SJB993

For some time now I've not been entirely happy with the handling of my car. I've read many, many posts about the improvement to be had by fitting decent shocks, but I have to say I was a little sceptical about the shocks alone making a substantial difference. I thought it more likely that the greatest improvement was gained by having the alignment reset after the shocks had been fitted (i.e. the alignment may have been off to start with).

Before I decided on whether or not to spend a lot of money on the new shocks, I decided I would have my alignment reset - I did notice a very slight improvement, but I'm still not happy with the handling.

Yesterday I had my mechanic test drive the car, and he agreed the steering felt "skittish" to use his word, and said that new shocks would sort it out. So, I've bitten the bullet and ordered some Bilstein HDs from Gert (the car already has factory fitted M030 springs, so I'm sticking with those). I'll obviously get the alignment reset after the installation of the shocks.

Now to my question .....

When I had the alignment reset back in January I was given a computer print out showing the before and after readings. Just about everything was originally out of tolerance, and all but one were measured to be back within tolerance after the work.

The alignment was done at my local OPC (the independent Porsche Specialst who normally does all my work doesn't have the alignment gear), and they told me that they couldn't get one setting in tolerance. That setting is shown on the computer print out as "Front Axle Castor 10deg left".The inital measurement was 4deg44min, and the target is 5deg20min +/- 30min - because they couldn't adjust it, it remained at 4deg44min. The same measurement on the right side was OK.

What would cause them to be unable to adjust this?

geolab

Hi Steve,
With all my do respect, tell the ........... not to touch your car.
The caster is the easiest to adjust on the 993. And if he told you that crap its that he doesn't know how to really adjust the suspension.
The caster is adjusted by a bolt under the wheel hub carrier, called the caster eccentric. part# 993.341.455.00
Please do me a favour and read the suspension section in the workshop manual. This way you will be 100% aware of how things should be done by porsche, and slam the guy who tries to bullzhit you.
The reading will take 5 minutes, and it really helps.

Worst of all? If we supose that he knows how to do it and If he reaaally cannot get the wheel castor to 5*20', means that something in the suspension is not straight, thus NOT within the norms. AND HE SHOULD INFORM YOU OF THIS FACT.

Red rooster

Steve,

Just about the most important point is what type of aligner is being used.

The factory Beissparth is the best as it remebers the alignment as the car is being lifted for adjustment . Most other stuff looses track .
The 911 is probably the most difficult car out there for alignment as it combines a wide track with a short wheelbase. Thats why the set up numbers are so tight compared to everything else.
There is also a hidden little trick to actually arrange the nearside/offside numbers to be slightly different.
Thats done to hide NS pull down the edge of RHD roads !

I would have an ask around to find an operator who has real talent in this area.

I know one UK company who are very good. PM me if you are interested.

Good luck

Geoff

clinchy993

Steve ,As you are local to Windsor ,why not try Tognolia Engineering at Datchet 01753 545053

I have seen nothing but praise for him on geometery set ups on the UK forums

AS soon as i fit my new shocks and springs ,Its off to him for set up

SJB993

Thanks Clinchy993.

I know of Tognola, in fact my car has been serviced there by a previous owner. I must admit, I didn't think of them. I'll give them a call. Also within striking distance are JZM and Autofarm, but I don't have any experience of either of them. I use my (really) local specialist, Ray Northway, for all my work - but he doesn't have the alignment gear (yet).

What I was really trying to establish with my post is what could cause OPC Reading to be unable to bring that particular setting within tolerance i.e. does it indicate a problem with some part or other (although I would have expected them to point it out to me if that was the case).

Thanks.

SwissCarrera

Hi Steve, I know Ray uses the OPC in Reading for his alignment, but i have heard good things about Tognola in Datchet so perhaps try them? JZM also have a good rep, but its a bit of a trek from Reading. BTW - my car matchs yours (except mine is a C2) and im a Reading boy as well (cept i dont live there any more) !
I think the general consensus is that the OPC just dont "get" the older cars and your better off taking your car to somewhere that sees plenty of 993s and has a good working knowledge of them.

SJB993

Hi SwissCarrera,

Thanks.

I had my last alignment done at OPC Reading, and was planning to use them again after Ray has fitted the shocks. However, last time I was given a discount due to the age of my car, but when I rang them to book it in again, they said they had withdrawn the discount and wanted £370 to do the job. Needless to say, it won't be going to OPC Reading!

BTW - I'm not actually a "Reading boy" myself. I'm a Mancunian who has been exiled in Reading for the last 30 years! ;o)

Take care.