Engine braking in a Griff ?
Discussion
I’ve just been reading Steve Heath’s section on engine braking and why you mustn’t do it. Brake and gas at the same time, match the revs. Now, very soon I will hopefully take delivery of a 4 litre Griff, or perhaps a 4.3 litre and I have zero experience in TVR’s. Although I’ll be booking a training day, am I likely to be able to drive the car home from the seller’s ? Is there a rev range in which you can down gear safely without matching the revs. I just want to get the car home. Seem’s like everything you do in a TVR is going to end up in a tail end mishap. It’s all very unsettling. Could someone reassure me possibly ?
Just take it easy and you will be fine. Use the brakes to stop, get the car's speed down to what you want then select the gear you need and things should be fine. The problems start coming when you mismatch the revs deliberately to get engine breaking or simply the red mist descends and you make a mistake.
Take care and don't push it and you will be fine. GEt some training ASAP and enjoy the car.
Take care and don't push it and you will be fine. GEt some training ASAP and enjoy the car.
You and me both Shawn - I read that bit a few weeks ago 
wot, no more pops bangs and crackles 
No need to worry too much - from what I can gather Steve is talking about pretty drastic and sharp down changes, on normal driving you should be fine.
Double de-clutching will give you a smoother down change but is not to be tried unless you have plenty of time to think about it... coming up to a roundabout and going from 50 to 15 and trying to match all the revs as I go down usually sees me sailing serenly onto the roundabout... in neutral! Thinking, "now which bit did I get out of order"
As for heel & toe braking - behave!
You will have so much fun in that car just driving it normally - there'll be plenty of time to worry about operating two pedals with one foot at the same time once you get the inevitable pull to get competitive on a track day!!! Oh yes, it will happen!
Meanwhile - ENJOY!
al.
wot, no more pops bangs and crackles No need to worry too much - from what I can gather Steve is talking about pretty drastic and sharp down changes, on normal driving you should be fine.
Double de-clutching will give you a smoother down change but is not to be tried unless you have plenty of time to think about it... coming up to a roundabout and going from 50 to 15 and trying to match all the revs as I go down usually sees me sailing serenly onto the roundabout... in neutral! Thinking, "now which bit did I get out of order"
As for heel & toe braking - behave!
You will have so much fun in that car just driving it normally - there'll be plenty of time to worry about operating two pedals with one foot at the same time once you get the inevitable pull to get competitive on a track day!!! Oh yes, it will happen!
Meanwhile - ENJOY!
al.
Don't get to paranoid.....
This is mainly a problem when really going agressively on a track. at high speeds, abrupt cornerning, not braking in a straight line.
On the road just drive normally, just don't change down a gear to get engine braking in a rear wheel drive car (especially one with high torque - light weight as TVR's are), use the brakes to slow down and then put into the lower gear.
On normal road driveing, if you do this, if the lower gear/revs don't quite match you won't have any problems, unless particulary WET/ICY..
B
This is mainly a problem when really going agressively on a track. at high speeds, abrupt cornerning, not braking in a straight line.
On the road just drive normally, just don't change down a gear to get engine braking in a rear wheel drive car (especially one with high torque - light weight as TVR's are), use the brakes to slow down and then put into the lower gear.
On normal road driveing, if you do this, if the lower gear/revs don't quite match you won't have any problems, unless particulary WET/ICY..
B
This problem can happen on dry roads and doesn't take that much of a mis match and is responsible for most of the "the car suddenly spun on me" accidents. The problem with not matching the revs is that 99 times out of 100 you can get away with it but on that 100th time it is goodbye NCB or worse. The problem is that many born again sports car drivers were taught to engine brake because when they learned to drive the brakes were so crap. Engine braking on a four pot mundeo is not a problem as the torque isn't there. Do it on a TVR and that's a recipe for an accident waitinmg to happen.
Heel and toe techniques are derived from racing but they do allow you to control the car and have the ability to prevent rear wheel lock up syndrome.
It is scary enough when it happens on a track with plenty of run off. You don't want to experience it on a busy road!
Heel and toe techniques are derived from racing but they do allow you to control the car and have the ability to prevent rear wheel lock up syndrome.
It is scary enough when it happens on a track with plenty of run off. You don't want to experience it on a busy road!
Having experienced loss of control under severe engine braking on a public road, I can whole heartedly agree with Steve Heath's comments. That said, I was 'making progress' - as the police term it - with a Caterham quite close behind me when it happened.
Since then, if I am in a hurry I have started to heel/toe and although uncomfortable to start with, is actually much easier than it sounds. What I tend to do the rest of the time is to blip the throttle to match the revs when changing down. Let's face it, a Griff under engine braking is a sound to behold, and a real crowd pleaser!
IMO, engine braking whilst driving normally shouldn't cause you too many problems. I feel that too much power too soon out of a bend is a far bigger concern, particularly on wet roads.
If you take care and respect the car and it's power, you'll be fine.
Since then, if I am in a hurry I have started to heel/toe and although uncomfortable to start with, is actually much easier than it sounds. What I tend to do the rest of the time is to blip the throttle to match the revs when changing down. Let's face it, a Griff under engine braking is a sound to behold, and a real crowd pleaser!
IMO, engine braking whilst driving normally shouldn't cause you too many problems. I feel that too much power too soon out of a bend is a far bigger concern, particularly on wet roads.
If you take care and respect the car and it's power, you'll be fine.
No 1 said:
IMO, engine braking whilst driving normally shouldn't cause you too many problems. I feel that too much power too soon out of a bend is a far bigger concern, particularly on wet roads.
If you take care and respect the car and it's power, you'll be fine.
The problem is, as I think Steve said, when drive on a trailing throttle (i.e. take your foot off the throttle and let the engine slow the car down) you make the car inherently unstable. If/when it starts to slide, the back wheels will slide first, they will slide suddenly and abruptly and there will be very little you can do about it. Unless you're *very* quick off the mark you're going off backwards. This is a classic too-fast-into-a-corner-on-the-first-day-of-winter scenario. If you're slowing down and there's any doubt at all about how much grip you have, use the brakes. This puts the braking on all four wheels and keeps the car stable. The problem is much, much worse if you change down without matching revs and use the clutch to spin the engine up (what most people mean by engine braking) as the amount of braking is much greater. In extreme cases this can be enough to make you spin in the dry in a straight line. As Steve says, just say no to engine braking, and get used to slowing down on the brakes not the engine.
GreenV8S said:
The problem is, as I think Steve said, when drive on a trailing throttle (i.e. take your foot off the throttle and let the engine slow the car down) you make the car inherently unstable. If/when it starts to slide, the back wheels will slide first, they will slide suddenly and abruptly and there will be very little you can do about it.
I think this happened to me on Sunday, going down a hill which leads into a 70 degree right hand bend in the road. Like a numpty, I changed down from 4th into 3rd at a fair lick as I went past the pub on my left where some people were enjoying a drink in the beer garden. "Hmmmm", thinks I, "I wouldnt mind a pint right now". Next thing I know, the arse end was decidedly out, fortunately to the left hand side, so I was pointing the correct way when I reached the right bend. Whether I was lucky or whether I reacted quickly and caught it I don't remember, it happened so fast.
Much squealing of tyres ensued, along with some major sphincter control as I approached the bend sideways, with the wife reaching for a non-existent ejector seat button. Luckily I got round the bend, but I could not believe how fast it happened!
Now whether that was caused by engine braking, or whether the car was unsettled by a hump in the road I don't know, but I'm guessing it was engine braking.
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