Chuck Z

My 1993 GTS had been lowered by a previous owner and last week I had it raised to factory specs. I know how dangerous it is to drive a lowered 928 and the risk of tearing the starter from the block if you hit something. Before I get it aligned I thought I would ask a couple questions. The car has sport suspension with Weltmeister springs.

My questions are:

1. The fender measured at the center of the wheel measures 26" in the front. Judging from the pictures, does the front need to be dropped 1/4" - 1/2" or will it settle that much?

2. If after its lowered, the measurement becomes 25.5" - 25.75" am I back to the same issue I had earlier?

I should also mention that the 95 GTS measures 25.5" in the front, perhaps I have the answer already?

ErnestSw

The fender lip measurements are relatively meaningless. There are four suspension points, one on each corner, from which measurements should be taken on a flat surface. You'll need to drive about 50 miles before you re-measure. Factory specs are about 175mm.

Chuck Z

Thanks for the info. The height adjustments were made by measuring the suspension. The measurements I quoted were after about 25 miles and easier for me to measure.

worf928

I'll assume that you are running stock size tires - i.e. not ones that are too small in diameter. If you are, I'd say that your '93 has not settled yet. Keep driving, do a few near-threshold-braking stops. My '91 will settle with some driving. The '89 will settle only if I give it some hard braking.

Chuck Z

Stock tire sizes and I'll tried to settle it with some pretty spirted driving on Saturday.

WallyP

27" front, 24.5 rear from the ground to the fender lips per dr. bob...

Not as precise as the measurements to the machined points, but a lot easier to do.

UKKid35

Setting Ride Height

SteveCo

Wally is dead on with those fender lip measurements. They are useful for estimating purposes, however, you need to check the factory spec measurements once you get close. My car is at 26.5" front and 24.25" rear with the suspension ride height measurement points at about 170mm at each corner. My car is just a tad lower than factory spec....I will eventually get it dead on before the next wheel alignment.

On suspension settling, I found it necessary to run up almost 100 miles to get to a final, stable measurement. It is also imperative that you have a near-perfectly level and consistent surface to measure from.

Regards,
SteveCo in St. John's

Earl Gillstrom

Chuck,

I use Dr Bob's recommendation: 27" front, 24.5 rear from the ground to the fender lips.
Some owners like it a bit lower. I consider 26"front 24" rear my lower recommended limit. When you get below 26" the feel of the car gets progressively worse as well as the chances of losing an alternator/ AC compressor/ engine block. If you are not using a perfectly flat floor (cement garage floors are hand trowelled and not flat) or alignment rack for measurments, the fender lip might be more accurate than the suspension flats. Check my website for more alignment recommendations and how to level a floor.
I have found that on relatively normal roads, it takes at least 100 miles to settle the later cars. Older cars settle faster. I have a road near me that is the roughest road that I have ever seen and it takes about 30 miles to settle late cars.
http://members.rennlist.com/captearlg/

Chuck Z

Thanks for the info. BTW, my measurements were done in my garage on a relatively (perhaps not perfectly level but close) level floor. Perhaps I'll leave where it is for a while.

SteveCo

Chuck;
I had the same basic reaction to the "raised" car that you had. Mine was even more dramatic that yours and looked, well, unnaturally high. After settling and a few fine tunings to get it to where I wanted it to be, it did not look so abnormal any more.

I had several family members comment that the car looked like a 4 wheel drive 928! Granted this was immediately after the height adjsutments with no road test to settle the suspension. Even after a 5-10 mile run, it still looked "high" and I was beginning to think I had made a mistake. A few days and several road trips later, the car looked more normal. Closest I could peg it would be that it looked more "right".

It was about this time that it struck me just how low the car was before I started. I was well below 25" on the front...I think it was closer to 24"). The top of the tire was above the fender lip and, as your pictures attest, this is not the way the car was intended to be. I guess this is a function of having lived with the car for so long at a low ride height that anything else looked wrong. Now I know that this feeling was backwards.

Leave your adjustments were these are for now and drive the car for awhile. Then check your work and see where you are. I found one handle trick was the cut a series of short wooden sticks to measure the factory suspension ride height location. In my case I used 165, 170 and 175mm lengths. Fairly easy to stick these under the measuring points...I could guesstimate the 5mm between these lengths.

BTW:
Your car looks like it will be just about "right" after a slight bit more settling.

Regards,
SteveCo in St. John's



Regards,
SteveCo

Chuck Z

Guess the problem is, I have the 95 GTS and by these measurements appears to have settled a bit. Granted, the 95 GTS measures 25.5" in the front and 25" in the rear (rear is the same as the 93). I will drive it for a while (after getting it aligned of course) and see if it settles any. Thanks to everyone who responded.

Earl Gillstrom

Don't forget the gas. The car will be considerably different, front and back with the gas tank empty. Do your checks with the gas tank full.

Chuck Z

Good point. Just so happens the pictures were taken right after I filled it up with gas. I'll have to remember to fill it up b/f I check it again.

dr bob

Random thoughts:

I think that in that original post with the target fender lip heights, I mentioned that the dimensions were for estimating only. At the time I did the adjustment, I had almost-new tires, something to consider whether the measurement is made with a yardstick at the fender or with the calibrated wire gauges I used back then. Did what SteveCo mentioned, used some precision coat-hanger stock to make a series of sticks to stuff under there as go/no-go gauges.


Biggest factor is settling the front suspension seems to be some hard cornering and braking. The car design fights you, with the stiff anti-roll bars and all the anti-dive geometry.

I suspect that a few 100-mile "settling" jaunts will chew some rubber up if your height was way off before and the toe was set correctly while at the lower height. Might be worth at least a string check, if not the laser-level method of verifying the toe-in before you munch some expensive tires. Earl has a pretty good DIY toe-check method IIRC. I have a couple laser-levels and made some brackets that get strapped to the wheel. Tape measure and calculator after that, takes less than 30 mins total time after I find all the pieces and get them to the car. Thanks for trig lesson on that, Earl!


Anyway-- Back to work for a while. I'm in Houston for a couple weeks, and ned to find some time to rally the locals for an evening brew-n-bull session.