Maintaining two alignments?
 

I autocross my FD on some weekends drive it around town on others. I currently run street tires, stock ride height, and stock alignment specs.

Is it possible to mark the alignment adjustments such that I can switch from an alignment with negative camber and back?

Based on what I see on FSM R-8, I would simply need to change the cam nuts and tie rods (toe links). For the cam bolts, it would be as simple as painting across the 'dial' and scribing a line, or just relying on the number indicated on the dial. Then I'd have to adjust the toe by setting it to a particular length, maybe using a pair of scribed marks if there are no convenient reference points.

I'm sure this isn't a novel idea, so if this is routine for some, I'd like to hear how much trouble it is and how much difference it makes for tire wear (regular driving) and for racing times.

Thanks,

Dave

You're right on the money for camber. For toe adjustments you can see how far a full turn on the arm gets you or how much a 'flat' (the flat side of a jamb nut or adjuster) increases toe. This takes some time on an alignment rack but its well worth it to pay for the rack time if you can.
As for tire wear it really depends on how far from stock you need to go for it to feel good on course. I've seen cars that don't auto-x well until you have all four wheels pointing in strange directions.

A buddy of mine and I threw in together for a set of smart strings and a smart camber gauge. Learning to use it and setting it up is a bit of a pain, but once you've got it figured out it's easy to use.

http://www.smartracingproducts.com/alignment.htm

I can't justify several hundred bucks for alignment tools.

I think I'm going to try setting for a street alignment and a course alignment, and figuring out how to switch between them, either by turn-of-the-nut or by the dial readings. Then if I want to adjust, I can extrapolate using those readings to get approximate values for the course alignment.

I guess the big wild card is how much effort this will require. If it's a 30min thing with practice, I'd do it for every autocross, and do it at the site. If it's a 60-90min thing, I'd do it in my garage - most of the autox events are less than an hour drive from me. If anyone can comment on how they've done it and how long it takes, that would be great.

Dave

It seems like a lot of money, but we figured that over a lifetime of driving it would come out a lot cheaper than visiting the alignment shop all the time. It also makes it easier to experiment with settings. If you're handy you can fabricate your own toe equipment, and there are cheaper camber gauges than the smartcamber.

You should be able to do all four wheels toe adjustment in about 15 minutes. That is as long as you keep track of what you are doing each time you move something. Write everything down, don't try to remember all of it.

It may be good to take everything apart and cover the adjusters with never-sieze right before you head to the alignment shop the first time. That way there is no wrestling with anything when you go to make changes quick.

Another thing to do is mark the adjusters with an arrow pointing in the increase or decrease toe direction that way you know right away which way to turn. I use a + and - sign.

To double check your toe just use a couple pieces of aluminum and a pair of matching tape measures. Put the aluminum against each wheel and measure the distance in front and rear of the tire. It won't keep your steering wheel or thrust line straight but you will know your toe.

As someone who prefers to leave a streetcar on race tires on a trailer hooked up to my truck vs. driving to events on street tires and swapping out the tires I wouldn't even consider messing with alignment settings before and after every event. Of course with how low my miata is just getting it up on the alignment rack 2 or 3 times a year to make sure everything is ok is a chore in itself. Getting enough camber out of an RX-7 with a stock suspension setup to wear tires excessively I think would be very difficult. Toe is what kills tires. I have seen neglible difference in mileage on tires with 2.4 rear / 2.0 front negative camber and 1/16 toe in rear vs stock alignment on my Miata and 1.8 rear 1.4 front negative camber on the FD.

I would also prefer to trailer.

But I don't have a trailer, place to park a trailer, and the money for a trailer.

I can however take a little more time before/after each event and change settings.

I've noticed that since I've started autocrossing I'm not driving the FD outside of those events. I think that once I get a negative camber setup dialed in, I can probably leave it for several months of the year.

Thanks for the input everyone.

Dave

Agreed. I wouldn't worry about changing camber settings for street and track, just do the toe if you're concerned about wear. Even with lots of negative camber the tire still rolls freely down the road and doesn't wear much more than normal. However once you start running much toe in or out the tire never faces the path the car is traveling and constantly scrubs against the road. This eats tires.

Adjust the toe as jgrewe mentioned; lots of people do it this way and it works. BE CAREFUL just like he said. You don't want to get mixed up with which way you're going and get it all out of whack.

All that said I run stock wheels with 2* of negative camber at all four corners along with an 1/8" of toe in at the rear and a 1/16" of toe out at the front. The Kumho MX tires on the car are strictly street driven and I still get about 12,000 miles out of a set. Personally it's not worth it IMO to constantly monkey with the alignment, I just buy tires. If you only did a few events a season your opinion may differ.

To follow what Damon said, I too just leave my crazy camber (-2.5F, -1.8R) on all the time. I don't drive a lot. I don't autox the car though, I just use it on the street and for driver's ed, so I have a pinch(1/32nd) of toe-in front and rear for stability.