one side lower than the other

[Icarus]

Once the ride heights are about right, the F/R weight distribution maintains itself as you adjust the corners. An unfortunate scientific fact of life. Worth a bit of research maybe. .

Message from a close friend: "Get him down here!! he's just made a Honda engineer smile and that's f**king hard to do at the moment"

So thats at least 5 people mildly confused/amused by your post.

Cheers
M

 

[Pep]

Pepsi - i haven't read lordships reply yet, so this is off my head here

first of all, looking at what people generally go for on here, the general view is more camber = better, ie people are basically plucking camber settings out of thin air for fun (so it seems anyway)! Ok great some people have tried "x" amaount of camber and report back "its proper bo" etc etc, i for one go for minimal camber on a road/track car, my "1.2" for example runs 0.5 degrees and it could still (contrary to popular belief, keep up with the faster stuff round track) but that's what suits me. Its very hard to tell you what to go for due to the 2 main reasons

1) i don't know how you drive, you could be billy with all the gear and no idea, or you could be "if in doubt, flat out" Colin, or sideways Charlie, or even like 2live "fooking ave it"

2) i have no idea how you want the car to "feel"

to give you an example of what i'm banging on about here, Yoz's motor with him behind the wheel was on average 3-5sec per lap quicker than i was round spa. Is it because i'm not as good a driver? (he will have you believe that that is the problem the tw*t!) In my i opinion its because the car isn't quite how i like it and hence i don't have 100% confidence to push it.

basically what i'm banging on about here is basically don't do what some people do and have your car setup to "x" because someone on cliosport said its "proper bo"

imagine if you will your car is a custom made suit, it must be made (aka setup) to fit you

if you're like Cole Trickle and know nothing about cars, then no bother, we can help advise you on something to try (ie well try a bit more toe in, or a bit less camber etc etc)

hope that gives you some idea

Cheers Fred.

Still not too sure, it felt perfect for me at neg 2.5 as opposed to the neg 1.5 that I managed to guess it at.

I think an advantage to me is that of the 2 set ups I have had (not many I know!) compared to the standard car and then sportlines, the coilovers are 10 times better. Plus with me being an amateur I guess I wouldn't notice it too much.

I just want good turn in and the car to feel pretty planted and plenty of grip.

Also with wanting to run seperate wheels for track an road but have good performance on both will probably bring compromise performance on both.

Although I'm thinking now a road set up may be better... I think I'm going to need some more research into this...

 

[Gasket]

I fail to see why its a difficult concept to grasp - as its been one of the main fine tuning tools in motorsport since the 1920's. As you've spent the last page and a half banging on about 'rake' what do you think the effect the difference in front/rear ride heigh by adding 'rake' makes?

F/R weight distribution does not maintain itself as you adjust the corners.

Look at Brosters example above:

FR:338kg
FL:346kg

RR:194kg
RL:156kg

Thats a F/R weight distribution of approx 66.15%/33.85%

If I then had a shuffle around and the result was

FR:343kg
FL:344kg

RR:196kg
RL:151kg

Thats then a front/rear distribution of 66.44%/33.56% and thats with an actual change of just 3KG's

Cheers
M

Get the concept completely. You are just playing around with target values and a bit of calculation.


Had a shuffle myself.

[FONT=&quot]Brosters example above:

FR:338kg
FL:346kg

RR:194kg
RL:156kg

That’s a F/R weight distribution of approx 66.15%/33.85%[/FONT]


My shuffle:

[FONT=&quot]FR: 332 kg
FL: 352 kg

RR: 170 kg
RL: 180 kg

[/FONT]
That’s the same weight distribution of 66.15%/33.85% and a 52% cross weighting. NO CHANGE IN WEIGHT DISTRIBUTION FROM FRONT TO REAR.


The maths is nice but when you come to turn the platforms it will be the diagonals you adjust and the diagonals that make the big changes in distribution.

 

[Icarus]

Well done you've made up (and I say made up because on a Clio road car you'll struggle like buggery to get the rears within 10KG's) some numbers that retain the percentage split of 66.15/33.85 to prove that you can maintain constant weight distribution whilst changing corner weights in the same way I have proven you can change the corner weights and change the weight distribution?

Your point was "Once the ride heights are about right, the F/R weight distribution maintains itself as you adjust the corners. An unfortunate scientific fact of life. Worth a bit of research maybe."

Yet it doesn't, if I chuck 20mm onto one corner of the car then the weight distribution will not stay the same. If I choose to optimise the car for a RHD corner dominant circuit then I am not going to have equal diagnols and the weight distribution will change, if I choose to ignore working with weight distribution completely even though it may aid my driver etc. etc.

And this is before you start taking into account the face a race car may be carrying nigh on 100kilos of fuel, the distribution and centre of mass of which changes as the car puts in laps.

If your point is "It's possible to maintain the same front/rear weight distribution whilst altering the actual corner weights and therefore the cross weighting" then yes of course it is if this is what you want to achieve, regardless of the fact that influencing the weight distribution of the car with ride heigh, both static and dynamic as a result of anti-dive, damper rate etc. may be of use to your driver.

And remember:

So I prefer not to do it.

Cheers
M

 

[Craig]

lol

 

[Gasket]

Well done you've made up (and I say made up because on a Clio road car you'll struggle like buggery to get the rears within 10KG's) some numbers that retain the percentage split of 66.15/33.85 to prove that you can maintain constant weight distribution whilst changing corner weights in the same way I have proven you can change the corner weights and change the weight distribution?

Your point was "Once the ride heights are about right, the F/R weight distribution maintains itself as you adjust the corners. An unfortunate scientific fact of life. Worth a bit of research maybe."

Yet it doesn't, if I chuck 20mm onto one corner of the car then the weight distribution will not stay the same. If I choose to optimise the car for a RHD corner dominant circuit then I am not going to have equal diagnols and the weight distribution will change, if I choose to ignore working with weight distribution completely even though it may aid my driver etc. etc.

And this is before you start taking into account the face a race car may be carrying nigh on 100kilos of fuel, the distribution and centre of mass of which changes as the car puts in laps.

If your point is "It's possible to maintain the same front/rear weight distribution whilst altering the actual corner weights and therefore the cross weighting" then yes of course it is if this is what you want to achieve, regardless of the fact that influencing the weight distribution of the car with ride heigh, both static and dynamic as a result of anti-dive, damper rate etc. may be of use to your driver.


Cheers
M

No problem. You started the maths so it was worth a reply. They are only target figures.

Ask your Honda engineer how much a 10mm raise in the front ride height on a Clio (ie jacking the front of the car with no tilt about the longitudinal axis) will change the overall Front to Rear weight distribution as measured through the tyre contact points.

The concept you are still failing to grasp are the changes, when for example, you slightly raise the ride height only at a one corner, the weight on that corner will increase as will the weight on the diagonally opposite corner. The other 2 corners will correspondingly reduce weight. The total weight on the front remains the same and the total weight on the rear remains the same. The % across the diagonals significantly alters.

Like you say, you can still play tunes with the diagonals and optimise for a RH circuit by changing the cross weighting. But to shift the overall front to rear weight distribution you need to move mass in the car - or in extremis tilt the car into the vertical and have 100% of the mass acting through the back wheels!

Relax, its only a bit of discussion on corner weighting and static weighting theory.

I prefer to just keep the discussion balanced and dont feel the need to use cut and paste images.

 

[Fred@BTM]

can i cut and paste?? sod it i will!!

"Highest Points Scorers in the 2008 Britcar Production Championship - P1 in Class 5 (under 2000CC) in the 2008 Britcar/Silverstone 24 Hour"

let the c**k swinging begin!! LOL

 

[MarcoB]

I know nothing here but too add more fuel to the fire wouldnt the F/R weight distribution change during acceleration/deceleration anyway? Oh, and why/whynot?

 

[Gasket]

can i cut and paste?? sod it i will!!

"Highest Points Scorers in the 2008 Britcar Production Championship - P1 in Class 5 (under 2000CC) in the 2008 Britcar/Silverstone 24 Hour"

let the c**k swinging begin!! LOL

Ahh Fred are you trying to tempt me to pop my CV up.


Unlike many though, I don’t need to have my ego constantly massaged.

 

[Icarus]

Now Fred you know I don't trade on that sort of thing! My cars do well yes but I don't need to bring it up. However thanks had forgot that does sound pretty good

I'll go get my corner weights.

Cheers
M

 

[Fred@BTM]

yeah sorry boys

i enjoy a good discussion, its always interesting when two obviously well experienced/qualified people get into things!

reminds me of when i was working on a car for a team and the number 1 mech and the cheif engineer went at it over what spring rates to use, then the driver sticks his nose in and then along comes the test team head honcho, longest luch break i've ever had

 

[Icarus]

I know nothing here but too add more fuel to the fire wouldnt the F/R weight distribution change during acceleration/deceleration anyway? Oh, and why/whynot?

It does, hence lift off oversteer where you move the weight onto the front wheels by reducing or removing accelerative force i.e. throttle amount.

Staticaly the weights will be as per set buy dynamicaly they will change as the car accelerates/brakes/corners. If you have linear pots on your dampers then you can see the weight moving between the corners of the car as various events take place by the amount of low frequency extension/compression (away from static level) events the dampers move through. To make that clear high frequency events would be the dampers moving a lot in a short period of time e.g. when the car was rumbling a kerb on the exit. Low frequency events are long duration compression/extension events e.g. when the car is under a lot of lateral G shortly before the apex of a corner.

Cheers
M

 

[Naith]

^plus bloody one

a good read had by all, please continue

AFYI matt's hung like an arabian race horse on heat

 

[Icarus]

yeah sorry boys

i enjoy a good discussion, its always interesting when two obviously well experienced/qualified people get into things!

reminds me of when i was working on a car for a team and the number 1 mech and the cheif engineer went at it over what spring rates to use, then the driver sticks his nose in and then along comes the test team head honcho, longest luch break i've ever had

Ah the Brands Hatch Hotel Rockery Incident sticks in my mine rather well where we were sat in the bar with a beer watching two of an opponents team slog it out stood on the rockery ;-)

Cheers
M

 

[Tony Hunter]

I like this:approve:

 

[MarcoB]

It does, hence lift off oversteer where you move the weight onto the front wheels by reducing or removing accelerative force i.e. throttle amount.

Staticaly the weights will be as per set buy dynamicaly they will change as the car accelerates/brakes/corners. If you have linear pots on your dampers then you can see the weight moving between the corners of the car as various events take place by the amount of low frequency extension/compression (away from static level) events the dampers move through. To make that clear high frequency events would be the dampers moving a lot in a short period of time e.g. when the car was rumbling a kerb on the exit. Low frequency events are long duration compression/extension events e.g. when the car is under a lot of lateral G shortly before the apex of a corner.

Cheers
M

A few more for ya

Does the weight need to be even through a corner, on the outside/ inside of the corner?

Also Gasket is going on about having an even distribution, would a spoiler + extra height on the front give a more even distribution even though the engine is over the front wheels?

 

[Gasket]

I know nothing here but too add more fuel to the fire wouldnt the F/R weight distribution change during acceleration/deceleration anyway? Oh, and why/whynot?

‘Weight distribution’ is a general term. 'Dynamic' weight distribution is a different ball game though compared to 'Static'. Does a cars overall weight distribution change as it accelerates/decelerates? Yes, if measuring loadings from a road/tyre contact point. It is constantly changing.

Just the effect of aerodynamic loading through a mean centre of pressure is constantly altering the loadings during acceleration and deceleration. Even at constant velocity the weight distribution is different from the static state. Cornering is only a rotational moment of inertia about a constantly changing centroid position. Or as Icarus puts it - watch yer dampers move.

 

[Gasket]

A few more for ya

Does the weight need to be even through a corner, on the outside/ inside of the corner?

Only if you are operating outside the earths orbit and trying to turn a space ship in zero gravity. Down here, natures forces apply.

Also Gasket is going on about having an even distribution, would a spoiler + extra height on the front give a more even distribution even though the engine is over the front wheels?

No.

Gasket was suggesting a possible equalised cross weighting option. Many other options exist.