SDGuy

I've had my car 5 months. I've got fairly new Bridgestone Potenza P215/60R15 tires all around put on by the previous owner. Stock phone dials. I run 30/36 lbs of pressure front/back and the car handles great. A couple of weeks ago I noticed the car pulling a bit to the right, so I've set up a 4 wheel alignment appointment. I read lots of previous posts on track setup, but this is mainly a street car where tire longevity would be nice and cornering/handling is also very important.

Some questions if you please:

1) Am I supposed to rotate the tires front to back on this 944, i.e. is wheel width the same front and back on an NA? Should I rotate prior to alignment to see if the problem gets better without alignment? If rotation front to back is not possible, does anyone ever rotate left to right?

2) Looks like suggested Caster is 3 degrees if possible (L and R equal), Toe-in is 1/16" front and rear and Camber is hotly debated. An article by Jim Pasha says 3/4 degree and 1 degree front/rear. Does he actually mean a postiive Camber? See http://www.924.org/techsection/Suspe...reparation.htm
Most people on this board are saying negative Camber of about -1.75 front and -1.25 rear for a mild setup. Opinions please.

3) Any susprension/steering parts to have checked if alignment doesn't fix the pulling to the right? What are early signs of steering rack problems just so I know.

Thanks for the help. Howard

shiners780

Stock phone dials on an NA should be 7" front, 8" rear so don't rotate front to back. When I bought my car, the previous owner had one 7" and one 8" each on the front and the back. Doh! The wheel sizes are stamped on the inside of the wheels. Side to side rotation is fine as long as you don't have directional tires.
Camber will always be negative.
With performance tires, the crown of the road may cause the car to pull slightly to the right.

35thSLP

my sons na has 15x7 all the way around. My 951 has 16x7 up front and 16x8 on the rear. I think the na cars are running the same size on all four corners unless someone has changed them.

Stan944

If the car suddenly started pulling to the side, I would suspect a worn out bushing (rear side) in one control arm. Alignment hardly ever changes on its own, unless you hit a curb or went through a major whole. I would suggest not to change alignment from stock if your car is only for street driving.

You might want to describe the tire wear pattern.
I had more wear on the outside of the front tires, and when I was switching tires in the spring I had the front ones mounted so that the left front was switched with the right, but without changing the direction of rotation. I heard it's not good to rotate wheels with radial tires so that the tires change the direction of spinning.

jharding

...not to overstate the obvious, but check your air pressure when the tires are cold (i.e.; not driven yet). Even a 1lb difference in air pressure from right to left can cause the car to pull.

ibkevin

Howard, Jack the front up and check the basics, spindle nut tight, berring play, tie rod assembly loose or the rod end is bad. Stick with standard specs for street use. Differences in tire and wheel sizes should prevent you from forward to aft rotations. Side to side rotation will not work with directional tires.

A four wheel alignment will make that car feel new again, highly recommended!

SDGuy

I checked and all 4 wheels are 7x15's on my 86 NA. I've been so used to fatter rear wheels on Porsches that I am kind of surprised I can simply rotate. So I rotated and my pulling problem is cured! I almost forgot to redo tire pressures to 30/36, but remembered last minute. What may have happened to my fronts is that when I bought the car, the left front had 40 lbs in it. Probably caused some uneven wear. Thanks to all for the advice.

Kevin, I will have the mechanic check those items since I'm not sure I know where those things are. I've got to have the belts readjusted soon anyway since they were put on recently. Howard

ps and off topic - Kevin, let me know when you want to borrow my freon leak tester. BTW, a place called Eskimo Radiator on Bradley in El Cajon will do a complete A/C check for $45. They fill the system with R134 temporarily to check for leaks and function. They were the ones who helped me determine that my evaporator was leaking. Of course, they don't know Porsches that well so they had no idea how to pull the evaporator, but it was worth it to have them check the compressor and all the A/C components - and to prove that the system could blow cold air. As for the actual evap repair, Jeff at Fast Radiator in Escondido was great and let me do much of the work myself to save money (pull console, dash, air blower, etc). They also have real R12 which is probably best in our old cars.

ibkevin

Great tip, Thanks! I'm thinking there will be an incompatability problem with a temp 134 charge in an R12 system? But wait.....

Just talked with Tony and this sounds like a GREAT deal. If it's pratical to top off w/R12 and test they do that. If not, they evacuate the sys and do a temp cahrge of 134 all for only $39.95. I'm sure they will have they're "Porsche price" structure firmed up by Fri for my appointment.

Normally I would not admit this, but there are certian benefits to keeping wiefy happy!

Now back to our regularly scheduled topic.......

SDGuy

Hope this gets things sorted for you. He can evacuate any R12, run R134 temporarily in the system to pressure and function test everything (you wouldn't want to run R134 permanaently with mineral oil in the system) and if he fixes something, I believe he can put your R12 back and top off R12 as well. He swears he's never failed converting a system to R134, but if he has R12 in stock and won't charge you an arm and a leg, why not stick with R12? Oh, check out this thread for the compressor low switch jumper method to test the compressor clutch for no more than 10 seconds or so - https://rennlist.com/forums/showthre...2&page=1&pp=15 You can also go to the low side shrader valve and do a VERY quick depression of the center pin to see if you do or do not have any pressure in the system at present. Howard