rpmagazine
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| posted on 10/7/08 at 09:45 AM |
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The alternative to GRC theory
This thread is so that Syd can specifically have space to provide the full account of his suspension theory.
I attest that I will not publish one iota of any of Syd's original theory.
[Edited on 25/7/08 by rpmagazine]
www.racemagazine.com.au
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D Beddows
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| posted on 10/7/08 at 09:56 AM |
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Hmmmm, this is very grown up then 
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Mr Whippy
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| posted on 10/7/08 at 10:08 AM |
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as usual 
Fame is when your old car is plastered all over the internet
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rpmagazine
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| posted on 10/7/08 at 10:15 AM |
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if you have another solution I will listen.
www.racemagazine.com.au
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02GF74
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| posted on 10/7/08 at 10:24 AM |
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does the theory involve suspension being thin at one end, much much fatter in the middle and thin at the other end?
[Edited on 10/7/08 by 02GF74]
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mr henderson
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| posted on 10/7/08 at 10:27 AM |
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As somebody who is interested in cars, and somewhat involved with them, I have read the other thread carefully.
I have no theories of my own to offer, but if I was designing a suspension system I would be inclined to copy what has been known to have worked well
in the past, as long as it was relevant to the type of car I was working on, and took account of the time, money and effort that were available.
Having stated my own position I now feel free to say that I have found Syd's contributions to the other thread to be largely limited to how
clever and experienced he is, how silly most other people are, and to how he is going to keep his ideas secret (except to say how much better they are
than anybody else's.
Now is his opportunity to prove me wrong, and I hope he will.
John
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D Beddows
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| posted on 10/7/08 at 11:00 AM |
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The thing is though is that as a general rule in the mid engined section no one ever thinks they are wrong, admits they don't know or misses an
opportunity to demonstrate how clever they apparently are......... gets right on my t*ts to be honest so I only tend to read the threads if they are
on the 'most recent threads' page and I don't realise what section they are posted in.
Syds big enough to fight his own battles but if you don't agree with him or think he's a kn*b just ignore him, this handbags at dawn
nonsense just makes you look a bit of a twonk not him.
Having said that I know who's advice I'd ask first if I had a suspension related issue 
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mr henderson
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| posted on 10/7/08 at 11:31 AM |
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quote:
Originally posted by D Beddows
but if you don't agree with him or think he's a kn*b just ignore him, this handbags at dawn nonsense just makes you look a bit of a twonk
not him.
Who is the 'you' you are referring to?
It's a good idea to use the quote feature if you are replying to someone so that it is clear just who you are replying to
John
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rpmagazine
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| posted on 10/7/08 at 11:40 AM |
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This thread is not a 'throw syd from the train' and I would ask that we not get personal either (no I'm not being sarcastic). It is
possible that Syd has a very valuable contribution to make. I am fully prepared to admit I am wrong if Syd's theories hold some validity.
I asked Syd to give the detail in the other thread, but as you all know it became more than a little side-tracked and I am sorry for the thread
starter of the other thread and so here we are.
No hijacking other peoples threads, no personal insults, I just want to hear the whole kit and caboodle.
www.racemagazine.com.au
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Paul TigerB6
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| posted on 10/7/08 at 12:12 PM |
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quote:
Originally posted by D Beddows
Syds big enough to fight his own battles but if you don't agree with him or think he's a kn*b just ignore him, this handbags at dawn
nonsense just makes you look a bit of a twonk not him.
Just had to laugh at this thread and found the previous one too. It does strike me that if Syd is big enough to fight his own battles, isnt he also
big enough to also start his own thread if he wants to discuss his own theories?? If he wants to keep secrets and not discuss them at all then
fine.......... but why then come on a public forum which is all about helping others build their own cars to tell other contributors they are wrong,
but not offer anything further into why??? I am right with Martin's comments at the top of page 2 of the other thread
here - Syd's comments are clearly not designed to be constructive
and its stated very clearly that he intends to not share any knowledge with this forum but instead openly gloat in the fact that "he knows
better than everyone else"!!
I too would suggest that if he doesnt want to offer any constructive help that he either doesnt comment at all or leaves the forum. I'm sure
this forum would be a far better place for it judging by the other thread. This site is a fantastic source of information and often the best threads
are when there are two differing views from different contributors, and the discussion around which is the best option by showing the pro's and
con's - NOT just a simple you're wrong and i'm right - but i'm not going to tell you why i'm right because its a
secret!!!
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indykid
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| posted on 10/7/08 at 03:56 PM |
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but what if it is a secret? syd has suggested another starting point to begin your thinking.
you can't call him a miserable tw*t just because he won't hand his logic to you. i think the whole argument is pointless and of little
help to the OP.
while we learn from discussion of two points, you can also learn from someone saying no, i don't think that's right, start here and go
away and think about it.
rpmagazine has exaccerbated this issue as much if not more than syd and i don't see this thread should have been started.
tom
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MikeCapon
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| posted on 10/7/08 at 04:41 PM |
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"It's how I think. You look at everything you've done before. You look at other people's work. You feel you can improve and
don't give any secrets away. We do still look at roll centre and geometry, but if I gave you positions or camber change details my opposition
would think I was mental - or they wouldn't believe them."
Tony Southgate
"You cannot reduce the unwanted in a design to zero - you can only hope to minimise what is not good. You can draw the position of the Roll
Centre in static geometry but the dynamic position is a different matter. The point about which a car rolls can be totally modified by altering the
springs, or the weight transfer and the consequent loading on the tyres."
Trevor Harris
I think these two, very credible designers are worth listening to.
Also posted in the other thread.
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rpmagazine
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| posted on 11/7/08 at 12:54 AM |
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quote:
while we learn from discussion of two points, you can also learn from someone saying no, i don't think that's right, start here and go
away and think about it.
rpmagazine has exaccerbated this issue as much if not more than syd and i don't see this thread should have been started.
tom
Fair enough Tom you have your view. But you will need to explain how you think I have 'exacerbated' the situation.
Before I spend time (which I never have enough of like many here I am sure) following up Syd's theory I would like to know what it is. So far
there is not enough to work on and I think asking him to provide some detail as to how this theory came about and what experience he has is quite
reasonable in the circumstances.
I would suggest to you that this thread was primarily started so we can discuss Syd's theories and not have continual interruption in other
threads.
[Edited on 11/7/08 by rpmagazine]
www.racemagazine.com.au
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cloudy
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| posted on 11/7/08 at 09:55 PM |
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You should all be ashamed, stop posting in these threads and get back to building your cars!
www.warnercars.com
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Paul TigerB6
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| posted on 11/7/08 at 11:59 PM |
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quote:
Originally posted by cloudy
You should all be ashamed, stop posting in these threads and get back to building your cars!
errr why?? This thread was supposedly started so that a member could put across his theories I believe. I also believe that said member has no
intention of ever divulging any info so who should be ashamed here?? I'd love to hear about a new way of thinking about suspension design myself
but clearly it wont happen and never will (as stated prior to this thread)
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mr henderson
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| posted on 12/7/08 at 07:27 AM |
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quote:
Originally posted by Paul TigerB6
I'd love to hear about a new way of thinking about suspension design myself but clearly it wont happen and never will (as stated prior to this
thread)
Indeed, very much in the vein of "I've got a secret but I'm not telling what it is." Don't think I've heard
anything like that since I was at school (And junior school at that)
John
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Ians
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| posted on 12/7/08 at 09:08 AM |
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I have been an avid and enthralled observer watching the peaks and troughs as this thread has developed. I have said to myself probably better to
wait until things stabalise than to offer my two pence worth mid argument. In the first instance I have to agree with Syd. Basic roll centre
thinking once dyanamic loadings have been applied offer less than the normally accepted relevance in the design process. RC migration is so transient
it is difficult to visualise with just a basic kinamatic drawing even when using Bill Mitchell's forced based roll centre design programme.
Whilst it's a good indicator of movement it does not offer any solutions in where chassis/suspension design should start. Being primarily
involved in race car design I tend to gloss over static roll centres. Once a vehicle has a dynamic change it needs to be tuneable for optimum
handling, it is then too late to make any MAJOR alterations to what would have been a fixed perameter within roll centre construction.
SO ARE STATIC ROLL CENTRES IMPORTANT, of course they are. They are important to any newby/first time designer as a tried and tested starting point.
Case studies are numerous and well documented. A newby designer has enough problems and choices to contend with without having to visualise concepts
that he has yet the knowledge nor experience to understand. Will he achieve the optimum in handling and performance, I suspect not, but will he
produce a vehicle that contains fewer bad handling characteristics, I would guarantee so.
I have always been a great advocate of outside the box thinking but this can only be done afer one has gleaned some knowledge through one's own
experience or the experience of others. I would like to pose a secondary question to the RC debate, at first it may appear to have no relevance but
with some thought it makes one visualise points beyond the confines of the chassis construction.
QUESTION roll centres are viewed from the front of the vehicle, if we view the vehicle from the side, where would the forum members think the ideal
pitch centre should be to prevent excessive nose dive under breaking and excessive squat at the rear (RWD) car. For the last few years my cars have
had the charateristic of the whole vehicle squating under braking how do the forum members think this is achieved ???? Ian Scott
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rpmagazine
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| posted on 12/7/08 at 10:21 AM |
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Ians I'll get to your question in time. My frustration with syd has been clearly stated. It helps no one on a forum where we try to help one and
other to claim knowledge or background without divulging information on either and we sceptics can do little other than doubt the veracity of the
claims.
Syd's claim about rolling around the outside front contact patch seems to assume:
1. That Newtonian physics apply to tyres which they plainly do not.
2. that we are assuming a rigid or extremely stiff suspension and on this forum that is unlikely.
3. A certain cornering event - having just gone over some data from a datalogger I can find few corners that would fit Syd's initial premise of
an immediate roll event
www.racemagazine.com.au
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Paul TigerB6
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| posted on 12/7/08 at 10:30 AM |
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quote:
Originally posted by rpmagazine
Ians I'll get to your question in time. My frustration with syd has been clearly stated. It helps no one on a forum where we try to help one and
other to claim knowledge or background without divulging information on either and we sceptics can do little other than doubt the veracity of the
claims.
Pretty much sums it up it seems. I wouldnt lose any sleep over his claims myself - treat them with the sceptiscism they clearly deserves. As you say
it helps nobody to make claims and personally i bet he's sitting there laughing at this and that people are spending time wondering. Dont give
him the satisfaction - if he wants to keep a secret then let him
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rpmagazine
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| posted on 12/7/08 at 11:25 AM |
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Ians I'm not so much stuck by the how of your question but the why?
www.racemagazine.com.au
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Ians
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| posted on 12/7/08 at 02:19 PM |
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I was just saying that thinking outside the accepted box can often quicken ones learning curve, people oten assume the pitch centre has to be within
the wheelbase and is the point about which the car rocks .My point was to simply get members to think how to move the pitch centre to get less pitch
fore and aft, the kinamatics /maths are easier to understand but the priciple is the same as for RCs migration ,ie having a point of rotation outside
the confines of the chassis structure. Ians
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Kaspa
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| posted on 13/7/08 at 09:14 AM |
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Blimmey i cant honestly beleive some of you blokes, I've been sitting on the fence watching this drama unfold from the beginning, and Syd has
on numerous occasions given you all the answers you require but you dont seem to see the forrest for the trees, i cant blame him realy for being a
little, shall we say arrogent, as i think i would to, if what i was saying was being listened to, but not heard.
and for what its worth i have discussed his ideas with a couple of very experienced race car builders that i no and they agree with Syd.
JMTBW, ill now jump back on the fence.
Kaspa
understeer= when you hit the wall front first
oversteer=when you hit the wall back first
HP= how fast you hit the wall
Torque= how far the wall moves when you hit it
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rpmagazine
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| posted on 13/7/08 at 11:16 AM |
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Kaspa you think I too have not discussed it? The opinions are mixed to say the least.
www.racemagazine.com.au
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pbura
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| posted on 13/7/08 at 01:52 PM |
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quote:
Originally posted by Kaspa
Blimmey i cant honestly beleive some of you blokes, I've been sitting on the fence watching this drama unfold from the beginning, and Syd has
on numerous occasions given you all the answers you require...
I may have missed it, but I've never seen Syd say anything here that would actually help anybody design a car. Not without a bootleg copy of
ADAMS or similar software, anyhow. Got a link?
Syd is right that there's a lot going on in cornering that the geometric models do not begin to pick up on. They ignore that most of the load
is on the outside tire patch, and all that implies, e.g., slip angle, deflection of tires and bushings, chassis jacking. Still, it's a usable
methodology, especially given the lack of anything else.
Syd reminds me of a schoolyard blowhard going around telling all the kids that their slingshots are poo because he has a sniper pistol at home...
that he's not allowed to show anyone. 
Pete
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kb58
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| posted on 13/7/08 at 04:37 PM |
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quote:
Originally posted by pburaSyd reminds me of a schoolyard blowhard going around telling all the kids that their slingshots are poo
because he has a sniper pistol at home... that he's not allowed to show anyone.
Or a comedian who gets on stage and says, "I know a really funny joke; it's much better than anything you've ever heard, but I
won't tell you because it was hard to find. If you want to know it, go find it for yourself". Then, he gets offended when the audience
doesn't appreciate his work.
Seriously, the Ortiz links I provided deal with what you mention, that the majority of the traction is being produced by the outside tire, so why does
the inside tire continue to contribute half the values to find the GRC?
On the other hand, our cars exclusive strong point is their light weight. This one factor is responsible for making more of a difference than anything
else, including the RC. Face it, we aren't building F1 cars, we don't have a national runoff at stake, and we don't have sponsers to
please. Plus, our driving skills are so inconsistant, any small improvement in RC placement will be buried in the noise of our scattered lap times.
(I'm sure there are exceptions here, but you know what I mean.)
Summed up, as long as the tires are wearing evenly, that's all that counts.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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