rcracerdude

somebody posted this here before. Might be of some help Look for "Roll Center/Camber links" section.

asw7576

Okay, I 'll test three and four shims, I'll report to you guys on Saturday after testing.

I read it somewhere...., Mike Swauger explained higher rear upright means more side bite for Mugen Cars ( side bite = cornering grip ? ) and less chance to flip.

I hope he is right j/k ( of course he is right )

ogreasurada

iTrader: (1)

I think lower roll center (higher upright) is mostly useful and effective on high-grip tracks. If the track cannot offer enough grip, a car with (too) low roll center will just slide out of the lane as it turns, it also makes the car harder to control.

Derby Bros Racing

iTrader: (7)

basic rule is:

rear end of car - loose feeling = add shim
rear end of car - too tight = less shim

cannot go over 2.5mm in shims. if the car still feels to loose in the rear, go to other setup options (i.e. tire compound, droop, etc.)

sohlman

iTrader: (92)

I've never tried it on my 4, but on my 3, I went as far as 3mm. Obviously, I had to change to a longer screw but it worked good. Swauger's 3 set up for the Texas Biggie had 3.5mm. I wonder if it's easier to just change something else like you're suggesting.

Derby Bros Racing

iTrader: (7)

aside from changing tires, taking off or adding shims is really easy as you know

the only reason why i said i don't go over 2.5mm was because that's the most i've used. and also, i remember reading XRC a while back and it was about the shimming not to go over 2 or 3 mm which was based on robbie collin's mtx-3 setup tips. i should still have that mag somewhere but it will be pretty tough to find it now but if i do, i'll scan it and post it over here.

next time, if i feel there's a need for more shim in the rear, i'll definitely try more like you suggested

reddishdsb

iTrader: (3)

Anybody looking for an mtx4 mine is on ebay, brand new in the box with
extra rear shock tower clutch bell and ball ends. I paid 419 for kit starting bid
400. Onroad has all but died around here, gonna stick to offroad. only 1 day
left.

Derby Bros Racing

iTrader: (7)

the 3racing titanium pivot balls for v1rrr is only $35 (yes, that is for 8 of them). i was wondering if they are the same size and can be used for the 4. because if that is the case, it will be a very cheap upgrade!

ogreasurada

iTrader: (1)

I can only assume if they fit the 3 then they should work on the 4.

MAVICXXX

yup is d same..i m having kfac titanium compatible for X3 and RR/RRR.
bit lightweight but stil working out bit more to fit d specs right.

Derby Bros Racing

iTrader: (7)

so you mean they are the same

if they are, then there shouldn't be any problem, right?

moot

whats settings are you guys using for the front and rear belt tensions?

SNACKPACK

Hi guys, this is my understanding of roll centre, so please correct me if I am wrong :
RAISING THE ROLL CENTRE: To raise the roll centre you make adjustments so that the top arm/link is at a greater angle in relation to the lower arm. To do this LOWER the INSIDE pivot point (the pivot point located on the shock tower on most cars) of the top arm/link OR RAISE the OUTSIDE pivot point (located on the suspension upright on most cars) of the top arm/link. Raising the outside pivot point of the top arm can be achieved by adding shims to the upright.
As raising the roll centre reduces the distance between the centre of gravity and the roll centre, the car will roll less when cornering forces are applied. Because the car rolls less, the wheels will have less weight transferred to them and therefore have less traction.
Effects of rasing the front roll centre: The front tyres will have less grip, and therefore the car may understeer at higher speeds (off power). However because less weight is being transferred from left to right, the car will react more quickly and feel more responsive in low speed corners.
Effects of raising the rear roll centre: The rear tyres will have less grip, and therefore the car will change direction faster and generally be more responsive.

LOWERING THE ROLL CENTRE: To lower the roll centre you make adjustments to the top arm/link so that it is more parallel (grammar?) in relation to the lower arm. To do this RAISE the INSIDE pivot point of the top arm/link OR LOWER the OUTSIDE pivot point of the top arm/link.
As lowering the roll centre increases the distance between the centre of gravity and the roll centre, the car will roll more when cornering forces are applied. Because the car rolls more the wheels will have more weight transferred to them, and therefore have more traction.
Effects of lowering the front roll centre: The front tyres will have more grip and therefore the car will have more off power steering. However because more weight is transferred from left to right the car will generally be less responsive (especially at low speeds).
Effects of lowering the rear roll centre: The rear tyres will have more grip and the car will have a tendency to understeer (on power). The car will react less responsively and will usually feel more docile and controllable.

As I said before, this is only my understanding of roll centre and am I by no means are suggesting that anyone else on this forum is wrong. If I am grossly misinformed please correct me.
I hope this helps...and makes sense

ogreasurada

iTrader: (1)

For my car: Front: middle (one level tighter than default) position, Rear: Default position.

moot

taken from previous page:

Quote:
Originally Posted by moot

so the 'standard' position is the tightest?





Yes.


so is standard tightest or the loosest