RedR1

iTrader: (5)

This may be a rookie question, and if so, my apologies. However, I know in a conventional piston engine, heal and toe is utilized to bring revs up before downshifting, to prevent throwing all the rods up at the same time. What goes up, will probably shoot thru the valve covers, or come down. However, in a rotary, since the rotors are always in a circular motion, if we downshift without heel and toeing, will it have any adverse effect? I mean, we are only throwing the rotors around a little faster, and making the E-shaft spin a little faster?

I was talking about this last night to a couple other rotorheads, and no one could really agree. This is for a road race application, not city driving. Any help is greatly appreciated.

Chris~

speedturn

iTrader: (1)

If you are driving at the limit of traction and want to downshift smooth and not break the rear tires loose, then heal and toe is mandatory.

If you are a slow driver and you are not at the limit of traction, then you can get by without heal & toe downshifting.

RussTypeS

iTrader: (3)

YES!!!!!!!!

heal-toe has nothing to do with saving the engine, it's all about not upsetting the car while braking and not destroying your clutch!

you should heal-toe any time you downshift in any car, unless you are allready stopped . why put the extra wear on the clutch?

cruiser

If you dont heel-toe when downshifting, engine will have to catchup on the revs in lower gear and by doing this it is effectively braking the rear wheels. When on the grip limit, this additional rear braking will unsettle the rear and most likely send you sideways

RedR1

iTrader: (5)

Awesome. Thanks for the quick response guys!

christaylor

Not to mention you'll end up changing your clutch, too.

Boswoj

In addition, when driving at the limit the whole point is to do everything in the most efficient manner possible. At the end of the straight, it's desireable to stop in the least amount of space and time so you can stay on the throttle until the last possible moment. Braking must be done at maximum efficiency without locking the rear wheels by adding excess engine compression as was noted above. At the end of your braking zone, you want to smoothly taper out of the brakes and turn in, in gear with steady throttle to stabilize the car. With competent heel-and-toe technique you will find yourself in the proper gear, and in the powerband ready to quickly transition back onto the throttle without wasting time or traction. Do this test some time - drive through a corner at a reasonable speed in gear, at a steady rpm contolling the car with the throttle, then try to go through at the same speed, coasting with the clutch in, and see which feels more comfortable.

All high performance driving is just an increased awareness of weight transfer to individual wheels, and how it can be exploited to your best advantage.

Dick Elliott

As a racer for the past 50 years, I can tell you that heel and toe is a big bunch of BS, used only by sporty little drivers, that weigh 120 lbs and wear a size 6 shoe. Get in to your RX-7, with your size 12 Rebocks, and try to heel and toe, and see what happens. More tranies have been screw'd up by this BS, than any other reason. No body that races for a living, uses a clutch any more any way, so what are you going to heel and toe? Left foot brake: OK!!! Heel and toe: 1962- Jacky Stewart( the last great heel and toe racer). Just my two (2) cents worth.

RussTypeS

iTrader: (3)

lmao

Boswoj

Dick's full of crap. If you've got a racing transmission - and I mean something specifically made for racing which costs thousands of dollars and is only used in the fastest club racers and pro racing - then maybe something different is sometimes done. The cheap-assed local racers that make up about 99 percent of all the racers in the United States pretty much all heel and toe. I instruct many times a year and every single race and advanced lapping driver that I work with is able to do it adequately after a very reasonable amount of practice. Oh - and I have size 11 feet, which I put proper racing shoes on and have no trouble finding the space to heel and toe smoothly and properly in my tiny little 1st gen race car that I can hardly squeeze my lumpy body into. Nice troll Dick.

Dick Elliott

Gee! Isn't crap a four (4) letter word? I really would not want you for a driveing instructor, if you get that upset over my ideas. You must be one of those Pooshusss driveing instructors. They always get up tight over ever little thing. Lets see: toe on gas/heel on brake or is it heel on gas/ toe on brake or is it oh #@%& too late!!!! My old driveing instructor (1957) told me to go as deep as the other car, then deeper, then put both feet on the brake pedal. pray. and then pass the weenie, heeling & toeing in the other car. Since then (1957) I,ve passed more cars in the turns than elseware. You really should try it. You might like it. You really should learn to respect other peoples ideas, even if you don't agree with them. What will you be racing when your 71 ?

peejay

No it's not, it's to prevent upsetting the chassis with a lurchy shift (which you will still get with a rotary). Also makes like a hell of a lot easier on the transmission.


Of course, a rotary generally has a wide enough powerband that you find yourself shifting a lot less often.

As soon as I find a way to shrink-wrap my feet into shoes as small as US Size 12, I will let you know.

scotty305

iTrader: (2)

Dick, if your pedals don't fit your feet, it sounds like you should look into changing your pedals, wearing smaller-profile shoes while racing, or both.


Rev-matching is still a good idea, regardless of whether it's easy for you to learn or not. If you're not capable of doing it well, I'm sure you can get by without it, but it's still best to be as smooth as possible, and for most people this will include matching the flywheel speed to the driveshaft speed before releasing the clutch.


Re: the original question, I don't believe that heel-and-toe downshifting is AS necessary in a rotary compared to a piston engine, because the rotors have less inertia compared to the pistons rods, crankshaft, etc... You will not get the same level of 'engine braking' , so the rotary will be less likely to upset the balance of the car. I do think it's a good habit to get into: smooth is fast, and rev-matching is smooth.


-s-

cruiser

If I dont heel-toe under under trail-braking (braking & turning into apex at the same time) I will upset the rear. There is no way around it, unless you brake in straight line and use your clutch to match the revs.

Dick, I would love to hear how you avoid rear end from breaking away if you dont heel-toe. Thanks!

aznpoopy

heel toe is necessary if :

1) you want to downshift while braking.
2) you drive a regular car (i.e. you don't have some uber special paddle shifting nonsense)

do you revmatch when you downshift in rotary? yes.
so if you want to downshift while braking a rx7, you heel toe.

simple.

cruiser

You dont actually need to use your heel and your toe. I use sidestepping technique, but yes, everything as ^ said

RedR1

iTrader: (5)

Awesome, thanks for all of the feedback I love this forum~

855m0n0

iTrader: (1)

I use the side step technique (my feet are too big for heal toe) in a car. I also race sportbikes and we have a similar tech. for them too. I dont use the clutch for up or down shifts in the race bike, but still have to blip the throttle to keep the rear tyre from spinning up and upsetting the stability of the bike. The same holds true for any wheeled vehicle.

Most cars that have trannys that dont require clutchs (sequential, dog box, etc.) either have a clutch that slips to prevent wheel spin during down shifts, have the ECU rev match for the driver, or require the drive to blip the throttle to ensure rev matching.

It doesnt matter if it is a F1 car or a Go Cart or a 598cc race bike, tyres only have so much traction. If you are using 100% of it braking then there is none left for rear tyre movement due to non-revved matched down shifting. If you are not braking at the limits of tyre adheasion then you can get away with not doing some sort of heal toe-esk action and not losiong traction.

aznpoopy

whats a sidestepping technique? using the two sides of your foot held upright? you guys must have big feet! :P

Dick Elliott

If possible, all brakeing should be done in a straight line, as you should be back on the gas as you make your turn. The sooner you get back on the gas, the faster you will exit the turn. I've been driveing a race car for 52 years, and I couldn't heel and toe if my life was at stake. Maby that why I never won Daytona. Could be!!! DICK (its better to be a has been, than a never was)

scotty305

iTrader: (2)

Here's a good article on heel-toe downshifting:
http://web.archive.org/web/200312022..._heeltoe.lasso


Supporting article on pedals: the stock pedals are decent, but there is room for improvement.
http://web.archive.org/web/200312041...g_pedals.lasso


-s-

cruiser

Yes, I figured it would be this way. However, for the ultimate speed trail braking is required IMHO and this is where heel-toe comes into play.
With only straight line braking you are effectively loosing time. Its a proven fact - you need to brake earlier and you spend more time coasting then the other guy. But its hard to master trail-braking. I know I cant do it properly just yet

cruiser

Yes. You need either wide feet or a wider gas pedal. Your choice

cruiser

http://web.archive.org/web/200312022..._heeltoe.lasso :

On the street when you approach a corner, you were probably taught to complete your braking before the corner, coast through the turn, then as you straighten out from the turn downshift, and start accelerating again. This works on the street, but it is entirely too slow a process for the race track.

855m0n0

iTrader: (1)

Dick, I agree with you that most if not all braking should be done in a straight line and one should be on the throttle as soon as possible once into the turn. That is also what I was taught in race school. This is also what has yeilded me the best lap times. However, blipping the throttle to ensure rev matched down shifting, usually via a heal toe type action, was always taught at race school. It was not a big subject. Usually, the subject encompassed about as long as it would take to say this, "make sure when you get on the gas after a down shift that you have the engine at a high enough RPM to keep the rear tire(s) from unsettling".

The side step method is for people that have very wide feet (me) and when down shifting one blips the trottle with the outside of their right foot and brakes with the other side of the foot.

This arguement is actually very silly. In racing no one cares how you get the best consistant lap times, all that matters is that you do it. If heal toe results in fast consistant lap times then do it. If not, then screw it. Simple as that.

Brakes are for sissys anyway!