SLC alignment

[Craig Sinasac]

Hi All,

I looked for a similar discussion and haven't found one and it goes without saying I've watched Alan's videos. I want to discuss alignment settings and I know it is a function of car purpose and personal preference to some degree.
I plan to use my SLC for street use and one day a month track days. I set up the ride height and corner balanced my SLC, then set the alignment in my garage. I just took it to a local performance shop to have it professionally measured and here is what they have come back with:

Front
Camber (degrees): Left -1.8, right -2.0
Caster (degrees): Left 5.0. right 5.7
Toe (degrees): Left 1.57, right 1.22

Rear
Camber (degrees): Left 0.2, right -0.7
Toe (degrees): Left 0.56, right 0.24

Total Toe (degrees): 0.56
Thrust Angle (degrees): 0.04

So:
- looks like I should move the front camber down to -1.0 to -1.5 or so but it is not bad where it is.
- The front toe I had closer to 0, but added toe in as it was very squirrely on me ... should probably move it back closer to 0
- The rear camber should be closer to -0.5?

Other comments or suggestions? I've not had such a tunable suspension before and I haven't found good suggestions online.

First track day for this car is Sept 10.

cheers,

Craig

 

[Will Campbell]

Have you looked at what the manual suggested? Those numbers are pretty good for a street driven car.

My car is close to that, and handles great on the street.

Last weekend I did a lap at Summit Point, a track at which I have hundreds of race laps (though not with the SLC). I was surprised by how good it handled, even as I was really taking it easy. So the street numbers aren't too far off from a leisurely track day setup.

 

[Bill]

Like Will said, just use the alignment specs in the front of the manual.

I did my own alignment, using those specs and it steers straight, not twitchy, no bump steer, and tires seem to wearing evenly. Since my car is for the street, I increased the ride height to 4.45" front and 5.25" rear to clear the speed bumps and curbs.

If you don't have the specialized alignment tools, I have a method that gets consistent results with just a tape measure, a digital level, and a couple angle irons.

 

[Craig Sinasac]

Thanks guys, I forgot the specs were in the manual.

 

[Dan Carter]

Bill

Share your technique. :idea:

 

[Dr. David]

Share your technique.

These videos may provide some valuable information:

https://www.youtube.com/watch?v=v6MIRHnhZ4w

https://www.youtube.com/watch?v=YctjZ7SzFbo

If you want different settings for track days, you can actually change the settings at the track,....then change them back again before the drive home. Check your alignment whenever you think you have a reason......No "hoping it is OK."

Works on any non-level surface, which is every garage and every paddock.

That's just how I do it.
David

 

[Dan Carter]

Perhaps an obvious question, but which screw gets turned to adjust the camber on the front? I presume it's adjusting the heim joints but they will not turn without unbolting the bracket from the frame. What am I missing here?:stunned:

 

[Will Campbell]

Perhaps an obvious question, but which screw gets turned to adjust the camber on the front? I presume it's adjusting the heim joints but they will not turn without unbolting the bracket from the frame. What am I missing here?:stunned:

You can adjust them that way, but as you say, they must be removed, adjusted and reinstalled.

Or you can just screw the upper rod end in or out as needed. Very fast and easy.

It's a good idea to get the camber close- by eye or with an angle finder- with adjustment available on both the upper and lower adjusters. In other words, don't begin the camber adjustment with the lower arms screwed all the way in when you need more negative camber and you've already moved the upper joint all the way...

 

[PeteB]

Nothing, you have to unbolt the brackets. On my car the inner heim joints were screwed all the way in from the factory. They need to be closer to the middle of the adjustment range. The way they installed the bolts, the only way to adjust the inner heims is to unbolt the brackets, unscrew the heims about half way, then re-install the brackets. This gives enough play with the outer heim joint that you can get the camber set correctly by just adjusting the outer heim.

 

[Dan Carter]

Well, like I said, an obvious question.....wanted to make sure I was seeing it right.

Thanks

 

[Mesa]

Nothing, you have to unbolt the brackets. On my car the inner heim joints were screwed all the way in from the factory. They need to be closer to the middle of the adjustment range. The way they installed the bolts, the only way to adjust the inner heims is to unbolt the brackets, unscrew the heims about half way, then re-install the brackets. This gives enough play with the outer heim joint that you can get the camber set correctly by just adjusting the outer heim.

Yep,
I missed this detail on my car (build manual was still a few years off at that point), it gave me a little grief when it was time to align. All good now although it would have been nice to have had a little room to move the control arms inboard if needed. With the rod ends all the way in, one does not have that option.

 

[Bill]

Bill

Share your technique. :idea:

The alignment instructions are buried in my "Rumbles SLC Build" thread.

It's easier to find in my Kindle book "Car Builder Journal: RCR SuperLite-Coupe". There is a detailed table of contents in the front of the Kindle book that hyperlinks to each logical part of the build (alignment, brakes, interior, body mods, engine mods, etc).

 

[Terry Oxandale]

Can anybody tell me what the Steering Inclination Angle is for the SLC uprights?

 

[Fran Hall RCR]

Yes I can....

 

[Dan Carter]

Bill. Forgot to check your book, I have it somewhere.