Loss of power ..... Whilst braking ????
Discussion
Having read several articles in different car mag's (Autocar, Evo, etc) about a time delay from applying the brakes to braking actually happening in various VW Group vehicles (Golf/Bora, Audi A3, Skoda Octavia) in wet weather.
And several articles by Steve Sutcliff on the benefit of Left Foot Braking I thought I'd 'TEST' what the effects were in my wifes Golf TDi a) To see if there was a tangible delay when road was wet. b) To see if advice given to Sutcliff about LFB had any benifit in the real world.
What I found was, if I apply the brakes with my left foot whilst still keeping the power on with the right is that the engine suffered almost total power loss. I did this on numerous occassions to see if it re-occured, which it did.
Can anybody shed any light as to why? I can only think the Turbo release valve is being opened! If this is the case, again, why?
Just interested, that's all.
And several articles by Steve Sutcliff on the benefit of Left Foot Braking I thought I'd 'TEST' what the effects were in my wifes Golf TDi a) To see if there was a tangible delay when road was wet. b) To see if advice given to Sutcliff about LFB had any benifit in the real world.
What I found was, if I apply the brakes with my left foot whilst still keeping the power on with the right is that the engine suffered almost total power loss. I did this on numerous occassions to see if it re-occured, which it did.
Can anybody shed any light as to why? I can only think the Turbo release valve is being opened! If this is the case, again, why?
Just interested, that's all.
Its a safety thing ,i have driven a golf TDI and it done the same the throttle runs through the ecu so if you stamp on the brake and accelerator the engine cuts out to stop you having fun 
The astra doesnt though had some fun in that in the wet on roundabouts with left foot braking started doing it when hooning down my favorite roads as well !
>> Edited by ZZR600 on Thursday 18th April 17:15
The astra doesnt though had some fun in that in the wet on roundabouts with left foot braking started doing it when hooning down my favorite roads as well !
>> Edited by ZZR600 on Thursday 18th April 17:15
quote:
What I found was, if I apply the brakes with my left foot whilst still keeping the power on with the right is that the engine suffered almost total power loss.
If the brakes are servoed they generally rely on the inlet manifold depression for their power. I'm speculating but I suspect that suddenly opening up the inlet manifold to the brake servo as would happen if you brake hard would significantly affect airflow into the engine and be the root cause.
This wouldn't normally be a problem as you would typically be braking on a trailing throttle but would show up if you brake under power.
Any further thoughts?
Don't try left foot braking in a big Alfa !
After a couple of good pumps on the brake pedal, you will find you have virtually no brakes! All the power assistance is removed and you are left with not enough brakes to overcome the power of the engine.
All is restored to normal as soon as the right foot lifts off the loud pedal. Or as I found out - if you keep pressing the brake pedal while you lift off the accelerator then you will be lucky to avoid headbutting the steering wheel.
This has got to be the exact opposite of the thread title; Total loss of brakes ..... While accelerating ???
After a couple of good pumps on the brake pedal, you will find you have virtually no brakes! All the power assistance is removed and you are left with not enough brakes to overcome the power of the engine.
All is restored to normal as soon as the right foot lifts off the loud pedal. Or as I found out - if you keep pressing the brake pedal while you lift off the accelerator then you will be lucky to avoid headbutting the steering wheel.
This has got to be the exact opposite of the thread title; Total loss of brakes ..... While accelerating ???
Ah !!!!
Or in my case, the other way round.
Or in my case, the other way round.
quote:
If the brakes are servoed they generally rely on the inlet manifold depression for their power. I'm speculating but I suspect that suddenly opening up the inlet manifold to the brake servo as would happen if you brake hard would significantly affect airflow into the engine and be the root cause.
The servo issue may be the answer. However, this is an instant power loss, also, is this as relevent on a diesel car. The other thing that makes me think it is not the servo is that none of the articles I've read on left foot braking mention this side effect. Sutcliff drove several cars in the main article, FWD, RWD & 4WD to see the effect it has on each type of car. None from memory were diesel powered tho'.
I think it is a 'nannying' thing as ZZR600 said. In case some numptie happens to jump on both pedals in blind panic!
I think it is a 'nannying' thing as ZZR600 said. In case some numptie happens to jump on both pedals in blind panic!
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