v8_ranch

I remeasured the ride height on my 83 cabriolet this morning with a better tape measure than I could find at home.

My car is stock suspension pretty much, and just had new Fuzion ZRi 205/55/16 (F) and 225/50/16 (R) installed 2 days ago. When I am measuring, I am placing my tape on the floor at the CL of the wheel and parallel to the face of the wheel at the outermost spot on the well lip. Is this the correct placement? If it is, then I am curious about my measurements. They are as follows:

FL: 25" FR: 25 1/4"

RL: 24 3/4" RR: 25"

I am certainly a suspension novice. I am just wondering if this is normal or not. I thought the front pair and the rear pair would have matched up to their opposite side. Am I missing something.

theiceman

have someone sit in the drivers seat and redo it ... the front might be closer.

imcarthur

It may be slightly different side to side just due to manufacturing differences. But it is the measurement that we all use . . .

To get consistently repeatable measurements:

Your car must be on an absolutely level surface. Use reuseable wooden platforms under the wheels to achieve this if necessary.
3/4 tank of fuel.
Simulate driver's weight with ballast. I use patio bricks that weigh 10lbs each distributed on the floor & the seat.
Use a yard stick. It's easier.

Confirm with other measurements. Maybe the ends of the crossmember to ground in the front & the springplate '****' in the rear just to make sure the suspension is truly level.

When you get it where you want it, a corner balance would be the finishing touch.

Ian

imcarthur

And one other point:

If your suspension bushings are tired, this can greatly effect things. For example, I have one front bushing - passenger inner bushing - which has started to 'flow'. This has buggered all of my leveling & home alignment attempts. I have Polybronze on BO with Pelican to rectify this.

Ian

psychoideas

Factory tolerance from left to right on a 964 is 5mm. 6mm is 1/4" I wouldn't worry too much.

At the front measure down from each side of the crossmember to the ground, and at the rear measure down from the bottom of the torsion bar covers to the ground. (Level surface like Ian said)

This will tell you if the inconsistencies that you are encountering are due to suspension settings or inaccuracies in the location of the fender lips on the body.

theiceman

oow good call Frank ... imagine doing all that adjustment and your body work is off a quarter ..... ouch.

911 Rod

Only a scale will tell the true tale.

Peter Zimmermann

Shane: You must know that the chassis is "square" and has no damage. If the car has gas pressure shocks the car should be driven just before measurements are done. Your car has been lowered to Euro height, but the front is too low - 25.5" is a better height. If you raise the RF to 25 3/8", and do the same to the LF, that might also level off the back a little bit. Be sure that your tire pressures are set at 29F/34R - it's anybody's guess where the tire store set them at, then drive and re-measure. If you've had the car aligned recently there is a chance that was done wrong also, so try to feed us a little more info...

v8_ranch

Thanks all. A friend of mine who is helping me to try to resurrect the SCWDP is pretty adept at corner balancing and alignments. He is in Ohio though. We are going to possibly get together so I can learn more about this part of the car. He also mentioned the fact that I was forgetting that these were handbuilt cars and might be off a little here and there. He has the weight setup for corner balancing so I guess that will be interesting to participate in. I have had the car 1.5 years now and no alignment since I bought it. I have to dig through the records to see the last time it was done. I just figured now would be a good time now that I have new tires. The inside of my old tires were wearing more than the rest of them, so I was wondering if something might be a little off somewhere on suspension.

v8_ranch

Pete, I did not know that about the gas charged shocks, but what you say certainly makes sense to me. How do I tell what I have on my car? Again, it is a 1983, but I do not know if the shocks had ever been changed.

flatsixnut

Pete...I am glad you brought this up. What is the proper tire pressure for the tires and why? Also does it matter what the outside temps are? For instance I am in Flroida so it takes less time for the tires to warm up. I hate to sound like a greenie, but you can never learn too much.

Thanks,
Michael

Peter Zimmermann

Shane: If your shocks are black (check the rears, they're visible from under the rear bumper) they are Boge. That means that they could be either hydraulic or gas, and I'm not sure that you can tell unless your car still has the option sticker on the underside of the trunk lid. If your shocks are green, they're Bilsteins (gas), or yellow, also Bilsteins (but Sport gas). Gas shocks, after an unknown point in their life, will "pump up" while driving, so the most accurate way to measure height is shortly after using the car.

Michael: I think that tire pressures recommended by Porsche are for the typical car, on a typical day, with correct alignment settings, etc. You probably know that it gets very hot, also, where I live, and I use 30(F)/35(R) cold. My car (Euro height, semi-track alignment and corner-balanced) seems to react better with only that one pound increase. Hot temps aren't negatively affected by the increase, and a shorter warm-up time is probably good, although I don't think that a significant difference exists between a 75 degree F day, and a 95 degree F day. Hope this helps!

v8_ranch

Oh great, I must have the el cheapo's! I just looked and after brushing off the road grime and scrubbing with a little degreaser, it appears both of mine are black or dark grey...

theiceman

i'd be swapping those puppies out before doing any aligning ... they are " relatively " cheap . i got bilstein sports all round for less than 500.

Peter Zimmermann

Shane: Boges, not surprising. Almost all Targas and Cabs were fitted with them (softer ride/reduced cowl shake)...