Thanks Tom, This is fun. Right?


Sorry I didn't include your name with the initial post. You get your 4 letter word just fine also.

 

Thanks for all the useful info.
I plan to use cannga's alignment specs.

As mentioned, I just want to maximize my street driving experience.

Don't worry, I'm not tracking my car on the street like an idiot.

That being said, anyone who owes a 911 Turbo and doesn't actually push the car some on the street bought the wrong car...or they're lying that they don't push the car.

 

Not saying you are. However his specs are there to take out understeer. This leaves the car ONE option. Oversteer, there is a reason porsche built in the understeer and dicking with your setup to take it out when you should be trail braking or fixing understeer with other options. Braking harder in a straight line then smooth power after turn in. Etc.

 

Thanks for the input.
What change in the alignment will lessen the understeer?....the change in toe?

Those who have done this change...is the decreased understeer noticeable?

Anyone know what the difference is between cannga's specs and GT3 specs?

 

why do you want to decrease the understeer with parts??? you can do that with your driving. You don't need parts.

A gt3 is a different car.

And yes cans setup will get rid of it Good luck on it and I would be very careful, at the limits you will be in an unrecoverable situation. Power oversteer is one thing.... widow maker oversteer is another.

 

1. Both, but primarily the camber change. The change in toe is for the "lazy" steering relative to GT3 (better turn-in response).

2. For me, YMMV: You are not going to do enough speed on the street to see a remarkable change in understeer vs. oversteer. What I sense more is being more planted in curves, faster cornering speed, more responsive steering response, and less of the weird sensation of the tire rolling on itself. All subjective but note well that suspension tuning is about *both* objective (track speed) and subjective (supratentorial ) results.

3. To best of my knowledge, yes, this is the "street" setting for 997 GT3. There is a track setting also I would assume. Relatively, it is a very very very :-) benign setting, both for street driving and especially for canyon runs.

 

Very good and important point. Not for Tom or Elite1 of course, but for the OP: The car does NOT suddenly go from understeer to oversteering, blistering, blood-thirsty monster :-) because you change camber from -0.8 to -1.2. It's a continuous AND relative change, a -1.2 car is not an "oversteering" car, neither is a -0.8 an "understeering" car; it depends on cornering speed and -1.2 is literally "nothing," *depending*.

Another very extremely important point : what is the goal of changing camber? It is to maximize traction by keeping the tire parallel to road surface, at the speed that you **TEND** to corner at. The change in camber allows you to do this (there's an explanation but that's topic for another day). At the track this is say -2.5 camber, but for the street at the speed that the 997 tends to corner, it is -1.2. A -2.5 camber is "bad" for street speed because most of the time you tire will be on edge (too much neg camber); vice versa, a -1.2 might be inadequate for track because of a possible rendez-vous with the outside wall. And how do you know what's best? Look at the tire wear. At -1.2 I could all but assure you, and probably most Porsche drivers, that your front tire wear will be perfect inside to out.

Bottom line: there is NO single "best" camber, and it is accepted practice to adjust your alignment depending on your driving style. The best number depends on the cornering speed that you tend to drive at. More aggressive for the track, less aggressive for the street. No matter what camber, common sense prevails for safety, starting with slow in fast out and avoidance of sudden changes, such as possible reaction in an understeering car. The argument is appropriate camber such as -1.2 (NB, no right or wrong, only "appropriate") is safer because of the better traction in the front. BTW, this is a good basic article for anyone interested: http://www.ozebiz.com.au/racetech/theory/align.html

 

^ I agree the Lucent motors alignment setup did improve tire wear and performance on the street. Its a safe sporty set up and will not result in oversteer.

I also agree with Squat's point and this should be used as reference when on the track. Even with -3 camber up front you can drive the car in a manner that will result in oversteer. Trail breaking is a great technique to learn and will help with lap times however, one should not be pushing their car hard enough on the street to be able to experiment with these techniques.

 

BTW, to give credit where credit is due, the "street GT3" alignment (-1.2 front/-1.6 rear) was first pioneered by eclou, the moderator of this forum, on his also-red 997 Turbo with Bilstein. Lucent used the same, and added the secret sauce, the very slight toe out.

The primary point for anyone new to this is, nothing is etched in stone and YMMV. The beauty is all changes are of course, **reversible**. Try to see and reverse if you don't like and don't sense any change.

 

Awesome discussion y'all.

I'll be getting the alignment done tomorrow along with the Sport Cup 2's.
I'll report my observations.

 

Where are you located? Usually the local PCA has a track day. Race against yourself and you dont have to worry about anything.... well at most tracks. I did hit the inside wall at NHIS on turn #4 Same turn Adam Petty died in, thanks to a horrible corner man who let a dude with a leaking radiator continue.

 

Can the alignment specs posted by cannga be done on stock Turbo suspension?

 

Yes you can

 

Thanks. Given exact same driving style/conditions, will the tires wear faster compared to stock/factory alignment?

What is an acceptable delta between each side? I noticed the specs posted aren't identical on each side.


Called my dealer this morning and they said that the alignment specs are very aggressive on the street (for a Turbo) and are also saying that the stock suspension cannot allow that aggressive negative camber as posted. Thoughts?

 

1. As mentioned, very likely, NO worse tire wear. With respect to tire wear, -1.2 camber and slight toe out is very, very, VERY minor change based on my experience over the last 6 years.

2. Yes, equal numbers is what the tuner will try for (this was but one of many attempts that day/over the years; Tom doesn't give the alignment prints to me anymore for obvious reason :-) - kidding), and NO I wouldn't worry about the little delta, you likely are not going to feel it. If you take 10 of our Turbo's off the street and put them on the rack, the chance is all 10 will have delta from side to side - you don't feel it in your car now right? BTW, cars' alignments "float" out of specs and this is why you should have alignment checked every so often.

3. Who gave you that answer? Service rep or head tech? If the head-tech truly said -1.2/-1.6 is not possible then you should take car elsewhere, at all cost . As already mentioned, it is doable on stock cars. Regarding that "very aggressive" comment: Dealer probably gave you that answer because in this litigious society some people wouldn't want to hand-hold customers to an alignment spec different from stock. Depending on how s/he perceived your question and his own level of experience, it's understandable some would "freak out" :-) and made you the decision maker, the one "responsible." A different dealer such as Champion may give a different answer and might even ask if you want to add sway bar and springs :-). In general I would recommend to adjust your alignment at a trusted Porsche indie shop, NOT a dealer, and obviously, not this dealer.

BTW, for anyone new to this, I should add that if you are looking for a more sporty feel for our 997 Turbo, alignment change alone is not enough, for me anyway, since the factory springs are very soft even for non-track driving. True transformation only happens when you add stiffer springs (whether lowering springs or coilover) and sway bar. See Bilstein thread in my signature; very good summary LOL on first page.