Tuesday, July 14, 2009

Alignment & Corner Balance for Nirvana

I made the short jaunt to my friend Carl's for an alignment & corner balance today. Carl is a track enthusiast who has been running his sports cars for years on racetracks. This interest led him to learning how to align his cars - which he has been doing for over 20 yrs. One of the fastest LCS competitor, Jack, swears by Carl's work. I figured Carl was my man for Nirvana. Over the years, Carl has developed some creative & effective ways to align his cars.

I spent the afternoon with Carl getting Nirvana sorted. We started by baselining the car. We learned that the front toe was zero (as I had set) and the rears were way off. Since I had installed an RTVbrace, this was not a suprise. The drive up showed that the car was very nervous - the handling was not right. We also disconnected the V2linx to insure that the swaybars would NOT have any undue influence on our corner balancing.

Both of the front cambers were at -2deg. The V2arms provided me the
needed additional camber. I set these myself at our shop by leaving the stock ABS bracket + 1mm shim + .5mm shim. These delivered the ideal front negative camber that can not be achieved with the stock steering arms. In fact this becomes an even great boon when you begin lowering your car significantly as bump steer issues are dialed out. I wanted to set up this car so that it is still reasonable on the street. So ride heights of 120mm front & 125mm rear was the goal.

I had not yet measured the weight of Nirvana since making all of this past weeks mods. The car weigh 1923lbs on Carl's scales. That is a 40lb savings. After a few spring perch adjustments, we achieved a 50% cross weight on the car with 160lbs of ballast in the driver's seat. We pulled shims from the rear to achieve -2.4 of camber. We achieved the final ride height #s of 119/121 front & 123/125 rear.

We then checked the swaybar endlinks - our V2linx - we saw that they needed to be adjusted. When I had originally connected them at our shop, I thought that I had them aligned well, but once we placed Nirvana onto the scales, we discovered that the swaybar was loaded and had added 15lb influence to the corner weights. By adjusting the length of the V2linx, we were able to eliminate this issue. The Lotus responds well to properly set-up and alignment. This excercise proved to me that even a small item like a swaybar end link can have a serious impact on the
cars balance.

We then changed the brake fluid as it had not been changed in a year. Carl again showed his ingenuity with his powerbleeder set-up. He uses his air compressor to keep the brake system pressurized with 20psi. This made the fluid change a simple and quick process. One of his secrets is to tap the calipers with a soft mallet to exorcise any trapped bubbles.

We then took the car out for a quick dash around his favorite test circuit. What a difference a proper alignment & corner balance can make! The nervousness was gone - along with the oversteer at corner exit. BTW: the HNTpad sure made heel and toe a snap.

I can't wait to get Nirvana on to Laguna!

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