New tyres - which end?
Discussion
Nigel_O said:
are the "gurus" just working to the lowest common denominator and advising everyone to do it, just in case?....
Pretty much. I certainly don't practice what I have been preaching here, The only reason I would rotate tyres to different corners of the car is to stop the rear tyres getting ancient. Apart from that I replace them in axle pairs as and when necessary. I buy decent quality tyres so the grip disparity is never massive, and I don't buy this theory of 'one end aqua-planing'.I do drive quick and I have had my Mondeo oversteer a few times without consequence.
powerstroke said:
Orillion said:
Looks like he lost vision when he hit the puddle, and turned in too much or harshly and was going a little fast as a result unballanced the car causing it to spin out... 
Statistical risk is simple.
Is it really that hard to understand that not all questions have only one answer?
With new tyres on the front of this car, it will still be less prone to oversteer than other cars with new tyres on the rear.
Does that mean that all those cars are not safe to drive?
No.
Of course not.
One simply drives accordingly.
The problem with catch-all procedural systems is that the glove never quite fits.
On the back will sometimes be the correct choice, and sometimes not.
It is folly to try and come up with one rule for a problem with so many variables.
Is it really that hard to understand that not all questions have only one answer?
With new tyres on the front of this car, it will still be less prone to oversteer than other cars with new tyres on the rear.
Does that mean that all those cars are not safe to drive?
No.
Of course not.
One simply drives accordingly.
The problem with catch-all procedural systems is that the glove never quite fits.
On the back will sometimes be the correct choice, and sometimes not.
It is folly to try and come up with one rule for a problem with so many variables.
Bacon Is Proof said:
stuff
But the point is that the advice on where to fit new tyres is actually statistical advice. It's about overall reduction of risk - just like speed limits. It might mean that there are individual situations that are safer with the new tyres on the front - although I may have missed the rationale for new tyres on the front reducing oversteer
I was objecting to the post you made as you made it as though the statistical advice about new tyre positioning were wrong because you hadn't had an accident. I know it was tongue in cheek, hence my answer in the same vein. Thus to try and debate what I said as if it were not tongue in cheek is completely missing the point.
BB
I'm still struggling to get my head around this topic, i am glad to see on this forum there is still a divided of opinion on this issue, many forums i have looked at the opinion is that the tyre manufacturers advice must be correct and to suggest otherwise is ignorant / trolling.
Here's my perspective, I like many people have always favored having more grip at the front end, particularly on a FWD car, I understand that some people's driving preferences might make them want to go against the 'norm' for good or bad reasons and that there cannot be general advice that applies to everyone, but in this case it seems i am going against the normal advice being given for the average motorist, which i think it totally the wrong way round.
I understand after studying plenty of advice from manufacturers and suppliers that the situation which can occur where having more tread at the front than the back can lead to sudden over-steer due to rear aquaplaning where even a very skilled driver would find it difficult or impossible to control. The tyre manufacturers have proved it, they've put out statements, videos and have even run events inviting people to experience it to really hammer their point home.
My problem is that they seem to have gotten hold of 1 situation where you can see the effects quite dramatically and ignored all others, my feelings are that this is a rare but possible circumstance. I'm not sure i believe that the average motorist is now so oblivious to road condition that they cannot identify the risk of aquaplaning and adjust their speed accordingly reducing the risk significantly.
There are many more common circumstances that can lead to an accident or a near miss where extra front grip would almost certainly be beneficial and some of these circumstances cannot be foreseen by even the most prudent motorist.
Here are some statistics from a study of 20,000 accidents listed on the Michelin website
http://www.michelin.co.uk/why-michelin/safety#did-...
70% of accidents happen on dry roads
60% of accidents happen at slow speeds in urban areas
75% of accidents happen on straight roads (of which 20% when wet)
25% of accidents in bends (50% of which when wet)
99% of accidents on wet roads happen with very little water depth
The first 4 statistics could lead you to believe that perhaps 7-15% of accidents could potentially have been caused by rear aquaplaning on a bend (doesn't mean 15% were, just that at-least 85% could not have been)
But the thing which really blows all of these statistics out of the water is the final stat that "99% of accidents on wet roads happen with _very_ little water depth."
of the 20,000 accidents they analysed approximately 30% (6,000) were in the wet, and of those 6,000 accidents 99% (5,940) were described as having very little water depth. I am sure you cannot aqua plain in very little water depth, even with tyres right down to the legal limit.
so now of those 60 or so accidents which did involve higher levels of water, where there was a risk of aquaplaning, we can only speculate if they were at speed and on bends, but if we assume that all 60 could have been, and that aquaplaning at the rear could have been the cause, it's still only 60 maximum out of 20,000.
How many of the other 19,940 accidents could have been avoided by one or more of the cars involved having a little bit more stopping power or steering grip? Particularly the other 5,940 in the wet
At the very least those statistics show it's not all one sided, but if you ask me it show the manufacturers have it very very wrong.
But what i can't get my head around fully is why does the tyre industry feel so strongly about it, do they really care so much about road safety, or is something else going on?
I have my own conspiracy theory based on the idea that the tyre manufactures have figured they can lock customers in who want to keep all 4 matching tyres, and generally people are more likely to pay more and buy premium branded tyres when they only need to replace 2 not all 4 at the same time.
Here's my perspective, I like many people have always favored having more grip at the front end, particularly on a FWD car, I understand that some people's driving preferences might make them want to go against the 'norm' for good or bad reasons and that there cannot be general advice that applies to everyone, but in this case it seems i am going against the normal advice being given for the average motorist, which i think it totally the wrong way round.
I understand after studying plenty of advice from manufacturers and suppliers that the situation which can occur where having more tread at the front than the back can lead to sudden over-steer due to rear aquaplaning where even a very skilled driver would find it difficult or impossible to control. The tyre manufacturers have proved it, they've put out statements, videos and have even run events inviting people to experience it to really hammer their point home.
My problem is that they seem to have gotten hold of 1 situation where you can see the effects quite dramatically and ignored all others, my feelings are that this is a rare but possible circumstance. I'm not sure i believe that the average motorist is now so oblivious to road condition that they cannot identify the risk of aquaplaning and adjust their speed accordingly reducing the risk significantly.
There are many more common circumstances that can lead to an accident or a near miss where extra front grip would almost certainly be beneficial and some of these circumstances cannot be foreseen by even the most prudent motorist.
Here are some statistics from a study of 20,000 accidents listed on the Michelin website
http://www.michelin.co.uk/why-michelin/safety#did-...
70% of accidents happen on dry roads
60% of accidents happen at slow speeds in urban areas
75% of accidents happen on straight roads (of which 20% when wet)
25% of accidents in bends (50% of which when wet)
99% of accidents on wet roads happen with very little water depth
The first 4 statistics could lead you to believe that perhaps 7-15% of accidents could potentially have been caused by rear aquaplaning on a bend (doesn't mean 15% were, just that at-least 85% could not have been)
But the thing which really blows all of these statistics out of the water is the final stat that "99% of accidents on wet roads happen with _very_ little water depth."
of the 20,000 accidents they analysed approximately 30% (6,000) were in the wet, and of those 6,000 accidents 99% (5,940) were described as having very little water depth. I am sure you cannot aqua plain in very little water depth, even with tyres right down to the legal limit.
so now of those 60 or so accidents which did involve higher levels of water, where there was a risk of aquaplaning, we can only speculate if they were at speed and on bends, but if we assume that all 60 could have been, and that aquaplaning at the rear could have been the cause, it's still only 60 maximum out of 20,000.
How many of the other 19,940 accidents could have been avoided by one or more of the cars involved having a little bit more stopping power or steering grip? Particularly the other 5,940 in the wet
At the very least those statistics show it's not all one sided, but if you ask me it show the manufacturers have it very very wrong.
But what i can't get my head around fully is why does the tyre industry feel so strongly about it, do they really care so much about road safety, or is something else going on?
I have my own conspiracy theory based on the idea that the tyre manufactures have figured they can lock customers in who want to keep all 4 matching tyres, and generally people are more likely to pay more and buy premium branded tyres when they only need to replace 2 not all 4 at the same time.
As the OP, I have a little more information to add, in the form of actual experience, rather than theory.
I have two Fiat Coupes - one is a highly modded 450-bhp example, the other is one of the very earliest dealer 16v non turbos, that quite honestly struggles to keep up with modern diesel rep-mobiles.
Recently, the 450bhp car decided that the diff would like a sniff of the open air, so it punched a hole in the gearbox and then ate its own planet gears. The resultant rebuild caused me to put the 16v into daily use.
However, when I bought the 16v, the front wishbones were shot to bits, which had munched the outer edges of the front tyres, causing some VERY weird handling traits. I replaced the wishbones, but the handling was still iffy, with terminal understeer and a vicious self-centering effect. In an attempt to pinpoint the cause, I did a front-rear wheel swap.
All of a sudden, the neat handling was back - I could tip it into a corner with confidence, knowing it wasn't going to do something silly halfway round.
Then it rained....
Firstly, I'd forgotten what it was like to drive a car with an open diff (the 20vt Coupe has Viscodrive - a cheap stab at providing LSD-like handling benefits).
Secondly, I'd forgotten what lift-off oversteer was, but I was very quickly reminded, with a gorgeous slo-mo drift around a greasy roundabout.
All of this was down to a pair of rear tyres with shoulders at the legal limit (tread depth across the rest of the tyre is well within the limit)
So - which is best?
Well, personally, the handling was SO bad with the iffy tyres on the front that I still reckon they're better off on the rear, although I don't much like the slightly loose feeling when cornering modestly hard in the wet.
Ultimately though, even though the handling felt truly awful when the dodgy tyres were up front, it was inherently safer, as rampant understeer could be controlled by slowing down a bit. With the half-slicks on the rear, slowing down just made matters worse.
I got the 450bhp car back a couple of weeks ago, following a new gearbox, with a Quaife ATB. Just started to enjoy matters, when it ate its own cambelt and took two thirds of the valves with it, so the 16v is back into daily use again.
Time for some new tyres though, as the weather is turning.
Now - which end should I put them on?.....
I have two Fiat Coupes - one is a highly modded 450-bhp example, the other is one of the very earliest dealer 16v non turbos, that quite honestly struggles to keep up with modern diesel rep-mobiles.
Recently, the 450bhp car decided that the diff would like a sniff of the open air, so it punched a hole in the gearbox and then ate its own planet gears. The resultant rebuild caused me to put the 16v into daily use.
However, when I bought the 16v, the front wishbones were shot to bits, which had munched the outer edges of the front tyres, causing some VERY weird handling traits. I replaced the wishbones, but the handling was still iffy, with terminal understeer and a vicious self-centering effect. In an attempt to pinpoint the cause, I did a front-rear wheel swap.
All of a sudden, the neat handling was back - I could tip it into a corner with confidence, knowing it wasn't going to do something silly halfway round.
Then it rained....
Firstly, I'd forgotten what it was like to drive a car with an open diff (the 20vt Coupe has Viscodrive - a cheap stab at providing LSD-like handling benefits).
Secondly, I'd forgotten what lift-off oversteer was, but I was very quickly reminded, with a gorgeous slo-mo drift around a greasy roundabout.
All of this was down to a pair of rear tyres with shoulders at the legal limit (tread depth across the rest of the tyre is well within the limit)
So - which is best?
Well, personally, the handling was SO bad with the iffy tyres on the front that I still reckon they're better off on the rear, although I don't much like the slightly loose feeling when cornering modestly hard in the wet.
Ultimately though, even though the handling felt truly awful when the dodgy tyres were up front, it was inherently safer, as rampant understeer could be controlled by slowing down a bit. With the half-slicks on the rear, slowing down just made matters worse.
I got the 450bhp car back a couple of weeks ago, following a new gearbox, with a Quaife ATB. Just started to enjoy matters, when it ate its own cambelt and took two thirds of the valves with it, so the 16v is back into daily use again.
Time for some new tyres though, as the weather is turning.
Now - which end should I put them on?.....
ging84 said:
I'm not sure i believe that the average motorist is now so oblivious to road condition that they cannot identify the risk of aquaplaning and adjust their speed accordingly reducing the risk significantly.
Go and ask 10 relatives at random what aquaplaning is. I bet you at least half of them will have no idea or will get it wrong.ging84 said:
There are many more common circumstances that can lead to an accident or a near miss where extra front grip would almost certainly be beneficial and some of these circumstances cannot be foreseen by even the most prudent motorist.
Here are some statistics from a study of 20,000 accidents listed on the Michelin website
http://www.michelin.co.uk/why-michelin/safety#did-...
70% of accidents happen on dry roads
So 30% of accidents occur on wet roads. Are the roads wet for 120 days a year in the study area? If not then you are more likely to crash in the wet than in the dry.Here are some statistics from a study of 20,000 accidents listed on the Michelin website
http://www.michelin.co.uk/why-michelin/safety#did-...
70% of accidents happen on dry roads
ging84 said:
60% of accidents happen at slow speeds in urban areas
75% of accidents happen on straight roads (of which 20% when wet)
25% of accidents in bends (50% of which when wet)
99% of accidents on wet roads happen with very little water depth
The first 4 statistics could lead you to believe that perhaps 7-15% of accidents could potentially have been caused by rear aquaplaning on a bend (doesn't mean 15% were, just that at-least 85% could not have been)
But the thing which really blows all of these statistics out of the water is the final stat that "99% of accidents on wet roads happen with _very_ little water depth."
of the 20,000 accidents they analysed approximately 30% (6,000) were in the wet, and of those 6,000 accidents 99% (5,940) were described as having very little water depth. I am sure you cannot aqua plain in very little water depth, even with tyres right down to the legal limit.
so now of those 60 or so accidents which did involve higher levels of water, where there was a risk of aquaplaning, we can only speculate if they were at speed and on bends, but if we assume that all 60 could have been, and that aquaplaning at the rear could have been the cause, it's still only 60 maximum out of 20,000.
How many of the other 19,940 accidents could have been avoided by one or more of the cars involved having a little bit more stopping power or steering grip? Particularly the other 5,940 in the wet
What is "very little"? You need less than 3mm of standing water to aquaplane. When they say "very little" I would think they are referring to depths that don't cause a splash when you drive through them. Without referring to the actual source data it's impossible to tell.75% of accidents happen on straight roads (of which 20% when wet)
25% of accidents in bends (50% of which when wet)
99% of accidents on wet roads happen with very little water depth
The first 4 statistics could lead you to believe that perhaps 7-15% of accidents could potentially have been caused by rear aquaplaning on a bend (doesn't mean 15% were, just that at-least 85% could not have been)
But the thing which really blows all of these statistics out of the water is the final stat that "99% of accidents on wet roads happen with _very_ little water depth."
of the 20,000 accidents they analysed approximately 30% (6,000) were in the wet, and of those 6,000 accidents 99% (5,940) were described as having very little water depth. I am sure you cannot aqua plain in very little water depth, even with tyres right down to the legal limit.
so now of those 60 or so accidents which did involve higher levels of water, where there was a risk of aquaplaning, we can only speculate if they were at speed and on bends, but if we assume that all 60 could have been, and that aquaplaning at the rear could have been the cause, it's still only 60 maximum out of 20,000.
How many of the other 19,940 accidents could have been avoided by one or more of the cars involved having a little bit more stopping power or steering grip? Particularly the other 5,940 in the wet
ging84 said:
At the very least those statistics show it's not all one sided, but if you ask me it show the manufacturers have it very very wrong.
But what i can't get my head around fully is why does the tyre industry feel so strongly about it, do they really care so much about road safety, or is something else going on?
I have my own conspiracy theory based on the idea that the tyre manufactures have figured they can lock customers in who want to keep all 4 matching tyres, and generally people are more likely to pay more and buy premium branded tyres when they only need to replace 2 not all 4 at the same time.
Look in your car's manual, it will tell you to rotate the tyres from back to front when you get new tyres. You never need to replace 4 at the same time. But what i can't get my head around fully is why does the tyre industry feel so strongly about it, do they really care so much about road safety, or is something else going on?
I have my own conspiracy theory based on the idea that the tyre manufactures have figured they can lock customers in who want to keep all 4 matching tyres, and generally people are more likely to pay more and buy premium branded tyres when they only need to replace 2 not all 4 at the same time.
I have contributed in this topic before but I think since it has arisen from the depths again I will re-state what I prefer.
Having been bitten on the ass by the old failing of the MOT because the rear tyres sidewalls were cracking but the tyre still having loads of tread left I will always put the new tyres on the rear and move the rears to the front.
The difference in age is fairly small, the rears are worn in but have no significant wear, these are perfectly safe to take on the extra duty up front, the new tyres can do a year out back and then take their turn when I have worn the fronts out again.
When I was involved in MOT testing we would see loads of cars where the owners had replaced the fronts several times but the rears were the original tyres from new, many with cracks and the rubber quite hard, less grip due to age and design yet still with 5mm of tread, in my opinion this is unsafe, we can argue about grip and putting the newest on the front till the cows come home but if the rears are old then you will have as many problems as if the fronts are crap.
Since a lot of drivers dont care about the car at all and will put the cheapest ling longs on then I feel it is important to give them the newest tyres all round as a precaution against themselves.
Having been bitten on the ass by the old failing of the MOT because the rear tyres sidewalls were cracking but the tyre still having loads of tread left I will always put the new tyres on the rear and move the rears to the front.
The difference in age is fairly small, the rears are worn in but have no significant wear, these are perfectly safe to take on the extra duty up front, the new tyres can do a year out back and then take their turn when I have worn the fronts out again.
When I was involved in MOT testing we would see loads of cars where the owners had replaced the fronts several times but the rears were the original tyres from new, many with cracks and the rubber quite hard, less grip due to age and design yet still with 5mm of tread, in my opinion this is unsafe, we can argue about grip and putting the newest on the front till the cows come home but if the rears are old then you will have as many problems as if the fronts are crap.
Since a lot of drivers dont care about the car at all and will put the cheapest ling longs on then I feel it is important to give them the newest tyres all round as a precaution against themselves.
The focus seems to be on aquaplaning. I don't think that the tyre manufacturer advice is specific only to aquaplaning situations. I think it goes something like this...
New tyres are likely to perform better than old tyres. Statistically
It is statistically safer to have better performing tyres at the back as most drivers deal better with understeer than oversteer.
It's no more complex than that.
Bert
New tyres are likely to perform better than old tyres. Statistically
It is statistically safer to have better performing tyres at the back as most drivers deal better with understeer than oversteer.
It's no more complex than that.
Bert
If the issue was only about aquaplaning, my opinion would be that the new tyres should always go on the front, as the rears will follow in the front tyres' path, and thus have far less water clearing to do
However, this is inly one aspect, and it's looking more like the "new on the rear" argument is coming from Joe Public's ability to handle understeer more easily than oversteer. Quite understandable.
I would class myself as a fairly decent driver (trophies for safe driving, trophies for fast driving), but I still feel uneasy when the back end isn't doing as I want (apart from a recent quick blat in a Caterham round Curborough Sprint Course, which felt utterly natural going sideways).
For "ordinary" drivers who don't deliberately provoke a car at the limits of traction or grip, the normal reaction when one end starts to slide is to lift off or even brake. We all know what will happen if this is done while oversteering, so my opinion is that the tyre manufacturers' guidance is for the masses and is simply safety-related.
However, this is inly one aspect, and it's looking more like the "new on the rear" argument is coming from Joe Public's ability to handle understeer more easily than oversteer. Quite understandable.
I would class myself as a fairly decent driver (trophies for safe driving, trophies for fast driving), but I still feel uneasy when the back end isn't doing as I want (apart from a recent quick blat in a Caterham round Curborough Sprint Course, which felt utterly natural going sideways).
For "ordinary" drivers who don't deliberately provoke a car at the limits of traction or grip, the normal reaction when one end starts to slide is to lift off or even brake. We all know what will happen if this is done while oversteering, so my opinion is that the tyre manufacturers' guidance is for the masses and is simply safety-related.
davepoth said:
Go and ask 10 relatives at random what aquaplaning is. I bet you at least half of them will have no idea or will get it wrong.
i'd take that bet,but anyway i don't think you need to know the technical terms to know that you should slow down and take more care when there is standing water on the roads, and that in heavy or prolonged rain can lead to standing water on the roads, it even gets mentioned quite regularly on the weather reports on tv.
I'm not saying everyone will always heed these warning, but they must be aware atleast
davepoth said:
So 30% of accidents occur on wet roads. Are the roads wet for 120 days a year in the study area? If not then you are more likely to crash in the wet than in the dry.
you are missing the point of the statistic here completely, it doesn't matter if you are more or less likely to crash on a particular occasion, but over the course of time it suggest you are significantly more likely to have an accident in the dry than in the wet. Unless you want to go down the route of telling people to swap their tyres over on a journey by journey basis depending on the weather then it is not really relevant.davepoth said:
What is "very little"? You need less than 3mm of standing water to aquaplane. When they say "very little" I would think they are referring to depths that don't cause a splash when you drive through them. Without referring to the actual source data it's impossible to tell.
ok fair enough it's an unscientific term, but seriously? i don't think anyone would class a road where you could aquaplane as very little water depth, i would say quite the opposite davepoth said:
Look in your car's manual, it will tell you to rotate the tyres from back to front when you get new tyres. You never need to replace 4 at the same time.
you mean this ?Swapping wheels among the axles
The manufacturer of your MINI recommends
that you do not swap the front wheels with the
rear wheels as this may impair the handling of
your MINI
this is actually one of the things that set me off looking into the issue, wondering why between 2007 and 2009 the advice had been completely switched around from this
Swapping wheels among the axles
The manufacturer of your MINI recommends
that you swap the front wheels with the rear
wheels and vice-versa at intervals of 3,000 to
4,000 miles/5,000 to 7,000 km. This will counter
the varying rates of tire wear at the front and
rear axles, which will have a positive effect on
the handling characteristics of your MINI. The
direction in which the tires rotate should be kept
the same.
and seeing as BMW already has Michelin’s cock in it's mouth trying to lock people into using run flats it really would not surprise me if i found out this advice change had more to do with profits than road safety
Nigel_O said:
For "ordinary" drivers who don't deliberately provoke a car at the limits of traction or grip, the normal reaction when one end starts to slide is to lift off or even brake. We all know what will happen if this is done while oversteering, so my opinion is that the tyre manufacturers' guidance is for the masses and is simply safety-related.
Very nicely put, and I agree entirely. Even though I'm comfortable with "a dab of oppo" if it happens I still like the better tyres to the rear to avoid having to do it on a public road any more than is absolutely necessary. Should we look at this from a vehicle dynamics point of view?
Your car manufacturer has spent ages ensuring that your car is an understeer-characteristic car (by which I mean the steering angle required is greater than the d'Alembertian angle, rather than that it ploughs on into the hedge when you drive a corner too fast). Isn't the risk that by increasing the grip at the front you create an oversteer-characteristic car?
Oversteer characteristic cars have a critical speed at which the required steering angle for any turn reduces to zero -- or put another way - they spin out of control and you die* if you go fast enough.
I don't know how low that critical speed can be, but this is the reason I don't monkey with my suspension or put new tyres on the front.
Your car manufacturer has spent ages ensuring that your car is an understeer-characteristic car (by which I mean the steering angle required is greater than the d'Alembertian angle, rather than that it ploughs on into the hedge when you drive a corner too fast). Isn't the risk that by increasing the grip at the front you create an oversteer-characteristic car?
Oversteer characteristic cars have a critical speed at which the required steering angle for any turn reduces to zero -- or put another way - they spin out of control and you die* if you go fast enough.
I don't know how low that critical speed can be, but this is the reason I don't monkey with my suspension or put new tyres on the front.
- death is optional.
7db said:
Should we look at this from a vehicle dynamics point of view?
Your car manufacturer has spent ages ensuring that your car is an understeer-characteristic car (by which I mean the steering angle required is greater than the d'Alembertian angle, rather than that it ploughs on into the hedge when you drive a corner too fast). Isn't the risk that by increasing the grip at the front you create an oversteer-characteristic car?
Oversteer characteristic cars have a critical speed at which the required steering angle for any turn reduces to zero -- or put another way - they spin out of control and you die* if you go fast enough.
I don't know how low that critical speed can be, but this is the reason I don't monkey with my suspension or put new tyres on the front.
... and this is the reason why I HAVE arsed about with my geometry. I have a "safe" FWD car - a Fiat Coupe. It was already an OK handling thing, but with a 2/3 front weight bias, it was always going to understeer when pushed, especially when on the throttle.Your car manufacturer has spent ages ensuring that your car is an understeer-characteristic car (by which I mean the steering angle required is greater than the d'Alembertian angle, rather than that it ploughs on into the hedge when you drive a corner too fast). Isn't the risk that by increasing the grip at the front you create an oversteer-characteristic car?
Oversteer characteristic cars have a critical speed at which the required steering angle for any turn reduces to zero -- or put another way - they spin out of control and you die* if you go fast enough.
I don't know how low that critical speed can be, but this is the reason I don't monkey with my suspension or put new tyres on the front.
I've more than doubled the bhp, so I wanted to make it corner properly as well. Quaife diff, 25mm lower springs, adjustable dampers, uprated rear ARB, bit of extra camber at the front, polybushes everywhere. The end result is a car that turns in really well, but never feels like it wants to oversteer. It'll still understeer when hard on the throttle (although the Quaife has made an immense difference), but it is really planted. By comparison, I also have a completely unmolested Fiat Coupe non-turbo (about 1/3 of the bhp of my modded one), which now feels truly awful to drive - vague steering, roly-poly suspension, understeer everywhere, wet or dry
So - why do manufacturers build in such a huge safety margin to mainstream cars? I've spent many hundreds dialing out understeer on my quick Coupe and (IMHO) I've made the car much better, with no handling downsides (other than a slightly firm / jiggly ride at town speeds). It certainly won't bite back, but the precision is vastly improved.
Perhaps we're back to the conclusion about which end to put new tyres on - the reason that most people drive cars - it's simply a method of getting to somewhere else - the car is nothing more than white goods, with no involvement (or desire to be involved) from the driver's perspective. Damn - are PH'ers a dying breed?
7db said:
Your car manufacturer has spent ages ensuring that your car is an understeer-characteristic car (by which I mean the steering angle required is greater than the d'Alembertian angle, rather than that it ploughs on into the hedge when you drive a corner too fast). Isn't the risk that by increasing the grip at the front you create an oversteer-characteristic car?
Are you creating an oversteer-characteristic car, or just reducing the severity of the understeer-characteristic? Surely the stronger the understeer-characteristic the more extreme a change will be needed to return it to neutral, and beyond that to oversteer tendency.Gassing Station | Advanced Driving | Top of Page | What's New | My Stuff