Left foot braking in an Octavia vRS MK1

[phazed]

Having finished my Octy ready for a track evening as a shake down in a couple of weeks time, I took it out yesterday to check peddle positions for heal and toe etc.

While trying a bit of left foot braking, I was surprised to learn that braking automatically cuts the throttle! I assume that is a safety thing and can understand why.

Is there any way that this can be programmed out?

I assume that if I disconnect the brake switch, that function may be disabled but if so, I would defo want brake lights working on track so not what I'm looking for.

Any ideas?

[robek85]

Hello,

 

Yes it can be done via remmaping.

 

I think original limits are 1200rpm and 3,75km/h. So when over these values and you press brakes  -> cuts throttle. Plus two more pedal maps.

 

You can raise limits and youre good. 

 

 

 

 

Edited 23 April, 2021 by robek85

[phazed]

Who could do tis, a remapper?

[Schtum]

The quick and dirty way is to disconnect the brake light switch but you might not be too popular out on the track.   If you want to know the original reason for it, search 'Audi unintended acceleration'.   

[Breezy_Pete]

Just short the inner two wires of the connector. Brake lights will still work but engine ECU will no longer see brake pedal as being pressed.

[J.R.]

I did that on my Galaxy as I would left foot brake while keeping the throttle open when going over speed bumps laden with all my tools, it reduced the bouncing.

 

All was well but after several months a fault code was generated (cant recall if there was a MIL light) which said "brake light switch implausible signal), it had decided that travelling 5000 miles without the ECU seeing the brakes being applied was in their words "implausible", that was back in 1995, the systems don't miss a thing these days.

[Breezy_Pete]

Nothing to lose by trying it though.

[Octyvrs03]

Do you have cruise control installed by any chance?

[SuperbTWM]

54 minutes ago, Octyvrs03 said:

Do you have cruise control installed by any chance?

 

He won't have if he shorts out half the brake switch.

 

IIRC the ECU sees both inputs from the brake light switch so it will bring on EML, and it may still cut the throttle when braking, interested to see if it does though

Edited 28 April, 2021 by SuperbTWM

[KenONeill]

8 minutes ago, SuperbTWM said:

IIRC the ECU sees both inputs from the brake light switch so it will bring on EML, and it may still cut the throttle when braking

That's if it doesn't decide to put the car into limp mode.

[Octyvrs03]

1 hour ago, SuperbTWM said:

 

He won't have if he shorts out half the brake switch.

 

IIRC the ECU sees both inputs from the brake light switch so it will bring on EML, and it may still cut the throttle when braking, interested to see if it does though

 

Just curious because I happened to retrofit cruise control this week. 

 

Before I did though, I stumbled onto this thread and read about the revs dropping when pressing brake and accelerator at the same time.

 

I tried it in mine and nothing happened. Revs didn't drop if I tried to left foot brake. Then I ended up down the rabbit hole of "do I have a faulty brake switch" threads. 

 

In the end I chanced it and fitted the cruise control, activated the vcds code and the cruise works perfectly and cuts off when pressing the brake. So my brake switch is fine. 

 

I retested the left foot braking method and now the revs drop too.

 

I wonder if OP has cruise control and disables it vcds it would solve the rev drop conundrum.

[Schtum]

48 minutes ago, Octyvrs03 said:

I wonder if OP has cruise control and disables it vcds it would solve the rev drop conundrum.

 

 I doubt it very much.  Did you see my comment above about unintended acceleration being the origin of the issue?   Perhaps Škoda hadn't got round to it, for some reason, when your car was built some 18 years ago.  

 

However, every VAG car that we've owned since 2000, i.e, 1 Mk4 Golf GT TDI, 1 Fabia vRS, 1 Mk5 Golf GT Sport TDI, 3 VW Tiguans and 1 Karoq 190 TDI has cut the throttle when the brake was applied.  

[Octyvrs03]

6 hours ago, Schtum said:

 

 I doubt it very much.  Did you see my comment above about unintended acceleration being the origin of the issue?   Perhaps Škoda hadn't got round to it, for some reason, when your car was built some 18 years ago.  

 

However, every VAG car that we've owned since 2000, i.e, 1 Mk4 Golf GT TDI, 1 Fabia vRS, 1 Mk5 Golf GT Sport TDI, 3 VW Tiguans and 1 Karoq 190 TDI has cut the throttle when the brake was applied.  

Nevermind, I'm talking pish.

 

Took the car for a longer drive and left foot braking did nothing to the revs. Guess my car is too old for that feature after all.

 

I swear though, perhaps through my own delusion, that after I put in the cruise control it did drop the revs, at least in my imagination!

I also mean when CC was switched off.

I'm definitely mistaken though.

[phazed]

Just saw these replies!

 

The simple answer is yes, I do have cruise fitted.

 

At the moment, LFB is a bit academic as I am suffering hugely from inner wheel spinning up when exiting any corner on track. Did a shakedown of the car at a Brands evening TD on Wednesday and the inner wheelspin is epic! 

Will adjust ARBs but think an LSD is the long term answer....

 

I digress.

 

[phazed]

Just read on Darkside Developments site that they programme out the throttle cut if requested for LFB. Result!