-----Original Message-----
From: Tom Cloutier [mailto:tomasc@pacbell.net]
Sent: Friday, February 08, 2002 1:17 AM
To: 928
Subject: [928] front end alignment


The front tires on my 1989 S4 are starting to wear a little unevenly, so I guess it's probably time for an alignment. Do other listers generally go with the factory settings or are there other settings that have been found to provide better handling with no adverse side effects?

Thanks for the help.

Tom Cloutier
1989 S4, Scavenger exhaust system, Monster merge, Dastek
www.ThePowerBroker.net
====================

Jay Kempf wrote:

Tom,

I have been finding that my car is more stable in transitions with more camber and real close to no toe on any corner. If anything the fronts are a bit toed out. I am running near -1.25 and near -1.5 rear. My set up is basically standard ride height for a 79 although the front looks high with the following wheel tire combo: Design 90 7.5/16 front with 225/45 and 9/16 rear with 245/45 Kumho Ecsta 712. The car rocks. Ask the trackmeister how it handles. Oh I also have an old set of Koni reds on the back that came with the car. Tire wear has been near perfect with this setup but I have an inner tie rod going on one side that I thin is the cause of a tiny bit of scalloping on the left front. I will change that this spring. I got two seasons out of these tires. And no I didn't take it to the alignment store for this. I am all cheap lasers and home made plumb bobs :)

Pretty much everyone I know that has gone big on camber has been happy. Oh yeah, this is a street car if you were wondering, but it is driven by a certified loony at least when it's not stuck behind the snow bank.

North Jay
79 US 5ish speed.

================

Hey Tom, et al,

What Jay said - minimize the toe in and maximize the camber for an enhanced cornering experience without hurting your highway tracking or adversely affecting your tire wear (much). Just checked the Winter 210's for wear (been on since November) and there's only a modest difference inside tread wear to outside tread and I'm running with -3.1 degrees of camber (admittedly a bit much for street, but WONDERFUL on track - the big fat Hoosiers just love it). Toe-in is a main contributor to tread wear, and with it neutral, well...

Please note the above relates to FRONT END alignment - the back end still needs toe-in to keep it tracking accurately behind the front when heading down the highway (but you can still max out the camber for help in cornering).

Hope this helps . . .

Randy Faunce
sharkfest@mac.com
http://homepage.mac.com/on_track

========

James Wehl wrote:

> Yeah
> I've finally got the 4speed in the Car
> Found a limited slip diff and got a 3,500 rpm torque converter in
>
> We need to do a new suspension setup and wheel alignment. I think Stuart
> told me what the best setup was. I lost the info though
> What the best setup.
> Think it was moving the kingpin back or something??
> Use on Track and Strip
>
> Jim
> http://members.rennlist.com/1jim928/

============

Jim,

Here's a post from me from last Spring that kind of summarizes a number of alignment discussions.

I set it according to the "plan" for most of the Summer track season. I was satisfied with the results. Not too must camber that it wears my
street tires and really good handling.

Glen

>>>>>>

Just got finished with some substantial suspension work. (I'm gonna post in full about that another day.) New stiffer springs and shocks are in there. I plan to run Pilot Sport Cups or Hoosiers, maybe Kumhos.  Stock (7") widths all around. Maybe more than one type during the DE season. I'll be doing mostly street driving, but I'm aiming to do well at the track. :)

Now it's time to get it aligned. Here's what I'm planning:

FRONT REAR
Ride height: 155 mm 155 mm
Caster: 4 deg Not applicable
Camber: -1.5 deg -1.5 deg
Toe: 10 sec 10 sec (each)

For reference, here are some other numbers:

Stock for '80:
Ride height: 190 mm 173 mm
Caster: 3.5 deg Not applicable
Camber: -30 sec -40 sec
Toe: 15 sec 10 sec (each)

928 GT Cup - (info from Mr. Crumb)
Ride height: 90 mm 90 mm
Caster: 5 deg Not applicable
Camber: -2 deg 10 sec -2 deg 5 sec
Toe: 5 sec 12 sec (each)

Prof. Fiegl letter - (info from Mr. Crumb)
Ride height: Not given (or maybe my German is lacking)
Caster: "max" Not applicable
Camber: -1 deg 55 sec -1 deg 30 sec for Goodyear bias-ply tires
-3 deg 20 sec -3 deg for Dunlop radial tires
(tire types from notes on scan)
Toe: 5 sec 30 sec "total" (I think this means 15 each)

From the list these have cambers have been suggested:

-3 degrees camber (Randy Faunce) (is that front and back?)
-1.5 front and -1.2 back (John Veninger GT)
-1.5 front and -2 back (Mark Kibort for track "Early")
-1.2 front and -1.5 back (Mark Kibort for dual use "Early")

These numbers cover both early and late suspensions, so there may be
some discontinuity there.

For those wondering, a "second" is 1/60 of a degree. Toe is measured relatively between wheels on the front and individually to the centerline on the rear.

Here's my questions:

whaddaya think of the plan for my car?

Why does the tech spec book list the front at 17mm higher? Are even numbers running a bit nose down? For what it's worth, a level put along the trim strip on my car shows almost perfectly level. (So that's what that's for!)

Any additions or changes to the reference values?

Glen
'80 Euro S

-----

Local shop just installed my new tires and did a "specialty alignment" - total cost $206 ($110 for the alignment).

Manager claimed he used to "make a living working on Porsche" and his assistant claimed to be a former 944 owner.

Still, I provided him the shop manual and Wally Plumley's posting stressing the importance of settling the car correctly and keeping weight on the wheels...

They used a Hunter machine but I'm wondering about these numbers they showed post alignment.

Camber: -1.0 (Left front), -0.7 (Right front)
Caster: 5.3 (left front), 6.2 (Right front) *** isn't that out of spec still???
Toe: +0.13 (left front), +0.13 (right front)

Camber: -0.7 left rear, -0.7 right rear
Toe: +0.18 left rear, +0.12 right rear

The front's toe was out and off the chart prior to ... but the caster numbers haven't changed at all (pre to post alignment).

Do I need to be concerned by any of these numbers? He gave me a 6-month warranty on the alignment.

Ride's nice - I like the new Sumi tires.

Mike
------
Mike,

The hunter unit is considered the best.
I had my 86S aligned and corner balanced last week after new springs were installed at a Porsche suspension specialist shop.
My measurements are as follows:

Front left camber -0.39 FL Caster 4.47
Front right camber -0.35 FR Caster 4.56
cross camber -0.04 crosss caster 0.09

Front left toe 0.16
Front right toe 0.16
Total toe 0.32
Set back -0.11

Rear left camber -0.71
Rear right camber -0.62
Rear left toe 0.17
Rear right toe 0.18
Total toe 0.35
Thrust angle -0.01

Rich
-------
Mike:
Front:
Camber seems very aggressive for the front - plus they are not even close to being even. You may want these re-checked. I've posted the specs for the 928 below.

The caster figures are off, but too much caster shouldn't hurt much (this is setting that induces the steering wheel to re-center itself after a turn.) The caster figures should at least be equal from side-to-side.

Toe seems fine - this is the most critical measure for the 928's alignment. I have to ask... did they lift the car?

Rear:
Camber is out of spec but even. Depending on your driving style, this setting may suit you. I'm running -1.2 camber IIRC. At least they are even from side to side unlike the front.

Toe is out of spec for left rear. Right rear is in spec, but could be better. With the the two toes not being equal, you have a condition called thrust angle. Basically the leading edge of the left tire is pointing in more than the right tire. This is going to cause the entire back end to push to the right. I had this but on a much worse scale and when I hit bumps, I could feel the rear end wanting to shift directions. Your's isn't that bad, but they should have been able to make both sides even so you have zero thrust angle.

To sum up, if they did not lift the car, you got an okay alignment (only because the toe is in spec). Front Camber is VERY aggressive and way off from side to side and should not be this way unless you asked for it. I'd probably go back and tell them to re-do the whole thing and bring it into spec, or at least show you why they can't bring it into spec (those eccentrics will only move so far).
Andrew Olson
------
The caster is hard to get below 5, but the difference is out of spec and may cause the car to pull. Did they comment that 6.2 was as low as they could get the right side? If that was so, I would have set the other side up to 6.

Toe difference in the rear can cause dog-tracking.

Why is the camber high and different right to left in front?

How does the car track down the road?
__________________
Bill