Front end alignment specs?

[batchman]

Originally Posted by Racinfan83

Was thinking about doing the "Advanced Street" settings on that vb&p link above. Will that one be good???

It'll sure be better than the factory specs! I guess I'd agree with the toe settings and for street use the minimal negative camber should be fine although I sure like "moar".

Originally Posted by RussMcB

for occasional mountain runs, autocrosses and track days. In other words, a good compromise alignment.

I guess for your more handling oriented compromise I'd suggest doubling the amount of negative camber at both ends on the "Advanced Street" settings.

For both of you I'd expect a "0" toe front end might want to follow truck ruts in the road, more pronounced the larger (and/or grippier) the tire. This can make highway lane changes a little "interesting", and if the roads in your area are highly worn you may be happier with some front toe-in although total 1/8" looks like a lot to a guy who runs front toe-out .

Bear in mind the behavior of each car at the limits is a tuning exercise that includes tire choice, size(s) and pressures, shock settings and alignment. Each car and driver are different in their specific setup needs and there really is a huge amount of range-of-behavior in these few parameters.

Whatever the setup, in an emergency situation, one end is likely to break loose before the other. It seemed to me like the factory settings are designed to make the car plow like a tractor, unless you romp the gas in which case it spins like a top.

In any case when going "off book" with anything automotive you are changing your safety envelope so to speak and need to do some testing in a controlled environment to be sure you've got what you meant and/or are ready for the consequences before you are faced with an old racing adage, "Never run out of talent and ideas at the same time".

I highly recommend an autocross or street-survival type class for anybody doing anything more than getting groceries and parking in ideal weather. And that goes for anyone likely to be driving a given car. No need to worry about the competition aspect of an autocross, think of it as a full minute of emergency maneuvers as that's exactly what it amounts to. It should take a solid event to a few for anyone to be able to find the limits of their car in several situations, and learn what to do about each, and that is really useful to know before faced with an actual emergency...

I spent >25 years driving all manner of hotted up cars before I actually learned what works and how to drive. In fact, the first couple seasons of my autocross career were spent un-learning what I thought I knew...

One last thought, there is nothing more educational than an autocross in the rain. It makes the limits much more accessible and all the lessons are applicable to dry as well, but of course at different speeds.

YMMV,
- Jeff

[QMCMSS]

My experience: Did the following 4 new Sumotomo Summer only tires.New Upper ball joints. Front end alignment to advanced street specs. Result: Almost immediately I noticed a huge positive difference in the handling. Things just seemed tighter and smoother. The car tracks great and has absolutely no rattle or vibration with speed up to 110mph. Steering was effortless and positive. I'm a newbie so take my lesson for what its worth.

[Dynomite]

Originally Posted by QMCMSS

My experience: Did the following 4 new Sumotomo Summer only tires.New Upper ball joints. Front end alignment to advanced street specs. Result: Almost immediately I noticed a huge positive difference in the handling. Things just seemed tighter and smoother. The car tracks great and has absolutely no rattle or vibration with speed up to 110mph. Steering was effortless and positive. I'm a newbie so take my lesson for what its worth.

Are these the Advanced Street Settings you used?

Advanced Street

Front
Toe 0 inch
Camber .25 deg negative
Caster 5-7 deg positive

Rear
Toe In 1/8 inch
Camber .50 deg negative

[QMCMSS]

Yes those are the ones. I got them from the link in an earlier post.

[Hib Halverson]

For a street driven ZR-1 where handing performance is more important than tire tread life.

Camber -½° in the front -¼° at the rear
Front caster...as much as you can get with those camber settings.
Front toe zero (Note: the front end parts must be in good condition if you're going to set zero front toe.
Rear toe 1/32 to 1/16-in per side.

The above is the alignment specs I've used since I bought my ZR1 in 1995.

PS: I just reread your post and it says track days.

The above alignment config. is good for street but not for track. If you're going to track the car. For camber use -1.5° in the front and -1° in the rear. All the front caster you can get and zero front toe and 1/16-in rear toe per side.

[QMCMSS]

Just to clarify: When I wrote the car tracks great I didn't mean it drives well on the track I don't track my car. I meant to point out that the car just wants to go straight effortlessly no pull in either direction when I am going straight at any speed the car just wants without much steering effort to continue in a straight line with the steering wheel in what feels like a happy place.