push in the clutch and select the gear that will either allow you to maintain your speed through or accelerate through or out of the curve. Since you will soon be needing power to gain acceleration out of the curve, obviously your revs will need to be matched to your selected gear, if if possible, while braking, putting in the clutch, and selecting your gear (all while approaching your corner entrance), blip the throttle to bring your revs up. This is where heal and toeing come into play (in a modern car). It's not totally necessary to rev match, especially if you are going to use the engine deceleration in conjunction with your braking, but it is much smoother, and smoother is usually faster. If you are quick with your feet, you can easily get the revs matched immediately after disengaging the brake and clutch.

    The key though is to have all of your braking done prior to entering the corner, as additional braking (foot or engine) will upset the car's balance and line, thus causing you to correct with throttle or steering, which will impact your exit speed. With experience, braking during the turn is sometimes used to help the car to rotate and get it pointed where you can make more use of the entry speed you gained by trail braking.

    Heel and toeing is great, but it's too complicated for myself to use, as my times have been comparable using it vs not using it. When you are at +140 MPH entering a hair pin, it becomes very hard to focus on the footwork when you are feeling your way around. But I'm sure others are better at it than I am so don't take my word for it. It is also a "holdover" method of driving a car from when flywheels are so light that you have to heel and toe (and rev match...inherant with heel and toeing) in order for the car not to bog or die. Modern cars with their heavier flywheels are much less susceptable to stalling when off throttle, and our revs don't need to be as high to keep the flywheel momentum up where it is generating HP.

    So summary: Curve coming up. Clutch in, on the brakes (hard), while selecting lower gear. Wait for the curve entry. Blip throttle to rev match, Let off brake, Let off clutch. Modulate throttle to maintain or increase speed. These are not all individual steps, but a smooth

    Absolutely. The easiest, most trouble free method is to get all your braking done while going straight. However, finishing all your braking before turn-in unloads the nose of your car and your front tires bite/steer less. Therefore, trail braking allows you to steer/point the car (as you've stated). I like the brake pedal tied to the steering wheel by a string analogy....
    ...When you enter your brake threshold, counterintuitive to street driving, you brake HARD. If a string were tied between your brake pedal and the bottom of your steering wheel, this would keep your steering wheel straight. As you scrub speed and slow down, you begin to let off your brake pedal to turn in, the string loosens and you can steer the wheel. The more slack on the string created as the brake pedal is unloaded, the more you can turn the steering wheel.
    2005 SAAB 9-2x - Stage II

  7. #6
    Registered User monduConstruct's Avatar
    Join Date
    Aug 2005
    Posts
    130
    So in everyday street driving you do not use these techniques? you guys just let the clutch out while still breaking and not applying gas (engine braking)?

    The WRX manual talks about engine braking so it can't really damage the car that much. I just worry about shortening the life of my clutch significantly by driving that way. I suppose for everyday driving I could just leave my car in the higher gear, get around the corner, then downshift appropriately as I go into the straight-away. though this seems like it would put a lot of additional wear on the brakes and potentially leave me in the middle of a turn w/ no power. Sigh.

    I do greatly appreciate the tips though. Its a topic which has been on my mind a lot freqently as I am often coming down a hill in let's say 3rd gear, there is a stop sight at the bottom at which I am taking a right hand turn for instance, and so I brake coming down the hill, and as I get to the turn I am often left wondering what the appropriate (puts the least wear on clutch/brakes) method of downshifting is to go smoothly around the corner. "Engine braking" has worked well for the last 9 years (ha!) but now that I have my new WRX, I want to drive correctly, and not be burning through clutches/brakes.

    Keep the advice/tips comin', this is a giant help!

  8. #7
    Registered User SouthFL_9-2x's Avatar
    Join Date
    Sep 2005
    Posts
    104
    Quote Originally Posted by monduConstruct
    So in everyday street driving you do not use these techniques? you guys just let the clutch out while still breaking and not applying gas (engine braking)?

    The WRX manual talks about engine braking so it can't really damage the car that much. I just worry about shortening the life of my clutch significantly by driving that way. I suppose for everyday driving I could just leave my car in the higher gear, get around the corner, then downshift appropriately as I go into the straight-away. though this seems like it would put a lot of additional wear on the brakes and potentially leave me in the middle of a turn w/ no power. Sigh.

    I do greatly appreciate the tips though. Its a topic which has been on my mind a lot freqently as I am often coming down a hill in let's say 3rd gear, there is a stop sight at the bottom at which I am taking a right hand turn for instance, and so I brake coming down the hill, and as I get to the turn I am often left wondering what the appropriate (puts the least wear on clutch/brakes) method of downshifting is to go smoothly around the corner. "Engine braking" has worked well for the last 9 years (ha!) but now that I have my new WRX, I want to drive correctly, and not be burning through clutches/brakes.

    Keep the advice/tips comin', this is a giant help!
    For street driving, I'm always heel/toe-ing and rev matching because I'm always practicing and it has become second nature. Braking with your foot is preferrable to engine braking because you do in fact wear your engine dunring engine braking. It's cheaper to replace your brakes than it is to relpace your engine. Rev matching prevents axle lock-up and over-revving and saves your synchros for endurance racing.
    2005 SAAB 9-2x - Stage II

  9. #8
    Registered User monduConstruct's Avatar
    Join Date
    Aug 2005
    Posts
    130
    so you use that method of heel/toe'ing that you described to me (Skip Barber method) in everyday driving huh? When you "blip" the throttle, how high do you run the rpm's up to? and is the idea to be entering into (in your example 2nd gear) the next gear down before the rpm needle has fallen all the way back to idle?

  10. #9
    Registered User Mr Kooyulator's Avatar
    Join Date
    Apr 2003
    Location
    Boston, MA
    Posts
    1,038
    i dont like the skip barber method. i learned by watching japanese race vids. i figure you dont need to drive loike a race car driver but if youre gonna learn the technique, they should be right. well, i like to downshift from 4-3 without braking. for me a downshift is one action, it all takes place in a fraction of a second. i throw the shifter from 4-3 at the exact instant i get on the clutch. i blip the throttle the exact instant the clutch releases the gear and then immediately let off the clutch. the clitch pedal basically goes in and out in a half a second or less for me. everything i just described happens in that window. 3-2 usually is a heel toe shift where you brake with your toe and then do what i just described above for the 4-3 but instead, using the heel to blip the throttle. it's amazingly effective and ridiculously fast once you get it down. i heel toe and rev mach every day in any situation of driving (actually not so much lately given gas prices). it just takes practice and a hunger for that rev match sound. vrRRMMMMM...
    <= i plan on abducting her in the wag

  11. #10
    Registered User SouthFL_9-2x's Avatar
    Join Date
    Sep 2005
    Posts
    104
    Quote Originally Posted by monduConstruct
    so you use that method of heel/toe'ing that you described to me (Skip Barber method) in everyday driving huh? When you "blip" the throttle, how high do you run the rpm's up to? and is the idea to be entering into (in your example 2nd gear) the next gear down before the rpm needle has fallen all the way back to idle?
    Well, what the blipping does is get the input shaft of the the tranny spinning (hence why it must be in neutral for the blip with the clutch engaged) if you would blip with the clutch pedal pressed in (clutch disengaged), the input shaft would not engaged and in would not spin. The spinning input shaft helps with the gear shift. Today's synchros eliminate the need for all of this choreography.
    The amount you blip (in RPMS) is determined by both your vehicle speed and engine speed. If you're coming from 130mph into a threshold brake zone, you want that blip to be strong (about 4-5K rpms) because you will be braking damn hard and the lower gear is coming quickly. The revs will die back down quickly, but again, it's just a matter of getting that input shaft spinning. Getting the whole driveline- from flywheel to axle shaft to work in unison really stabilizes the car and when everything is engaged (especially on RWD and AWD cars), from flywheel to tranny to driveshaft to rear end- you essentially have another structural member acting as a spine for rigidity.

    And yes, I actually do all that heel/toe work when driving to and from work .
    2005 SAAB 9-2x - Stage II

  12. #11
    Registered User SouthFL_9-2x's Avatar
    Join Date
    Sep 2005
    Posts
    104
    Quote Originally Posted by Mr Kooyulator
    i dont like the skip barber method. i learned by watching japanese race vids. i figure you dont need to drive loike a race car driver but if youre gonna learn the technique, they should be right. well, i like to downshift from 4-3 without braking. for me a downshift is one action, it all takes place in a fraction of a second. i throw the shifter from 4-3 at the exact instant i get on the clutch. i blip the throttle the exact instant the clutch releases the gear and then immediately let off the clutch. the clitch pedal basically goes in and out in a half a second or less for me. everything i just described happens in that window. 3-2 usually is a heel toe shift where you brake with your toe and then do what i just described above for the 4-3 but instead, using the heel to blip the throttle. it's amazingly effective and ridiculously fast once you get it down. i heel toe and rev mach every day in any situation of driving (actually not so much lately given gas prices). it just takes practice and a hunger for that rev match sound. vrRRMMMMM...
    I learned by driving around Sebring's Short Course and Daytona International Speedway's 24 hours of Rolex course in a race car.
    2005 SAAB 9-2x - Stage II

  13. #12
    Registered User rallymaniac's Avatar
    Join Date
    Nov 2003
    Location
    Special Stage
    Posts
    2,833
    Quote Originally Posted by SouthFL_9-2x
    Braking with your foot is preferrable to engine braking because you do in fact wear your engine dunring engine braking. It's cheaper to replace your brakes than it is to relpace your engine. Rev matching prevents axle lock-up and over-revving and saves your synchros for endurance racing.
    Hmmm, and how exactly do you wear your engine by doing that. That's first time i've heard about it.
    Straights are for fast cars...
    Turns are for fast drivers...
    Colin McRae

    My PHOTOGRAPHY

  14. #13
    Registered User SouthFL_9-2x's Avatar
    Join Date
    Sep 2005
    Posts
    104
    Quote Originally Posted by rallymaniac
    Hmmm, and how exactly do you wear your engine by doing that. That's first time i've heard about it.
    Brake wear is preferrable to engine wear. Engine braking done in an unmethodical fashion can result in a mechanical over-rev (something your rev limiter can't save you from) if you select the wrong gear. Heel/toe downshifting/ braking is more about stabilizing your engine and drivetrain than it is about scrubbing speed- That's what your brakes are for.
    2005 SAAB 9-2x - Stage II

  15. #14
    Registered User rallymaniac's Avatar
    Join Date
    Nov 2003
    Location
    Special Stage
    Posts
    2,833
    Yes you're right, but when you rev match you still engine brake because you don't have your foot on the throttle. So i guess you were talking about braking with your "clutch" technically because it's the clutch that brings the engine up to tranny speed in that situation and than once the driveshaft is properly engaged, engine braking starts.
    Straights are for fast cars...
    Turns are for fast drivers...
    Colin McRae

    My PHOTOGRAPHY

  16. #15
    Registered User SouthFL_9-2x's Avatar
    Join Date
    Sep 2005
    Posts
    104
    Quote Originally Posted by rallymaniac
    Yes you're right, but when you rev match you still engine brake because you don't have your foot on the throttle. So i guess you were talking about braking with your "clutch" technically because it's the clutch that brings the engine up to tranny speed in that situation and than once the driveshaft is properly engaged, engine braking starts.
    Clutch brings engine up to tranny speeds? No, other way around, engine blip brings the input shaft up to tranny speed (whilst braking with the left portion of your right foot in a continuous fashion).
    The key is to be able to apply continuous brake pressure with the left portion of your right foot while the right portion rolls over the throttle pedal for the blip. The brake is always braking during the procedure. Any resulting engine braking would be minimal.
    Last edited by SouthFL_9-2x; 09-20-2005 at 06:06 PM.
    2005 SAAB 9-2x - Stage II

+ Reply to Thread
Page 1 of 2 12 LastLast

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself. We strongly suggest that you stay away from using aol, yahoo, msn, and hotmail accounts. Sometimes the mail server blocks the emails from our server. As a result you will not receive any notifications including the confirmation email.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •