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Discussion Starter #182
Ah, 'handbags'... :D

This will not degenerate into some form of low-rent Supra Site vs Mycroft slagging match.

Much as that would please you as I have proven to be correct in what I say.

I think you have been warned once about just emotional outbursts, so please be part of the discussion not just some moronic claque applauding anything that isn't posted by me, in short son, GROW UP!
 

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Mycroft said:
Ah, 'handbags'... :D

This will not degenerate into some form of low-rent Supra Site vs Mycroft slagging match.

Much as that would please you as I have proven to be correct in what I say.

I think you have been warned once about just emotional outbursts, so please be part of the discussion not just some moronic claque applauding anything that isn't posted by me, in short son, GROW UP!
Mycroft - has it occurred to you that the fact I (and others) think you are wrong has nothing to do with the cars we drive or the forum which we "come from"?

You clearly have a hang-up with Supra owners - the fact that you keep mentioning it suggests that you are the one letting "emotion" get the better of you. How sad.

How about sticking to the topic?
 

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Mark

Trust me. It's better to ignore him. Everyone here is intelligent enough to work it out for themselves.

All the best

Simon
 

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Discussion Starter #189
Your reluctance to even defend your own evidence just about says it all about you Simon.

The fact that no-one on here has defended them either is just the icing on the cake.

Simon defeated by his own posts... coolest of cool.

:D

I await your next assertion with bated breath...
 

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Let's avoid turning this into a tit for tat match please.

Simon,
I'm fascinated by your explanations and a number of emails I'm having with various experts in the field back up your comments.
From a non technical standpoint, the most valid example to me was the comparison between a 1000kg car and a 2000kg car together with an unlimited budget - Idiot's Guide to Handling (I believe I have it somewhere) ;)

Mycroft,
Is it true to suggest that if F1 cars were heavier, we'd have better cornering performance?

Cem

p.s. Hi Logiclee
 

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Discussion Starter #191 (Edited)
Cem in answer to your question... No! [unless the wrong tyres had been specced in the first place]

The 1000kg and 2000kg example I gave differs greatly from that in the 'Idiots Guide to Handling' by the looks of it, so is not valid to this thread.

The 'conflict' here is very simple, on the one hand we have Simon saying that...

At no point is there an ideal weight for a given size of tyre, all weight is negative, you always lose with its imposition by whatever means.

Simply, from ANY point on a Grip vs Load graph there is never a 'doubling for doubling' portion.

I contend that this is entirely wrong, the graph shows a 0-0 at the start point [naturally enough] in very short order the weight above self weight will show a 1 to 1.4 - 1.7 table established, this alone disproves Simons contention immediately, the graph will then maintain this 1 to 1.4 - 1.7 until at some point the tyre is unable to maintain this.

Simon has posted a link pages back to a set of graphs, each one clearly shows what I have asserted.

http://www.neohio-scca.org/clubinfo/comp_clinic/hand_out_reprints/LoadTransfer reduced 2.pdf

Third one down is the one Simon denoted as being the most pertinent. Whereas I see the 1st graph as the one to look at as the others are x-axle transfer graphs with which I agree but are not relevent to this discussion.

it has been flagged with the little insert something like 600 = 850 [that is this 1 to 1.4-1.7 static friction effect]

Now moving down the graph to 300 it seems to me [when you capture the image and blow it up] that the line shows 425 and although it is a little bit of a stretch 150 does look to produce 213 or very damned close.

So even the graphs posted by Simon to support his asertion seems to quite catagorically support my assertion that the drop off in performance only occurs after the tyre has been loaded to its optimal capacity.

Cem, I have seen nothing from a single person who has posted here any graph or published proof that supports Simons asertion, everything i can find says that once correctly loaded if you THEN double the load you will not get double the grip, this is in total agreement with my assertion also.

This is also shown on the graphs presented by Simon you can see that for yourself as the 'idealised' line carries straight on and the 'true plot' dips away from it.
 

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SDB said:
I can't take any credit for the following as it was given to me by Damian Harty (who I will try to temp to post) as a great way to think about the dynamics of tyres... but it was (paraphrased) as follows...

The grip produced by a tyre should not be though of a single object creating friction. Each tread block (remind me to talk about slicks if I forget) is a block of rubber providing friction individually. As the tyre skews, so do they, the load on each one is slightly different, the angle of attack of each one is slightly different, and they all produce slightly difference amounts of friction.

So when a tyre is nearing it's limit, it is not the overall tyre that is simply starting not to work as well, but a greater percentage of the tread blocks letting go.. this is why a tyre starts to make noise even before it actually lets go.

So... whilst friction is part of the story, it cannot be taken as the entire explanation of how a tyre produces grip.

All the best

Simon

You see, that makes sense! :)

But... what does the way a tyre progressively loses grip say about the load you place on it?

Oh: you forgot to talk about slicks ;)
 

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Discussion Starter #193
I have just blown that graph up hugely using the + feature and there is a dot at that 600 = 850 point and it is only after that point that the 2 lines split... so even the originator is telling us in no uncertain terms that what I assert is true.
 

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Discussion Starter #194
BTW, that point I have just realised is the PP... had forgotten that... PP is the Pneumatic Pivot, a point described variously as the 'optimal load point for and given tyre'.
 

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Discussion Starter #195
OK, so far we have had Simon argue vehemently that this:-

''2 cars... 1 weighs 1 tonne the other 2 tonnes they both have equal power-to weight ratios and torque curve/gearing coincide exactly for each... they are perfectly matched... even down to the 'G' force each can generate in any given curve...
In a race the 2 tonne car will eat the 1 tonner... quite easily....''



Was wrong.

...only to find that after a half dozen or so pages he agrees that the statement is correct.

----

We then have the same man state that there are ''lots of Centres of Gravity'' along the length of the car

Thanks to my continued questioning and much vascillating on Simons part that was changed to something else, that something else being what many of us knew all along.

----

We now await Simons explanation of the graphs he has presented as proof of his latest stance.

So far, everyone studying these 'proofs' finds themselves looking at the phenomena I describe, not Simons.

After 2 retractions perhaps a third is too much to bear.

Hence the refusal to engage in debate about these 'proofs'.

There is nothing more humiliating than to have your own 'weapon' wound you so mortally.

I am away for most of the day, I hope that we don't just get 2 or 3 pages of waffle, I would like to see a clear and distinct post from Simon explaining why that damned line stubbornly won't split until 600kg downforce is achieved.

Have fun... :D
 

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Mycroft said:
Andyf, a question for you?

As the original poster of the question, tell us which side of this debate are you on, little ol' me or our good friend Simon and the multifarious cast of trolls projecting him forward as The Great White Hope?

[Just a time out for us to draw breath, breathe in... hold... and ... relax.]


[Edit... breathe out.]

Sorry for the rather lengthy reply, several more pages have shot up since and I've only got this far this morning!

I'd have to say i'm not on either 'side' at the moment.
The problem is this: There is a lot of technical speak on this thread and I am not an engineer :( I can't judge myself who is right, who is wrong, etc. So, for the moment, I see this as a healthy debate in which both sides of the coin are being shown.

Gonna read the rest of the thread now :smokin:
 

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Morning all

Just on the off-chance that anyone think mycroft has posted anything that makes any sense or has any point to it, could you please let me know.

Otherwise, let's use the time we have with him away, to do the thread justice.

I look forward to your quetsions.

All the best

Simon
 

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Discussion Starter #198 (Edited)
Andyf, I would like to hear how you view that graph in Simons link.

...Simon, stop 'calling for others' in an attempt to avoid the issue, you are here and the originator of this topic is also, use this time to explain clearly and succinctly what that graph shows.
 

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Mycroft

The points you are raising are either completely irrelevant, made up or have been dealt with clearly enough for everyone else to see long ago. You continuing to pose them has spoilt this thread to an almost criminal degree.

This is not even to mention the way you are trying to twist my words to state that I mean subtly different things to that which everyone here can clearly see.

You have made a laughing stock of yourself and a mockery of this thread. This does not entice me to engage you in conversation.

Before posting once more asking OTHERS for any answers to questions, I suggest you regain a little bit of respect by at least answering the questions posed to YOU. That way people will be more likely to want to communicate with you as they will have more confidence that their replies will be met by a useful response. Until then, it's ridiculous to even consider trying to discuss this with you.

The reason I have asked if anyone else believes you deserve a response is that I am here to share knowledge with those who actually want it. I am not willing to continue spoiling the thread by discussing fairy tale physics with you alone.

Regards

Simon
 

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Discussion Starter #200
Explain 'your' graphs, so far you have not been willing/able to.

Surely if it is so simple Simon, a couple of sentences will put me firmly 'in my place'.

Incidentally I have been particularly careful to ensure I have quoted you correctly.
 
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