Attn mr felstead
#121
Also...
Q3/. What effect can be traced directly to wheel offsets... for example on an IFS car what would be the apparent change to the handling and roadholding if the OS of an 8" rim was changed from 50mm to 32mm... that shouldn't prove too hard.
Correct answer this time, the effect is more than just a track width thing!
Q3/. What effect can be traced directly to wheel offsets... for example on an IFS car what would be the apparent change to the handling and roadholding if the OS of an 8" rim was changed from 50mm to 32mm... that shouldn't prove too hard.
Correct answer this time, the effect is more than just a track width thing!
#122
Mycroft thank you for answering.
I disagree. Increasing the rebound rate of the front dampers will INCREASE the load transfer to the rear on rearward longitudinal pitch (during acceleration). In the same way as increasing rear bump damping would.
This is a VERY common mis-understanding held (this is not meant as dis-respect, just a statement of fact) by people who have read a lot of text books but haven't had any practical experience. The reason for this, is simply that the text books are often written to appeal to a wide audience, and make simple sweeping statements, that *appear* to mean more than they actually do.
If you disagree with me, perhaps you could explain again, in simple laymans, terms, how exactly this action would reduce load transfer to the rear?
All the best
Simon
I disagree. Increasing the rebound rate of the front dampers will INCREASE the load transfer to the rear on rearward longitudinal pitch (during acceleration). In the same way as increasing rear bump damping would.
This is a VERY common mis-understanding held (this is not meant as dis-respect, just a statement of fact) by people who have read a lot of text books but haven't had any practical experience. The reason for this, is simply that the text books are often written to appeal to a wide audience, and make simple sweeping statements, that *appear* to mean more than they actually do.
If you disagree with me, perhaps you could explain again, in simple laymans, terms, how exactly this action would reduce load transfer to the rear?
All the best
Simon
#123
RWD... Independent suspension... throttle on... sorry mate, can't see it! But more to the point, it has never worked that way for me.
The car is understeering... as you press on out of a bend, weight is naturally transferred to the rear, but more to the outer rear wheel, for the car to understeer in those circumstances the front must have less adherence.
So the front end is causing the main concern, providing you believe (from the results of the other parts of this bend) that you have the correct Bump settings.
So the choice is soften or harden the springs or adjust the dampers.
By increasing notional weight transfer to the rear.. the front end is lighter still... so, if by increasing the rebound rate the result was to decrease the understeer the only conclusion would be that such action to have done exactly as I have stated... the weight was not transferred to the rear to such an extent...
QED.
The car is understeering... as you press on out of a bend, weight is naturally transferred to the rear, but more to the outer rear wheel, for the car to understeer in those circumstances the front must have less adherence.
So the front end is causing the main concern, providing you believe (from the results of the other parts of this bend) that you have the correct Bump settings.
So the choice is soften or harden the springs or adjust the dampers.
By increasing notional weight transfer to the rear.. the front end is lighter still... so, if by increasing the rebound rate the result was to decrease the understeer the only conclusion would be that such action to have done exactly as I have stated... the weight was not transferred to the rear to such an extent...
QED.
#125
I had to think a little about this, as I tend to adjust damping on feel rather than formula, and it can go both way.
However, one has to remember that you're not dealling with stead state conditions, you have to accomodate the impulse of the sprung weight. Soft rebound (low rate) on the front will leave the front wheels in contact with the ground more readily. Increasing the front rebound rate may lower the change in measured pitch, but there will be an increase in weight transfer. In extreme circumstaces with fixed front suspension, 100% weigth transfer can happen due to sudden loading, but the front ride height will not change (ignoring tyre flex), the only pitch change will occur as the rear squats.
Paul
edited because it's sprung weight not spring weight
[Edited by Pavlo - 17/04/2003 20:10:53]
However, one has to remember that you're not dealling with stead state conditions, you have to accomodate the impulse of the sprung weight. Soft rebound (low rate) on the front will leave the front wheels in contact with the ground more readily. Increasing the front rebound rate may lower the change in measured pitch, but there will be an increase in weight transfer. In extreme circumstaces with fixed front suspension, 100% weigth transfer can happen due to sudden loading, but the front ride height will not change (ignoring tyre flex), the only pitch change will occur as the rear squats.
Paul
edited because it's sprung weight not spring weight
[Edited by Pavlo - 17/04/2003 20:10:53]
#126
Pavlo has hit the nail on the head. Layman's terms as follows.
The mis-conception comes from the appearance (at the first simple level of logic) that the car moves less, pitches rearward less. So people can often think this means that there is less weigh transfer.
This mis-conception is extended once the student starts to learn about steady state dynamics (meaning a snapshot of the car under steady loads) rather than transient states (the point at which the car body is moving around on the suspension) as in a steady state situation (which doesn't exist in the real world BTW - but is ideal for teaching the first level of understanding of vehicle dynamics) a car that is pitched more is exhibiting more load transfer.
So...
Imagine the car is pitching backwards (the actual point where it is moving before the suspension has settled) ...
First we'll take the rear dampers.
If you add bump resistence, that basically means that the rear dampers are resisting the movement. They are pushing between the wheel and the body of the car. This means that more of the weight is being pressed through the body and down to the road at the rear.
Then take the front dampers.
If you Increase the rebound rate of the front dampers (meaning the dampers RESIST the rebound motion (the extending motion of the suspsension) more) the wheels are effectively being lifted away from the tarmac in order to try to stay with the body (more so than if you had less rebound damping).
Hope that's clear.
Regards
Simon
The mis-conception comes from the appearance (at the first simple level of logic) that the car moves less, pitches rearward less. So people can often think this means that there is less weigh transfer.
This mis-conception is extended once the student starts to learn about steady state dynamics (meaning a snapshot of the car under steady loads) rather than transient states (the point at which the car body is moving around on the suspension) as in a steady state situation (which doesn't exist in the real world BTW - but is ideal for teaching the first level of understanding of vehicle dynamics) a car that is pitched more is exhibiting more load transfer.
So...
Imagine the car is pitching backwards (the actual point where it is moving before the suspension has settled) ...
First we'll take the rear dampers.
If you add bump resistence, that basically means that the rear dampers are resisting the movement. They are pushing between the wheel and the body of the car. This means that more of the weight is being pressed through the body and down to the road at the rear.
Then take the front dampers.
If you Increase the rebound rate of the front dampers (meaning the dampers RESIST the rebound motion (the extending motion of the suspsension) more) the wheels are effectively being lifted away from the tarmac in order to try to stay with the body (more so than if you had less rebound damping).
Hope that's clear.
Regards
Simon
#127
Hello Simon, your wlecome to have him as your own stalker if you like.
Mycroft wrote:
“Q3/. What effect can be traced directly to wheel offsets... for example on an IFS car what would be the apparent change to the handling and roadholding if the OS of an 8" rim was changed from 50mm to 32mm... that shouldn't prove too hard.
Correct answer this time, the effect is more than just a track width thing!”
My response to this is:
I know, that’s why in my previous reply I wrote “I won’t answer the rest of the question relating to the effect of this, as that would be pandering to your whims, rather than correcting a mistake.”
You understand yet? I dont have any need to answer your useless questions. If i am going to spend time on this BBS answering questions it will be for people who will apreciate that time and get some benefit from it.
Mycroft wrote:
“Q3/. What effect can be traced directly to wheel offsets... for example on an IFS car what would be the apparent change to the handling and roadholding if the OS of an 8" rim was changed from 50mm to 32mm... that shouldn't prove too hard.
Correct answer this time, the effect is more than just a track width thing!”
My response to this is:
I know, that’s why in my previous reply I wrote “I won’t answer the rest of the question relating to the effect of this, as that would be pandering to your whims, rather than correcting a mistake.”
You understand yet? I dont have any need to answer your useless questions. If i am going to spend time on this BBS answering questions it will be for people who will apreciate that time and get some benefit from it.
#128
So you disagree with my conclusion that if your car is understeering out of an exit that the front shocks are too stiff in their rebound rate?
Are you serious?
[Edited by Mycroft - 17/04/2003 20:55:16]
Are you serious?
[Edited by Mycroft - 17/04/2003 20:55:16]
#129
If you're going to resort to that kind of tactic I'll get bored very quickly indeed.
everyone here knows that you said you should INCREASE the front damper rebound rate. You are now saying that you should reduce it as they are "too stiff" ("stiff" being a term that I have never heard used to describe a damper - as a side note).
If you really want, we can go through every other part that I picked up in "your" check sheet. But it really will be pointless unless you are strong enough to admit that you have just argued yourself in to a huge hole.
If not, I'll bid you good day and leave you to it.
All the best
Simon
everyone here knows that you said you should INCREASE the front damper rebound rate. You are now saying that you should reduce it as they are "too stiff" ("stiff" being a term that I have never heard used to describe a damper - as a side note).
If you really want, we can go through every other part that I picked up in "your" check sheet. But it really will be pointless unless you are strong enough to admit that you have just argued yourself in to a huge hole.
If not, I'll bid you good day and leave you to it.
All the best
Simon
#130
What kind of tactic?
My explanation is perfectly clear... and conforms with everything I have ever read or found on the track...
No edits nothing...
Quote...
IF by increasing the rebound rate the result was to decrease the understeer the only conclusion would be that such action to have done exactly as I have stated... the weight was not transferred to the rear to such an extent... End quote
I put the 'IF' in to qualify the statement...
My explanation is perfectly clear... and conforms with everything I have ever read or found on the track...
No edits nothing...
Quote...
IF by increasing the rebound rate the result was to decrease the understeer the only conclusion would be that such action to have done exactly as I have stated... the weight was not transferred to the rear to such an extent... End quote
I put the 'IF' in to qualify the statement...
#131
It seems to me that your tactic is to try to turn the argument around so that what you said means something else.
I completely agree that a possible cause of understeer on exit is too much rebound rersistance on the front. This is different to what you said. You said that to reduce the understeer you should INCREASE the rebound rate, which would then make the problem worse, should the rebound rate be the cause.
Let's get something clear here.
1) Do you think that increasing the rebound rate creates more rebound resistance or less?
I'm sure that question is an insult to you, but humour me anyway.
Regards
Simon
I completely agree that a possible cause of understeer on exit is too much rebound rersistance on the front. This is different to what you said. You said that to reduce the understeer you should INCREASE the rebound rate, which would then make the problem worse, should the rebound rate be the cause.
Let's get something clear here.
1) Do you think that increasing the rebound rate creates more rebound resistance or less?
I'm sure that question is an insult to you, but humour me anyway.
Regards
Simon
#132
Mycroft,
I think what is being got it here is your check sheet says one thing, now your saying another.
So you don't have to go back and look at your check sheet, I have shown it below:
################################################## ###########
################################################## ###########
In said check sheet you clear state that a cure for exit understeer is to "increase rebound of front shocks".
But now, after having that statement to be shown as wrong we get this:
Which clearly says your conclusion is that exit understeer would be reduced if the rebound rate of the front shocks is reduced.
Now I think you can see the confusion here. You started by saying that increasing rebound reduces exit understeer, but now there is a turn around, and through a few stages of obscufication you have stated the direct opposite, inline with what Simon has said.
So it would appear that either:
You were very confused when you typed the problem and cure sheet.
OR
In realising your mistake, you have tried to turn the argument round in your favour.
Now seeing as you have been challenged on this a few times before the turn around, you haven't corrected the problem and cure sheet, that my second assumption is true? Or is there another more plausible reason you can enlighten us with?
You seem intent on digging another hole, and with every post I see you are delving deeper into fantasy. A seasoned engineer that has worked at all levels of motorsport, competed in most, sells his services as a consultant, writes papers and so on and so forth, admits finally to having cribbed said P&CS from Doug Milliken, who is apparently your friend.
I think this is a accurate presentation of the facts, but I will of course await to be advised otherwise, and will ammend accordingly.
Paul
I think what is being got it here is your check sheet says one thing, now your saying another.
So you don't have to go back and look at your check sheet, I have shown it below:
################################################## ###########
################################################## ###########
In said check sheet you clear state that a cure for exit understeer is to "increase rebound of front shocks".
But now, after having that statement to be shown as wrong we get this:
So you disagree with my conclusion that if your car is understeering out of an exit that the front shocks are too stiff in their rebound rate?
Now I think you can see the confusion here. You started by saying that increasing rebound reduces exit understeer, but now there is a turn around, and through a few stages of obscufication you have stated the direct opposite, inline with what Simon has said.
So it would appear that either:
You were very confused when you typed the problem and cure sheet.
OR
In realising your mistake, you have tried to turn the argument round in your favour.
Now seeing as you have been challenged on this a few times before the turn around, you haven't corrected the problem and cure sheet, that my second assumption is true? Or is there another more plausible reason you can enlighten us with?
You seem intent on digging another hole, and with every post I see you are delving deeper into fantasy. A seasoned engineer that has worked at all levels of motorsport, competed in most, sells his services as a consultant, writes papers and so on and so forth, admits finally to having cribbed said P&CS from Doug Milliken, who is apparently your friend.
I think this is a accurate presentation of the facts, but I will of course await to be advised otherwise, and will ammend accordingly.
Paul
#134
"got you"?
Well, perhaps that's what some people will think, but it's no attempt to "get" anyone. I am merely trying to get to the bottom of this.
My judgement of Mycroft has passed, he is as I always expected him to be from the very first post of his that I read, probably on the subject of Optimax. So in that respect I have nothing to prove here, to myself or others.
I am calm and happy.
We'll see what there is through the, arch, window.
paul
Well, perhaps that's what some people will think, but it's no attempt to "get" anyone. I am merely trying to get to the bottom of this.
My judgement of Mycroft has passed, he is as I always expected him to be from the very first post of his that I read, probably on the subject of Optimax. So in that respect I have nothing to prove here, to myself or others.
I am calm and happy.
We'll see what there is through the, arch, window.
paul
#135
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SDB, JF & Pav,
Just don't bother.
It's not worth the energy expended in typing.
Most people would be happy to read your posts but this ****wit just isn't worth the air.
Ian
Just don't bother.
It's not worth the energy expended in typing.
Most people would be happy to read your posts but this ****wit just isn't worth the air.
Ian
#136
Tell me guys...
You do know the difference between 'rebound' and 'rebound rate'... don't you?
Ohh... obviously not!
One is cyclic, the other is ratable.
You really must read my stuff more carefully guys...
You do know the difference between 'rebound' and 'rebound rate'... don't you?
Ohh... obviously not!
One is cyclic, the other is ratable.
You really must read my stuff more carefully guys...
#139
If you go here... (I hope the link works)
http://www.koni.com/_racing/_damper_series/2812/2812_specifi.html
You will read that there are 2 separate code letters L and V... now try real hard and guess which is rebound and which is rebound rate.
My lecture rates are £1500 a day... fvcking good value for money I think you'll agree...
[Edited by Mycroft - 4/18/2003 2:50:29 AM]
http://www.koni.com/_racing/_damper_series/2812/2812_specifi.html
You will read that there are 2 separate code letters L and V... now try real hard and guess which is rebound and which is rebound rate.
My lecture rates are £1500 a day... fvcking good value for money I think you'll agree...
[Edited by Mycroft - 4/18/2003 2:50:29 AM]
#140
Personally I think its amusing that someone would choose to start with a subaru svx, remove the eg33 and replace it with an ez30.
Why put it an inherently worse weaker and smaller engine with siamesed exhaust ports, when a 50%long 2.2 is already in there?
Why put it an inherently worse weaker and smaller engine with siamesed exhaust ports, when a 50%long 2.2 is already in there?
#141
Mycroft
I see you didn't answer my question, so I can only assume that you know what increasing the rebound rate means.
Secondly, the link which clearly shows that L is the code for the length of the damper, and V is the code for the valving type.
-----
A damper's "rebound rate" is a representation of the amount of resistance it imposes on rebound. (Just for everyone else).
"Rebound" is a term used for the extending motion of the damper. It is not something that is rateable, except maybe to say how long the rebound stroke is, but has no baring on this discussion.
So.. we are talking about rebound rate, and you stated that you should increase the rebound rate of the front dampers in order to reduce exit understeer. This means that you should increase the resistance of the front dampers in rebound.
If you are changing your mind about that, at least tell us, so you don't continue to make a fool of yourself.
-----
Now. Let's assume that in the last 10 minutes, the world of vehicle dynamics has changed it's mind, and that increasing the rebound rate actually now means that you reduce the resistance in rebound (as I think you are now saying)...
By your new terms, this means that you should reduce the resistance in rebound. Unfortunately, in that case, this is wrong, as you should increase the resistance in rebound on the rear dampers.
The same oposites apply to many of your other statements.
So Mycroft.
Which is it going to be? There is absolutely nothing wrong with making a mistake, and there is no shame in being wrong, as long as you are man enough to stand up and admit it.
All the best
Simon
I see you didn't answer my question, so I can only assume that you know what increasing the rebound rate means.
Secondly, the link which clearly shows that L is the code for the length of the damper, and V is the code for the valving type.
-----
A damper's "rebound rate" is a representation of the amount of resistance it imposes on rebound. (Just for everyone else).
"Rebound" is a term used for the extending motion of the damper. It is not something that is rateable, except maybe to say how long the rebound stroke is, but has no baring on this discussion.
So.. we are talking about rebound rate, and you stated that you should increase the rebound rate of the front dampers in order to reduce exit understeer. This means that you should increase the resistance of the front dampers in rebound.
If you are changing your mind about that, at least tell us, so you don't continue to make a fool of yourself.
-----
Now. Let's assume that in the last 10 minutes, the world of vehicle dynamics has changed it's mind, and that increasing the rebound rate actually now means that you reduce the resistance in rebound (as I think you are now saying)...
Understeer on entry to a bend - Increase the 'rebound rate' of rear shocks. Decrease the 'bump rate' of front shocks. Increase the rear brake bias or just brake earlier!
The same oposites apply to many of your other statements.
So Mycroft.
Which is it going to be? There is absolutely nothing wrong with making a mistake, and there is no shame in being wrong, as long as you are man enough to stand up and admit it.
All the best
Simon
#142
I posted my answer and it is correct... Not only did I answer your question quickly but I also incorporated a 'catch' for the unwary...
Let me explain...
As the rebound portion of the stroke is lengthened or increased the rate bound rate decreases... now take a look at that sheet of MINE it is different in that subtle way... it has been purposefully twisted to catch people... so it really is MINE
Now return to my text and look at the subtle inclusion and exclusion of that little word RATE...
Don't beat yourself up about it... I do this all the time to serious Engineers and Designers... only half a dozen have twigged it in nearly 15 years...
Somehow... you know... I don't need answers to my 3 questions now do I?
I shall return and watch the prevarication and squirming thatr will ensue... but take no part... You can confirm all I say by getting the Paper I co-wrote with Koni engineers years ago...
Happy Easter... and get out in the Sun and go down the Pub...
and relax...
Let me explain...
As the rebound portion of the stroke is lengthened or increased the rate bound rate decreases... now take a look at that sheet of MINE it is different in that subtle way... it has been purposefully twisted to catch people... so it really is MINE
Now return to my text and look at the subtle inclusion and exclusion of that little word RATE...
Don't beat yourself up about it... I do this all the time to serious Engineers and Designers... only half a dozen have twigged it in nearly 15 years...
Somehow... you know... I don't need answers to my 3 questions now do I?
I shall return and watch the prevarication and squirming thatr will ensue... but take no part... You can confirm all I say by getting the Paper I co-wrote with Koni engineers years ago...
Happy Easter... and get out in the Sun and go down the Pub...
and relax...
#143
What a shame
I was really hoping you would be able to actually discuss this.
It is absolutely 100% clear to me now that you have no intention or ability to explain your mistakes. Instead you resort to trying to baffle people with "round the houses" explanations of detatched subjects.
I can see that you don't want to continue to discuss it, and knowing a little more about your inability to admit your mistakes, I can completely see why.
Any time you want to discuss it, please see my previous post and answer the question in it, which was basically "Which is it? Does increasing rebound rate (in your mind) increase or decrease the resistance of the damper to rebound?"
Pavlo
As it is clear to me that you have a depth of actual understanding rather than a simple academic glosary of terms at your disposal, would you be good enough to keep an eye out for any posts Mycroft offers and correct any bad advice. I would hate for the scoobynet community to be fooled in to doing something that could see them hurt themselves due to bad advice. I'll do the same.
All the best
Simon
I was really hoping you would be able to actually discuss this.
It is absolutely 100% clear to me now that you have no intention or ability to explain your mistakes. Instead you resort to trying to baffle people with "round the houses" explanations of detatched subjects.
I can see that you don't want to continue to discuss it, and knowing a little more about your inability to admit your mistakes, I can completely see why.
Any time you want to discuss it, please see my previous post and answer the question in it, which was basically "Which is it? Does increasing rebound rate (in your mind) increase or decrease the resistance of the damper to rebound?"
Pavlo
As it is clear to me that you have a depth of actual understanding rather than a simple academic glosary of terms at your disposal, would you be good enough to keep an eye out for any posts Mycroft offers and correct any bad advice. I would hate for the scoobynet community to be fooled in to doing something that could see them hurt themselves due to bad advice. I'll do the same.
All the best
Simon
#144
I'd watch out Simon - Mycroft apparently likes to try and shut down BBS's if he doesn't get his own way. Fails of course, but it's funny watching him say he's trying...
[Edited by Evil Beef - 4/18/2003 1:53:01 PM]
[Edited by Evil Beef - 4/18/2003 1:53:01 PM]
#145
That is a little dis-ingenuous... Simon and this forum has nothing to fear from me.
I must say though that if I were Simon then I would be more concerned with some of the less savoury members here.
It is they who can bring this ediface crashing down around him.
I don't take things too seriously, it's a bit of knockabout, the mockery and taking the Stuffed Shirts down a peg or 2 is good fun.
It is true that late last year with the MKIV site 'promoting' the 'Mycroftmustdie' site did make me think I ought to just wipe them off the net... but 60 seconds later I just thought 'How fvcking sad would that make me?' so decided to wind them up instead...
It has proved hugely enjoyable and the TICK [The Idiotic Condiment King] is one of the bonuses... my ancestors had to pay for a Jester to come and entertain them... I have TICK [The Idiotic Condiment King]
[Edited by Mycroft - 4/18/2003 4:13:00 PM]
I must say though that if I were Simon then I would be more concerned with some of the less savoury members here.
It is they who can bring this ediface crashing down around him.
I don't take things too seriously, it's a bit of knockabout, the mockery and taking the Stuffed Shirts down a peg or 2 is good fun.
It is true that late last year with the MKIV site 'promoting' the 'Mycroftmustdie' site did make me think I ought to just wipe them off the net... but 60 seconds later I just thought 'How fvcking sad would that make me?' so decided to wind them up instead...
It has proved hugely enjoyable and the TICK [The Idiotic Condiment King] is one of the bonuses... my ancestors had to pay for a Jester to come and entertain them... I have TICK [The Idiotic Condiment King]
[Edited by Mycroft - 4/18/2003 4:13:00 PM]
#146
Adam M:
-shrug- Only a suggestion: I know precisely jack-fish about the SVX engine, hence my choice of swap. If you want to convert the 2.2 prior to turbocharging it, be my guest: I have a mental block (like an engine block, only different) when it comes to going internal.
[Edited by Turbo_Steve - 4/18/2003 3:28:38 PM]
-shrug- Only a suggestion: I know precisely jack-fish about the SVX engine, hence my choice of swap. If you want to convert the 2.2 prior to turbocharging it, be my guest: I have a mental block (like an engine block, only different) when it comes to going internal.
[Edited by Turbo_Steve - 4/18/2003 3:28:38 PM]