Riketsu

iTrader: (34)

Adding shims to the rear uprights gives you more rear grip, in other words rear traction. You can even notice this from Mugen Driver's settings in their website. Youll notice they use more shims when they specify the track traction is low.

Slotmachine

iTrader: (4)

I say go ask Swagger, I will defend my answer.

afm

Rear Camber Links

The following generalizations apply in most cases:

1.- An upper link that is parallel to the lower A-arm will make the Roll Center sit very low when the car is at normal ride height, hence the initial body roll when entering a corner will be big.
2.- An upper link that is angled down will make the Roll Center sit up higher, making the initial roll moment smaller, which makes that particular end of the car feel very aggressive entering the corner.
3.- A very long upper link will make that the roll moment stays more or less the same size when the chassis leans over; and the chassis will roll very deeply into the suspension travel. If a lot of camber is not used, this can make the tires slide because of excessive positive camber.
4.-A short upper link will make that the roll moment becomes a lot smaller when the chassis leans; the chassis won't roll very far.

So in general, you could say that:·

1.-The angle of the upper link relative to the A-arm determines where the roll center is with the chassis in its neutral position
2.-The length of the upper link determines how much does the height of the Roll Center changes as the chassis rolls.
3.-A short, angled down link will locate the Roll Center very high, and it will stay high as the chassis rolls. So the chassis will roll very little.
4.-A long, angled down link will reduce the car's tendency to roll initially, but as the chassis rolls it won't make much of a difference anymore.
5.-A long, parallel link will locate the Roll Center very low, and it will stay very low as the car corners. Hence, the car (well at least that end of the car) will roll a lot.
6.-A short, parallel link will make the car roll a lot at first, but as it rolls, the tendency will diminish. So it will roll very fast at first, but it will stop quickly.

In terms of car handling, this means that:

1.-When the link is angled down (higher Roll Center) gives the most grip initially, when turning in, or exiting the corner,.
2.-When the link is angled up (lower Roll Center) gives the most grip in the middle of the corner.
3.-If you'd like more aggressive turn-in, and more low-speed steering, set the rear upper link at less of an angle.

What's the best, a high Roll Center or a low one? It all depends on the rest of the car and the track. One thing is for sure:

1.-On a bumpy track, the Roll Center is better placed a little higher; it will prevent the car from rolling from side to side a lot as it takes the bumps, and it will also make it possible to use softer springs which allow the tires to stay in contact with the bumpy track.
2.-On smooth tracks, you can use a very low Roll Center, combined with stiff springs, to increase the car's responsiveness.

AFM

gentleman81

iTrader: (2)

i use the a block in the rear and a thick and thin shim on the rear uprights.

toe front about 1

rear about 2

camber f 2

rear 3

gentleman81

iTrader: (2)

any rules of thumb for low traction tracks? Parkinglots

TigeRyan

iTrader: (7)

For parking lots I will generally run more rear camber (up to 4 degrees) parking lots tend to be rough on tires so to prevent sidewall chunking I do this, I also usually run more rear toe-in to help stabilize the car....You can also run zero to 1 degree front toe-out to help it further.

Also on parking lots I tend to run a bit more droop to help absord the bumps a bit more.

Just what I have found out for myself over time....

ira

iTrader: (18)

The tracks that we race on are mostly parking lot tracks, low to medium tracktion. I use the B block bolck in the rear of the car and a 1mm shim under the camber link, If the car is to loose I add a 1mm shim to the camber link (a total of 2mm under the camber link) If your car wants to step out off power are you using a one-way with drag brake? What is your setup? Is the track bumpy?

Scott Fisher

iTrader: (28)

Lots of info, except one thing. When you say angled up , or down, where are you starting from. In other words if the camber link sits low on the bulkhead/shock tower and goes up to the rear upright is that angled up or down.

I won't take sides on either here, but Barry told me if you add shims under the link where it attaches to the rear upright it adds steering (less grip)

Slotmachine

iTrader: (4)

[/qoute]I won't take sides on either here, but Barry told me if you add shims under the link where it attaches to the rear upright it adds steering (less grip)[/QUOTE]




I think that is what I said?

asw7576

AFM is great man, just like in the text book

325i

hi i have an mtx-3 prospec
i woulk like to learn about set-up
front and rear ride height
you know front 4mm and rear 5 mm
by making this which onei must use?
NEW WHELLS or
SET-UP WHELLS
WHİCH one is true?
thanks

afm

In our Mugens with the original bulhead/shock tower, we can only change the lenght of the link bar by attaching it on the inside or outside hole.
We can only change the angle (up or down) by adding or removing shims on the upright side.

AFM

Scott Fisher

iTrader: (28)

Yes, I am aware of all of tha. I will rephrase the question, because I didn't see an answer. When you add shims under the camber link at the rear upright, are you raising or lowering the camber link? If your beginning point is at the upright, you are lowering the link (raise one side has the effect of making the other side look lower). If your beginning point is the bulkhead you are raising the link.

Scott Fisher

iTrader: (28)

I think that is what I said? [/QUOTE]


I was agreeing with you as opposed to the other person that disagreed with you.

afm

You are changing the angle of the camber link with respect to lower arm:
--adding shims makes a steeper angle
--removing shims makes link flatter (less angle)

GUIDE CHART
1.- A long link gives a lot of chasis roll in turns.It feels as is the chasis is willing to keep on rolling, until in the end, the springs prevent it from rolling any further. It gives more rear traction in turns, and coming out of them. Rear end slide is very progressive, not unpredictable at all. Make sure that there's enough rear camber though, or you could lose rear traction in turns.
If there is already is a lot of traction, long camber links can slow the car down in turns.

2.-A short link makes the chasis don't roll as far, its tendency to roll drops off as it rolls. It feels as is the car generates a little less grip.The rear feels very stable. It breaks out later and more suddenly, but if it does, the slide is more controllable.It makes the front dive a little more, which results in more steering, especially when braking.

3.-More Parallel Link (More Parallel to lower arm) gives a little more roll than an angled one. It feels very smooth, and consistent as the chasis rolls in turns.

4.-Angled Link (Less Parallel to lower arm) makes it feel as if the car has a tendency to center itself (level, no roll), other than through the springs or anti-roll bar. It gives a little more initial grip steering into corners. It makes it very easy to 'throw' the car. The chasis rolls a little less than with parallel links. It's possible to use softer settings for damping and spring rate than with parallel links, without destabilizing the car.

AFM