BlueBorderRC

I know how to adjust ride height thru the suspension but how do you measure or set your squat? My buggy has a set screw thru each A arm that go's all the way thru and bottoms out on top of the actual chassis plate. It supports the A arm. You screw it in it pushes the arm up you let the screw out the arm drops (squat). Whats the proper static squat (car fully decompressed up on stand)? Whats the best way to measure that?

Maj_Overdrive

My Feedback: (11)

The screws you speak of are actually called "droop screws" and restrict the suspension's downtravel. Downtravel is the amount of suspension extension (or droop) availible from ride height. With the vehicle at ride height, lift the chassis, the amount of suspension extension before the tires leave the ground is downtravel or droop. Excessive downtravel can cause excessive suspension rebound. What I mean by this needs an example. Drop a buggy on the workbench and the suspension compresses then decompresses or rebounds. During this period of rebound the suspension is unsettled and the vehicle is not as stable. The more downtravel you have the more opportunity there is for the shock springs to accelerate the movement of the suspension arms and act on the chassis. Going fast over rough terrain needs more downtravel but too much can unsettle the suspension as well. Smooth tracks where the ride height is set lower need less downtravel. If you want an example just look at full size cars. Indy cars, formula 1, there is virtually no downtravel when they jack those cars up, yet there's tons on Trophy Trucks, Monster Trucks, etc. The moral of the story is with the right amount of downtravel the suspension will settle quicker and the vehicle will be more stable.

Downtravel can also be an issue when jumping. Hit the face of a ramp and the suspension compresses, as you go up the ramp face the suspension will start to decompress pushing the chassis up away from the jump face. Since the amount of downtravel dictates how much opportunity the springs have to accelerate the suspension's movement, tuning the amount of downtravel will alter the vehicle's attitude just before it leaves the jump face.

That much I do know. Squat as far as I understand is the rear suspension compressing under acceleration. The droop screws are not going to help you there. Droop screws are meant only to limit downtravel, not to set the ride height and they do nothing for compression. The droop screws should not be touching the chassis at ride height for off-road and possibly just touching the chassis for onroad applications. I've used the droop screws to lower the ride height on my old LX1e. For onroad this worked ok, just barely ok. Even then I had to back off the preload adjusters on the shocks to prevent the springs from being too stiff and still would've needed to change shock oil and diff fluids. Lowered to arms level by changing shock position was better to drive than any shock position where I also used the droop screws to lower the buggy. I never used the droop screws to lower the buggy for off-road but I imagine the results would be the same.

BlueBorderRC

Your right there called droop screws. Nobody talks much about them. Im not trying to set the ride height with them though. Im trying to figure out (with the car on the stand) how do you measure when adjusting to make sure all arms are level?

Maj_Overdrive

My Feedback: (11)

This entire post is an edit since I think I misunderstood some of what you were saying.

Theres only so much you can do with the buggy on a stand. Most of setting up a vehicle actually needs to happen on a flat level surface with just wheels (no tires) or axle stands on the vehicle. The term "arms level" means the vehicles suspension arms are parallel to the ground at ride height. Arms level at ride height the droop screws should not be touching the chassis. If you want to make sure the droop screws are set equally side to side you'll need to measure. The easiest thing to do is use a block to support the buggy off the flat level surface. With the buggy chassis level to the surface measure the distance from the each wheel to the surface and adjust the droop screws to make them equal.

If you want to make sure all the arms are actually level at ride height you also need to measure on a flat level surface. Again no tires, measure from the surface to each hinge pin. Now measure from the suspension arms attachment point at the knuckle to the surface and compare them. "Arms Level" is just a term and doesn't mean exactly level or that it's the best setup for you , your buggy or the track. Knowing the exact measurements of everything will give you a more accurate setup though and make sure things are equal side to side.

If you're that serious about the suspension setup of your buggy you should really look into a setup station. A setup station is a stiff, flat board with measurements and markings on it used in conjunction with axle stands (that replace the wheels), camber and toe gauges and other measurement tools. Setup stations also often include guides for measuring various aspects of your setup. A setup station will also help you create more accurate setup sheets and help you to recreate any setups you find online and want to try.

BlueBorderRC

OK thanks. I think the measurement from the arm to the table with the car on a perfectly flat block would be a good method to get the droop screws to a equal setting. I didn't think of doing it like that.

Maj_Overdrive

My Feedback: (11)

No problem. I mentioned measuring from the wheel to the surface because it a easily repeatable point. if you don't have extra wheels without tires the outer hinge pin would be a good repeatable place to measure from.