Heel toe issue

[menchi]

I wonder if anyone else has this problem or knows why this is happending, I have been practicing heel toe downshifting in my daily driving routine and for some reason at times it will work as planned but other times, when I goto blip the throttle I have absolutely no engine response. nothing happens, I'll try again and again but it won't work, for at least a few seconds, and untill I let off the brake. so I tried braking while accelerating and the same issue reappeared the engine response slumped for a second and then back to normal. any ideas?

 

[VelvetFoot]

The ECM doesn't like the brake and accelerator pressed at the same time. I think there are ways around it.

 

[menchi]

I'll just drive around it, I guess no heel to for now, thanks I thought it might have been a flaw in my technique

 

[LightningTDI]

Always wondered about this...you put your heel on which pedal?

 

[GoFaster]

If you are *completely* off the accelerator at the time that you press the brake pedal, and you stay on the brake pedal through the time that you "blip" the accelerator pedal, it will work correctly. (This is the sequence of a correctly-executed heel-toe downshift.)

If you F it up, the drive-by-wire logic intervenes because it can't tell the difference between your F-up and a technical failure of the accelerator pedal sensor. If you are on the accelerator at all, and you subsequently press the brake, it kills the accelerator input because (as far as the ECU is concerned) maybe the accelerator pedal is stuck down and you are trying to stop the car.

You can thank the sue-happy clods who went after Audi for "sudden acceleration" for having this "feature" ...

 

[VelvetFoot]

Interestingly our drive by wire BMW does not have this 'feature'.

 

[GoFaster]

They're not the ones who got sued!

 

[menchi]

that makes perfect sense, thank you. it will help alot. and lighteningTDI I don't use my heel at all, size 14 feet make that hard, but I hear a proper heel toe is executed without it, anyway, it just got the name from a funnt pedal configuration from a ferarri in the 50 where you would actully have to use your heel and toe, but for the TDI I brake with the ball of my foot and pivot my foot over and press the accelerator with the edge of my foot.

 

[Stealth TDI]

Hi,

I remove the brake switch for autocrossing. I don't heal-toe; but I've noticed the car reacts more quickly to pedal input while exiting corners. My brake switch comes out with a simple half-turn.

Just make sure you put it back after the races. Otherwise, you'll have no brake lights.

Take Care,

Scott

 

[compu_85]

And remember how easy it is to break the switch if you don't install it right!

 

[eisenkrote]

Does anyone know whether this "feature" can be modified using Vag-com?

 

[Stealth TDI]

Hi,

And remember how easy it is to break the switch if you don't install it right!

I'm not sure. It's much larger than one would think. It's about 1/2-3/4" in diameter and about 2-3 inches long. It's pretty stout. You'd have to be a blindfolded gorilla to booger this thing up.

Scott

 

[compu_85]

Not with the A4 cars... they made the switch self adjusting... if you don't ratchet it correctly, it breaks

-J

 

[Jon Hamilton]

You can not bypass it in Vag-Com. We modified the Rally Car so I can left foot break, but it throws a DTC that makes the glow plug light blink...we fixed that with electrical tape

All you need to to do is jump two of the wires on the brake switch. The tail lights still work but the fuel cut off is bypassed.

 

[Jackilus]

Is there a reason why I shouldn't do this to my car? I hate not being able to heel-toe. There's got to be a clean way to do it...

 

[GoFaster]

You CAN heel-toe without changing anything on the vehicle - provided that you do it *correctly*. Read the whole thread - it was already explained.

Left-foot-braking simultaneously with using the accelerator is a different story, that will not work with the stock set-up, but stuff like that is best left to closed-course rally driving only - and Jon Hamilton's work-around for rally racing (closed-course) is posted above. You will disable some of the safety features built into the ECU if you do this (consequently it's not a good idea for street use), and I'm pretty sure that the cruise control will not work because it is also dependent on seeing both channels of the brake lamp switch ... but in rally racing they don't have much use for the cruise control anyway!

 

[xracerbob]

I've been doing heel and toe downshifts since I got my 06 tdi a few weeks ago. No problems/issues executing so far. To me the gear box and shift feel is very good for a front driver.

 

[Matthew_S]

You CAN heel-toe without changing anything on the vehicle - provided that you do it *correctly*. Read the whole thread - it was already explained.

This heel toe issue is the one thing that I really hate about my car. I really don't understand what you mean be 'doing it correctly'. If I read your explanation correctly you are saying that as long as you completely release the accelerator before stepping on the brake you can rev the engine while braking. I don't see how it could be done any other way because the accelerator is so much lower than the brake applying it without releasing the accelerator is nearly impossible.

After reading this thread today I tried this and a few other techniques on my way home from work. I found out that in my car the accelerator will not work for more than approximately 1/2 second anytime the brake pedal is being pressed no matter what. The engine simply revs up about 500 rpms or so then falls to idle speed regardless of what the rpms are when you do it. Unless there is something wrong with my car it is impossible to heel to downshift regardless of the technique used.

 

[Golf_GTDI]

No clean way that I know of. As I understand it this is a safety issue that true driving nuts do not care for. Then again VW could care less if real drivers love their cars.

Please consider trying to work on your rev matching (rather easy with a TDI) and or left foot braking (which you also need to be careful with as it can cause the same issues). It takes tons of time to get good at both and will keep you busy and help get you in touch with your inner pro wheelman.

 

[eb2143]

I understood this problem to only be certain model years
My '01 loves to heel and toe, I do it every day...

 

[fastvicar]

In my experience the newer ECUs (i.e. A4 & I assume A5) are much easier to please on the rev-matching end of things. My B4 has its good days and bad days. What I don't like is that it can occasionally shut down all "throttle" inputs if you have to do a mid-corner correction while trail-braking (very lightly). Suddenly you have a numb pedal that does nothing to correct the car's attitude. Of course this only happens on the track, so I pose no danger to the general public.

 

[jnecr]

No clean way that I know of. As I understand it this is a safety issue that true driving nuts do not care for. Then again VW could care less if real drivers love their cars.

Honestly... with our drive by wire engines, I would not feel safe if they didn't have the safety feature on the car. You can't always trust an electric sensor you know...

 

[OilBurnerBob]

I've never had trouble with heel & toe on my A4... now I know why.

Heel & toe worked wonders on my old '67 beetle! Put 200K on that car.

 

[fastvicar]

Honestly... with our drive by wire engines, I would not feel safe if they didn't have the safety feature on the car. You can't always trust an electric sensor you know...

But you can trust your brakes. They will overcome any torque that the engine puts out.

 

[Uisge]

I found that if I apply the brakes on my 02 Jetta and then blip the accelerator once, it revs slightly, then the ECU drops the revs back to idle, but if I immediately reapply the accelerator, the ECU gets fooled, and I can rev the engine up. I want to learn to heel/toe but in this car, it looks like I'll have to hit the accelerator twice to get the revs up; a little more complicated...

 

[troyg54]

But you can trust your brakes. They will overcome any torque that the engine puts out.

There is always neutral too.

 

[jnecr]

But you can trust your brakes. They will overcome any torque that the engine puts out.

True, and the comment about neutral is probably an even better idea. Still, when properly done, the safety feature does not get in the way of heel-toeing...