Hmmmmmm....... Learning Experience

[ghosty o''shark]

I completed my first track day over the Christmas break, at Mallory Park. I've put this in the Tuscan section because its more to do with the car than the track day.

Before I went I had no idea that I was going to learn something that could save my life. I am not totally daft, I know that all that power in the wet could spell disaster so I was very careful, I only accelerated in a straight line, I was cautious in the corners until I felt comfortable with the levels of grip, I gave myself plenty of time to break and I thought I would be fine. I was wrong!!!

During my first tuition session I managed to leave the track whilst traveling in a straight line, decelerating from 100+MPH, TWICE! Luckily the car slowed as it slid sideways and no harm was done, although the instructor said he honestly couldn't believe my luck.

So what I want to share with you, although I am sure many of you are aware, is changing down the 'box at speed and being a little to enthusiastic with the clutch will lock the rear wheels and you will go off!
It was the consensus of the instructors during lunch that this is one of the habits of most TVRs, especially the Tuscan. Too much speed, the revs die when you depress the clutch, bring the clutch up again in a lower gear and the 'box asks the wheels to bring it back up to speed. The wheels have a go but its wet, no traction so they lock and you slide. There are few cars that do this, Caterhams and the McLaren F1 do apparently.

So I just wanted to share this in case it could be of use to anyone else. The secret to prevent this is Heel and Toe braking which I intend to learn. This was demonstrated to me later that day when I was a passenger with a guy in a Tuscan S who went round the track in about half the time I did!!

The guys at RMA (the organisers), were excellent and I am going to go for further days, probably at Bedford as its got huge run offs!!

[danh]

Surely it shouldn't spin unless you are trail breaking or the surface has varying levels of friction?

Heal toe is definitely worth learning (I had a driver training day a couple of weeks ago where I learnt it), but I'm a bit horrified it span so easily. Do you have the standard suspension as I do recall reading the base Tuscan have high speed breaking stability issues.

Just wondering as I'm still toying with the idea of getting one.

[PetrolTed]

Bear in mind that the Tuscan is relatively light and if you're decelerating the forces will be acting on the front so the rear will be light anyway.

It's possible in any car. I had my first spin at Cadwell in my old S Series when I tried to change down from 3rd to 2nd approaching a corner.

[trackdemon]

I've had this happen on the public road - scary! Luckily it didn't result in a spin as I got the clutch back in sharpish. Slowly but surely I'm learning to heel and toe, but it's a bit scary when you give it too many revs and extend you're braking zone. I used to drive round this by changing down very late, ie when the engine revs are lower and deliver less engine braking.
As a general note I think both from experience and from what I've read that TVR's don't tend to be the most stable cars under braking - combination of relatively supple springs/dampers and light weight. I've learned that it's very important to start braking in a straight line and initial turn has to be very gentle if still braking - indeed this can be used to help turn the car in during the initial phase; its quite entertaining oversteering in, through, and out of a corner if not very fast!

[CraigAlsop]

danh said:
Surely it shouldn't spin unless you are trail breaking or the surface has varying levels of friction?

Nope, they all do that sir In fact the Tuscan & other speed six engined cars are probably less susceptible to this than the earlier Rover engined cars.

This is something I also found on my first track day in the Chimaera - second lap, end of the main straight at Knockhill - was heel-n-toeing, but didn't quite match the revs correctly. Car went completely sideways, but fortunately I managed to catch it, much to my Instructor's relief
In fact this behaviour is something that will happen in any powerful naturally aspirated RWD car (hell, it even happened in my old Capri, all those years ago, not that I'm suggesting it was powerful, you understand)

Go along as a spectator to any Ferrari Owners club track day, and position yourself at the end of any straight that has a good corner after it & you will see that same thing happening
It doesn't mean the car is crap, just the driver needs training...

[daydreamer]

CraigAlsop said: Nope, they all do that sir

If you think about it, if the car is already on the limit of grip, asking it to suddenly accelerate the engine is always going to push it over the edge. .

The reason that they go sideways is that the forces never exactly balance in the real world, so one side will go first. There is also feedback bewteen the wheels through the diff. I'm sure that you can do fancy things to reduce these effects, but they will never be totally abolished.

While doing a single seater day at Donnington, the instructors encouraged us to heal-toe using the left side of the foot to brake, and the right side to dab the accelerator. As a novice, I found this a bit easier than the doing what it says on the tin approach, especially wrt keeping pressure on the brake pedal. Anybody else tried this?

[Leadfoot]

That's the method I use as well. To actually 'heel & toe' would require me to break & reset my ankle first!

[CraigAlsop]

That's kinda the way I use as well - left side of toe/ball of foot to brake, right side of heel to blip throttle.
Most of the in-car shots I have seen of racing drivers feet in action seem to do something similar....

[DanH]

I don't think anyone actually has to use their heal these days. That name arose before pedal offsets shrank when people drove what are now classic cars.

If you think about it, if the car is already on the limit of grip, asking it to suddenly accelerate the engine is always going to push it over the edge. .

The reason that they go sideways is that the forces never exactly balance in the real world, so one side will go first. There is also feedback bewteen the wheels through the diff. I'm sure that you can do fancy things to reduce these effects, but they will never be totally abolished.

Except that its the rears that are locked, and 70%+ of the breaking force is at the fronts (if not going backwards ). It does sound like something better suspension setup could alleviate.

While doing a single seater day at Donnington, the instructors encouraged us to heal-toe using the left side of the foot to brake, and the right side to dab the accelerator. As a novice, I found this a bit easier than the doing what it says on the tin approach, especially wrt keeping pressure on the brake pedal. Anybody else tried this?

My instructore mentioned this, and he said it works fine in single seater race cars (formula renault etc), but its not a good technique in a road cars as the pedals are always further appart. I twist my heal outwards about 45 deg and then roll my foot to the right hitting the pedal with the right hand edge of my shoe (not the sole). Works a treat that way and makes it easy to control the size of the blip.

Also easier in thin soled driving shoes like Puma speedcats.

[Don]

CraigAlsop said: That's kinda the way I use as well - left side of toe/ball of foot to brake, right side of heel to blip throttle.
Most of the in-car shots I have seen of racing drivers feet in action seem to do something similar....

Yep. That's the way I do it too. Left side of foot braking. Clutch in. Twist foot so that right side shoe blips the throttle. Let clutch out as revs fall to match road speed.

I also tend to do the majority of the braking before changing down (last third of braking I was taught) so that helps too. In fact - its not far off the IAM thing of doing all the braking then actually being off the brakes before slotting the car into the desired gear. It'd be too slow on the track but on the road it works fine...

[DanH]

I also tend to do the majority of the braking before changing down (last third of braking I was taught) so that helps too. In fact - its not far off the IAM thing of doing all the braking then actually being off the brakes before slotting the car into the desired gear. It'd be too slow on the track but on the road it works fine...

Am I missing something, but surely the IAM way of doing it is simply double de-clutching (assuming you match the revs). Thats just a technique for people who aren't limber enough to heal toe, or to match the revs when you aren't actively breaking as far as I'm aware (i.e. maybe when coasting to a lower speed etc)?

[Pelo]

A good example of heel toeing here:
www.taylormarine.co.nz/motoring_5.mpg - Best one
And:
www.taylormarine.co.nz/motoring_1.mpg
www.taylormarine.co.nz/motoring_2.mpg
www.taylormarine.co.nz/motoring_3.mpg
www.taylormarine.co.nz/motoring_4.mpg

And its REAL LIFE Gran Turismo(Japanese production sports car series)
AND an RX-7 is winning
Ive been making some (rather dodgy) attempts at HTing, difficult but im getting there

[daydreamer]

Just waiting for the mpegs to download, so thought I'd put another couple of thoughts forward.

DanH said:Except that its the rears that are locked, and 70%+ of the breaking force is at the fronts (if not going backwards ). It does sound like something better suspension setup could alleviate.

Braking forces are on the front, but so is the weight. F=muR and all that, so even if 70% of the force is on the front, setting the rear bias too high, or overdoing the engine braking will lock the rears first.

Don said: In fact - its not far off the IAM thing of doing all the braking then actually being off the brakes before slotting the car into the desired gear.

Brakes are for slow, gears are for go - still remember this even though I haven't really been involved in the IAM for over ten years now .

More about only concentrating on one thing at once rather than maximising the braking forces on the car though. If you are concentrating on pressing two pedals with different forces at the same time, with the same foot, as well as changing gear and preparing for the corner, less chance of seeing numptie pedestrian stepping out in front. So, you see the corner in loads of time, have a gradual deceleration using the brakes, select correct gear and gradually accelerate around the corner.

Very safe driving, but as you said, not the way to minimise the lap time .

[CraigAlsop]

DanH said:
Except that its the rears that are locked, and 70%+ of the breaking force is at the fronts (if not going backwards ). It does sound like something better suspension setup could alleviate.

Sure, you could do what many manufacturers do, which is decrease the rear braking, so that you are never getting maximum braking.
With the TVR setup though, if you get it right, the car is probably stopping as fast is it can (i.e. maximum decelerative force at each corner).
The downside is that any extra deceleration at the back is going to destabilise things.

[Don]

DanH said:

I also tend to do the majority of the braking before changing down (last third of braking I was taught) so that helps too. In fact - its not far off the IAM thing of doing all the braking then actually being off the brakes before slotting the car into the desired gear. It'd be too slow on the track but on the road it works fine...

Am I missing something, but surely the IAM way of doing it is simply double de-clutching (assuming you match the revs). Thats just a technique for people who aren't limber enough to heal toe, or to match the revs when you aren't actively breaking as far as I'm aware (i.e. maybe when coasting to a lower speed etc)?

No. Double de-clutching is a different thing. This is letting the clutch out whilst you are in Neutral prior to selecting the next gear and letting the clutch out. Hence "Double" de "Clutch". It used to be necessary with older gearboxes...with syncromesh...its no longer required.

The IAM thing is simply to do all your braking. Then come off the brakes. Then declutch. Then select the gear you want. If necessary use the throttle to match revs with road speed. Then let the clutch out.

Achieves the same thing as heel and toe - but without any difficult foot fiddling. It works on cars whose pedal arrangements do not allow H&T as well.

And yes. Its the observation stuff that is much more important on the road...

[tuscanyes]

Ghosty,
That'll be me then that took you round Mallory Park that day. Hope I didn't scare you too much.....
As I said at the time, it's all good and well talking about heel n toeing etc etc but what you need to do is practice, practise practise. I'm on a track day at Bedford on Sat 25th Jan which is an excellent place to learn as there is nothing to hit (i.e. armco).