Whiteline RCK & NV Auto Alignment

Whiteline Roll Center Adjustment Kit

This weekend I had my friend Ken help me install the Whiteline Roll Center Adjustment Kit on my car which I picked up from Touge Tuning a while back.

The roll center is an imaginary point in space around which the chassis rolls. This point is usually a couple inches off the ground on a stock car. Lowering the car on lowering springs or coilovers moves this roll center closer to the ground, or sometimes even beneath it (it's just an imaginary point in space, remember).

Having such a low roll center has the negative side effect of adding more body roll (think of a larger lever) and adding bump steer. Bump steer means that when the suspension is compressed and the wheels move upward, they will have a tendency to steer themselves outward (toe out). In other words it adds rolling understeer.

As you can see from the diagram above, the roll center is determined by the angles at which the lower control arms sit. The Whiteline RCK corrects this angle closer to the factory setting by providing longer ball joints and tie rod ends that force the control arm back into a parallel position to the ground.

After installing it the car will need an alignment. We tried to do one ourselves but failed miserably due to some seized bolts. With shakedown this weekend at TMP that meant I needed an alignment ASAP. My local shop, CanJam, was out all week testing so I decided to ask NV Auto considering their solid reputation.

Alignment 

Dov @ NV Auto was able to help me out and get me an alignment in less than 24 hours! I'm glad I found another reputable shop I can count on when I need something done. It was a bit of a drive out from east Markham but worth it in the end.

I decided to go with -3° front camber due to not having enough last year at -2°. I knew I didn't have enough -'ve camber by how my front tires were wearing relative to the rear. The outsides would wear down at a much faster rate than the inside of the tire, and I had to keep swapping them to the rear for the next track day. Tire temps also confirmed this by the outside of the tire consistently being 4-6° hotter than the inside after cool down lap. Finally, in some of my GoPro footage you can see the tire rolling over (and this was after installing 24mm front/rear swaybars).

They had to use camber bolts in the front to achieve the -3° because my camber plates were installed diagonally for the sake of caster. +6° caster ftw.

In the rear, I decided to stick with -1.5 degrees because tire wear and tire temps were even. Zero toe all around because I daily drive my car. 


Bdon's Track Tip: If you're trying to sort out your suspension, try to record as much information as you can after every session on the track. I wouldn't have known what alignment settings to start out with this year if I hadn't taken notes last year. Even if you don't have a tire pyrometer you can use GoPro footage or just visual cues from the wear marks. I've heard using chalk to mark the sides of the tires is also a good indicator. I'll upload my track data template for anyone to use once I find it... (EDIT: uploaded it!) 


Corner Weights

NV Auto threw my car on their scales just for the hell of it. I didn't have my car corner balanced there, just a regular alignment. Although I did have the car previously corner balanced at CanJam in 2010. The corner weights looked really good. The 3.2 lb Antigravity battery really helped even out the LF.

Total weight was 2987 lbs without driver, 3/8 fuel tank, full washer fluid, all the interior bits and my street wheels! I'm guessing without the back seats and my forged track rims on will be another ~50 lbs in savings. I secretly wanted my car to be under 3000 lbs this year with 1/2 tank of gas and in track trim, so I think I've definitely exceeded that goal! :D