Litespeeds

OK guys. I still need to locate an alignment tool in order to set the rear toe to spec. The question that I have is on the alignment sheet print out. The specified range for a 1983-1989 Porsche 944 is:

Front Suspension:
Camber -0.6 degrees to -0.1 degrees
Caster 2.3 degrees to 3.0 degrees
Toe 0.04 degrees to 0.13 degrees

Rear Suspension:
Camber -1.3 degrees to -0.7 degrees
Toe -.08 degrees to 0.08 degrees

Right now without setting the rear toe correctly, my Actual specs are:
Front Suspension: Front Left Front Right
Camber -3.2 degress -3.1 degrees
Caster 2.5 degrees 2.3 degrees
Toe 0.06 degrees 0.06 degrees

Rear Suspension: Rear Left Rear Right
Camber -2.1 degrees -2.0 degrees
Toe 0.08 degrees -0.25 degrees

I know I want negative camber which the fronts are ok but I wanted -2.5 degrees for the rears. The front caster is correct but I am not understanding the numbers for TOE.
Am I suppose to have (negative) -0.06 degrees or (Positive)0.06 degrees? The alignment shop told me that Toe In is Positive and the color on the print out is green. If I have Toe Out, it is Negative and the color of the print out is red.
Since this alignment does not indicate Toe by inches, but rather by degrees, how do I know if I actually have Toe In or Toe Out?
Please explain. I have a track day on Wednesday so I need to get this taken care of asap. Thanks.

Serge944

I'm pretty sure the toe is in inches. Yes, positive toe is toe in.

Trucho-951

By looking at an alignment conversion chart one can convert the toe measurements from degrees of toe to inches. There are curves drawn for different diameter tires. So assuming you have 25 inch diameter tires, my chart tells me that 0.015 degrees is equivalent to 1/16 inch total toe. So your front toe of .06 + .06 = 0.12 deg is approximately 3/64" . For comparison, most street cars do well with 1/8" toe, so your 3/64" toe is more track worthy.

Your rear toe should be as even as possible, right now your left rear is at approx. 2/64" toe-in, and the right rear is approx. at 5/64" toe-out. So I would leave the left alone and only adjust the right rear back to as close to 2/64" toe-in to match the left.

No need to use a rear toe tool, you can use a scribe to mark the hub and trailing arm and some love taps from a rubber mallet. good luck.

Serge944

I tried to follow your calculations, but couldn't. If .015 deg. = 1/16, then how does .12deg = 3/64.

Is the angle measured from the hub or through the total wheel diameter? Calculated both ways, the range seems much too small. IIRC, my alignment sheet had degrees for toe, when in fact the measurements were in inches.

Anyways, I run 1/4" total toe in up front on my e30. Thats 1/8" on each side, which is very close to the upper range of .13 (if the specs are indeed in inches).

Oddjob

Factory alignment specs for a 944 (from the FSM) list toe in degrees. Toe is commonly measured in degrees. Angle of the wheel relative to the center line of the car - very simple. Most current alignment racks measure toe in degrees.

Trucho-951

oops! I meant 0.15 deg = 1/16 inch.

Serge944

Glad it's very simple. My main question was whether toe was in reference to the hub or the entire wheel. It's the entire wheel.

The fact that the alignment specs are so tight are what threw me off. Even just 1/8" total toe in up front is way out of spec.

Oddjob

I was not making reference to Trucho's calcs or your questions regarding his math, I was just stating that is common and simple to use degrees for toe.

And any of the confusion about the measurements just illustrates why using an angle is simple compared to a distance; it doesnt matter if its in reference to the hub or the wheel, the angle is the same relative to the centerline of the car.

If using a length/distance measurement for toe, its critical what the measurement is in reference to: 1/64" relative to what? Hub center to the edge of a tire? A 24" toe plate? Leading to trailing edge of a tire (what size of tire? 225/50/15 or 275/40/17), etc. I had one guy try to explain that its measured from leading to trailing edge of the wheel, not the tire (if that was the case, the spec would have to be changed depending on what size wheels are on the car).

Camber is the same way, angle from the vertical centerline of the car. If someone said they are running - 0.73" camber, you would have some questions about exactly how that is measured. If they say they are running -2.5 deg, there is less confusion.

Yep, toe specs are much tighter and variations have a more noticeable effect on handling, relative to camber specs.

Serge944

Yeah, that's obvious. But when you want to compare to length values, it makes a difference whether you're referencing the hub or the entire wheel.

As far as I know, toe is the delta in length between the tires facing the front and the rear of the car.

I agree that the angle is a better way of measuring, but it's something a lot of people aren't used to, myself included. It's like power ratings in KW - I'm not used to using that system so when I see the ratings, I don't really make an opinion until I use a conversion factor.