Jadz928

I think we'll cut you some slack.... given you just drove 2000+ miles.

145mm = 25" at fender for you. That means I should be around 155/158mm @ 25 1/2", and mine are rubbing. 160mm may get you close to not rubbing.

I will check the real ride height spec on the 87 tomorrow and post here to give you a x-reference.

FWIW, I just had the new Bilsteins installed on the 84, and thought the new ride height looked too high. Just measured the fender at 26", which would equate to somewhere around 170mm. Too high.

JPTL

Chris, you're right....fender measurements are a rough reference, and can vary from car to car. Crawling under the car and doing it the way you're doing it is the way to go. Nothing worse than second guessing your thoroughness in getting the ride height right - particularly after an alignment.
BTW, where in Loudon are you? Near Landsdowne?

Jadz928

Same here, right along the center. Much agree, fenders is not the best reference.
Perl is at the garage at work. I will get you some better numbers tomorrow.

Jadz928

As Dr. Bob would say... for those of you playing along at home.

BeerFish

J.P., He says Western Loudoun, so I assume he is closer to Summit Point.

JPTL

I was thinking about swinging by and snagging those wheels and maybe the drilled rotors

dr bob

I played with ride height a lot soon after I got the car. Started out sagged pretty low at 140mm in front. I think I foolishly posted some fender lip heights way back when. As you see they are literally a yardstick measurement, intended to let you see if in fact the car has sagged a lot. Don't adjust to them.

The factory numbers assume that you have original tires and wheels installed. Most of us don't. They also assume that the tires are new, and most aren't. There's probably some consideration for having new shocks too so the car will sit higher.

The ultimate goal is to have the front lower control arm and the tie rod as close to level as practical. This allows for a minimum amount of toe change as the suspension moves from rest. In the meanwhile, my car needs to survive over the roads I drive. SoCal roads ate pretty free of potholes compared to other places. We have some pretty significant rain gutters at a few intersections, and there are speed bumps on some streets and certainly in a lot of parking lots. Front spoiler has to clear all of them without slowing to a crawl. My driveway apron is another test for front clearance. I'm sure you all have your own obstacles to manage. So I set the height on the car exactly as the WSM recommends, middle of the range. It rides and handles well, tire wear is immensely improved, and the original front spoiler and undertrays are still in great shape. Would it be OK 3/4" or 20mm lower in front, at the bottom of the factory recommended range? Probably. That would mean I would have to slow down a lot more at the bottom of my hill to survive the rain gutter. The only downside is the comment stream when it's parked next to other 928's that have sagged significantly. Looks like a 4x4 in comparison they say. But I do get 3-4x the front tire life, brakes last longer since I don't slow down and swerve so often, etc. Plus the original height numebsra actually have the car a little nose-high, different from the raked forward look that many seem to have.

Just some thoughts to consider.

dr bob

Cut from welding rod. Coat hanger wire is an acceptable substitute.

Jadz928

Dr Bob,
Neat idea. Noticed your "front normal" should read "front max".

dr bob

That's "front normal" and "front max" in the WSM, and is "front normal" for my car. I know they allow for some used spring sag and also the 20mm adjustment allowance; Those are reflected in the "front min" at 170mm. You can see in my avatar pic that there's room at the top of the tire to inspect the wheel well liners and spring/shock for cleanliness.

Whatever ride height you "settle on" to use, make a set of wire gauges that exactly reflect that height. This 'target height' is important to determine immediately after (before you drive anywhere!) you get an alignment done. A regular height inspection after that will warn you of impending tire-wear doom since toe changes as the ride height changes. Remember also that the farther your target height is from 190mm original height, the more pronounced the toe change will be for any given height change. You will find that you are making little adjustments to maintain your target height (and alignment settings) a couple times a year. You'll need to compensate for tire wear at the same times, so a tread depth gauge is also a tool you should have in your arsenal. Along with the tire pressure gauge. This is all logbook stuff, by the way.

Jadz928

Chris,
Got you some real numbers...

87 Perl (Pictured below)
FL-145
FR-140
RL-185
RR-180

84 Chewy (Just had new Bilsteins installed, shop set ride height)
FL-155
FR-160
RL-203
RR-210

Keep in mind both fronts are rubbing, just FR is just more noticable

I have a toe-out situation on the FR. It tracks noticably to the right. This could also affect wheel rubbing.

Looks like I have some work to do too...

G Man

I am also in the process of setting my ride height back to factory specs. Thanks 928 Specialists for the spanner! What is the best place to access the front measuring point from? I can't even see it from the front of the car. This is being done on the garage floor not a lift. Also, when at the alignment shop is it necessary for the rack to be pinned with the centering tool. When I had my last alignment done they did not pin the rack when adjusting the toe.

Jadz928

The measurement points is shown in on the first page of the this post. It's easier to get to from the back of the wheels. Generally, it's needs to be on the ground. A lift is not neccessary.

I'm not sure about the pinning...

Jadz928

FWIW, the local Porsche dealership said the alignment does take 3 hours, but the only charge the customer $125. If this is true, then you know it doesn't take 3 hours.

None-the-less, they also said I needed to replace all 4 front eccentrics because they were "stripped". Quoted me $540 for the job, plus $125 for the alignment. I pulled the car and had it done elsewhere. And guess what?... my eccentrics were just fine. Vondelier did the alignment for $70.

BTW, there a lot of good info ou there for DIY 928 alignments.

JPTL

Chris,
I'm sorry to hear that you're looking at $300 for an alignment. That is an excessive charge at any shop.
I was recommending Funktion based on their capabilities @ Michael's "IIRC" $150 rate.
I shouldn't have weighed in w/out actually having had an alignment done by these guys at $150.
Sorry to have steered you wrong (no pun intended).
I will be curious to see what takes 3 hours, however.