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Old 12-28-2009 | 07:31 AM
  #51  
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Honestly, I just shift to neutral then coast, if I happen to need to move like if a red light turns green before I get there, I shift into the respectable gear, give some gas and go. I sometimes downshift when entering a turn say from the highway or If I hit a 25mph zone from like a 40 and have to downshift then.
Old 12-28-2009 | 08:27 AM
  #52  
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Why is there 3 pages of posts on this thread...

Some people drive on public road like it's a track, and some people drive on the track like it's a public road, who cares? It's your brake pads and transmission, other members on this board won't pay for your wear and tear parts, so let people do whatever they want.

That being said, if anyone wants to pay for my transmission, I'll only downshift instead of braking from now on, heck I'll even double clutch to prolong the need for your payments. Holla at me for my paypal account.
Old 12-28-2009 | 09:12 AM
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Originally Posted by Kevo
Anytime you let off the accelerator and go to the brakes there will be a fraction of a second where there is a drag on the engine. That is true ALL of the time, but this is NOT a component of trail braking.

Certainly, the higher rev drag on the engine can help with rotation and is a dynamic you need to be aware of...but that is not engine braking as described in this thread...you are still trailing off the BRAKE as you turn in. The brakes are doing the braking...not the engine.

And you sir, are still an idiot.

My apologies to Mesaboogie for jacking this thread. Kevo out.
Sorry, but you are not correct. I was trained in a Formula Ford race car (I later raced RX7's in competition). We were taught to double clutch down shift when trail braking into the corner as the transmission, on those cars, don't have syncros. While your brakes are the primary braking force, you do leave the car in gear and foot off the clutch peddle while entering the corner. Because the RX8 trans has syncros, only simple rev matching is required.
When driving on the street, I would recommend not engine braking and simply use the brakes. It is cheaper to replace worn parts in the braking system than in the transmission.

(putting Moderator hat on) And, please avoid calling people names. Let's keep this discussion civil.

Last edited by alnielsen; 12-28-2009 at 09:15 AM.
Old 12-28-2009 | 03:23 PM
  #54  
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Good to know I wasn't doing it wrong.
Old 12-28-2009 | 03:38 PM
  #55  
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I think "Mr. Moderator" is right on. However, many of us who drove sports cars in the 60's,
70's and 80's always downshifed, even when on the street. It was kind of expected, and it was part of what having a "sports car" was all about. Even now, although my current RX8 is an AT, every now and then I'll put it in Manual Mode and play with the paddle shifters up and down to relive "old time"!
Old 12-29-2009 | 12:32 AM
  #56  
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Originally Posted by AJ's Shinka
Downshift always, engine brake on occasion, rev match rarely.
F**k your clutch.

-1.3L
Old 12-29-2009 | 08:57 PM
  #57  
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Originally Posted by alnielsen
Sorry, but you are not correct. I was trained in a Formula Ford race car (I later raced RX7's in competition). We were taught to double clutch down shift when trail braking into the corner as the transmission, on those cars, don't have syncros. While your brakes are the primary braking force, you do leave the car in gear and foot off the clutch peddle while entering the corner. Because the RX8 trans has syncros, only simple rev matching is required.
When driving on the street, I would recommend not engine braking and simply use the brakes. It is cheaper to replace worn parts in the braking system than in the transmission.

(putting Moderator hat on) And, please avoid calling people names. Let's keep this discussion civil.
When did I say that I kept the clutch in while entering the corner? You people need to stop reading what you want to hear and actually read what people write. Do yourself a favor and read my posts again. Maybe it will sink in this time.

Once people stop being rude, sarcastic and idiotic in their replies I will stop calling them the names they deserve.

Last edited by Kevo; 12-29-2009 at 09:48 PM.
Old 12-29-2009 | 09:06 PM
  #58  
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Originally Posted by bse50
The fact is your ego is probably bigger than your brain. Engine braking doesn't only happen if you don't use your brakes as well, it is an aid indeed in common braking, that's why you have to carefully downshift. In this way you actually reduce your stopping distance...
Duh...there is always a drag on the engine to one degree or another when you shift into a lower gear at a higher rev...thus always some level of "engine braking"...if that's what you want to call it...but it IS NOT a primary component that you should depend on to slow the car down...that is what the brakes are for. You would be smart to use them for that.

Make comments about my ego all you want...you don't even know me...??? Oh yeah, I drive a bimmer...I must be a *****. I made a comment about the content of your actual post which did indeed paint you with the previously mentioned "name".

And yes...you proved once again, your are indeed the name that shall not be mentioned.

Last edited by Kevo; 12-29-2009 at 09:16 PM.
Old 12-29-2009 | 09:41 PM
  #59  
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I downshift and rev match everyday...who cares about gas mileage...i know i didnt buy the car for that reason.
Old 12-30-2009 | 04:52 AM
  #60  
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Originally Posted by Kevo
Duh...there is always a drag on the engine to one degree or another when you shift into a lower gear at a higher rev...thus always some level of "engine braking"...if that's what you want to call it...but it IS NOT a primary component that you should depend on to slow the car down...that is what the brakes are for. You would be smart to use them for that.

Make comments about my ego all you want...you don't even know me...??? Oh yeah, I drive a bimmer...I must be a *****. I made a comment about the content of your actual post which did indeed paint you with the previously mentioned "name".

And yes...you proved once again, your are indeed the name that shall not be mentioned.
Nevermind about calling me whatever you want, it's the interw3bz and you can be as cool as you want without risking too much.
The drag that you get when down shifting is part gearing related and part engine brake. Since your braking distances are affected by the way you downshift to use this kind of braking saying, as you did, that you just have to let the brakes do their job seems like a stretch.
That's what i wanted to say in my first post, i think that we all know that you can't just downshift like a pig to brake before a corner. Again you can't just slam your brakes if you're willing to go enter the corner fast
Old 12-30-2009 | 11:36 AM
  #61  
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Originally Posted by Soaring Eagle
... many of us who drove sports cars in the 60's,
70's and 80's always downshifed, even when on the street. It was kind of expected, and it was part of what having a "sports car" was all about. Even now, although my current RX8 is an AT, every now and then I'll put it in Manual Mode and play with the paddle shifters up and down to relive "old time"!
Exactly. It's part of the ambiance and fantasy. Back then we were all Nuvolari, who thought so little of brakes that he once had them removed entirely from his car. Nowadays people with ATs can go into paddle mode and be Michael Schumacher or Alex Yoong. Or they can leave it in D and be Jim Hall or Hap Sharp.

Ken
Old 12-30-2009 | 11:39 AM
  #62  
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Originally Posted by bse50
Nevermind about calling me whatever you want
No worries...I am not gonna call you anything since you are not being rude, sarcastic, inflammatory or just flat out nonsensical. Please accept my apologies for the previous name calling. It was uncalled for.


Originally Posted by bse50
The drag that you get when down shifting is part gearing related and part engine brake. Since your braking distances are affected by the way you downshift to use this kind of braking saying, as you did, that you just have to let the brakes do their job seems like a stretch.
This is a simple easily understood concept...and is a well known artifact of downshifting...any higher reving engine that is under reving compared to the drivetrain will always cause more drag than a lower reving engine that is equally under reving compared to the drivetrain. When coming into a corner at highspeed while threshold braking and heel-toe downshifting engine drag is at best a secondary braking force EVEN when you are trying to use it to help with rotation. Your brakes are still doing almost ALL of the braking (nevermind inertia, tire scrub, drivetrain losses, etc that are also present)...and that is how it should be...that is what your brakes are designed to do. IMO it is not a stretch to ask the brakes to do their job.


Originally Posted by bse50
That's what i wanted to say in my first post, i think that we all know that you can't just downshift like a pig to brake before a corner. Again you can't just slam your brakes if you're willing to go enter the corner fast
Most people on this forum do not track their cars regularly (I realize many of you do)...but even fewer do to the point where they know enough about the dynamics involved to make the distinctions being discussed here. For those that do and can make them...they know what I am talking about. Yes, "downshifting like a pig" as you say is a terribly bad idea.

Agreed, it's never good to slam your brakes...squeeze them quickly and firmly so as to not upset the balance of your car. Let off the brakes just before you turn in...or if you prefer, you can trail brake (let off the brakes as you turn in) to help with rotation if you need it. I realize not everybody subscribes to trail braking...to each his own.

In a nutshell...If you are downshifting properly your engine never overwinds or drags your car down in any noticable way...it is smooth and seamless...essentially in lock step with your drivetrain. Those that have ever mis-blipped or under rev'd a downshift know how unpleasant it can be for the car's balance to have that extra dynamic thrown into the mix. For the times when you want a little help with rotation you can use it to your advantage provided you know how to control it.

But as I stated in my first post (and using your colorful description)...it is not a good idea to "downshift like a pig" and use your engine as a brake...especially at the track.

Last edited by Kevo; 12-30-2009 at 01:56 PM.
Old 12-30-2009 | 12:18 PM
  #63  
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Years ago, when I was in the Air Force, I bought my first car from this guy for $40. It was an Austin Healey Sprite - that had no working brakes except for the handbrake! And so, you better believe I downshifted that sucker like crazy, and yes, the engine most definitely "overwhined" as I brought it down to first gear to slow it enough to stop it with the handbrake!
Old 12-30-2009 | 12:28 PM
  #64  
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If your not down shifting your not having fun.
Old 12-30-2009 | 01:22 PM
  #65  
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You may not agree with Ross Bently's race driving techniques, but here is an excerpt concerning downshifting from one of his books...i have included an extra bit on heel-toe for those that are interested.
"Proper shifting technique is an often overlooked racing skill. Many drivers feel they have to bang off their shifts as fast as possible to go quickly. Wrong! In fact, the amount of time you can save is minimal, especially compared to the time you can lose if you miss one single shift. A shift should be made gently and with finesse. Simply place the shifter into gear as smoothly as you can. A shift should never be felt. You may be surprised at just how slowly and relaxed the world's top drivers shift.

Downshifting is one of the most misunderstood and misused techniques in driving. And it is a must for extracting the full potential of your car. It's not always easy - it requires timing, skill and practice - but when mastered, it will help you drive at the limit.

What is the real reason for downshifting? Many drivers think it's to use the engine to help slow the car down. Wrong again! The engine is meant to increase your speed, not decrease it. In fact, by using the engine to slow the car you can actually hinder accurate brake modulation and balance. Race drivers, and good street drivers, downshift during the approach to a corner, simply to be in the proper gear, at the optimum engine RPM range, to allow maximum acceleration out of the corner.

Again, the reason for downshifting is not to slow the car. I can't emphasize this enough. That's what brakes are for. Too many drivers use the engine compression effect to slow the car. All they really achieve is upsetting the balance of the car and and hindering the brake effectiveness (if the brakes are right at the limit before locking up and then you add engine braking to the rear wheels you will probably lock up the rear brakes), and more wear and tear on the engine.

Brake first then downshift...Think about it. If you are at maximum RPM in 4th gear and you downshift to third without slowing the car, you'll over-rev the engine. Remember that downshifting is not a means of slowing the car - unless you have no brakes.

To complicate things a bit, in racing you must downshift to a lower gear while maintaining maximum braking. This must be done smoothly, without upsetting the balance of the car. But if you simply dropped the gear and let out the clutch while braking heavily, the car would nose-dive - upsetting the balance - and try to lock the driving wheels because of the extra engine braking effect.

The smoothest downshift occurs when the engine revs are increased by briefly applying, or stabbing, the gas pedal with your right foot. This is called "blipping" the throttle. What this does is matches the engine RPM with the driving wheels' RPM. The tricky part is continuing maximum braking while blipping the throttle at the same time. This technique is called "heel and toe" downshifting...It is important to remember that you are constantly applying consistent brake pressure all the way through this maneuver. You are simply pivoting the right foot to blip the throttle while braking at the sme time...If you don't blip enough, the driving wheels will lock up when the clutch is re-engaged. That'll cause big problems. If you blip too much, the car will attempt to accelerate...and you are supposed to be slowing down...

Make sure that you always complete your downshifts before you turn into a corner. One of the most common errors I have seen drivers make is trying to finish the downshift while turning into a corner. As the driver lets out the clutch (usually, without a smooth heel and toe downshift), the driving wheels try to lock up momentarily, and the car begins to spin. Time your downshift so that you have completed it, with your left foot off the clutch and over onto the dead pedal area, before you ever start to turn the steering wheel into the corner."
Take it for what it's worth, but this is coming from a professional race car driver not me...although I have used these techniques on the track and can attest to their efficacy.

Last edited by Kevo; 12-30-2009 at 01:42 PM. Reason: spelling
Old 12-30-2009 | 01:37 PM
  #66  
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Originally Posted by SPHINX144
I only down shift before entering a curve. otherwise I shift into neutral, coast and brake, then engage the proper gear.
Me too. I real use downshifting at track days or tacking a curve. To come to a stop just put it in neutral and then brake.
Old 12-30-2009 | 01:45 PM
  #67  
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Originally Posted by Soaring Eagle
Years ago, when I was in the Air Force, I bought my first car from this guy for $40. It was an Austin Healey Sprite - that had no working brakes except for the handbrake! And so, you better believe I downshifted that sucker like crazy, and yes, the engine most definitely "overwhined" as I brought it down to first gear to slow it enough to stop it with the handbrake!
LOL! I bet you downshifted like a mad man!
Old 12-30-2009 | 03:13 PM
  #68  
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From: Caput Mundi
Originally Posted by Kevo
You may not agree with Ross Bently's race driving techniques, but here is an excerpt concerning downshifting from one of his books...i have included an extra bit on heel-toe for those that are interested.
"Proper shifting technique is an often overlooked racing skill. Many drivers feel they have to bang off their shifts as fast as possible to go quickly. Wrong! In fact, the amount of time you can save is minimal, especially compared to the time you can lose if you miss one single shift. A shift should be made gently and with finesse. Simply place the shifter into gear as smoothly as you can. A shift should never be felt. You may be surprised at just how slowly and relaxed the world's top drivers shift.

Downshifting is one of the most misunderstood and misused techniques in driving. And it is a must for extracting the full potential of your car. It's not always easy - it requires timing, skill and practice - but when mastered, it will help you drive at the limit.

What is the real reason for downshifting? Many drivers think it's to use the engine to help slow the car down. Wrong again! The engine is meant to increase your speed, not decrease it. In fact, by using the engine to slow the car you can actually hinder accurate brake modulation and balance. Race drivers, and good street drivers, downshift during the approach to a corner, simply to be in the proper gear, at the optimum engine RPM range, to allow maximum acceleration out of the corner.

Again, the reason for downshifting is not to slow the car. I can't emphasize this enough. That's what brakes are for. Too many drivers use the engine compression effect to slow the car. All they really achieve is upsetting the balance of the car and and hindering the brake effectiveness (if the brakes are right at the limit before locking up and then you add engine braking to the rear wheels you will probably lock up the rear brakes), and more wear and tear on the engine.

Brake first then downshift...Think about it. If you are at maximum RPM in 4th gear and you downshift to third without slowing the car, you'll over-rev the engine. Remember that downshifting is not a means of slowing the car - unless you have no brakes.

To complicate things a bit, in racing you must downshift to a lower gear while maintaining maximum braking. This must be done smoothly, without upsetting the balance of the car. But if you simply dropped the gear and let out the clutch while braking heavily, the car would nose-dive - upsetting the balance - and try to lock the driving wheels because of the extra engine braking effect.

The smoothest downshift occurs when the engine revs are increased by briefly applying, or stabbing, the gas pedal with your right foot. This is called "blipping" the throttle. What this does is matches the engine RPM with the driving wheels' RPM. The tricky part is continuing maximum braking while blipping the throttle at the same time. This technique is called "heel and toe" downshifting...It is important to remember that you are constantly applying consistent brake pressure all the way through this maneuver. You are simply pivoting the right foot to blip the throttle while braking at the sme time...If you don't blip enough, the driving wheels will lock up when the clutch is re-engaged. That'll cause big problems. If you blip too much, the car will attempt to accelerate...and you are supposed to be slowing down...

Make sure that you always complete your downshifts before you turn into a corner. One of the most common errors I have seen drivers make is trying to finish the downshift while turning into a corner. As the driver lets out the clutch (usually, without a smooth heel and toe downshift), the driving wheels try to lock up momentarily, and the car begins to spin. Time your downshift so that you have completed it, with your left foot off the clutch and over onto the dead pedal area, before you ever start to turn the steering wheel into the corner."
Take it for what it's worth, but this is coming from a professional race car driver not me...although I have used these techniques on the track and can attest to their efficacy.
Al said another thing and he too was a driver so...
What the dude your quoting forgets to say is that it is true that we downshift to turn in the proper gear but by doing so you're engine braking anyway, unless you just start braking and select the correct gear without doing a complete downshift or worse, you downshift while braking and keeping the clutch pressed.
Either way you look at it you use your engine brake while you downshift
Again, we can argue about the percentage of the braking duty being excerted by the 2 parts (brakes, engine brake) which will differ from driver to driver and from turn to turn.
What i think we got wrong at the beginning was the fact that you took my comment about heavily relying on engine brake and not the braking system of the car and not about it as an aid.
Old 12-30-2009 | 03:59 PM
  #69  
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I generally don't down shift to slow down. I don't put it in neutral to slow down either. I Just let off the gas and brake.
Old 12-30-2009 | 04:46 PM
  #70  
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Originally Posted by bse50
Al said another thing and he too was a driver so...
What the dude your quoting forgets to say is that it is true that we downshift to turn in the proper gear but by doing so you're engine braking anyway, unless you just start braking and select the correct gear without doing a complete downshift or worse, you downshift while braking and keeping the clutch pressed.
Either way you look at it you use your engine brake while you downshift
Again, we can argue about the percentage of the braking duty being excerted by the 2 parts (brakes, engine brake) which will differ from driver to driver and from turn to turn.
What i think we got wrong at the beginning was the fact that you took my comment about heavily relying on engine brake and not the braking system of the car and not about it as an aid.
The shifting/braking scenarios above seem to describe a shifting sequence that was somehow botched up and the poor guy is basically screwed in the corner. I am not interested in what happens when trying to salvage a botched turn sequence (although we have all had to deal with that at one time or another!). In my mind there is really only one true way to properly heel-toe downshift when threshold braking into a corner (there may be slight variations due to the driver but the basics still hold true), so I really can't even follow the exact point you are trying to make...but that's ok.

The good thing is that we both generally know where the other is coming from...and can agree to disagree over the finer details of how much engine braking actually occurs when properly rev-matching...my experience says it is virtually zero where yours says it is something more...no harm in that.

The rest of the forum goers can digest all this dialog as they see fit and hopefully come away with a bit of information that they can use to their benefit.

Last edited by Kevo; 12-30-2009 at 05:02 PM. Reason: spelling and grammar
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