I will be getting some coilovers with front pillow ball top mounts next week, it will be my last modification and I wonder what will be a good Fast Road and light Track Day (visit only once every 6 months) alignment settings.

2000 996tt

Yokohama Ad08 tires (f34psi r38psi) stock hollow 225/40/18 , 295/30/18
DV
100 cell exh.
1.1 bar remap
stock air box
on stock suspension
stock dog bones (everything else)

I have spent no less than 3 hours reading all the alignment posts on here including the sticky and now I am completely lost. I know this is purely my own problem

I have learnt that I can try the following settings

I learnt that front and rear camber have to be within -0.4

Front:
-2.3 camber
0 toe
+7.5 degrees caster (as much as poss)

Rear:
-1.9 camber
0.1 toe in

Please recommend an alignment setting and ride height that can get close to my goal. My dream goal is to remove the the stock understeering tendency but still retain a very neutral handling characteristics. I want it to be like it is driven on rails.

Thanks a lot

 

Your advice on ride height and alignment would be truly appreciated.

 

While their is a **** ton of info here, the percentage of track drivers here is relatively low. Their are several really smart ones here for sure. I would checkout renntrack under the 996 turbo section. Read there a bit and you may find an answer without even needing to post a thread. I am by no means an expert.

The bottom line is what works for you does not necessarily work for others. If you can achieve GT2 alignment settings, that is a good starting point. From there you can usually tweak toe and camber alone to get fine tuned to your driving style. To get these settings you may need additional hardware.

 

These are my alignment settings. This is more of a track / occasional street set up for RWD but will work well for AWD also. For more of a street set up I'd back the camber numbers down a little to something like -2.3F and -1.8R or maybe even a little less. In most cases you'll max out the front and set rear about 1/2 deg less. Without adjustable LCAs you probably won't even be able to get that much unless you are at a very low ride height. If I were you I'd run a touch of +toe in the front (as opposed to 0 or neg) for straight line stability. With all the rubber in the suspension, your front end will naturally toe out as soon as you load up the front end under braking. Caster is non adjustable unless you run adjustable caster pucks. Default GT2 alignment setting will work just fine for the street if you don't want to reinvent the wheel.

Front camber: -2.83deg
Front toe: +0.03' per side (+0.06' total)
Rear camber: -2.25deg
Rear toe: +0.17' per side (+0.34' total)
Ride height: Front 102mm, 125mm rear
Tires: 245/40/18 and 305/35/18

 

Thanks for your recommendation. I have in fact read through all 10 pages on renntrack. The problem is I really cant go as low as a GT2 because of clearance issue at my car park. Can I have my ride height set half way between stock and the GT2 while keeping all the GT2's alignments?

 

Thanks pwdrhound for your advice. I have definitely learned something from you. I didnt know that with my rubber bushings that toe out will come naturally during braking. I do trial brake whenever I can apply it so I guess that's important for me to know while trying to achieve a suitable alignment for myself.

For caster, without caster pucks, can I still ask the alignment shop to try to get as much positive caster as possible? Or is it really impossible?

In which order should the shop alignment? height -> camber -> toe -> ??? (I am just trying to illustrate my question)

I should try asking the shop to set
camber -2.3F and -1.8R
F toe +0.03' per side and R +0.17' per side

Lastly, is there a relative ride height difference that I should keep between the front and rear? Obviously, the front has to be lower than the rear due to the driving dynamics of our cars.

thanks a lot again for the advice

 

You're welcome. You'd be surprised how much toe change you get with the stock rubber bushings compressing on the lower control arms, especially in the rear which is heavier and and subject to a lot of torque. The rubber bushing can easily compress 1/8" or more in either direction so you can imagine what that does to your toe. The toe moving around is mainly what kills the inside of the rear tires. I can tell you that if you lock down your toe in the rear by installing monoballs and solid thrust arm bushings (caster pucks) in the LCAs, your tire wear in the rear will drastically improve. Added NVH is negligible. I'd highly recommend that. Leave the stock dog bones in the rear. They are the same ones used even on the 996Cups so no need to mess with that. Your should have plenty of camber adjustment in the stock camber eccentrics to get you -1.8 in the rear unless you go super low. Depending on how low you go, you may need adjustable toe arms and those are a great upgrade since they get rid of the rubber in the factory toe arms. The adjustable toe arms will not add any NVH.

The front I'd leave alone for a mainly street car. If anything, I'd install the adjustable GT3 arms if you need more camber at some point. There is nothing you can do to adjust caster without adding adjustable thrust arm bushing to the LCAs.

Every shop has their method of doing an alignment but you should normally set your desired ride height, check the corner weights to see if you are in the ballpark and then set the alignment. After that you want to double check the corner weights and fine tune the alignment if necessary. Make sure they disconnect the sway bars when they are doing the alignment to eliminate any preload on the suspension. I am assuming you have adjustable drop links, if not, you will need those. The factory drop links are very weak and non adjustable.

I would have you shop set the car up with about a 20-25mm height difference measured front to rear at the specified factory suspension locations (obviously the rear being the higher of the two). Finally I'd get an adjustable rear sway bar to give you the ability to dial in the handling to your liking. The 996GT3 sway is great.

Best of luck with everything...

 

Thank you so much, pwdrhound! I have learned a awful lot here and I am sure this information will help others as well.

Your advice and info are truly appreciated.