Steering & Alignment Issues

Tidybuoy · 11:16 AM

I just had the wheels balanced and the car aligned.

Prior to the alignment:
The car felt like it wandered a tiny bit and required my attention while driving in traffic - I felt like the car could easily drift into the next lane if I wasn't paying perfect attention. The car did not pull and felt aligned but it did not track to center perfectly. I also feel like the car had a bit of oversteer and when going over 80mph, it did not feel stable to me and felt like I could do a complete u-turn if I was not careful.

At the alignment shop:
The mechanic had the car on the alignment rack, they have a good setup that uses lazers and mirrors and analyzes all 4 wheels and displays on a computer monitor.

The car was very close to spec. The toe was off and the mechanic adjusted this. The caster and camber were only a hair out of spec and the mechanic convinced me to leave it alone. The told me that his corvette was setup with similar camber adjustment which improves handling in the curves. He didn't make any adjustments to the camber or caster as they were very close to spec but a hair off.

Last weekend's drive to LA:
I went to Los Angeles last weekend which is about a 500 mile trip (round trip). Anyone who's every driven over the grapevine knows that traffic goes really fast. I don't think there was a single car going less than 90 - and I occasionally got to about 105 (when a z3 tried to pass me and I wouldn't let him win).

My issue is that the car still feels unstable at high speed. My hands actually got sore from gripping the steering wheel and I did not feel safe at high speed. The car feels fish-taley and does not hold a straight line with ease. I feel like I could do a complete u-turn if not careful. I have a 1988 BMW 528 and when going fast, the car feels safe as can be.

What can I do to improve this and if I need to take it back to the alignment shop, what do I tell them (i.e., caster is off, etc..)

My suspension consists of Koni adjustables front & rear. The rears are currently set at the softest setting. The fronts can be adjusted with a knob and I tried both soft and firm - it was worse on firm. Half way thru the trip, I stopped and checked my tire pressure which was at 32psi. I noticed that the tires (Brigestone Potenza's) state 44psi, so I pumped them up to 40psi which improved the ride quite a bit but did not solve the stability issue.

Thanks in advance for any input......................Vern

mattdavis11 · 04-04-2007, 11:32 AM

How are the tie rods, sway bar bushings, ball joints, and the wheel bearings? Is there play in any of these items?

jwade944 · 04-04-2007, 12:03 PM

No more caffine for you. Try setting the toe to factory specs with you in the car. I align my race car with a little bit of toe out and it works well on the track, but you aren't driving on the track. Adding weight to the car (as in you and passenger and stuff) changes the toe towards toe out. (As does braking.) If your mechanic started with a little toe in with no weight in the car, then you may have zero toe with a loaded car and that can make the car wander. Wider tires can also tramline and you noted larger than stock wheels. 40 psi seems too high for cold pressure. Watch for signs of overinflation on your tires (wear in the center of the tread.) These cars do not oversteer unless something is really wrong. With stock size tires, they tend to understeer and with larger tires on the rear, they should plow like a mule. You might try setting the rear shocks tighter and leaving the fronts on soft. There is another thread here about items to check (tie rods, ball joints, etc.)

Techno Duck · Techno Duck's Garage

What were the specs on the alignment you got? Did he give you a print out?

40psi is way to high. Factory calls for 29 front and 36 rear, i personally go 34 / 36.

Tidybuoy · 04-04-2007, 02:58 PM

I will have to check to see if the specs got printed - I don't think they did and I think I just got a receipt.

As far as the tires, the guy who balanced the wheels (who did a great job balancing, double checking and re-balancing) asked me how I liked my air in the tires. I had no idea and I told him probably the normal 32. He then said that some Porsche guys like them set at 35. At that point, I looked at the sidewalls which said 44psi and the mechanic told me that that seems really high. But, after driving 200 miles, I decided to add air and see if that helped - which is did a little bit.

I wish I had gotten the spec sheet. I brought my owners manual and we compared to what his computer stated it should be and they were identical. And the mechanic showed me all the settings and how far off everything was (which is not much. The most out of whack was the toe and he adjusted it (albeit I was not in the car as you stated above).

As far as the condition of the tie-rods and ball joints, I believe they are near perfect. My car has 20k miles on it and underneath looks brand new. I have inspected all suspension parts and everything is tight and no rips or tears in ball joint covers or steering bellows, etc..

Thanks for all the great tips.

As far as the caffeine, I can't help it....there's a Starbucks on every corner in California. I don't usually drive over 100 but having a z3 pass me was just not acceptable - M3 maybe

jwade944 · 04-05-2007, 04:05 AM

The pressure stamped on the sidewall of the tire is the maximum inflation pressure - not the recommended inflation pressure.

mlue · 04-05-2007, 09:28 AM

Take it to another shop to get it aligned TO SPEC!

It sounds like the alignment tech just did the bare minimum toe adjustments. There are alot of adjustments on the rear of the 944 compared to other cars. Most mechanics don't know how to allign the 944 so they talk you out of adjusting it (as making an adjustment affect another), essentially the car is sensitive to rear specs/adjustments.

If the car feels unstable chances are the rear adjustments are out of wack. Even messing with the ecentric that adjust the rear ride height when installing the sway bar drop links can mess up the handling/feel of the car if you loosen the bolts, resulting in the car steering to the left or right (ask me how I know).

I recall my alignment shop saying that Porsche used different alignment specs for North America and Europe. The difference being in the rear specs to promote more stable rear for the North American market.

Good Luck!

Tidybuoy · 01:12 PM

I'm probably going to take it to another shop - even though I have had good experience with this shop (regarding tires).

Just wondering, my car sits a little lower in the back - especially if the tank is full. Is this normal or should I raise the rear a bit and how will this affect handling. I'm guessing that it could have some effect as this may put more weight towards the front.

Thanks for all the input. I'll speak up after I get things fixed.

Vern

onZedge · 04-05-2007, 10:20 AM

Get a new mechanic that isn't so lazy. Does he get a comission on how many "alignments" he can do in a shift? A correct alignment on a 924/944 is a little time consuming. Out-of-spec is out-of-spec. I'll bet he didn't even tell you the readings on the rear alignment, which is also adjustable.

Dave L · 04-05-2007, 11:29 AM

Quote:

Originally posted by Tidybuoy

Just wondering, my car sits a little lower in the back - especially if the tank is full. Is this normal or should I raise the rear a bit and how will this affect handling. I;m guessing that it could have some effect as this may put more weight towards the front.
Vern

NA spec is to have the rear a little higher than the front for bumper impact regulations. Euro and the much better way is to have the front and rear level. Measure from the bottom of the rocker panel in the front and back.

If the rear is lower this could cause some funky handling, also how are the shocks on the car?

Tidybuoy · 04-05-2007, 01:07 PM

Thanks for the replies.

The shocks on my car (front & rear) are brand new Koni yellow adjustable. However, the car's unstableness was there before I put in the new shocks and struts. I was hoping that new shocks & struts would cure the problem but it only improved cornering (by a lot).

I'm definitely going to find a shop in Fresno that can do it right. I just joined the local Porsche club and I may inquire about local shops. I would like to get the ride height adjusted because I am always keeping the tank empty - just because it looks better.

I have a 914, and the factory initially had the front end higher than the rear so I thought this may be the same with the 944.