If so:

1. what were you running before?
2. what was the biggest difference you noticed?
3. tire wear changes?
4. are you still running it, or did you change to another setup or modify the Kussmaul settings?

I already have a few ideas in mind, but want to hear the group-think.

TIA

 

I'm running pretty close to that. I gave the Kussumaul setup to the shop and we used that as the starting point. And then do some adjustment as the shop owner sees fit. (I leave that up to him as he has a lot of experience setting up cars)

So what we end up was -2.4 up front (instead of -2.5) and -2.5 on the rear. Instead of 0 toe up front, we have a very very slight toe in. I guess for a beginner like me (maybe I'm now intermediate now? ha! got signed off to drive solo now), he wanted more stability instead of all out agility. He was also able to pull 8.3 degree caster, which is slightly more than the 8 degrees that's called out. So again, slightly more stability.

But basically, very close to the Kussumaul setup.

 

Yeah, me too.

All cars I have changed had factory set alignments.

I started with the Kussumaul on my personal GT then tweeked it very slightly over several track days to suit my exact style. I have set other GT3 to the Kussumaul and they happily remain that way to date.

I get a powdering - dusting of tire rubber on the rear wheel splash area, but my tire wear is even and acceptable for the way I drive.

Biggest difference I noticed on all the candidates was that the chassis did not twitch/twist any longer on lift throttle or full throttle application.

 

The settings recommended to Bob Rouleau by Porsche Motorsport‘s Roland Kussmaul for his GT2 running Michelin Pilot cups are very similar to the most common recommended settings for Porsche GT cars used by tuners around Europe today.
Bob post about them in 2002 : ) So the aka “Kussmaul settings” definitely do work and there is no doubt.
But what you have to do is use them as a basis and add your small personal twist taking into account the following:
1. Tires you will use
2. Where you drive the car
3. How you like the car to behave
4. Level of experience
5. Absolute Performance vs. tire longevity
6. Suspension used and ride height

Some standard to-do items regardless of the above points:
-To retain a decent caster and avoid rubbing issues and fix your camber to the correct numbers rotate struts and use shims in the arms.
-Lock the rear toe arms.

Now do tell us more.. : )

 

I think this is what I am going to ask for as a good starting point:

• front struts rotated
• front camber; not to exceed -2.5
• front toe: Kussumal?
• front caster: Kussumal
• rear camber; not to exceed -2.3
• rear toe: Kussumal?
• Install Tarret Toe Locking Plates (link) (or do I need the control arms? (link))

Usage:

• driven to coffee on weekends + 5 track events = ~4kmi/yr
• NT01s
• advanced solo; still learning and picking up seconds

 

You will need the adjustable toe arms if you are going to install the locking plates.

I had the locking plates installed last time the car went in for alignment / setup. (Had the adjustable arms before)

 

OK, thanks. Should I get the 'boots' on the arms? Are there any other nice-to-haves I should get when ordering from Tarret?

 

If they would fit the arms that you are getting, I'd definitely get that.. !!

My plan is to do full alignment once a year (since the GT3 is very sensitive to alignment).. so once a year, I plan to upgrade some more suspension components. ("while at it" kind of thing, since you'd need an alignment after swapping out any components)

This year I did the locking plates (previous owner did the adjustable arms + monoball upper shock mounts already). Next year, probably change out the dog bones (4 upper links).

 

First I cannot exactly comment because of the tires as I don't have them here: (

But assuming they don’t have any weird characteristic soft walls or something else then treating them like a normal R tire MPSC or 888’s with what you are describing and with stock suspension I would do:

Front
Camber 2.5 to 3 depending on what your car will let you have as minimum when you rotate the struts so that you add some shims. It is important to add them because Porsche never had the intention of us using them rotated with such a low camber values and note that the cup lower control arms are longer and delivered with the diagonal control arm set in the eccentric hole vs our cars that use the center one, hence the caster is off and also you wheel will be pushed inside. BTW caster isn’t adjustable by itself..

I think that by using 7mm of shims and with a ride height of 110m (remember ride height affects camber) you 'll end up at around 2.50 degree and your caster will be in spec.

Toe +4m total I don’t like zero or a bit negative toe front but some do like so it’s up to you

Height 110mm

Rear camber 2 to 2.30 (if 315s I like better a closer to 2 value )
Toe total +30m and adjustable arms / eliminating eccentric bolts Don’t over do it with +toe there it has side effects as the less rear toe also has. : )
Height 125mm
A F to R rack of 15mm is ok

I think the above is pretty neutral setup with good turn in nice front bite not loose rear not edgy under braking or accelarating downside is that for lets say highway use it will kill tyres more quickly.

Also remember that after it you can play with your sway bars for fine tuning.

I will let the others who have experience with NT tires correct me if disagree

Have a nice weekend.

 

Tarret has the option to get boots, so figured I'd ask; they must dust boots of some sort I am guessing.

Once or twice a year is my alignment plan; I experienced no alignment drift over my 5 events; I must not be driving it hard enough

Thanks John; this sounds like what I am looking for; a great starting point

Yes, rears are 315s.

Great info, Thanks!

 

After talking with Dell about his experience, and him being familiar with my driving style, this is what we came up with:

Front

• rotate front struts
• front camber; not to exceed -2.5°
• use necessary Porsche shims to adjust front caster to factory setting
• front toe: 0° to 0.05° toe out

Rear

• Install TRG Rear Upper Monoball Kit (link)
• Install Tarett Toe Control Arm Links (link)* No locking plates.
• set rear camber; not to exceed ~ -2.2°
• rear toe: 0° to 0.25° degree toe in

* I wanted to order both from TRG but their toe arms are on backorder, and after comparing them both sets, they look nearly identical (link)

 

I chose specifically to not rotate the front struts, because you lose a lot of caster. I run -2.5 front by shimming alone and don't find any rubbing issues with either 235/40 PS2s or 245/40 NT-01s.

 

Hi looks like a good set up,but 2 questions
Is the toe you quote total toe or each side,and also why did you choose to not get the locking plates for the control arms?
cheers

 

Toe quoted is for each side. I have not had any toe drifting issues, so I didn't feel the need for the locking plates, at least not at this point.

 

Ok great thanks for the info,the rear adjustable arms are the next on my shopping list along with rear shock top mounts