Realistic Wheel Alignment Setting Condition.

my friend has a Formula V race car. It toes in with the driver in it. About 1/32 of an inch.

We've concluded that it's not worth the hassle.

And... let's say that factory alignment is 1/16 toe in and it toes in another 1/16 fully loaded, that's 1/8 total. But, if you set it to 1/16 fully loaded, then it's actually zero with just the driver. I would assume the factory settings would be calculated the same way - if they want 1/8 toe in with a normal load, they say 1/16 and assume that you're doing it empty.

Lastly, most cars have a pretty big range of allowable alignments, and most shops are pretty lazy, so you're lucky if the damn car is any better afterwards. (Personal experience here, which is why I've pretty much given up on anyone else doing my alignments that's not a performance shop. I can do just as "good" of a job with string and a tape measure.)

Ray

ChrisCoaster wrote in news:3076049b-7d16-4f01-8f5a- snipped-for-privacy@x35g2000hsb.googlegroups.com:

I've wondered about this as well. However, I see no ill effects from aligning the car properly without a driver, so there can't be much practical difference either way.

I have noticed the springs on my car appear to have different calibrations, manifested as paint markings, which are different left to right (the springs are otherwise identical). I wonder if this is evidence of an effort to compensate for the effects of the presence of the driver?

Because that is a dependable baseline for the vehicle. Could you do an alignment with the vehicles owner and typical load in the vehicle? Sure. Would it make a noticeable difference from the empty settings? Nope.

Most manufacturers do a LOT of testing of the vehicles and they set up the steering geometry so that as weight is increased the geometry allows the various settings to change with a predicted amount.

Once they get it the way they want they take the measurements with the vehicle empty.

And what do you do about the car that is driven by the 300 pound guy with a 300 pound wife?

Several years ago I was working in a shop that did alingments. I did an alingment on a 1975 Ford LTD station wagon afterwhich the owner complained that it still pulls to the left. I put it back on the rack and everything was still as I set it. A road test didn't show any pull to me. I was then around 160 lbs. When the customer returned for the car I met with her. She was a huge woman. I'm talking big enough to burn 2 barrels of fuel getting out of bed.So I put the car back on the rack and loaded 350 pounds in the driver seat and reset the alingment. On the road test it pulled right with me driving. When she returned the next day she was happy because it didn't pull left anymore. So from my experience, loading the driver seat does make a difference. ch

Fixing the problem was perhaps ingenious, but the real test of your skills was how you explained the problem to her and still kept her as a customer...

And cars aren't always operated in the same configuration. With a driver and a passenger, the alignment ought to be about what it is empty. With just the driver, it'll be a little bit off, though still well within tolerances.

Change shocks and springs to keep the suspension tuning right.

--scott

I have seen cars come into the bay with a significant measureable difference (measure with a ruler, not a micrometer ;>) in height from ground to sill on the driver side versus the passenger side.

These were normally older cars, surely, of the large American variety. I suppose that with time, road miles, and heavy loading, these things just got tired and sagged.

In a few cases, we had to replace the springs, and what impressed me was the variety of different springs which were available for some of those boats. With Fords of that day, the springs were color coded, and we just had to select some that would relevel the car. Maybe there was a more scientific method, but that was the way it was apparently done at the time.

Not to come off like a typical web tv user but, when I was a young man we would order "station wagon" springs for the rear end of our late '60s- early '70s Chevrolet Malibus to get that "drag race" rake. Yes, the spring options were staggering. There were at least 20 different choices, depending on the car's original options.

We would usually choose "six cylinder" springs for the front end to get that dramatic rise on "lift off".

This was in the mid 1980s. By that time, these cars were all rusty, sagging and nearly worthless (Usually $500 cars, picked up with about

_______________________ Well, I've decided what I'll do the next time my car need its alignment checked: sneack a cinder block or two, or some bricks, under the driver's seat to simulate a *partial load* on that side. I never go into an alignment shop with a full gas tank, the shop might take away some caster(!) - always half a tank full, or slightly less. Maybe this combination will result in their spec alignment pulling slightly to the right, the way I like it.

-CC

Exactly!

When it comes to toe in, I can usually do just as well as "manny, moe and jack" with string and a tape measure.

There is no substitute to a trusted, independent when it comes to alignment!

The color coding is still used today. The various springs are for different ride height, ride quality, handling and to offset the various options and engines. It can make things VERY interesting.

When we were doing our SCCA "american sedan" roadrace cars, we would check alignment at the same time we were doing corner weights...and thus already had a dummmy weight in the driver's seat.

--Ken

What did that do to the handling? I would think at least a reduction in the factory-programmed understeer...

--Ken

I dont remember anyone thinking about handling when they were putting a rake job on their car.

A lot of people would just torch the front springs.

Some of the cars of that era were of the most vile handling characteristics I can think of. As the sporty cars came along, handling packages and aftermarket parts became available that made them handle, if not like true sports cars, rather than wallow through a curve.

Handling? As long as we could go really fast from stoplight to stoplight all was well. Actually, oversteer would have been a characteristic that we would have found "desirable".

Factory, pre-programed, safe handling was really not on the priority list in my "more horsepower=go faster down the strip" young man's mind.

The daily driver was a pickup truck capable of pulling the wreckage home.