Alignment (long)

[Sabenza]

I've just installed a set of Gemballa one way-adjustable (bump/rebound) coilovers suspension, which are basically H&R units with H&R springs. I was told by the local porsche specialist (the only one in my area) that no alignment is required for lowering the car by 30mm. This makes me worried because I would like to have it aligned properly and preferably corner balanced. Since the mechanic is not interested in doing the job, I have to take the car to do alignment elsewhere.

Would any professional alignment specialist with the right equipment know how to align a p-car? The problem with these specialist in my area is that they have no experience with p-cars (mine will probably be the first p-car they will lay their hands on) as they are mostly involved with WRX, EVOs, Skylines, Merc, BMWs. They have a "HUNTER" machine. If they do not have the correct parameters to aligh the p-cars, can I use those in this forum-are they sufficient or further parameters are required?

Additionally, can someone explain how to properly measure the ride height so that I can make sure that all four wheels are lowered by 30mm. Then, I can take it to an alignment shop to dial in the GT3 spec. Can someone please verify that this is the GT3 spec:-

Rear Axle:

Camber: -1.50 degrees +/-.10 degrees

Toe: +08' +/- 05' Total Toe +16' +/- 10' axle angle: 0' +/- 10'

Front Axle:

Caster: +8 degrees +/- 3 degrees

Camber: -1 degree +/- .10 degrees

Toe: +03' +/- 03' Total Toe: +05' +/- 05'

I would appreciate your valuable advice on the above. Many thanks.

[Loren]

Any time you change the ride height you are changing the camber - so, yes an alignment is always needed.

Any good quality shop that can to a four wheel alignment and corner balance should be able to handle a coilover suspension.

Why did you choose GT3 specs? What model and year car? 6 speed or Tip? Coupe or Cab? All of these make a difference in what suspension tuning you use.

[Sabenza]

Loren, I have 02 Coupe with Tipronic. It is mostly for street use with maybe 5 to 6 track days per year.

Anyway, I just had the alignment done yesterday. I gave the 2004 GT3 spec (slightly different from those above provided by another person) to the alignment shop, as follows:-

Front axle height: 115 + 5mm (115 to 120mm)

Rear axle height: 128 + 5mm (128 to 133mm)

Front axle:

Toe unpressed (total): +8' +/- 2'

Toe difference at 20¢X lock: -1¢X30' +/- 30'

Camber: -1¢X +/- 5'

Max camber difference, left/right: 10'

Caster: 8¢X +/- 30'

Max caster difference, left/right: 40'

Rear axle:

Toe per wheel: +13' +/- 2'

Max toe difference, left/right: 5'

Camber: -1¢X50' +/- 5'

Max camber difference, left/right: 10'

The alignment shop has a "Hunter" computer alignment machine and surprisingly, the software already has all the details of GT3, X74, ROW & USA M030, ROW & USA std alignment specs. and with detailed built-in instructions of what and how to measure ride height, etc. I compared the computer GT3 data with mine and they are almost identical- within 0.05 degree (3'). So I ended up using theirs.

The alignment and ride height settings took three hours (I was there all along) and they tried to set everything up to within 0.01 of a degree. When I went into the shop, they measured the ride height and the front has 132mm and rear 110mm (what a joke). I guess it takes longer for them to get the job done because this is their first P-car. Anyway, I am very pleased with the job and they charged me US$230 (This is a more expensive package where I can go back and change the spec anytime within one year free of charge).

I cannot find a shop in my area that do corner balancing and I think I'll have to stick with the current settings until I find one.

Do you the 2004 GT3 spec. is suitable and appropriate because i can always go back and ask them to change it.

Many thanks.

[Loren]

Yes, the MY04 GT3 spec is very close to the X74 specs so it should be ok. You are a little low in the front as the spec is 115 mm so expect some scraping on driveways etc. Also, expect that the front brake ducts are going to scrape or be ripped off.

[Sabenza]

Thanks, Loren. I'll try to very careful at driveways. Where are the front brake ducts located?

[Loren]

Thanks, Loren. I'll try to very careful at driveways. Where are the front brake ducts located?

On the front suspension lower arm (see the curved arrow in this pic).

[Sabenza]

Great picture, Loren. I'll check whether the conditions of the duct when I change the tires coz the rear pilot sports are bald. Does anyone have any experience on P-Zero "Corsa"? They seems to be quite popular in my area for p-cars.