Rob Edwards

After several iterations of adjusting ride heights the last few weeks, and changing tie rods yesterday, I went to the local Sears in Costa Mesa this morning to get a suspension, after verifying that they have a Hunter DSP-400 (actually, they have 4 of them). I spoke with a manager about not lifting the car, and they got me right in on the alignment rack. The tech that did the car was extremely friendly, and let me watch the whole process. There was a tense moment at first when he got under the rear end and had this sort of 'WTF' look on his face, but went back to the Hunter's display and there were actually annotated pics of a 928 suspension pointing to what adjusts what. Impressive.

A scan of the results is below, with a link if the damn picture is too small to be legible:



This is with ride heights as follows, after 20 miles of driving beforehand:
LF: 169mm
RF: 171mm
LR: 172mm
RR 172mm

I like how much toe I had .... Any comments on the still out-of-spec caster?


FWIW, with new tie rods, Carl's solid bushings, and a re-sealed PS pump, the steering feels GREAT- now I just need to R&R the shocks and springs and go back for another warranty alignment......

EDIT: 'Cause I can't read...- REadout says '78-'90...

dr bob

Rob--

How does it drive now? And did you manage to get enough miles in to settle the suspension before it went on the rack? I keep a close eye on ride height, especially around the alignment time. Measure, get it aligned, drive it home and measure again. If there's any serious change in height, it goes back for another toe-in check. I've made two minor height adjustments since the car was aligned a year ago. So far so good on front wear.

Also-- What was the solution to the PS pump noise following the MM session?

cfc928gt

Looks good to me! The caster is barely out of spec and equal side to side so I wouldn't worry about it. They say better at the high end for a better centering feel anyhow. How many miles on the GT? What surprises me is how little camber you have on your rear wheels. Seems like as the cars get older the camber goes more and more negative. My left rear is now -1.3 and can't be moved more positive and I only have 70K miles on my '89 GT. How do you like the solid steering rack mounts? I had a friend talk me out of the solid mounts because he thought there would be too much road harshness transmitted back through the steering wheel...

Rob Edwards

Bob-

The car drives great now, though honestly I can't say whether it's more the alignment or the fact that there are new motor mounts in there. The steering is fantastic, nice turn in, smooth as silk. I really need to go on a real drive now, vs tiptoeing around before the alignment, and having to go straight home post-alignment....

I put about 15 miles on the car before the alignment, but 5 of that was 4 laps around the UCI campus, each lap of which has about 10 of the most driver-unfriendly speed bumps anywhere, so I hope that that was enough. I took a ride height as soon as I got home (so essentially a full tank of gas, all tools and spare in back, and I put the original muffler back on yesterday), so I have a data point to check against in the future.

RE: the power steering pump noise, I got a Rennbay kit and pulled the pump and re-sealed it. I got Jenn to help turn the wheel while filling, and the pump is now silent!

Most of this was probably unnecessary, but I wanted to clean, and there was still a dribble from the reservoir to 'cooler' PS hose, so I ended up draining the radiator (so I can pull the upper rad hose at the rad, so that the fan shroud can easily be removed), dropping the alternator, and removing the alternator cassette and PS pump. The pump re-seal literally took 30 minutes, and half of that was fiddling with the circlip on the pump shaft. I finally gave up on my snap ring pliers and used a small screwdriver, just as shown in the video. The whole thing took about 4 hours start to finish, but most of that was degreasing and sonicating (See pic below)

Also- If you buy a PS pump re-seal pump, splurge the $5 and get the trick rubber/metal o-rings for the high-pressure output line from the pump. They look like a better sealing solution than the copper o-rings, though time will tell.

EDIT: When it's big enough to be visible, the picture below shows gleaming aluminum Porsche part **** in all its glory. Free beer to anyone who can explain (in kindergarten level instructions) how I can post larger photos! I have a webhosting server- how is it done?

Rob Edwards

cfc (Sorry, can't find your first name!)

My '90 GT has 108,300 as of this morning. The springs (3-brown) and the front Boge reds are original, the rears were replaced with Boge Gray's about 50K ago, so I suspect the ride is a little floatier than it could be, but the steering now is great, it just feels SOLID. (But hell, the rack was replaced by the PO 20K miles ago, the tie rods are new, the fluid's flushed, and the pump is re-sealed- it ought to feel solid......). The roads around here are in pretty good shape, so I can't really comment on whether the solid bushings transmit too much vibration. I will say that the old bushings were totally oil-soaked and shot (Bob will attest), so anything would have been an improvement.

Now all I have to do is actually drive the darn thing enough, and then ride along with some other owners to get my brain calibrated for where my car falls in the spectrum of 928 road feel......

Airflite40

to post pics, you can simply type [*img]http://www.linktoyour.com/image.jpg[/*img]

except remove the *'s


here is your pic

Rob Edwards

Hmm, just like in all Vbulletin-driven forums (fora?). Let's try:



EDIT: Well, I can't seem to get the image to appear. Guess I'm doomed to small-picture syndrome....

EDIT #2:

Hey, I'm not doomed. Cool!

Airflite40

no rob, youre not doomed. for some reason, there is a little extra crap at the end of your links to your pictures. the links still work, but you cant put them in img brackets since the link is not pointing directly to the image. just remove the "?uniq=3ni78a" after .jpg in your link and try again.

whitefox

Don't try to post that picture, its way too big.

EDIT: too late

Airflite40

nah. its fine. get a bigger monitor

whitefox

I would but last time I checked they didn't sell 50" computer monitors.

Rob Edwards

Sorry, I'll try to keep them to 8x6 from here on out.

cfc928gt

Rob, thanks for the opinion on the solid mounts. Replacing mine with the rubber ones made such a difference that I wish I had opted for the solid ones even if it meant a little vibration. It ended my tramlining. Enjoy the car.

Fred Clark
'89 GT

Rob Edwards

Fred-

If (big 'if') your current rack bushings are not peened in place, you could easily change them out from below. For what it's worth, should anyone order them and go to install them, don't freak out if/when you can't push the rack mounting bolts all the way thru the bushing. It's a really tight fit, but enough of the bolt goes through that you can get the bolt started, and it'll pull itself up on the bolt while ratcheting- you end up with zero lateral slop.

Sorry if I sound like some ad for Carl's buishings, I don't mean to. I'm just happy with the product.

Rob Edwards

So after having driven the car an additional 50 miles yesterday, I remeasured the ride height all around. Compared to Monday's reading, the front dropped another 6mm on the left, 5 mm on the right. The rears are +/- the same.

Data: 9/4: LF: 169mm 9/7: LF: 163mm
RF: 171mm RF: 166mm
LR: 172mm LR: 172mm
RR 172mm RR: 173mm


So, suspension/alignment gurus: Is another 5 mm drop going to wipe out my front tires rapidly? Captain Earl's page says an additional 1/4" of settling will remove all toe-in and wipe the tires in 2500 miles. I've got 5 mm, or just about 1/4".....

So it seems that 20 miles of driving, even with lots of speed bumps, isn't enough to settle my beast completely. Do I head back to Sears now, or crank the front shock collars 3 turns?