Heel-Toe on track

[Symmetrical]

Originally Posted by GTM_Challenge

It truly is an art that takes years to get down just right.

^This.

It just takes practice. It's like driving a manual for the first time. You stumble and stall, but once you get the hang of it, it becomes second nature.

[wheelhaus]

Originally Posted by Howardwei

I'm just a little confused now. It's been really good help from you guys. So say I'm at 50mph and I slow down for a corner and not knowing what's the proper speed. Wouldn't it always be good to shift to a lower gear? For ex. Like going through all the gear till like maybe 2nd gear since I take most street corners with 20 mph? Lower gears give you more torque right?
And do you shift into gear before you blip?

If you're approaching an unknown corner, you will naturally slow to a speed you're comfortable with, a speed that gives you enough confidence that you'll have time to react to any more unknowns. That being said, driving around the street is a far different mindset than driving on the track, where repetition builds familiarity and you naturally begin to push for later braking zones, more aggressive throttle application, better lines, and better lap times. The street is no place to push the car's limits (or your own), but certain techniques can be practiced, such as heel-toe.

As far as choosing which gear, it's entirely up to you and what RPM you want. At the track you may rarely be below 4k RPM, whereas on the street you may rarely be above 6k. There's too many variables to say "do this" or "do that" for any situation. If you're trying to keep the car "in the powerband", you typically want to keep it somewhere above 4k where the power and torque pick up. So as you are braking, if the current gear drops below 4k, you can downshift to keep the engine in the sweet spot. If you need to continue braking (and again the engine drops below 4k), downshift again. This may all happen over the course of two or three seconds.

Watch as many videos as you can to see how it all works together:
apply brake
clutch in
shift into lower gear and rev match to proper rpm (using your heel)
clutch out

KKaWing's video above describes it well, and trippinbillies40's video shows it in practice (watch his tach when he downshifts). Personally I was mesmerized by the pile of dirt rolling around the passenger footwell, it was hypnotic, lol

Lower gears do provide more torque, but it's relative to engine RPM. For instance, 2nd gear at 2000 RPM might feel sluggish compared to 3rd gear at 6000 RPM. But, both gears at 6000 RPM, 2nd will feel a bit stronger, but 3rd will carry the car to a higher speed. Ideally for performance driving or racing, you want to be at the beginning of the powerband as you exit a turn. This isn't always perfect for every turn, but you also don't want to exit a turn at really high rpm, where you'll instantly bounce off the rev limiter.

[rice_classic]

It's often hard to know what's right for a few reasons:

1: while there's some basic principles, there's more than one way to skin a cat (aka: there's more than 1 "right" way)

2: It's very difficult to teach someone via a message board

3: It's almost impossible, on an internet message board, to really know who you should be getting advice from.


So take all this advice cum-grano-salis.


Here's how I heal-toe rev match on track: (I overlayed a foot cam in the video so you can see my feet)

[ame="http://vimeo.com/70389681"]Spokane 2013, ITA Race on Saturday on Vimeo[/ame]

[rice_classic]

And you'll notice... I skip gears (always at this track but not always at others). Your brakes do the braking, not your clutch/tranny. Also, every time you're having to blip the throttle under threshold braking you risk a misplaced revmatch throttle blip that will upset your braking causing you to lock up or opposite; unnecessarily elongate your braking zone. Both are very bad if following a competitor closely into a corner.

There's one track locally where I go into turn 2 and shift from 5th to 3rd but then we go down a steep hill in 4th (90mph) into a 2nd gear corner. In that down hill brake zone, for some unknown reason (I've examined the data), the car just feels better when not skipping gears. However, even then (like in last weekend's race there) I will occasionally over rev the engine during the "blip" and as a consequence have to either push on the pedal harder to compensate or alter my braking line.

Ok, that's about all the info I can get across on a message board. Good luck, have fun at the track and be safe. Remember, enter the corner in the gear that you're going to leave the corner.

[Anthony]

I wish I could see these videos at work. SUBSCRIBED.

My FR-S should be arriving mid-August or so, and I should be arriving home late November to meet it. I'm very excited to start learning to heel-toe. I miss the experience of learning to drive a manual, so it's kind of like getting a second chance.

Like when you've seen a really good movie, one that you would/have watched multiple times, and are jealous of the people who haven't seen it because they still get to see it for the first time.

[rice_classic]

Originally Posted by CSG Mike

Always go into the gate, even if you don't let the clutch out. This will reduce wear on your synchros, and extend transmission life.

Hey Mike,

Can you elaborate on this because it's been my experience that the opposite is true. I've rebuilt several transmissions (albeit FWD and just recently in the paddock at the race track) but at looking at the operation of the various forks, collars and rods; I cannot see how skipping gears increases synchro wear. If you're skipping from 5th to 3rd then your not putting wear on the 4 gear synchro on that corner, lap after lap after lap. To me, that reduces wear. It looks like what you're advocating is trading 4th gear synchro wear in exchange for 3rd gear synchro wear.

Now where I would recommend what you suggest is in the instance where the 3rd gear in your transmission is going bad, it "crunches" on the downshift and you don't know how to double clutch while heel-toeing. With a bad 3rd gear synchro, you can down shift from 5th to 3rd and row through 4th with the clutch still depressed which will aid in slowing the main/counter shafts allowing for the collar to slide over 3rd gear more easily without a "crunch". But doing this is trading 3rd gear synchro wear for 4th gear synchro wear. It's kind of a moot point anyway though because the revmatch downshift to the 3rd gear synchro isn't anywhere near as stressful as the upshift from 2nd to 3rd is when you're doing so at redline. At this point, it's all just 6 of one and half a dozen of the other I suppose.

[CSG Mike]

Originally Posted by rice_classic

Hey Mike,

Can you elaborate on this because it's been my experience that the opposite is true. I've rebuilt several transmissions (albeit FWD and just recently in the paddock at the race track) but at looking at the operation of the various forks, collars and rods; I cannot see how skipping gears increases synchro wear. If you're skipping from 5th to 3rd then your not putting wear on the 4 gear synchro on that corner, lap after lap after lap. To me, that reduces wear. It looks like what you're advocating is trading 4th gear synchro wear in exchange for 3rd gear synchro wear.

Now where I would recommend what you suggest is in the instance where the 3rd gear in your transmission is going bad, it "crunches" on the downshift and you don't know how to double clutch while heel-toeing. With a bad 3rd gear synchro, you can down shift from 5th to 3rd and row through 4th with the clutch still depressed which will aid in slowing the main/counter shafts allowing for the collar to slide over 3rd gear more easily without a "crunch". But doing this is trading 3rd gear synchro wear for 4th gear synchro wear. It's kind of a moot point anyway though because the revmatch downshift to the 3rd gear synchro isn't anywhere near as stressful as the upshift from 2nd to 3rd is when you're doing so at redline. At this point, it's all just 6 of one and half a dozen of the other I suppose.

First off, lets return to the basics. This is what a (simplified) drivetrain looks like:

Engine <-> Clutch <-> Midshaft <-> Transmission <-> wheels

Effectively, it is the clutch's job to connect the engine to the midshaft, and the transmission's job to connect the midshaft to the wheels. The clutch is engaged/disengaged via clutch pedal, and the transmission engaged/disengaged to connect the midshaft to the wheels at different ratios.

The clutch can "slip" to make up for differences between the engine and midshaft rotation speeds during the engagement process. Likewise, the synchros on the transmission will "slip" (technically incorrect, but same purpose) to bring the midshaft rotation speeds in line with the wheels at the ratio of the gear selected.

Now, for example's sake, lets say you're going 70 mph, in 5th gear, and this is roughly 4000 RPM. In 4th gear, this would be roughly 4800 RPM, and in 3rd gear, roughly 6200 RPM. When the transmission and clutch are both disengaged, the midshaft, momentarily, is spinning at the same RPM as the engine. Friction will slowly bring this speed down, but for the purposes of our example, lets assume there is no friction. If you're downshifting from 5th to 4th at 70 MPH, then the 4th gear synchro is bringing the midshaft up to 4800 RPM so that the gear can engage as you go into the gate, a load of 800 RPM. If you go from 5th to 3rd, then the 3rd gear synchro needs to bring the midshaft from 4000 RPM to 6200 RPM, a load of 2200 RPM. However, if you go into the gates sequentially, then going from 4th to third at 70MPH reduces the load to 1400 RPM.

Not only are you splitting the RPM load between the synchros over two gears, when you factor in the speed of gear engagement, you're also effectively doubling the amount of time being allowed for the RPM changes to happen. The amount of time being allowed for a synchro to do its work also affects wear. If you gently hold the shifter against the gate of a gear, it'll eventually "slip in" effortlessly when the synchro has brought the midshaft up or down to the appropriate speed of the gear. Conversely, if you shift very quickly, you'll need a lot of effort to get into the gear. This is why it's very difficult to get into 1st gear when you're doing 60MPH. Can you do it? Yes, but the load on the synchro is so large that it takes a while for the midshaft to speed up to the appropriate RPM, even if you push HARD.

Please let me know if I need to clarify anything here; I'm typing this train of thought while constantly getting inturrupted at work.


*note* the total amount of work being done by the synchros is the same. The key here is splitting the load, and allowing the work to be done over a larger period of time.

[rice_classic]

Edit: Things in this post by myself are factually inaccurate because transmissions are little more than black magic and created by elves in dark places from far away lands. I have corrected the oversights in the later post.

Originally Posted by CSG Mike

Likewise, the synchros on the transmission will "slip" (technically incorrect, but same purpose) to bring the midshaft rotation speeds in line with the wheels at the ratio of the gear selected.

The gears spin freely via needle bearings on the main-shaft they are only being rotated via their corresponding gear on the counter-shaft until they've been locked to the shaft via the shift collar. This is semantics but the distinction is clear: The synchro does not bring the input or output shaft into speed with the gear. The synchro brings the gear into speed with the shaft.

Originally Posted by CSG Mike

If you're downshifting from 5th to 4th at 70 MPH, then the 4th gear synchro is bringing the midshaft up to 4800 RPM so that the gear can engage as you go into the gate, a load of 800 RPM.

However, if you go into the gates sequentially, then going from 4th to third at 70MPH reduces the load to 1400 RPM.

*note* the total amount of work being done by the synchros is the same. The key here is splitting the load, and allowing the work to be done over a larger period of time.

That would make sense if what we were doing was synchronizing the shaft speed but we're not, we're synchronizing the gear speed in relation to the shaft.

For sake of argument, lets assume a 5 gear is a 1:1 ratio. This way we know that the input shaft and output shaft at 4000rpms are both spinning at 4000 rpms and we will use 70mph for this. Now if I want to change down to 3rd gear while maintaining 70mph our output shaft will remain at 4000rpms (70mph) and in our "frictionless vacuum", with the clutch depressed the input shaft (shaft that goes into clutch) remains free spinning at 4000rpms. When we shift from 5th to 4th we are matching the gear to that shaft speed not the other way around so now we have engaged 4th to the shaft via the synchro and since all we did was change the speed of the gear (and not the shaft) that means the shaft is still spinning at 4000rpms when we select 3rd and the synchro will have to do the same work regardless of whether or not we went from 5th to 3rd or 5th-4th-3rd in the same clutch depression.

So all we have achieved by using the 4th gear gate in between 5th and 3rd is a slowing of our shift which gives the gearset time to slow down (by a fraction of a second) in the oil which negligibly reduces any wear on the 3rd gear synchro but yet puts unecessary wear on the 4th gear synchro and to absolutely no benefit in lap time.

So I guess I stand by my argument that using the 4th gear "gate" while the clutch is still depressed while going from 5th to 3rd does little to nothing to reduce the wear on 3rd and only adds wear to 4th unnecessarily.

Thank you for the polite discussion as always. Your turn.

[rice_classic]

Non-related to the debate Mike and I are having..


Heel-Toe-Double-Clutch

This is my 72 year old dad in my race car:
[ame="http://vimeo.com/70975448"]heeltoedoubleclutch on Vimeo[/ame]

[CSG Mike]

We'll agree to disagree... because I know we can go on forever.

Strong anecdotal evidence the skip shifting causes premature failure, based on my S2k experience, however.

[CSG Mike]

Woodwork from S2ki. This post is 12 years old!

I am the woodwork and I work for American Honda.
I am writing this to hopefully help S2000 owner/drivers understand the importance of shifting properly to minimize the damage to 2nd gear synchronizer rings. I'm not the Warranty Police but will from time to time quote warranty policy when I read things like "Shifting without the clutch".

My overall objective being in the woodwork is to keep S2000 owners from hurting themselves and hurting their cars. Everytime a transmission or engine gets replaced in an S2000 I get the part. I've seen a lot of damaged transmissions.

Before flaming me please read this and keep an open mind.

You have an engine that revs to 9000 RPM. That means that the transmission mainshaft and clutch disk are also revving to 9000 RPM. When you disengage the clutch (push in the pedal) to shift from first to second the engine and the transmission are disconnected. The engine will slow down from compression when you lift off the throttle. The mainshaft of the transmission is not connected to the engine any more so it is freewheeling in the transmission. Given enough time the mainshaft will slow down but not as fast as the engine. The countershaft is connected to the rear wheels and the speed stays constant during the shift.

When you shift into 2nd gear the synchronizer of the 2nd gear must SLOW DOWN the transmission mainshaft to match the speed that the engine WILL be going when the shift is completed and the clutch is engaged.

The transmission mainshaft and the clutch disk together weigh 19.75 lbs. (not including the pressure plate and flywheel that are connected to the engine) When you shift from 1st to 2nd at 9000 RPM the engine speed drops to 5900. That means that the little brass synchronizer rings have to push on the 2nd gear to slow the mainshaft from 9000RPM to 5900 RPM. It not only has to slow down the mainshaft it has to do it in the time that it takes you to shift. So if you have a tendency to shift fast you may be making the sleeve blow past the synchro rings before it has a chance to do it's job and it will smash into the 2nd gear.

The early '00 cars needed a little change to the sleeve to make the synchros work a little harder. That is what the new parts in the service bulletin are for. Cars after VIN YT006255 already have the new parts. Grinding in a car produced later than 6255 is possible if the synchros have been damaged and now are not able to slow down the mainshaft properly.

Shifting without the clutch, or, shift too quickly and not letting the synchros do their job may permanently damage the gear, sleeve and synchros and make the 2nd gear grind more often.

It makes sense that if shifting at 6000 makes the engine speed drop to 4300 RPM, (1700) into 2nd gear then you should give the 2nd gear synchro twice the time to do the shift from 9000 RPM.

If your car does grind once in a while you may not want the transmission removed, disassembled and a new 2nd gear put in. If it does it quite often, show it to the dealer and have it replaced.

If you hesitate for another 1/2 second while putting constant pressure on the shifter while the 2nd gear synchro does it's job, I'll bet many of your cars would not grind any more. Try it. You might like it.

Added 5-2-03:
Skipping gears:
I have seen many 6th gear sleeves that have been damaged.

The typical story is this: Stop light, 1st gear, engage the clutch, rev to 9,000 RPM, shift quickly to 2nd, rev to 9,000 RPM, same into 3rd, look down and find the car going 80 MPH on a city street and the engine noise is screaming, recognize that any cop is going to write a ticket. Shift to 6th quickly to lower engine noise.

Dragging the mainshaft speed down from 9,000 RPM to 4,000 when going from 3rd to 6th takes time. 6th gear has only a single synchro ring and it doesn't like it. It will grind if you are shifting hard and fast. By shifting hard the synchro ring does not have time to slow down the main-shaft and the sleeve will slip over the synchro and grind the gear. If the sleeve is ground enough in 6th then it will not slide the other way to engage 5th.

So if it is hard to get your car into 5th or 6th it may be because the sleeve is being damaged by skipping gears. Hope this makes sense.


Woodwork

[rice_classic]

Originally Posted by CSG Mike

We'll agree to disagree... because I know we can go on forever.

Strong anecdotal evidence the skip shifting causes premature failure, based on my S2k experience, however.

NO WE WON'T! Someone here is wrong!


.....and it's me (sort of). So I will eat crow.

Yup, the gears on the mainshaft (input) spin with it. You were right about that. The gears do ride on the shaft with needle bearings but because of the counter shaft they spin in relation to the mainshaft so slowing the gear, is slowing the shaft.

Thank you for the correction.


Now, woodwork. Let's address that. Woodwork is specifically talking about upshift and even skipping gears during the upshift. Why? Because downshifting isn't done when the engine is at redline, the engine speed is always lower when downshifting under braking, the synchro is doing exponentially less work. The upshifts are the primary wear feature on the synchros.

However, I do concede that a row through 4th (with clutch still depressed) before snagging 3rd will transfer some wear away from 3rd and onto 4th and that you are right. I still maintain that the wear savings is negligible in this regard though.


I still won't do it.

A) Well because I have triple cone synchros on my 3rd gear and not on my 4th!
B) I want my right hand spending the least amount of time off the steering wheel as possible when threshold braking at 130mph. Doing the extra "row" just isn't worth it.
C) The more time you spend whipping your shifter about puts more wear on aluminum runners on shift forks.. once these wear out, it's a lot more expensive than some brass synchros. (also see: don't rest your hand on the shifter)
D) All of this is moot if you can heel-toe-double-clutch, then you have no wear on downshifts, skipping or not. Heck, you'd be able to downshift with no synchros at all.
E) It's too slow and for God's sake, I'm racing over here!


Oh yeah, and I just like to argue with you Mike.

[CSG Mike]

I need to practice my heel-toe-double-clutching...

On a side note, I thought I broke my trans on the s2k. Turns out my clutch disk failed. Not wore out, but failed. Waiting on pics to see how much clutch disk I have left after 115k miles of mostly track, canyon, and bumper to bumper traffic.

[Anthonytpt]

Does that mean you'll be up and running sooner? !

Originally Posted by CSG Mike

I need to practice my heel-toe-double-clutching...

On a side note, I thought I broke my trans on the s2k. Turns out my clutch disk failed. Not wore out, but failed. Waiting on pics to see how much clutch disk I have left after 115k miles of mostly track, canyon, and bumper to bumper traffic.