How accurate is the Porsche factory alignment to their recommended settings?

 

when I had my car first aligned at around 25k miles, the rear was in great shape, but the front sucked. Factory had a lot of toe in. Rear just needed a slight camber nudge, toe was spot on.

 

From everything I've read the factory specs are pretty broad and it is a good idea to get the car aligned after break-in. A good shop can dial it in for optimal cornering and tire wear.

 

Can anyone with experience recommend street alignment settings that are an optimal compromise between cornering and tire wear?

 

take a look at this thread for some good info:
http://forums.rennlist.com/rennforum...track-use.html

especially post #23

 

What I am running:

Front camber - -1 degree - max. possible without going to GT3 lower arms

Rear camber - -2 degrees - 1 degree more than front

Front toe - 0

Rear toe in - 1.5 mm total (about 1/4 degree)

This feels very good on the street - I am considering going to the GT3 arms to get -2 - -3 degrees on the front so that I can run R6's for track days - with fairly aggressive driving style I don't think that I will have excessive inside tire wear.

 

Not to hi-jack, but I think it's related...what is this "corner balancing" I keep hearing about? Can this be done during an alignment at the dealer?

J

 

My 997 cars came with terrible alignments from the factory. Dealer checked at my request, saw things were way out of specification, and did a great job tweaking my car to maximize negative camber up front for crisper turn-in (with no negative side effects). On my 997.1 S they got about -0.80 degrees, about -1 on my 997.2 S w/ Sport PASM. Plenty of threads here and at RL - try a search on "alignment".

 

It is not so much the camber that wears the tires...it is the amount of toe that wears the tires. My 09 C2S is set up for the track with mods to allow -2 camber up front and I have -1.8 camber in the rear, however I drive it everyday on the street. In 11,500 miles I am no where near the wear marks on my street tires. Go with minimum toe with in factory spec. With a stock 997S the most camber you will get up front is -1...and that is no where near too much camber. Keep the rear camber with in .5 degrees of the front. So if you can get -1 up front do not go more that -1.5 in the rear. These camber suggestions with zero to .02 toe up front and no more than .14 toe in the rear your car will turn in much better and tire wear will be great.

 

Quote:

Originally Posted by xXxGhotimanxXx

Not to hi-jack, but I think it's related...what is this "corner balancing" I keep hearing about? Can this be done during an alignment at the dealer?
J

Corner balancing refers to getting equal weights on diagonal corners - LF + RR weights should equal LR + RF weights. On our Miata with Spec Miata suspension, we set cross weight and ride height by adjusting the coil over spring perch locations while all four wheels are on individual scale pads - I'm not clear how one could adjust corner weights with a stock 997.

mdrums - I totally agree that toe kills tires and camber helps handling. My alignment shop (RSR in El Cajon, CA) recommends max neg camber possible, but no more than 1 degree difference front to back - this seems to work for me, but YMMV. I will be running my car next weekend at Fontana and I am very curious to see how it feels, what tire temp's I see, and how tire wear goes...

 

what kind of degree camber/caster did the shop recommend for daily driving out of curiosity?

 

Those settings are their suggestion for "spirited" daily driving.

 

Huge 2nd on this one. Everyone thinks 2 degrees negative camber will kill your tires, which is true, IF you're running 1/4" toe in. But with zero Toe, camber doesn't hurt your tires that much (within reason, 2-3 degrees max).

As stated, I think -1 camber and zero toe up front and -1.5-2 camber rear with 1/16" toe in per rear side, 1/8" total toe. I think in degrees that's like 0.7 degrees in.

 

Zero toe in the front has got to make the front end a bit wiggly at speed right?

The stock alignment has so much toe I can take my hands off the wheel at 100 mph and it tracks perfectly straight.

 

Also if I understand correctly, the toe-in and negative camber actually balance wear. Negative camber causes wear on the inside edges. Toe in causes wear on the outside edges.

If you increase negative camber and decrease toe in, you will greatly increase wear on the inside edges (unless you are doing a lot of hard cornering all the time).

That said in my next alignment I'll be getting "RoW performance" as the car is just too understeery stock.