larry47us

I should have done this before, but for whatever reason, I was just waiting. I guess that I never realized how much that camber on the rear wheels wears the inside of the tires. It rained a few weeks ago, and I hit the tollway, accelerating from 40 mph at the bottom of the ramp.

The car was hydroplaning like CRAZY. It was then that I realized that I was the one that was crazy, having waited so long to buy new tires. Spent some time researching tires on Rennlist, and came to the conclusion that the Sumitomo HTR III Z was the way to go. My wrench buys from Tire Rack, and sells to me at the same price that they would sell to me (he keeps the additional discount.)

Then, he'll replace a bad upper strut bearing on the driver's side, wash my wheels, mount and balance the new tires, and do an alignment and a full corner balance. I have no way of knowing how far out the corner balance is, and somewhere between $250 and $400 is a lot of money for an alignment, but with the corner balance, it will depend on how far it's out of kilter, and how much time he needs to spend on the alignment and CB.

Any comments on having a corner balance done on a car? Is there any way to tell if it is out of corner balance just by driving the car? I'm willing to bet that on a AWD car, a corner balance is more critical than on a 2WD car. Is that right?

larry

Page

I believe unless you have adjustable suspension, i.e. coil-overs there is no option to corner balance stock suspension. (maybe by shims..)

Corner balance on cars with coils-overs is a greet way to dial in weight distribution 50 / 50.

Get a proper wheel alignment by the shop. If you want to try and dial out some of the negative rear camber get some rear upper adjustable control links or gt3 cup adjustable lower control arms.

blockhed

stock 996tt cannot be corner balanced, as far as I know a person with great knowledge can align the car and be almost within a corner balance.

nick49

I was going to mention that I did't think you had coil over shocks so corner balancing isn't feasable. I don't know if corner balancing is even necessary in the least on a street car. An occasional passenger, any weight carried in the rear or front and full tank fuel vs. 1/4 tank will negate the effects of CB.

Another thing, unless you are driving at 10/10ths or even 8/10ths on a relatively smooth surface (race track) I don't think corner balancing is of any benefit. If you want better handling, lower the c of G with shorter sports springs and some adjustable sways.

GL Larry.

LVDell

Larry, is the suspension on your Turbo stock? If aftermarket, what shock/springs do you have?

As others have said, if it's the stock suspension then you cannot CB the car. You need adjustable shocks like the GT3 has. Here is a picture of what an adjustable shock looks like. You can see the threads allowing for vertical adjustment of ride height.

Macster

As others have pointed out there is no ride height adjustment for the stock 996 Turbo and therefore load balancing can't be done.

If your 'wrench' believes otherwise I think you need to upgrade to someone who knows these cars better.

A stock Turbo with a good alignment is a very sweet handling car and a pleasure to drive, across town or across country.

Be sure the car is empty of junk (weight) and the gas tank is full before you have the car aligned.

Also, these cars come with PSM and the steering angle sensor needs to be calibrated as a 'test' ask about how he will calibrate the steering angle sensor. My info is this requires the use of a PST2 (Porsche diagnostics computer). The wheels need to be in the straight ahead position when this is done.

My reference says that there is danger of injury and damage to property due to malfunctions in the PSM control range if the steering angle sensor is not calibrated or calibrated incorrectly. Course, if this is not done you may not know it. You enter a marginal traction situation and the car goes off into the weeds and no one will ever know the PSM was unable to save the situation due an improper calibration.

Sincerely,

Macster.

MechanicalEng

Larry, the 996TT can not be corner balanced unless it has aftermarket adjustable coilovers...

larry47us

As far as I know, I have a stock suspension. I had initially asked the question about a CB, but then thought twice about it, not just from a cost point of view, but if it really made any sense considering that I don't track the car.

Now that the consensus is that a stock suspension CAN'T be CB'd, I guess that I'll tell my wrench that I really don't want a CB done after all, and just go with a standard alignment. Thanks for the comments, guys. The next round is on me.

larry

Kevinmacd

Don't buy the Sumitomos, but get the Hankooks ventus 12 evo, they have the same load rating as the N spec tires Sumos don't They are as close you will come to an N spec tire. I just bought a set of 295-30-18 for the rear 449 delivered from online tires. They beat Tire Rack.
Here is a comparison test:
http://www.caranddriver.com/reviews/...12_evo_page_10

Renn 951

Good info! A set of practically new Ventus 12 evo's was on the 996tt I just picked up last week. I haven't had a chance to really push them yet, but the previous owner said he researched tire choices extensively before opting for these. The C&D comparo seems to back that up; now I just need to get the car out in the country where I can push it a bit more and see for myself!

SSST

Good post. The Hankook sounds like a heck of a tire for the money. I have an almost new set of PS2's, but think I will try the Hankooks when they wear out. I don't want to give up performance and comfort, but it doesn't sound like there are many trade-offs at half the price.

doubleurx

I just put on the Kumho Ecsta XS and they are a huge improvement over the Conti sport Contacts. They are pricier than the V12's, but in dry performance, I am fairly confident they are better. They are quiet and the dry traction transformed the handling of my car. Tires will always be the number one, best performance mod you can do to a car. They effect overall performance more than any power, brake or suspension upgrade you can possibly do. Everything relies on the tires.

blockhed

I love my XS' tires.

doubleurx

Thanks for the previous heads up. You are the one that turned me onto these.

SSST

How is wet performance on the XS. I live in Houston so that's important.