camber,castor,tow and ride height

[thirteen]

I need a bit of a hand figuring my front end set up. my 260 is nearly ready to race, i have adj lower control arms, adj castor rods, adj spring platforms, adj sway bars and aj dampening. Im running 17/9 rims and 350f and 300r springs.

I need to get a base set up so i can get out and start running the car. i need to know what you guys out their would run. The car is only going on the race track.

castor

camber

tow

ride height

thanks in advance

[2ManyZs]

Not sure about the caster as most of us don't have any caster adjustment.

Toe would be best about 1/4 negative to 1/8 positive. I usually ran my 280 at 0 toe, front and rear.

Ride height is going to depend a lot on where you run and what rules you have to abide buy(if any). I would start with setting it up to have 5 inches from the bottom of the rocker panel to the ground and go from there.

Camber, now there is one that is going to be different for everyone, due to tire sizes, track, and a whole pile of other variables. I would start at probably 1 1/2 negative in the fornt and maybe 1/2 negative in the rear. You should check your tire temps after exiting the track and adjust you camber according to your tire temps. Higher temps on the outside, more negative, higher temps on the inside, more postive. Take your temps at three places on the tire tread, inside, center and outside. Adjust your camber and tire pressures to get the tire temps as even across the tread as possible.

Tire pressures are a matter of what tire you are running as well, some tires like a cold psi of 36-38 and a hot psi of 44-46. It is going to depend on the tire itself and how you adjust your suspension and what you want the car to do. This is kind of a "seat-of-the-pants" type of adjustment.

Hope that helps get you started!

[zr240]

This is a fairly large question and it depends on alot of things. I wil try and aswer as best I can.

on my car I run about 2mm toe in because the z tends to dip a bit at the front under very very heavy braking if you have large sticky tyres and big brakes. The reson for toe in is that if you are driving through a high speed coner and you ease a bit of brake on, the toe evens out and if you dont run toe in it goes to toe out and the car gets unstable. (trust me Ive done it heaps of times)

with caster I run standard caster as per the manual (workshop manual)

Camber depends on your tyre eg. bias ply etc you shoould ask the tyre manufacturer for there recomendation as I find most of the seem to of heard of zeds and canm offer some good advice. Also ask him what the tyre pressure should be for your type of tyre. Make sure you know the approx weight of your car aswell as that has alot to do with how much pressure etc to run.

ride hight. dont lower the car to much as it can stuff up the handleing big time. I have lowered my car so the front and rear lower control arms are vertually parralel to the ground (It seems to work very well)

Please note this is just a guide i am by no means an expert on this subject but I have put all of the above mentioned into practice

[kmack]

I'll revive this old thread due to some questions I have regarding these issues:

I just got the alignment checked on my 240 today. Had them set the camber to my specs (camber bushings installed) and set the toe-in to factory specs. Question has to deal with the measured caster. Here's what I got from the machine:

___________"L" "R"

Camber: -.28* -.33*

Caster: 1.08* 2.15*

Toe-in is factory spec and I don't remember what the reading was. (They pulled the car off the machine before I could get them to print it out.) Above measurements are in degrees.

Does anybody know how these caster measurements will affect the car's handling? Are they good or bad?

I'm sure the higher measurment on the right is due to the sheetmetal work I had to do under the battery area during restoration. I can work around this if it is neccesary to change these numbers. Basically, I want to know if 1* of caster is better than 2* or vice-versa.

The car is driven on the street rather irregularly and used to Autocross. I have MSA's Performance springs installed (blue in color).

On a side note regarding slotting the strut towers for additional camber adjustment:

Does anybody know at what measurement of movement of the strut equals what degree of camber change? Put another way, does 1/4"= 1* of camber change? Or something similar to that.

[2ManyZs]

FSM calls for 2 degrees55' without load, so the right side is close to being correct, the left could use a little more though.....

Maybe you have the T/C rod end too tight?

Here's a good little steering geometry explanation...

http://www.familycar.com/alignment.htm

1/4 inch would be close to a degree in camber, however, with the camber bushings, the effect might be exaggerated a little, since most people don't use the bushings.

The slotted camber plates only have approx. 2 inches of adjustment, but I don't know exactly how much = or - degrees that translates too...probably close to 3-4 degrees total.

In lieu of slotting the strut towers, I'd look for some of the upper camber plates that you use the stock mounting holes... they are still out there, but at the moment, I can't remember the manufacturers names....:stupid:

Tilton used to be one, but those are long gone now....

[kmack]

Based on the information provided in the link you gave:

The lower angle of positive caster on the left is the reason it pulls to the left slightly. Understandable now.

I can (somewhat) adjust the angle of caster on the left by placing washers in front of the bushing, thereby pushing the tension rod out towards the front of the car. But this will again affect my toe-in, right? I just hate to think that if I make an adjustment again, then I'd have to go through the alignment process all over. (It's only the fourth time, due to other changes I've made)

I don't think the bushing on the tension rod is too tight. I torgued both of them the same under load. But there is always room for error.

So with 2 different caster settings, will I need to worry about any adverse handling or tire wear? I'm going to be looking for a new set of tires for Autocross and I want to make sure they don't wear faster than neccesary

[260DET]

Thirteen, for the front and to start with, caster can go up to 5 degrees, camber around 3 degrees negative assuming you are using race radials. For the rear, camber around 1.5 neg. All to start with.

I would have the springs the other way around ie the 300's at the front, assuming you are using stock 260 anti-sway bars. Ride height may be dictated by your suspension components eg available shock bump travel, suspension arm angles, etc. Ideally it should be just high enough that it doesn't hit anything underneath but make absolutely sure that you always have bump travel available.

That should give you a ball park package although with 350 springs on the rear, the stock sway bar may be a bit heavy ie you may get a bit too much oversteer.

Let us know how it goes, good luck and enjoy.