SPL Camber arms & New alignment specs Rear is super loose
 

Hello everyone,

After installing my SPL upper control arms last week I finally got the alignment done and as luck would have it yesterday I ran a winter x event at Miller Motor Sports park to test these and to test a new oil cooler.

Tires: Stock Advan Sports: New tires once these wear out.

New Alignment Specs:

Front:
Camber -2.5
Caster 5.3 More on this spec later
Toe 0

Rear -2.5
Toe 0

When I went in for the alignment the intent was to get the front to not over-steer (push) which is what I was feeling last year in auto cross especially and to a lesser extent on the track day events.

I asked for the front camber and toe above but, had asked for the stock caster setting which I think he messed up and put in the non-nismo spec. I have stock nismo rear end and had no idea he could get -2.5 from the stock adjusters. I thought i would get -1.5 to 1.8 but, I didn't clarify enough and that's what I got.

Driving impressions:

The winter x is run on the miller track but, has the apexes of most corners coned off to slow things down. Which actually adds allot more steering input.

Steering:

Steering is very touchy, the difference in steering input it night and day from the stock settings. I would say for my level to twitchy at this point.

Cornering: The front compresses into a corner and is planted feels like it is on a rail. Absolutely confidence inspiring. I really liked the feel of the front at zero toe and -2.5 camber.

Rear: As good as the front feels the rear feels the opposite. When cornering as I said above the front compresses into the corner then feels like it plants on a rail. The rear end compresses as well and plants initially but, keeps on going loosing traction. I had one big spin stayed on the track but spooked me pretty good. Definitely keeps you on your toes

Before the new alignment I always felt the rear was pretty grippy and the front was the problem. Now it is the opposite.

I think I will take the back camber back to -1.8 or so and have the caster moved to 7.0. Hopefully that will do the trick.

I'm running -2 camber, +6 caster, zero toe front. -1.7 camber, zero toe rear. The front is good, but I think I need alittle toe in the rear to settle it down. -2.5 camber in the rear is alot.

Yep agree to much I think as well. How much toe in the rear are you thinking? By settle did you have any loosness in the rear with your settings?

Think the min factory spec. Yeah, it's a tad loose for my taste for now.

Just got done doing an string alignment and resetting the camber on all 4 corners. Sphon mentioned the string alignment in a earlier thread and I did the research and decided to have a go at it.

Come to find out the shop alignment was off in a lot of area's. I can with out a doubt say that you can get the numbers your looking for doing it yourself. A caveat to that is I did go to one of the chain auto shops here in Utah. A good race shop that will take the time to do it right would be a :tup:.

I went from --2.7 & -2.8 deg camber in the rear to -1.75 & -1.78 deg. Front -2.05 on both sides. for toe I straightened the steering wheel and remained at zero front and went with just under spec in the back. 1.25mm for the RR and the best I could do with maxed out adjustment for LR was 1.4mm.

I used solid-works to figure the math out and give me a visual. It was very convenient to take a measurement and punch it and see the change in 1/100th of a deg.

FYI, for the SPL upper control arm adjustment one full turn of the adjustment bolt gives just over .5 deg of adjustment.

SO have fun doing your alignment. Double and triple check your measurements and you will be fine.

Camber measurement.

[IMG]http://i937.photobucket.com/albums/a...psrwr7tdcz.jpg[/IMG]

This was for toe adjustment in SW

[IMG]http://i937.photobucket.com/albums/a...psbxfitqey.jpg[/IMG]

I used green fishing line for my parallel line to measure off for toe adjustments. For the 370 add 1/2" from the front hub to line. The rear is 1" wider overall.

[IMG]http://i937.photobucket.com/albums/a...psafyg7cra.jpg[/IMG]

You need to create a parallelogram by making the front and rear jacks equidistant across the front and rear.
I use a piece of conduit drilled at equal measurements.

http://i1089.photobucket.com/albums/...ps26049a82.jpg

is there a book that I can buy that will teach me this? or some sort of online resource? I'm super interested in this topic but need a starting point. unfortunately, an amazon search "string alignments" yields nothing of value.

I watched about ever youtube vid that camw up for string alignment, performance string alignment, etc.. I got a couple of hit for string theory as well.....that reminds me I need to return Stephen Hawkins call

you might try sphon. He said he found a book on it. Some of the web pages I found also reference book and articles you can use as a resource.