I put 4 new tires on the car (Sumitomo HTR Z III ) so figured I'd let NTB align it to for $89 I think they charged. The guy really took his time on it but it doesn't drive perfect so hoping some of the alignment guru's will give me any feedback on these specs. Depending on what you say I'll decide to take it back and ask for specific changes or I'm open to going somewhere else.

The car is a 96 C2 with PSS9's set to 7 or 8 firmness where 10 is firmest and she sits at ROW height, maybe a smidgeon below. That's one doubt in my mind - if NTB set it to fact specs but the car is obviously modified does that make a difference or not?

Here are the symptoms. And this may not even be alignment. But I thought I had a car once that had this problem and was fixed with an alignment.

Car drives straight at any speed.

However,,,, she starts to wander as speed progresses.

You can notice a little at 60 but by 80+ it increases. Up to 50 she feels rock solid. Cornering, stick around corners is amazing. But I would really like to fix this wandering at speed and have solid straight no wandering handling at 80+

I am not a tracker but am a spirited driver.

 

1) That's not acceptable symmetry in camber settings. I really try to shoot for +/- 0.1 left to right. Also I would keep it simple and set the car up square, i.e. -1.5 on all four corners.

2) Usually like a wee bit more difference in caster side to side. That may be a partial cause for your high speed wandering.

3) IMHO those are bargain tires and may be part of your symptoms.

Now the important stuff:

4) Rake?

5) Kinematic numbers? Did he have the specific tool to set your kinematic alignment? If not, you didn't get a 993 alignment.

6) Front a-arm bushings?

7) Tie rod bushings?

8) Bearings?

 

^ +1

Matt's got all the right observations.

993's are very very sensitive to alignment, even the smallest changes can be the difference between a great driver and something that feels worse than an old buick.

Kinematic Toe would not have been touched, and if anyone doing alignment has changed both toe and camber on the rear (especially camber) then the KT needs to be checked and adjusted accordingly.

 

You got what you paid for. There is no way you can go into your average tire shop, pay $89, and expect a proper alignment on a 993. Heck, you will be lucky they don't do damage to your car somehow.

A proper alignment is in the $hundreds, by people experienced.

 

Mike,

On camber. You say to get them at little closer 1.5 But that is out of spec range. L is at -1.5 and R at -1.1 from what you are saying you would make R match L even though that is farther from spec range, correct?

on caster - when you say wee bit more caster from side to side can you elaborate a little? They both are at 5.7ish? Are you saying make both 5.9? 6.2? 6.5?

BTW the car is new to me. I had an extensive ppi done and nothing in the suspension bushings came up. But of course that doesn't mean it doesn't need some.

The tires are bargain, but they get great reviews. Lots here use them with no issues. You should try a set sometime - they stick like glue.

 

I have PSS10's and ROW ride height and my guy set me to "modified specification" settings.

Front camber is -1.4 to -1.1
Front caster is 3.5 to 4.5 left and 4 to 5 right
Front toe is 0.05 to 0.13
Cross caster is -1.5 to 0.5
Total toe is 0.1 to 0.26
Rear camber is -2 to -1.5
Rear toe is 0.08 to 0.25

He matched toe and camber L vs R to fractions of the tolerance and front caster is 4.0 and 4.9 (L-R)
Car drives like a dream.

Looks like all your guy did was play with the toe and leave everything else out of whack. Even that isn't set right for your suspension.

 

Take it to a shop that knows what they're doing and give them the list from my previous post.

Again, those tires are mediocre. Like your alignment, some things aren't a bargain in the end

Good luck!

 

If you don't track the car, add some front toe (in), that should help.

 

Matt,

If you don't want to share the knowledge with more details that is ok but the put downs / wisecracks are pointless you may as well not reply and save us both the time.

 

This!

Find a shop which KNOWS these cars.

 

You're welcome for my time invested. No wisecrack intended. Good luck with your car.

 

How many miles on the car? What are your actual ride height numbers? Fix that first if needed, and corner balance. Then figure out where you want your alignment numbers- depending on ride height, rear camber may be limited to a minimum of 1.4 degrees or so, which will dictate the range of front camber, which will dictate the range of the other numbers. Have a real alignment done by a shop that works on Porsches generally and 993's specifically.

The shop that did your alignment did a little bit of good on the rear, but it will still need a lot of improvement. The front was made worse.

 

The fact is, you have to start over. You paid some guy $90 to goof up your toe settings and print you out some specs.

A bit of time searching here, would show you that REAL alignments on 993's take quite a bit of work, and that not just anyone can or, more importantly sHOULD, touch them.

 

Matt, thank you for your time invested.


Jimbo, 50,000 miles. It had a corner balance when the car was lowered. I don't know the exact ride height or how to measure that. I'm not against doing an all fresh alignment at a 993 shop and even a fresh corner balance in fact I've been leaning that way, but I havn't had the car that long and I'm looking for new rims at the moment so I would PREFER to wait until those are on the car as it seems that could make a difference.

You know, I'm really trying to learn as much as I can about the car in general and the why's. Rather than the take it in and 'just make it right' stance. So I am grateful to the knowledge shared on this site. I realize that for the vets the newbie questions must seem tiresome, but we are trying to learn. We have such a range of members from avid diy'ers to racers, master engine rebuilders - it really is a great place. I think for you vets for the most part are really patient with the newbie questions - thank you- and I admit the newbies, myself included, could use the search more....

Ed - you said that already lol

 

The street front camber range is up to 0.5, and you are over a degree. If your wrench can't even make the camber match side to side, I'd find another wrench. Excellent point about the kinematic toe. Around here, only dealers or specialty shops know how to set it and have the tool.