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Author Topic:   wheelbase questions?
OppendikeRacing29
Member
posted May 15, 2003 01:37 AM
Will someone explain to me how wheelbase works? shortening left side compared to right and oppisite.


outlawstock17
Member
posted May 15, 2003 07:04 AM
right side shorter....tighter.

left side shorter....looser.

restore1
Member
posted May 19, 2003 10:16 AM
Could someone go into a little more detail on how this works. We're in the process of rebuilding a hobby class camero. The right side wheelbase measures 106 3/4 inches and the left side measures 108 3/4 inches. Does this sound about where it needs to be? I did race the car one time, the last race of the season last year. It did seem to handle the turns well.
Also how would you adjust this on a leaf spring car?
Thanks for any help.
Larry Staton


jammin
Administrator
posted May 19, 2003 10:56 AM
I would start off at 108 on both sides and see where you are. On leaf springs, there are slider spacer blocks you can buy to adjust this.

jammin


RC Racing
Member
posted May 19, 2003 10:59 AM
I personaly would start out with your wheelbases "square" (that is, left side & right side wheel bases the same). That's how I did it on the Late Model I had. From there, I adjusted the wheelbase as necessary.

And at this moment I can't say as I explain the physics behind wheelbase relationships. However, from experience, to loosen the car, you want the passenger side longer than the driver side. Inversely, if you want to tighten the car, the passenger side should be shorter than the driver side.

As far as "how would you adjust this...", if you have lowering blocks, you can buy adjustable lowering blocks. I had one on the driver's side leaf.

Hope this helps

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outlawstock17
Member
posted May 19, 2003 11:49 AM
restore, these guys are right.....start off with the wheelbase square and make small changes from there. 2" longer on the drivers side might make the car push.

this is how wheelbase length difference works.....you're basically angling the rearend....with a longer wheelbase on the drivers side, the rear end is angled towards the infield. thats the direction the rear will tend to go. if the rearend is pointing towards the infield, the front wheels will have to be turned a little left to make the car go straight and even farther left to make the car turn left, possibly creating a tight condition, although this may be helpful under certain track conditions.

restore1
Member
posted May 19, 2003 05:12 PM
Thanks guys, You've all been a big help.


o5racer
Member
posted May 19, 2003 09:18 PM
You guys forgot one important thing. When you crank a lot of caster in the right front it moves the upper ball joint back and shortens the right side wheel base. you are better to measure from the axle tubes up to the back of the subframe to determine of the axle is straight.


RC Racing
Member
posted May 20, 2003 01:28 AM
o5racer, here'shat I was taught (shoot holes if applicable)

1) Set Ride Height
2) Set Caster
3) Set Camber
4) Then measure wheelbase (method I was taught was to hang a plump bob from the lower A-arm grease fiting to the ground, mark it on the ground; plump bob from the middle of the rear axle to the ground, mark it. And then measure the wheelbase.

Was told this will give you a measurement of the actual geometry of the car (takes into account caster, camber, bent parts .... which, by the way, one should check for squarenesss of the car/frame by starting with a straight car/frame, scribe some points on the frame for future reference, and then always measure to see if your car/frame is square. but excuse me, I'm rambling .......)

Anyway, I believe using this method will account for the caster settings.

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outlawstock17
Member
posted May 20, 2003 08:05 AM
we always measure from the grease zerk on the lower balljoint. this way caster doesn't play into it.


RC Racing
Member
posted May 20, 2003 10:06 AM
outlaw, thanks! That's (lower ball joint) what I meant to say.

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OppendikeRacing29
Member
posted May 20, 2003 11:26 PM
do most of you guys run a little shorter on the right side


stevewm
Member
posted May 27, 2003 05:55 PM
I have found that running 3/4 of an inch shorter on the passenger side on a 108" wheel base car works very well if you run the car hard into the turns.

The dry slick tracks love it.

Just a thought.
Steve.


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