Lift-off understeer

[zadocbrown]

Quite. Not really sure why you would need the confusion of having to adapt to 2 different throttle maps as opposed to just moving your foot a bit more to go faster - an idea as simple as it is effective.....

Exactly. I wish these 'clever' technical people would stop faffing about with things that worked perfectly well without all the added complexity.

think of it more as allowing you two cars for the price of one - so your car can be a sports car with sharp responses when you want, but in the evening you can gently cruise home without having to worry about every twitch on the pedal sending you into the ditch!

sounds good value to me

Alasdair

But I don't want a 'sharp' throttle response even for fast driving, perhaps particularly not. I just want it to be linear and consistent so I can achieve the right amount of torque at any given moment. Am I weird?

[trashbat]

think of it more as allowing you two cars for the price of one - so your car can be a sports car with sharp responses when you want, but in the evening you can gently cruise home without having to worry about every twitch on the pedal sending you into the ditch!

You don't need technology for this. You could just pick up some fat hitch-hikers in a very small car.

[akirk]

But I don't want a 'sharp' throttle response even for fast driving, perhaps particularly not. I just want it to be linear and consistent so I can achieve the right amount of torque at any given moment. Am I weird?

but some people do...
I believe some cars will learn your style and adapt - causes huge confusion when couples have different driving styles!

Rob - love your idea, solves public transport issues as well

Alasdair

[akirk]

I believe some cars will learn your style and adapt - causes huge confusion when couples have different driving styles!

Only gearboxes do as far as I know. It's interesting watching the woolly thinking at work on the shift scheme after you've calmed somebody down from clog and anchor.

that makes sense I think it was a VW passat DSG box that caused chaos - one agressive driver, one very cautious driver - gearbox nearly exploded trying to be intelligent about it!

Alasdair

[faboka]

Wow just finished reading this. Took me two evening Not sure what I got out of it other then entertainment. Does make me think I need to spend more time playing to see the different outcomes.

Still think 5star should have just paid up and when for a drive with Dave or gone to Don and his playground to put things into practice. I went this time of year to Don and almost had snow

As for the throttle maps. Here's an example of the "drivers wish" map from the older VAG PD130. Peak torque happens around 2000 rpm and requires 56mg of diesel dropping to 47mg at 4000rpm which is peak power. http://www.hidden-power.co.uk/guides/bosch-edc15p/

[jcochrane]

But I don't want a 'sharp' throttle response even for fast driving, perhaps particularly not. I just want it to be linear and consistent so I can achieve the right amount of torque at any given moment. Am I weird?

I believe somewhere here StressedD has mentioned how today's throttles do not give a linear response. When next with Andy Morrison ask him how to achieve a linear response. The solution is dead easy. PM me if you want to know how. You are not alone or weird in wanting the more satisfactory linear outcome.

[titian]

My contribution to this debate is really small beer.

Driving an auto vehicle I approach my driveway at home, up hill on the right side of the lane. Stop, select reverse foot off brake and vehicle moves away down hill with right foot brushing the brake for control. Right hand down to enter driveway which is uphill. Right foot onto gentle accelerator as the vehicle is turning in, vehicle slows, more gentle pressure on accelerator vehicle reluctant to move, more gentle pressure and suddenly the revs surge and vehicle "rockets" backwards and I swiftly move right foot to brake for control.

There is cerainly nothing linear about that!

I have noticed however that there is a slight difference, slightly more controlled if I select the "dynamic" driving mode - accelerator mapping software changes?

[zadocbrown]

But I don't want a 'sharp' throttle response even for fast driving, perhaps particularly not. I just want it to be linear and consistent so I can achieve the right amount of torque at any given moment. Am I weird?

I believe somewhere here StressedD has mentioned how today's throttles do not give a linear response. When next with Andy Morrison ask him how to achieve a linear response. The solution is dead easy. PM me if you want to know how. You are not alone or weird in wanting the more satisfactory linear outcome.

Mathematically you're correct. But from a drivers perspective linearity is relative. The throttle map on my car is much easier to work with than that on my other half's, despite having about 5 times the torque. What I don't understand is how having the option to put nearly all the throttle response in a third of the pedal travel is worthwhile.

I assume what you are referring to is the technique of getting ahead of the car and letting the electronics sort it out? It works fine when you want max torque straight away, but honestly I hardly ever do that. I hate the feeling of the throttle not actually being connected to the engine, and I'm quite fussy about getting the amount of torque I want, when I want it rather than taking what the car wants to give me. So generally I use the throttle the same way as the brake - squeeze until satisfied with the result. Yes, I have a control freak in place of a normal limb....

[TripleS]

My contribution to this debate is really small beer.

Driving an auto vehicle I approach my driveway at home, up hill on the right side of the lane. Stop, select reverse foot off brake and vehicle moves away down hill with right foot brushing the brake for control. Right hand down to enter driveway which is uphill. Right foot onto gentle accelerator as the vehicle is turning in, vehicle slows, more gentle pressure on accelerator vehicle reluctant to move, more gentle pressure and suddenly the revs surge and vehicle "rockets" backwards and I swiftly move right foot to brake for control.

There is cerainly nothing linear about that!

I have noticed however that there is a slight difference, slightly more controlled if I select the "dynamic" driving mode - accelerator mapping software changes?

in the circumstances I think beer, not necessarily small, would be welcome.

What you have described there sounds like unsatisfactory vehicle behaviour.

As far as I'm concerned you should not have to select a particular mode (other than engaging R with the transmission selector) if you want to reverse onto your drive in an easily controlled manner.

Is it possible that your car has a fault, a potentially dangerous fault moreover, that is causing the seriously unlinear throttle response, or is it a by-product of some feature on that model that you would probably be better off not having?

I suppose you could overcome the problem by using left foot braking, but you should not need to do that.

[waremark]

What I don't understand is how having the option to put nearly all the throttle response in a third of the pedal travel is worthwhile.

I have had several cars with switchable throttle maps. Using the sportier maps, maybe giving two thirds throttle from the first one third of movement, the car feels more responsive and (wrongly, but subjectively) quicker. I find that changing the map means re calibrating my right foot, so in cars where you can change the throttle map independently of other settings I work out which I prefer and stick with it. In one car I always used sport because that was easier for H&T.

[5star]

Returning to the original topic, I have a question:

Body slip angle, outside of drifting, isn't something you have any control over. Its down to the tyres and the vehicle dynamic engineering department.

I thought body slip angle would change if the ratio of front to rear tyre slip angles changed.

For example, if I reach a point in the turn with 7 degrees tyre slip angle at the front and 3 degrees at the rear, vs 6 degrees tyre slip angle at the front and 5 degrees at the rear, assuming the same line in each case, wouldn't this result in a different body slip angle?

[5star]

slip angle is a function of body slip angle rather than the other way around.

This is like me saying 1+1=2, and you saying No, 2=1+1. As I read it, the two are related and changing one changes the other. The relationship cannot be altered by the driver as it is set by the suspension, chassis, tyres, wheelbase and so on. So from a driver's perspective, it isn't about cause and effect, it just is.

As a driver, short of finding strong winds or getting someone to crash into me, I cannot alter body slip angle directly to manage my tyre slip angles. But I can manage the front/rear tyre slip angle ratios, and this will result in a different body slip angle.

[Silk]

Don't feed the troll.

A troll would be a welcome relief. I can't believe this tedious thread is still going.

[Astraist]

I also cannot believe it is still going on.

Nevertheless, I believe we should be a bit more patient with our new member, even though the answers to his main question (being, "how to corner") had already been answered ad nauseam.

5star, look at it empirically. You can see quite a prononced body angle at slow manuevering. You can observe how little your inputs effect it. As to how it effects it, to the little degree that it does, refer to Dave's first post in the thread.

[Astraist]

Your patience would not last nearly as long with the majority of my clients, or the people I advise online.