Alignment questions
 

I did a search through the achrives for about a half hour but couldn't come up with the info I need so I'm hoping you guys can help. I am considering doing an alignment and it seems using a shop with a hunter machine is a good way to go. I want negative camber up front as it seems right now there is none. Also maybe maybe slight toe out up front. I basically want better handling, grip and response for autocross and track use. What is a good set up and what is the best I can do with the stock suspension?

Adam,
My target settings were taken from some hot shoe drivers in the area who know Boxsters well. This is what I have done with stock suspension:

Front:
Toe= zero
Castor=maximum
Camber= .7 negatve (max negative)

Rear:
Toe= 1/16 total toe in.
Camber= 1.2 negative

This should get you in a pretty neutral grippy place and tires should still wear well. Good luck.

Topless, thank you for the guidelines. Ok so .7 is the max negative camber available up front. That's better than nothing. I always thought it was strange that Porsche dialed in some negative camber in the back from the factory, but not the front. What do you guys think about some slight toe out up front? Bad idea?

Not needed from the fact that as the car is under heavy acceleration, the front tires will toe-out normally a smidge, so keeping the toe at 0 is going to be the best for a rear drive car.

BC.

Some high level (National SCCA champion) AX drivers will add a little front toe out to make quick transitions. They will tell you that it is only for tight quick 30 sec. AX courses and it does make the car twitchy. My typical courses are longer, faster, and I don't drive at their level. Zero toe is a better choice for me. I don't like "twitchy" at 120+. :eek:

Ok, good to know. You guys have been great. I didn't want to go to a shop without some specs to shoot for. One more thing, I just had the tires changed and now the car seems to pull to the left slightly all the time. Before it seemed to track straight. What the heck could that be?

Hey do you guys know what the stock alignment specs are for a Boxster S? I searched all over the net and found nadda. I don't know if the Bentley book has that info, but I'll check it when I get home.

Boxster S
 

I am getting my tie-rod replaced so I will get a new alignment too on a stock Boxster S.

From what I gathered for a mix of daily driving and DE use, these are the specs I am thinking of using:

Front Camber: -1.5 deg
Front Toe: 0 deg

Rear Camber: -2.0 deg
Rear Toe: .01 deg toe in

Anybody care to comment?

Thanks.

:cheers:

From the Bentley manual:

http://img183.imageshack.us/img183/8595/boxfront.pnghttp://img183.imageshack.us/img183/b...png/1/w611.png

http://img6.imageshack.us/img6/9790/boxrear.pnghttp://img6.imageshack.us/img6/boxrear.png/1/w618.png

Thanks for posting this Ekam, but now I'm even more confused than before. It looks like to be it says front camber is +5 degrees and rear is -1? That can't be right. Sorry for being a PITA, but can someone decipher this chart for me and put it on laymans tems?

Is everbody else as perplexed by this chart as I am? I can't tell what the range should be by this chart. :confused:

I am also confused???

I just corner balanced and aligned my Box this last weekend. I do the work myself. Now I've got JRZ coilovers and my car is dropped quite a bit, which will increase the negative camber, but I could swear you can get -1.5 degrees of camber in the front stock. Here's how I've currently got mine setup:

Front Camber = -1.2 (I could have gone more)
Front Toe = zero

Rear Camber = -3.0
Rear Toe = about 4 mm in on each side

With the JRZ coilovers, wide and sticky Falken tires, lower stress bars, strut braces, and a front GT3 sway bar this car is absolutely amazing. It just corners scary, scary fast without any kind of tire squeal. I have yet to get the back end to brake loose on dry pavement.

If you want more negative camber up front for autocross and track work, camber plates are the cheap way to go. They'll give you another -1.0 degrees of camber over stock. I've got some used Schnell camber plates that retail for $450 which I'll let go for $100. The bearings are a bit worn though and make noise, so you might want to replace those if it bothers you. PM me if interested.

Kirk

Kirk, you think -1.5 camber is possible up front on stock suspension? That's about double what toppless could get. I realize there are some variances from car to car, but that seems like a big difference. Is there a certain ratio or guidline to follow when adjusting camber? Seems like people run more camber in the rear than in the front, but how much more is optimum? I see you run twice as much camber in the rear as in the front, and some run less of a difference between front/rear. I want to make sure I'm educated on these things before I go in there and tell them to do a performance alignment and give them specs to shoot for. Thanks for all the help guys.

Boy, topless sure has a great alignment machine. He can get rear castor - 4 wheel steering anyone?

IF I recall correctly, yes I believe -1.5 degrees of camber is possible in the front with the stock suspension, but it's been years since I had a stock suspension - first lowering springs and then coilovers, so I could be remembering wrong. I was thinking of checking the Boxster Spec board to see what those guys run, but they're all using PSS9 coilovers....

Having so much negative camber in the rear is more a function of having the car lowered so much rather than a desire to actually run that much negative camber! When you drop the Box to an extreme level you're going to have high negative camber in the rear if you're also going to adjust the toe to slightly in. The two (camber and toe) are very much tied together. The only way to dial out some of that negative camber is with adjustable toe arms so that you can get BOTH good toe AND less negative camber. I don't have adjustable toe arms and don't really care to get them as the high negative camber in the rear does not concern me (as in, I don't care about the cost of higher tire wear).

The general consensus on how much negative camber you want is as much as possible. This is for track and autocross though. You have to be willing to throw away some money on tires to run this way. If I was going to seriously track my car I would slap the Schnell camber plates back on the front and run around -2.5 degrees of camber. Right now though I'm just autocrossing and not too serious about it, so I've got a more mild setup in the front. I have heard many times that slight toe out in the front will help with autocross, but again I've chosen to set my car up more for the road and secondarily for autocross, so I've made some compromises.

Hope that helps.

If you want to autocross and track your car - here's what you tell the alignment shop:

Max negative camber front and rear
Zero toe in the front
Slight toe in at the rear

IMHO.... :rolleyes:

Kirk

Max camber I was able to get with a stock '04S suspension was -0.8deg. Doesn't seem that -1.5deg is in the realm of possibility unless the suspension is modified, or unless lowering the car adds neg camber (I'm not sure if it does or not).

Thanks Kirk, yes that was helpful. Correct me if I'm wrong, but you're saying Boxster owners generally run less front camber than rear because they simply can't get as much up front. It seems Porsche gave the car adequate negative camber in the rear, but failed to give it any up front from what I see. Why would they do that?

It looks like a slight typ-o. Not +5 degrees, it's +5 minutes (+-30 minutes)
1 minutes = 1/60 degrees

So in degrees, front is +.08 degrees plus or minus .5 degrees for USA cars.

To approximate, it's pretty much zero camber nominally in front.

Demick, did they mention how much rear camber was possible? Thanks!

<Quote>
Demick, did they mention how much rear camber was possible? Thanks

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I did my own alignment. I was only trying to increase front camber. I measured rear, but didn't want to increase it for tire wear reasons (I forget off the top of my head what the measurement was, but I'd guess around -1.5deg). So I don't know what the max is. I'd be hesitant to go more than -2 to -2.5 deg on a street car.

Was was really interesting, is after setting the front camber to max (-0.8deg), the toe changed drastically (gave me about 1.2" of toe out!!). I expected the toe change, just not nearly that much. Needless to say, I reset the toe to zero, but not after driving 40 freeway miles and competeting in an autox. Craziest thing is that the handling on the freeway wasn't half bad with that huge amount of toe out. Go figure.

Interesting, with that much toe it should've been all over the place. Do you have any ideas why Porsche would dial in - camber in the rear, but not the front from the factory?

Front wheels generally don't need as much neg camber as rears, because they have caster. With caster, when you turn the front wheel, the wheels lean into the direction you are turning - essentially giving you neg camber on the outside wheel and pos camber on the inside wheel. Exactly what you want when you turn. The rear doesn't have this, so it has to be built-in.

Cool, thanks for the explantion. Caster is the hardest thing for me to wrap my head around. I've been researching it online trying to get a better understanding.

Caster not only gives you added camber in whatever direction you turn like I mentioned, it is also responsible for giving stability to the steering system. When you go around a turn and let go of the steering wheel, it has a tendency to self-center. Or just going down the highway, it's why you can let go of the steering wheel and the car will continue to go straight. Both of these can be directly (although not entirely) attributed to caster.

Very high tech indeed, or... he is kinda old and sometimes suffers from brain fade. Post has been edited for accuracy. :) Thanks Ren, I can always count on you.

Yes, lowering the car adds more negative camber. Just look at the Porsche specs for stock, RoW, and RoW sport. As the car gets lower the camber specification goes more negative.

I'm going to assume then that I'm wrong here about being able to get -1.5 degrees of camber stock in the front. My recollection must be a bit fuzzy because, again, my car's been lowered for a few years. I'm 99% sure that -1.5 is the max you can go with lowering alone. The Boxster Spec guys are trying to get max camber and I think this is the most they can get with just PSS9 coilovers. To get more they either use camber plates or GT3 control arms.

I've driven with slight positive toe in the front and I don't like it one bit. The car gets real darty on the highway. It may be ideal for a dedicated autocross car, but I don't think it's probably ideal for a street driven car or for a higher speed track setup.

Kirk

Does anybody know? Do gt3 arms start at 0 camber and go further negative with each shim, or start positive and go negative? My eibach'd car is at -2.8 (rear) and I'd like to get it to -1.5.

Is there any way to get stock camber on a lowered car if your adjusters are max'd out?

Very informative discussion and never seen before. Thanks for sharing with us.

I believe you can dial out camber or dial more in with camber plates. Also I think to get everything lined back up from the drop many people install aftermarket drop links.

Just to update the thread I took my car in for an alignment a couple months back and the most negative camber they could get up front was -.5. However, it had about .5 degree of positive camber on each front wheel when I took it in so there was about 1 full degree difference and it did handle better. Rear camber was -1.5 so I just left it there.