Forum Home / Ask the Experts! / Toe and Heel

18/04/2008 18:37:58
Tim Guy
Found a real need for this at Snetty yesterday dropping into second through Russel but missed the throttle a few times leading to a couple of 'moments' through putting too much engine braking effort onto the rear wheels at the wrong time. Stu was behid me for one of them and can vouch for the excitement :) Feel the accelerator pedal needs to be a bit lower for me to reliably succeed in this move. Does anyone else have this trouble in the F and has anyone found any extensions that might do the trick.
18/04/2008 21:51:41
JP12
[COLOR=black]I've never had the privilege to drive an F, but it's normally possible to heel and toe in most vehicles using the right technique. In my MGB racer it's very much a heel and toe technique, whereas in my old Renault Clio track day car it was more of a big toe on the brake little toe on the throttle technique.[/COLOR] [COLOR=black] [/COLOR] [COLOR=black]A good race shoe can make it a lot easier. It increases your 'feel' while still having a rigid sole. Plus, Alpinestar boots are a good fashion accessory[/COLOR]:D Joe
19/04/2008 09:30:12
Tim Guy
Thanks, its disgusting weather today, was going to do an oil change but instead might just sit in the drive for half an hour trying different methods. Any F'ers ;) want to comment.
20/04/2008 21:14:18
Neil
I find this quite interesting. On the whole with so much weight over the rear wheels in an MGF you can get away without heel and toe at speeds that many rear drive cars would struggle. However, a number of years ago when my MGF was purely a car for commuting I purchased a brake pedal lowering kit which as you may guess, lowered the brake pedal which assisted road driving. I understand that the TF, although I couldn't say about the Trophy, came with a lower brake pedal. Anyway, now on track I find that when braking the pedal is too low to easily use the accelerator. I will be experimenting with the height soon to see what difference it makes. In modern cars I think they try to design the pedal positions so that it isn't possible. Heel and toe in my wife's 68 Elan is so easy it's a natural reaction. Had the dubious pleasure of driving an A6 for a month recently and if you dared to touch more than one pedal at a time it instantly reduced the power from the engine. :eek: Maybe being allowed full control of the car was on the options list. Neil
21/04/2008 19:49:33
Debs
Personally, as a racing driver, I prefer to use the 'rolling foot' method for 'heel and toe', ie one uses the ball of the foot on the brake and rolls the foot sideways onto the accelerator. Unfortunately this isn't possible for me in a stock TF for 2 reasons: Firstly the pedal spacing is too wide for my wee feet (I cured this by fitting alloy pedal plates). Secondly the throttle pedal is too low with respect to the brake pedal. I will be addressing this by raising the throttle at some stage. Currently, therefore, I have to use the classic technique of using the ball of the foot on the brake and rotating the ankle so as to blip the throttle with the heel. Not the most comfortable of techniques, however it worked fine for me at Snett.
21/04/2008 21:36:07
Tim Guy
I understand what you are saying about the weight distribution Neil. What I was experimenting with was changing down whilst trail braking so the back was already close to going walkies without the extra engine decelleration. I was using the rotating ankle method at Snetty but having now had a bit of a play in the drive, realise that I was only really getting the edge of the throttle somehat unreliably with my instep, my heel is way to low to get it. The pedal levels appear quite good on the trophy with the throttle just a touch below the depressed brake pedal. If I try the rolling foot technique as Debs says there's too big a gap between brake and throttle for my size 7-1/2s. Think I might try a plate on the back of the throttle pedal extending it to the left.
21/04/2008 22:27:21
Dave
[quote=Debs]....Currently, therefore, I have to use the classic technique of using the ball of the foot on the brake and rotating the ankle so as to blip the throttle with the heel. Not the most comfortable of techniques, however it worked fine for me at Snett.[/quote] My approach too and one that Andy Walsh promotes for most modern sportscars. I also have the brake lowering kit that Neil mentioned, but actually find it helps!
21/04/2008 22:31:25
Dave
I should also mention that I was trail braking into quite a few of snetts corners - the F responds so well to it in my experience. Whenever you can do this with the left foot it helps even more, as you can bring in the throttle at the same time as you ease off the brake smoothing the whole process. Obviously, if you have a gear change to get in as well it's a bit of non-starter unless you have Andy Walsh's dancing feet. I've watched them first hand from his passenger seat and it's awesome.
22/04/2008 03:05:55
Tim
A picture (well, video!) speaks a thousand words. [URL="http://www.youtube.com/watch?v=cPj9XXW25GA"]http://www.youtube.com/watch?v=cPj9XXW25GA[/URL]
22/04/2008 07:14:33
Tim Guy
Thanks for your comments people. Going to have a play with these. Not a lot to loose if they end up in the scrap bin. [URL="http://cgi.ebay.co.uk/Classic-Non-Slip-Pedals-MG-MGF-MGB-MGFT_W0QQitemZ310042493507QQihZ021QQcategoryZ10414QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting"]http://cgi.ebay.co.uk/Classic-Non-Slip-Pedals-MG-MGF-MGB-MGFT_W0QQitemZ310042493507QQihZ021QQcategoryZ10414QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting[/URL] As for left foot braking Dave :eek: , I've a lot of practice before that works for me, can't quite get the feel of it. Tried it a couple of times but ended up either locking up or underbraking each with interesting results.
30/06/2008 19:05:32
adrian
I don't understand the point! Surely it is faster to simply brake properly, then rev match straight into the new gear ? surely heel toe will- -slightly spoil perfect foot control on the brake pedal -overstress the transmission -risk over revving the engine -unbalance the car by appling an extra braking force only to the rear wheels (in a rwd car) -generally get you in a muddle
03/07/2008 06:51:36
Tim Guy
Well, you're right about getting into a muddle - at least at first ;) You could really do without the added complication of changing down whilst braking into a corner but if if you don't, you pay the penalty of not being able to keep a balanced throttle through the corner and won't be able to accelerate out. Heel & toe allows you to change down whilst keeping optimum braking effort. Not raising the revs when changing down will unbalanced the car by putting engine braking load onto the driven wheels.
05/07/2008 14:23:31
adrian
[B]"if you don't, you pay the penalty of not being able to keep a balanced throttle through the corner and won't be able to accelerate out"[/B] -I can see an argument for heel toeing into your final gear, to avoid an interval between braking and throttle. But why bother blipping for all the other downshifts? eg, brake in 5th, heel toe straight into 2nd. [B]"Not raising the revs when changing down will unbalanced the car by putting engine braking load onto the driven wheels"[/B] -surely the exact opposite is true. I thought the braking force from the engine acting on the drive wheels is GREATER if the revvs are higher? Just imagine releasing the throttle at 60mph in 2nd gear compared to 5th gear!
05/07/2008 17:57:28
Tim Guy
[quote=adrian]-surely the exact opposite is true. I thought the braking force from the engine acting on the drive wheels is GREATER if the revvs are higher? Just imagine releasing the throttle at 60mph in 2nd gear compared to 5th gear![/quote] You have to put energy into getting the engine revs up in the first place (kinetic energy into the flywheel and other rotating parts) so if it doesn't come from your blipping the throttle to match the revs as you change down, it will have to come from the car's inertia via additional load on the driven tyres. The severity of this engine acceleration load on the tyres depends on how quickly you let the clutch out after you've changed down. Once you are in the lower gear, the deceleration / acceleration from the engine can be controlled by balancing the throttle. - but if you still require braking at this stage we're into using the left foot on the brake. There's a video by Andy Walsh that shows how this is possible in combination with a toe and heel gear shift. Not many are anywhere near skilled enough to do this. EDIT Ah, [URL="http://www.youtube.com/watch?v=QW4ef0E7DQs"]Here'[/URL]s the clip
18/07/2008 07:30:42
Shaf
[quote=adrian]I don't understand the point! Surely it is faster to simply brake properly, then rev match straight into the new gear ? surely heel toe will- -slightly spoil perfect foot control on the brake pedal -overstress the transmission -risk over revving the engine -unbalance the car by appling an extra braking force only to the rear wheels (in a rwd car) -generally get you in a muddle[/quote] If you are not driving right on the limits then you are better off not doing heel and toe. If you are able to do it properly though it helps smooth out the driving at one of the most critical points. The point is that you need to get good at it so that you don't disrupt your braking. It does not overstress the engine and in fact does exactly the opposite. You only blip the throttle during the gearchange so you are effectively in neutral. You use engine torque (which is otherwise redundant at that point) to raise the engine revs for the next gear down rather than using the synchromesh. It also means that the gear should engage more quickly as the input shaft and output shaft have the right speed matching so you don't slip the syncro (Which is basically like a little clutch on the gear). When you engage a lower gear then the engine has to be accellerated. If you don't do a throttle blip then it is accelerated only when you let the clutch out. This means anything it does is actually transmitted to the wheels. And as you are increasing the engine speed it will add a fairly sudden extra retading force to the wheel. Hence you are more likely to lock up the rears without a blip. Exaclty the opposite to what you suggested above. You cannot Over rev the engine doing heel and toe. The rev limiter will limit the revs during the blip. Of course you can rev the engine too high for the next gear, which loses you most of the benefit of the blip in the first place. Or you can over rev the engine if you engage too low a gear. But this is all about getting to know your vehicle and working with it. You are quite right though on your last point. If you do it wrong you can get in a muddle and make your life worse. The key is to first concentrate on your lines and steering. Once you are happy you are getting the best you can from that, try heel and toe. It takes a while to perfect but is very useful if you can do it correctly. Shaf
18/07/2008 07:32:37
Shaf
Some people have mentioned a brake lowering kit. What does this involve? I have a very firm pedal and my accelerator is quite a bit lower. Not ideal for heel and toe. Before I fitted the braided hoses I could heel and toe more easily because I had what felt like a few cm travel int he brake pedal but now I either need to raise the accelerator or lower the brake. Shaf
19/07/2008 08:40:40
Tim Guy
The brake lowering kit is an adjustable length clevis rod that connects the brake pedal to the cross tube. Item 8 [URL="http://www.mgfcar.de/epc/750.htm"]here. [/URL]Think they might have been supplied by Mike Satur but not sure if they are still available. I have gone the other way fitted a bolt on throttle pedal plate which raises the throttle by the 3 or 4 mm thickness of the plate and have also offset the plate about 10mm towards the brake pedal. This allows me to toe and heel by simply rocking my foot to the right without much heel movement.
24/07/2008 19:29:54
adrian
I think I see the problem. You need to simultaneously control three pedals with two feet. (clutch and throttle to gear change, whilst braking) This is impossible! I Kneel before you if you can do this! Which numpty designed the modern car to have three pedals? If there was some sort of clutch lever on the gear stick, we wouldn't have this problem? I'm going to try blipping with my right hand and steering with my knees.......
24/07/2008 20:04:41
Tim Guy
[quote=adrian] ...I'm going to try blipping with my right hand and steering with my knees.......[/quote] LOL, yes that's the idea. I'm pretty new to it as you can see from the start of this thread. Its not really as difficult as it seems. Practice it, engine off in the drive before you attempt it on the road. Its actually easier on track because you need a healthier dose of both brake and throttle.
25/07/2008 18:52:02
Dave
[quote=adrian]This is impossible! I Kneel before you if you can do this! [/quote]You obviously haven't seen Andy Walsh's driver training DVD - believe me, it is possible! Though, it has to be seen to be believed. I have had the pleasure of sitting in Andy's passenger seat and his feet are a marvel to behold! See [URL="http://www.1stlotus.com/pop.htm"]http://www.1stlotus.com/pop.htm[/URL][URL="http://www.mx5mad.com/popup_image.php?pID=222"][/URL]
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