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Downshifts?


thewheelman

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Several years ago, when I was teaching my son to drive, as a matter of habit, I work my way down the gears each time I come to a stop. Being the upstart teen he was, he questioned me about it and I could give no better answer than that was the way I was taught. Now that I'm driving a straight shift on a regular basis (and loving it!) I'm wondering if I'm stressing the synchros by walking down through the gears at each stop.

 

What do you do?

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I do most of my downshifting from 6th to 5th to 4th and 3rd, but then just put it in neutral to coast/brake to a stop. I sometimes shift to 2nd at low speed but never to 1st unless right before pulling into my drive way. I've been using double-clutching to keep from stressing the synchros.

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Be it cars or motorcycles, downshifting is a common and necessary practice in any road course style motorsports race. You are using the engine's compression to slow the car (or bike) down, assisting the brakes and taking some of the load and heat off of them.

 

However, having said all that, you are indeed adding additional stress on the drivetrain when you do, and in general shortening the life of the clutch, flywheel, differental, and syncros.

 

You can offset the load on those components by bringing the engine speed up just before releasing the clutch, but you also slightly diminsh the engine braking too.

 

I downshift all the time, but never put the transmission into first gear until I have come to a complete stop.

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Be it cars or motorcycles, downshifting is a common and necessary practice in any road course style motorsports race. You are using the engine's compression to slow the car (or bike) down, assisting the brakes and taking some of the load and heat off of them.

 

However, having said all that, you are indeed adding additional stress on the drivetrain when you do, and in general shortening the life of the clutch, flywheel, differental, and syncros.

 

You can offset the load on those components by bringing the engine speed up just before releasing the clutch, but you also slightly diminsh the engine braking too.

 

I downshift all the time, but never put the transmission into first gear until I have come to a complete stop.

 

Exactly... rev-matching, and it has been discussed here before.

 

Apply enough gas to match the engine speed for that next lower gear then you'll be greatly reducing the stress on your drivetrain.

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Using the engine to help slow the car is WRONG. period. the whole point of heel/toe is to match the rev's for the downshift, but you are using the brakes to slow the car...not the motor.

 

downshifting through each gear to come to a stop, is a waste of time, and puts undo wear on clutch/tranny components. FACT.

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Using the engine to help slow the car is WRONG. period. the whole point of heel/toe is to match the rev's for the downshift, but you are using the brakes to slow the car...not the motor.

 

Actually slowing the car with downshifts is a critical part of road racing. I'm just talking about pulling up to a stoplight or making a street corner.

 

BTW, with as much torque as this motor has, you can pull away in 2nd easily, and I generally creep through parking lots in 2nd also. Now, if she gets to clattering and bucking, go to first, but this thing has gobs of torque at your beck and call.

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Actually slowing the car with downshifts is a critical part of road racing. I'm just talking about pulling up to a stoplight or making a street corner.

 

BTW, with as much torque as this motor has, you can pull away in 2nd easily, and I generally creep through parking lots in 2nd also. Now, if she gets to clattering and bucking, go to first, but this thing has gobs of torque at your beck and call.

 

 

no offense, but keep your day job, and dont go racing! :) just kidding, but you are however mistaken. you dont want to use the drivetrain to slow your car while road racing. the reason you downshift is to be in the proper gear for the track out, and acceleration through the corner....not to slow you down!! they teach you this day one at any school.....use your brakes, not your driveline. what happens when you dont downshift correctly...you probably wheel hop and spin your car.

 

yes, when coming to a stoplight and lets say i'm in 4th gear. all i do is brake, when i get to about 20mph i put in the clutch and put it in neutral. i DO NOT go to 3rd, then 2nd, then neutral. that is a waste.

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no offense, but keep your day job, and dont go racing! :) just kidding, but you are however mistaken. you dont want to use the drivetrain to slow your car while road racing. the reason you downshift is to be in the proper gear for the track out, and acceleration through the corner....not to slow you down!! they teach you this day one at any school.....use your brakes, not your driveline. what happens when you dont downshift correctly...you probably wheel hop and spin your car.

 

yes, when coming to a stoplight and lets say i'm in 4th gear. all i do is brake, when i get to about 20mph i put in the clutch and put it in neutral. i DO NOT go to 3rd, then 2nd, then neutral. that is a waste.

 

Okay, fair enough..I've taken several professional driving courses as well as instructed at open track club events too.

 

Please expain to all here what you do when your coming off the front straightaway of any track anywhere doing 120 + M.P.H. in fifth or sixth gear, and then slowing down to enter the first turn. Obviously one would apply the brakes first and quite hard, but what do you do with the gear that your in; leave it in fifth or sixth going into and through the turn? Would you just push the clutch in and coast through the turn in netural, or would you downshift into a lower gear in order to stay within the necessary powerband to get through the turn and the rest of the course?

 

My point is that no one is this particular forum is advocating dumping the clutch after going from a higher gear to a lower gear, and that is why we are saying that engine speed matching is a critical component of good downshifting, but to make a specific and all emcompassing statement that downshifting is wrong and then tagging your comments with the word FACT is actually the complete opposite, it is indeed not a fact.

 

Your point about the car's geometry negitively changing, along with potental wheel spin is absolutely accurate, however if you drive a manual transmissioned car (or motorcycle) in any kind of road course racing event, you will and must downshift the transmission after coming out of high speed straightway and into a turn, BUT you must downshift prudently and at with the engine being at the proper R.P.M. when you do.

 

Lets also take this into a real world street enviorment... when your on the freeway or highway traveling 65 M.P.H. and your about to take a long sweeping off ramp onto another freeway and the posted signs state that the recommended speed for the ramp is 50 M.P.H., what do you do, brake to 50 and then coast through the rest of the turn or stay in the gear that you were doing 65 in and then bog the engine through the ramp? No, after you have slowed down to a resaonable speed with the brakes, you then downshift into a lower gear in order to get around and through the remaining part of the off ramp and onto the next freeway.

 

Downshifting is not a waste of time, if anything it is a necessary part of driving a manual transmissioned vehicle.

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Thanks sonofgt, thought I had dropped off into the twilight zone or something. I've been driving a straight shift for better than 35 years and if I've been doing it wrong, all those folks that taught me were too. I've never been to a driving school, but downshifting to slow the car makes perfect sense and, if I'm not mistaken, is part of the cornering process.......geez, I didn't want to confuse anyone about the facts, but fact is, that's the way I do it and have yet to had a synchro, drive shaft or universal give out because of it.....

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Any SCCA Autocrossers out there?

Engine - Engine - Engine keeps your vehicle under control in and out of turns. Bottomline - no shifting required.

Motorcycles? What "Son of a GT" said, its all about keeping within the power band, entering the turn and pulling (not pushing) yourself out of the lean. Newer Supersport bikes have slipper clutches designed to compensate for that too low of a shift gear selected number range preventing a wheel hop. At least my ZX-6R is set up that way.

 

Day to day driving? Does it really matter? Anyone who has hit 140 + mph parachuting down to zero knows brake fade. If your just tooling around town--pick the parts you can afford to replace and wear it down. Your choice, brake pads in neutral as you coast to a stop or ceramic clutches in 6-5-4-3-2 as you run down the gears. Your choice.

 

Airborne

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but downshifting to slow the car makes perfect sense and, if I'm not mistaken, is part of the cornering process......

I do down-shift, most of the time it's to 2nd gear, prior to taking corners and release the clutch as part of accelerating out of the turn.

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when i have been to road racing events the instructors have always stated that downshifting is not meant to slow the car down,that is what your brakes are for.while downshifting is neccessary it is for keeping the motor in the power band not for assisting your brakes.downshifting is part of the cornering process but all of your braking and downshifting should be done before you enter into the corner

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Thanks sonofgt, thought I had dropped off into the twilight zone or something. I've been driving a straight shift for better than 35 years and if I've been doing it wrong, all those folks that taught me were too. I've never been to a driving school, but downshifting to slow the car makes perfect sense and, if I'm not mistaken, is part of the cornering process.......geez, I didn't want to confuse anyone about the facts, but fact is, that's the way I do it and have yet to had a synchro, drive shaft or universal give out because of it.....

I don't think Sonofgt said that you are supposed to slow the car down with your engine. You downshift to put the engine at the proper RPM.

 

Yes, you often lift the throttle and slow down without using the brakes as a manner of speed control, but that's only for minor corrections, and is more accurately described as coasting or lifting. The engine, clutch and transmission are not the brakes. The brakes are the brakes.

 

Think of it this way. You have a clutch disc, and you have brake pads. They basically do the same thing - wear themselves out against a metal plate. Which part do you want to replace?

 

Skip the bit about downshifting through all the gears coming up to a red light in traffic. Use the brakes. Neutral is your friend, and you will save a bunch of wear and tear on the drive train, even if you have to replace the brake pads slightly more often.

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when i have been to road racing events the instructors have always stated that downshifting is not meant to slow the car down,that is what your brakes are for.while downshifting is neccessary it is for keeping the motor in the power band not for assisting your brakes.downshifting is part of the cornering process but all of your braking and downshifting should be done before you enter into the corner

 

I prefer to try and have all of the braking and downshifting done just before the apex of the corner.

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I prefer to try and have all of the braking and downshifting done just before the apex of the corner.

I second that idea.

 

Timing is everything, but I think you want weight forward entering the turn, which means braking. I'd say (at least for a simple curve) brake on the straight before the turn in, clutch in, enter the turn with brakes, blip the throttle and downshift, brakes and clutch off, throttle, apex, accelerate as you wind out.

 

All this happens smoothly in a split second.

 

I'll let you know if it ever happens in a car that I'm driving. I'll probably be so surprised I'll run off the course.

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I second that idea.

 

...brake on the straight before the turn in, clutch in, enter the turn with brakes, blip the throttle and downshift, brakes and clutch off, throttle, apex, accelerate as you wind out.

 

I third your idea and mimic the same technique.

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This is all well and good, but...

 

Downshifting into 2nd gear when approaching a stop just *sounds* so good... I can't help it.

I've had instruction on a road course as well, and apply it to my daily driving in subtle ways. I like to keep in a good power band, maybe the light is going to change as I'm slowing down, and I'll already be in the right gear to resume speed.

 

 

 

 

But mostly I just love the sound...........

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This is all well and good, but...

 

Downshifting into 2nd gear when approaching a stop just *sounds* so good... I can't help it.

I've had instruction on a road course as well, and apply it to my daily driving in subtle ways. I like to keep in a good power band, maybe the light is going to change as I'm slowing down, and I'll already be in the right gear to resume speed.

 

But mostly I just love the sound...........

 

That's like putting stripes on a car to make it "look" good. Nobody here would do anything like downshifting to sound cool, would they? Next thing you know, we'd all be putting different mufflers on the cars and silly things like that.

 

PAY NO ATTENTION TO THE SIG

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Blah Blah Blah

I like downshifting hard before a corner getting the ass end a little squirly, slide the car to 110 degrees in the direction of the 90 deg. turn

then finishing it off with a power slide to get the car going in the right direction. You know, the steering wheel spends more time turning right

to make a left hand turn. Just like on TEE VEE.

But what I normally do is just let off the gas and brake till the engine is at around 1200 rpm put in the clutch or put it in neutral and stop/turn.

Brakes are cheaper that trans. parts.

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when i have been to road racing events the instructors have always stated that downshifting is not meant to slow the car down,that is what your brakes are for.while downshifting is neccessary it is for keeping the motor in the power band not for assisting your brakes.downshifting is part of the cornering process but all of your braking and downshifting should be done before you enter into the corner

Yep and it is a lot of fun to downshift and hear the exhaust rumble.

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There are a couple of places downtown, where I live, that provide a really nice echo. I love to drop it down in second and let it rumble for the whole down-hill block. An added bonus is catching my reflection in the storefront windows as I rumble past.....vanity, all is vanity!

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