Just Did My First Trackday...

[Cameron 16]

So.....

 

*grabs coat and heads for the door*

 

i reckon I'll stick with what i have for now and practice my driving on the track a bit more. Might look into suspension and sticky tyres after that.

 

Thanks for the help guys.

 

 

Sorry to turn your thread into a debate! Hopefully you can pick some useful bits and pieces out of it.

[Cameron 16]

Oh i've always understood what you're getting at mate, it just doesn't change anything. And personally in the vid above, the car was back on level ground when it started to roll rather than on the hill, it was more the fast transition between sliding one way then the other and it gripping, LEVEL GROUND or not, it happens.

 

I have seen a 205 literally topple over going round a 180d hairpin on flat ground at level ground on an airfield runway, and seemingly not even going that fast, and it certainly wasn't being driven eratically, as yes, the one above was, Darren (VisaGTi16v) may have seen it too if he was there, i'm not sure.

 

My dad stood behind me earlier as i reminded him about it and he commented 'yes that was very odd'. So by your way of thinking as presented above in your little rant, irrelevant of what he does for a living thanks, i think he knows better than you.

 

He has a bigger cock too for that matter.

 

Well you must have missed something somewhere! I'm not denying rollovers happen, I'm just saying that it isn't down to the tyre / suspension combo. Fair enough stickier tyres could turn what would be a very near miss into a flip, I'd be a fool to try and deny that! I just mean that it isn't as pressing a concern as someobody (I forget who) made out it was. You aren't going to start flipping the car on every hard turn.

 

Well I hope you've never studied my man-parts in that sort of detail before, and your dad's for that matter!

[Alastairh 47]

 

Now thats 4 minutes of my life i won't see again. What a boring open track!

 

You lot have too much time on your hands writing long replys. Go have a wank or something!

 

Al

[Cameron 16]

Done and done.

[Rippthrough 98]

Tyre rollover isn't about the same axis as the body roll though, so it's not as simple as adding them together...halving the tyre rollover might knock perhaps a tenth off the overall roll...

Then you've got more grip, so your rolling more to start with (yes, yes, the roll is from cornering faster, but that goes hand in hand with more grip from the sticky tyres), perhaps more concerning is you now also have faster transitions from roll due to the low speed circuits on the dampers being too soft (which is what contributes to the aforementioned rollovers with sticky tyres and stock suspension, it's not so much the spring rate, it's that the momentum of the body isn't controlled if you take a bit too much kerb*, doesn't often happen, but it's still more likely with stickier tyres).

You also have the same effect even if you push a bit too hard when cornering, or the back comes out, the car doesn't settle fast enough and has much more of a tendancy to throw you into a bit of a tank slapper.

Which is then exaberated further by the track tyres tending to have a steeper dropoff after the peak slip angle (and a lower peak angle due to those stiff sidewalls).

 

Personally, I'd always fit decent dampers before stickier tyres, even though the latter give more pace per pound - I ain't racing, so control and feedback is more important.

 

 

 

My 2p, although, given the inflation rate, I might have to put it up to 3p next week.

 

 

*And if you're not on the kerbs you're not using all the track!

Edited February 18, 2010 by Rippthrough

[Baz 421]

I wrote this a while ago and then got bored and went to get a cup of tea, but it has to go down, mainly because for some reason you aimed it directly at me, despite others clearly not siding with you on the matter, and i think you need to be shown or told, not that i think it'll have much gumption to you coming from me of course.

 

 

Yes, he rolled over because he was being an idiot and whipping the car around down a hill. That's totally irrelevant anyway as you don't know what tyres he was using!

 

What difference does that make? You're saying that it wouldn't happen anyway irrelevant of tyres, but it clearly did, so i fail to see why you're now arguing it again. Then since then you've gone full circle after basically ridiculing my view of sticky tyres increasin the chances of rolling on standard suspension, only then you went back on that...

 

Coupled with..? Come on, it's not like they cornered so fast that the car flipped over! What did they do, clip a kerb or get airborne and land sideways?

 

Fair enough stickier tyres could turn what would be a very near miss into a flip, I'd be a fool to try and deny that!

 

I'm getting pretty fed up of this bulls*it to be honest. Every time I mention something slightly contrary to your opinions you make a massive bloody fuss about it and try and exaggerate and ridicule every point I make. Now I'm sorry but Baz, what do you do for a living? What other than what you've been told or read about on the internet qualifies you to such an extent that you believe you know more about vehicle dynamics than someone who is studying a course largely based on the subject?

 

This is exactly like the rear ARB argument a couple of months ago, I say something about a small area of a vehicle and suddenly I have a load of people jumping down my throat with all these arguments that are absolutely nothing to do with what I said!

 

It's like if I said fitting suspension component X would cause a tendency to oversteer, then people come back at me saying yeah but I've fitted components A, B, C, D, X , Y and Z and my car doesn't oversteer, it does backflips on command so you must be wrong. It's all bollocks, read my posts properly before you reply with some nonsense that has nothing to do with it.

 

Now i'm not rubbishing it for a minute because i don't know what they teach you there, but even you aren't niave enough to think that farting about at university for a while gives you free reign to think you absolutely must be Mr. Right, the be all and end all, and god forbid anyone that goes against the theory and the stuff that you've learnt?

 

Did that just do a great job of infuriating you? Yes, because that's equally the way you think of me isn't it!!

I'm not always right, and i'll admit what i want, but i have an opinion and i'll stand by it strongly, this is ultimately just that, exactly as you're doing!

 

 

What does what i do for a living have to do with anything? What do you do for a living? Whether i was a race/rally car designer or a bin man, does that change someone's worth, knowledge and experiences? By proxy then you think you know better than i, because equally that's what you assume i think. I don't, i just know a few things about cars because i've been lucky enough to have been gaining experience of dicking about with them since the silly age of 7. Yes i have also done some silly things and made mistakes and had accidents, because exactly you're arguing, things don't always happen the way they're supposed to! But i've learnt alot from doing so. Without trying to sound big-headed, i'm fairly capable in cars, somewhat clearly. But i've been in cars with 12-16 year olds that are a darn site better/quicker than me and can do amazing things in cars, i believe this is because equally, they've learnt from a young age, so much so it comes naturally. Coming with it for me is a great understanding of what a car's doing underneath me, so i speak from these experiences.

 

You study vehicle dynamics, so you think that gives you some kind of knowledge over actually getting out there and driving cars? From one POV it probably does, yes, but that's my point, they're 2 different schools of thought and opinion. Have you been in a car that's rolled? Not that i think these things change my opinions, i just don't see why you seem to do such. In fact we're seemingly arguing from 2 sides that should go hand-in-hand!

 

I think the fact that it's never just me that thinks a certain way should be proof enough that i'm not the only one with half a brain or ounce of common sense, yet you don't do yourself any favours and continue to make yourself look silly.

 

 

A car can roll in the wierdest of circumstances i'm afraid, despite physics, and everything else you think you know, strange things happen, you can't put numbers and figures in front of actual happenings claiming that it shouldn't have happened because the numbers and figures don't allow it, it's happened! And no, i don't say things for no reason, i'm only 25 years old but haven't been in the habit of telling silly fibs wasting my own aswel as anyone else's time for a looong time!

 

Physics and theory go a long way to explain things of course, but i'm afraid in real terms sometimes you just have to get out there and do, rather then waste your time thinking about it, reading books etc. Essentially doing what you've accused me of; reading the internet etc...

 

And this happens in all circumstances all over the world of course, not just to do with cars and driving etc...

[Rippthrough 98]

**Runs and hides under the stairs**

[Baz 421]

Tyre rollover isn't about the same axis as the body roll though, so it's not as simple as adding them together...halving the tyre rollover might knock perhaps a tenth off the overall roll...

Then you've got more grip, so your rolling more to start with (yes, yes, the roll is from cornering faster, but that goes hand in hand with more grip from the sticky tyres), perhaps more concerning is you now also have faster transitions from roll due to the low speed circuits on the dampers being too soft (which is what contributes to the aforementioned rollovers with sticky tyres and stock suspension, it's not so much the spring rate, it's that the momentum of the body isn't controlled if you take a bit too much kerb*, doesn't often happen, but it's still more likely with stickier tyres).

You also have the same effect even if you push a bit too hard when cornering, or the back comes out, the car doesn't settle fast enough and has much more of a tendancy to throw you into a bit of a tank slapper.

Which is then exaberated further by the track tyres tending to have a steeper dropoff after the peak slip angle (and a lower peak angle due to those stiff sidewalls).

 

Personally, I'd always fit decent dampers before stickier tyres, even though the latter give more pace per pound - I ain't racing, so control and feedback is more important.

 

 

 

My 2p, although, given the inflation rate, I might have to put it up to 3p next week.

 

 

*And if you're not on the kerbs you're not using all the track!

 

Sir, i salute you, you clearly have the same understanding of what the car is doing underneath as i, only you seem to be able to put it into words better!!

 

But yes, i agree with that totally. Hence to a point i don't think sticky tyres should be thought of as an easy bolt-on mod for just anyone to reduce lap times. They need to be respected too! There's somethign to be said for tyres with a nice progressive loss of adhesion and tyre-wall flex to tell you what's happenening and give you a chance to react before it cathces you out!

 

Pretty much as i think someone (again i think it was you Phil) put more simply earlier on in the thread.

[davidc 0]

So.....

 

*grabs coat and heads for the door*

 

i reckon I'll stick with what i have for now and practice my driving on the track a bit more. Might look into suspension and sticky tyres after that.

 

Thanks for the help guys.

 

Quarryman....what a cracking post this has turned out to be......

 

Anyway....if it was me that was in your position, if you want to spend a bit of money on the car then I'd do it in stages.......

 

1. Uprate the bushes to polyurethane or least fit new std items

2. Fit uprated suspension & possibly slightly lower (also upper & lower strut braces, uprated arb's, torsion bars, solid beam mounts, etc)

3. And finally....better tyres

 

Fitting the tyres first doesn't make sense to me and thats from experience.......I've found a std car on std suspension with sticky tyres is a bit of a handful (plenty of grip but the car wallows around a lot more) & handles like a boat (quite scary !).......however.........a car with decent uprated suspension on std road tyres is better to drive as it goes where you want it & will slide about more (as I found with Colway F2's)...ok....you still get roll from the road tyres as they dont have a stiffer sidewall compared to a competition tyre but the body roll that you've reduced by fitting uprated suspension makes the car sit on the road & handle better.

 

In fact.......if your feeling like spending a bit....go and buy the whole lot......fit the sticky tyres first & see how you go (be careful though !).....then fit the uprated suspension on road tyres and see how that is.....and finally.....put on the sticky tyres with the uprated suspension & you'll find that you have an excellent handling car.

 

Thats just my view from experience of racing, rallying, sprinting, hillclimbing & fast road/performance cars over the years.

 

 

Cheers,

David

[Batfink 201]

In 04 when I took my rallye on a trackday I could get it on two wheels round the chicane at Bruntingthorpe with 1.9 alloys and road tyres without touching the kerb. With AO48's I've only used them with proper suspension..

[Cameron 16]

What difference does that make? You're saying that it wouldn't happen anyway irrelevant of tyres, but it clearly did, so i fail to see why you're now arguing it again. Then since then you've gone full circle after basically ridiculing my view of sticky tyres increasin the chances of rolling on standard suspension, only then you went back on that.

 

No, no, no no. You still haven't listened! When did I ever say that rollovers were impossible? Quote me directly in my exact words saying that it never ever happens.

 

What I've been saying all along is that you will not just roll a 205 on level ground due to cornering quickly. There HAS to be another factor involved. weather that factor is clipping a high kerb, sliding across a pothole or handbraking down a hill.

 

 

Now i'm not rubbishing it for a minute because i don't know what they teach you there, but even you aren't niave enough to think that farting about at university for a while gives you free reign to think you absolutely must be Mr. Right, the be all and end all, and god forbid anyone that goes against the theory and the stuff that you've learnt?

 

There's a reason they teach this stuff though, it's because it is widely accepted as the truth! People have been using the theory for decades to get an accurate idea of what a car is doing dynamically. Now I know that you can't have an accurate idea of a whole car's performance by looking at just one factor (like the tyres) you have to look at everything, and that's where this "physics is not the real world" bollocks that everyone with no idea seems to be spouting comes from. But let me tell you physics IS THE REAL WORLD. There is absolutely nothing that goes on that cannot be explained.

 

What does what i do for a living have to do with anything? What do you do for a living? Whether i was a race/rally car designer or a bin man, does that change someone's worth, knowledge and experiences?

 

Sadly, everything. You can harp on about your experiences all you like, I'm not denying that they ever happened! I'm just stating that there is a reason why that you aren't seeing, it's not my fault that you're too closed minded to listen.

 

You study vehicle dynamics, so you think that gives you some kind of knowledge over actually getting out there and driving cars? From one POV it probably does, yes, but that's my point, they're 2 different schools of thought and opinion. Have you been in a car that's rolled? Not that i think these things change my opinions, i just don't see why you seem to do such. In fact we're seemingly arguing from 2 sides that should go hand-in-hand!

 

Yes, of course it does!

I could drive cars for my whole life and still have absolutely no idea what's going on. I could make it to the top of Formula 1 and still have no idea!

 

A car can roll in the wierdest of circumstances i'm afraid, despite physics, and everything else you think you know, strange things happen, you can't put numbers and figures in front of actual happenings claiming that it shouldn't have happened because the numbers and figures don't allow it, it's happened! And no, i don't say things for no reason, i'm only 25 years old but haven't been in the habit of telling silly fibs wasting my own aswel as anyone else's time for a looong time!

 

Physics and theory go a long way to explain things of course, but i'm afraid in real terms sometimes you just have to get out there and do, rather then waste your time thinking about it, reading books etc. Essentially doing what you've accused me of; reading the internet etc...

 

And finally, no a car does not roll despite physics. I bet if you (were sad enough to) run a simulation of that MG or that 205 where you modelled absolutely everything in those circumstances the sim would show the car rolling over! There is nothing that can't be explained, you just need a more complex equation.

 

Take F1 (again), I know a guy who does lap simulation for Brawn GP and they model absolutely EVERY variable, down to the minute bumps in the ground, and what they get out is really quite accurate! Otherwise they wouldn't bloody do it!

 

SO back to what I've been saying all along:

 

YOU WILL NOT ROLL A 205 JUST THROUGH CORNERING AT SPEED ALONE.

 

If you did manage to roll a 205, THERE HAS TO HAVE BEEN SOMETHING ELSE INVOLVED. Which is an argument you now seem to be trying to use against me.

 

WHILE STICKY TYRES AND STANDARD SUSPENSION MAY TURN A NEAR MISS INTO A FLIP, YOU WON'T BE UP ON 2 WHEELS ON EVERY CORNER. THE RISK IS VERY VERY SMALL.

 

How much longer are we going to drag this s*it out for?

[Cameron 16]

Tyre rollover isn't about the same axis as the body roll though, so it's not as simple as adding them together...halving the tyre rollover might knock perhaps a tenth off the overall roll...

Then you've got more grip, so your rolling more to start with (yes, yes, the roll is from cornering faster, but that goes hand in hand with more grip from the sticky tyres), perhaps more concerning is you now also have faster transitions from roll due to the low speed circuits on the dampers being too soft (which is what contributes to the aforementioned rollovers with sticky tyres and stock suspension, it's not so much the spring rate, it's that the momentum of the body isn't controlled if you take a bit too much kerb*, doesn't often happen, but it's still more likely with stickier tyres).

You also have the same effect even if you push a bit too hard when cornering, or the back comes out, the car doesn't settle fast enough and has much more of a tendancy to throw you into a bit of a tank slapper.

Which is then exaberated further by the track tyres tending to have a steeper dropoff after the peak slip angle (and a lower peak angle due to those stiff sidewalls).

 

Well no it isn't quite as simple as adding the two together but I was simplifying it for the good of everyone involved.

 

Yeah that's absolutely right, the damping does have a lot to do with it. But then you're talking about a rollover caused by taking a kerb or flicking wildly from one direction to another. In reality, on a track, that's pretty unlikely. If you're mad enough to be trying the Scandanavian flick at 100mph then frankly you deserve everything you get!

 

And to be honest, hitting a kerb on standard suspension is pretty unlikely to flip you over. As you say the springing and damping is quite soft so the suspension will absorb 90% of the impact. Hell I'd say you were more likely to roll on hard suspension because the kerb impact translates into more body movement!

 

You're still massively unlikely to roll a car through cornering at speed alone.

Edited February 18, 2010 by Cameron

[Rob Thomson 6]

What I've been saying all along is that you will not just roll a 205 on level ground due to cornering quickly. There HAS to be another factor involved. weather that factor is clipping a high kerb, sliding across a pothole or handbraking down a hill.

So how is 'handbraking down a hill' different from 'cornering quickly' in terms of the forces acting on the vehicle that might lead to a roll?

[Cameron 16]

My standard 1.6 on R888s is fine on track; never feels like it's going to roll even when attacking kerbs, it just slides nicely and progressively. Having said that it does ocassionally feel a bit marginal when autotesting. The airfield where I usually compete has a very coarse tarmac and ever now again it feels a bit dodgy when it bites whilst handbraking at high speed (40mph). I think it's the very sudden transitions combined with high grip levels that result in poor body control in those extreme circumstances.

 

Another one for you.

 

Seriously, people put track tyres on standard sus all the time. How many of them roll?

[Cameron 16]

So how is 'handbraking down a hill' different from 'cornering quickly' in terms of the forces acting on the vehicle that might lead to a roll?

 

Because the centre of gravity is higher than usual, think about it.

[davidc 0]

Why are you guys obsessed with if a 205 will roll or not on flat ground ???....Im sure the original post was just about how the car was handling & what people thought.....any chance you could make some reasonable suggestions ???

 

To me, it definitely looks as though it needs better suspension as there is quite a bit of body roll.

 

 

Cheers,

David

[Rob Thomson 6]

Why are you guys obsessed with if a 205 will roll or not on flat ground ???....Im sure the original post was just about how the car was handling & what people thought.....any chance you could make some reasonable suggestions ???

 

To me, it definitely looks as though it needs better suspension as there is quite a bit of body roll.

Are you in charge of this thread?!

 

The point is this; there's nothing wrong with soft suspension, it creates feel and progression and lets the driver bounce over kerbs. By fitting 'better suspension' you might raise the limits a bit but you begin to lose those nice characteristics of the standard car. People rave about the handling of a standard 205 GTi, so why f*** with it unless you have to?

 

However, one reason why you might want to f*** with it is that a standard chassis is not necessarily compatible with sticky tyres (ie. whether it'll roll over), and that's the point of this discussion.

[Cameron 16]

It's just how a topic evolves on the internet. Eventually someone says something that someone else misinterprets or disagrees with and the result is page after page of the same s*it spinning round and round.

 

No there's nothing wrong with soft suspension, it reduces weight transfer (believe it or not) and keeps everything nicely in contact with the ground without translating movement to the body. The downside is that soft suspension on a 205 plays havoc with the suspension geometry so you end up with horrible camber changes which lose you grip. Although stiffening the suspension will increase weight transfer and therefore reduce grip (this is another topic altogether though), the benefits of reducing the camber change far outweigh the disadvantages.

 

The standard handling of the 205 is good, but it can be greatly improved with the right mods!

[happygoron 2]

I'm by no means qualified to speak on the roilling issue as I have limited driving experiance and no vehicle dynamics knowladge. However I do have a fair bit of experiance with physics and I just wanted to pick up on this point!

 

There's a reason they teach this stuff though, it's because it is widely accepted as the truth! People have been using the theory for decades to get an accurate idea of what a car is doing dynamically. Now I know that you can't have an accurate idea of a whole car's performance by looking at just one factor (like the tyres) you have to look at everything, and that's where this "physics is not the real world" bollocks that everyone with no idea seems to be spouting comes from. But let me tell you physics IS THE REAL WORLD. There is absolutely nothing that goes on that cannot be explained.

 

Wrong! Real life is far too complex to be 100% explained. Physics theories rely on assumptions. The less you assume the more complicated something becomes. You have to comprimise between assumptions and the reality of getting data that is usable. I think this xkcd comic sums it up pretty well:

 

http://xkcd.com/669/

 

Even those Brawn guys will have made a series of assumptions. The trick is to understand the assumptions and the potential error they introduce into the data.

 

Anyway, carry on as you were lads!

Edited February 18, 2010 by happygoron

[davidc 0]

Are you in charge of this thread?!

 

No.....sorry....are you ???

 

I just thought the point of someone posting something he needed help with was to reply & try to help.....not to get personal & go off on a tangent on one particular point......going off topic ???

 

My point was that you really should upgrade the car in logical steps or do everything at the same time...depending on what you want to do & how successful you want to be.

 

 

 

Anyway......what does quarryman think ? What are your plans now ?

 

 

 

Cheers,

David

[Cameron 16]

I wouldn't be surprised if he'd hung himself after this load of bollocks!

[Tom Fenton 1,549]

Wowee........

 

 

Anyway to the original poster

 

Hopefully you have picked up some different views on the subject. It does depend to a large degree in my eyes, on what you use the car for MOST- e.g. is it your road car that you want to bash round a track a couple of times a year, or is it something that will be used for tracks and not much else?

 

This will really define how far you want to go modification wise.

 

As others have said, I have found some slightly harder front springs, coupled with a larger rear anti roll bar, and strut braces, make a reasonable improvement to a standard car, without making it too extreme for road use. Uprated dampers are also well recommended, but come at a cost.

 

Finally with no disrespect, but if possible get some tuition at your trackday- some organisers will give 20min free of charge. This will always help you go faster, and enjoy your day more.

[tagy 1]

Just remember to fold the rear seats down, so you're less likley to roll

[Baz 421]

... this load of bollocks!

 

You said it.

[TT205 42]

I've really enjoyed this banter ^^^

 

I would simply say that from being involved in sprint/hillclimb racing and watching many rolls - that if you are using a road tyre and try to corner too hard or you catch a kerb, typically the road tyre generally loses traction and the car may cock a wheel but simply slides wide. With a sticky tyre there is a real good chance that the tyre will 'dig in' and put you well onto two wheels or worse

 

 

Road tyres sliding :-

 

 

Stickies digging in