Cambur change

[DesertGuy1]

Lot's of ways to skin that cat... Looking at your pic posted and as an example, try setting negative camber, at ride height, around -1.5 degrees. then lower your spindle height by 69mm and increase your distance from your lower/upper arm from 300mm to 350mm and see what that does. Hard to tell from the pics posted but may get you in a neighborhood to start doing some work.

If that gets you in the ballpark, there would still be a lot of fine tuning to do.. just a thought with a "guesstimation"

[SPONSOR]

Membership in the largest desert racing community has its advantages - Participate in Forum Discussions - Send and Receive Private Messages - Maintain Public Photo Albums - Access to Groups - User Profile in our Social Network - Increased Access to more Sub Forums - Reduced Online Advertisements Join our community today

[scottm]

I have been harping on here about proper camber for years. It looks silly when both wheels lean out 5-10° in a corner, and that same poor geom also leads to a lot of horizontal wheel scrub. Parallel, equal length arms cause the tire to swing inward in droop - horizontal scrub. I have seen 6 inches per side! Imagine you are landing crooked, with initial contact on one front wheel. As the susp compresses, the scrub forces are trying to push the car away from the ground. This is very hard on the wheel, hub, bearings, and can pop the tire off the bead. By lowering and widening (moving out) your upper arm frame pivots, you can get negative camber in bump and droop, and reduce scrub to an inch or less. Here is a crude drawing I made some time ago to try to illustrate.

[scottm]

Your second pic looks pretty good, but it looks like you have designed for 0 steering scrub radius. You can get your lower ball joint further inside the wheel and lessen the sai to 8-9° to give positive steering scrub. You want the tire contact center to be 1/2 to 1" outside the sa-to-ground point. Also your tire will squish an inch with car weight, and camber will shift your contact patch inward.

[ErcegMotorsportAus]

Thanks heaps for all your feedback guys. I am back to the drawing board to make the camber change negative throughout the 23" of travel. I will take everything on board that has been spoken about on here and see what I can come up with. I dont have access to the CAD program anymore so it is back to the compass and protractor to get the results... I will keep you informed of the progress and keep an eye on the show and tell segment as the whole build of our new MATRIX pro buggy (class 1 car) will be on there.

Thanks again

Luke

[JCampbell]

No CAD program here either . I use a scale ruler, deg protractor and graph paper to figure out geometry on all my cars

[ErcegMotorsportAus]

Thats good to know Mr Campbell... Your cars always look wicked and they work great so I know there is hope for me yet haha I'll keep working on it!

[Zambo]

If you're of limited brain processing capability, rather than make scale drawings get a marker and a big T-square and draw it out full scale on a sheet of aluminum or a big ass white board.

[BNS 247]

Hey Luke check this out might help. http://www.racingaspirations.com/?p=286

[partybarge_pilot]

Wouldn't you want to move the inner UCA pivot up?

Yup LOL...... That's the kind of quality answer you get after a weekend at the river.........

[rally camaro]

Thanks heaps for all your feedback guys. I am back to the drawing board to make the camber change negative throughout the 23" of travel. I will take everything on board that has been spoken about on here and see what I can come up with. I dont have access to the CAD program anymore so it is back to the compass and protractor to get the results... I will keep you informed of the progress and keep an eye on the show and tell segment as the whole build of our new MATRIX pro buggy (class 1 car) will be on there.

Thanks again

Luke

Here's another way to design the a-arms starting with the wheel/tire and bottom arm. http://www.minibuggy.net/forum/how-d...ign-setup.html Let's you design from the wheel/tire in, i.e. wheel/tire dictates where your KPI needs to intersect to give 1/2" of scrub, design lower arm, then cycle spindle through travel setting desired camber at full droop, ride height and full comp. Best of luck

Rally