Collection: VLR Karts Emerald Chassis

VLR Karts 28mm Emerald Standard Setup

VLR Karts (Variable Line Racing) manufactures high-performance go-kart chassis like the Emerald and Sapphire models, optimized for national and regional racing in outlaw and dirt-track 4-cycle classes. This collection features Emerald chassis setups, parts, and guides for drivers 5'10" and under.

Standard Setup Specifications

• 125” Front Wheels (Spun Aluminum)
• 75” Rear Wheels (Spun Aluminum)
• Starting Air Pressure 12 to 16 lbs., depending on the tire and compound
• Standard Medium Axle (Green)
• Tillett VG Seat
• Front Width 44” (Outside to Outside)
• Rear Width 49” (Outside to Outside)
• Front wheel spacer: one small spacer
• Front hub 70mm and/or 50mm
• Rear Hubs 70mm and/or 35mm to reduce grip
• Front Bar: Start with Bar Out, then Test with Bar In, either metal or plastic

Using the 16-position pill on top and the centered pill (one hole) on the bottom. Place the flat spot toward the front of the kart, and then rotate to the “0” camber. The caster will be what it is, ~1/16th or so caster. Toe, to be .020”(.50mm) toe out on each side. Using Snippers 1-box negative camber and ½ box Toe Out. No additional Ackermann, using the widest of the three spindle holes, will offer all of the required Ackermann. This is the stock tie rod position. Standard Front Ride Height. The steering shaft pivot will be in the middle position. Side pod bolts, where they attach the side pod bar to the frame, should be loose. Total weight distribution will be ~44% Front and 56% Rear. Small changes here make a significant change to handling. Always have at least 5 lbs. on the front of the Kart and up to 15 lbs., depending on the track. Have at least 10 lbs. on the back of the Seat (high on the seat), the maximum on the seat back is 20 lbs. Seat struts, one per side. No rear bar. Ride Height to be Axle down, Chassis Up.

Additional Notes

• To loosen the kart, use narrow rear wheel hubs, 35mm, and place them about 1/8” from the end of the axle. If additional width is needed, use red plastic centering rings and widen the axle. Be careful not to go too wide and loose fixation of the wheel.
• Make sure the rear bumper is very loose, not so loose that it falls off, but it should not become a torsion member.

Seat Installation

To get the correct seat measurement as it relates to the frame rails use two 2” x 4” pieces of tubing wide enough to span the chassis where the seat will be placed with enough overhang to be clamped to the frame rails. Depending on the grip required, the bottom of the seat is set flush with or to the middle of the longitudinal frame rail.

First clamp the tubing to the bottom of the frame rail. Place spacers up to ½” on top of the tubing and tape them in place. Next place the seat on top of the spacers. (TIP: a weight inside the seat will help keep it stable and upright). When installing a flat bottom seat it is best to use the angle built into the seat when positioning the seat.

Next you must get the second vital dimension which is the actual position of the drivers back. In order to get the correct balance in the chassis it is important to understand where the drivers back is in relation to the rear axle. Take a 90° line (approximate) from one side of the spine recess and measure the shortest distance to the axle surface. (the spine recess runs down the middle of the back of the seat) You must not use the spine recess to measure this it varies in depth to much between each type of seat. With a 155 pound driver this dimension is currently an average of 6 3/8”. Please note bolting a substantial amount of lead weight to the back of the seat can make a difference to the seat position, it will force you to position the seat further forward to achieve the same balance.

Before marking the holes, bend the flat metal tabs of the seat struts so the flat parts are parallel to the surfaces of the seat. You can use a large adjustable crescent wrench to do this. Mark the holes, a good tip is to put a blob of paint on the end of an 8M bolt and pass the bolt through the strut spotting the seat in all the four main mounting points. Drill all four mounting points, use the nylon seat washers between the composite and the seat struts (additional spacers, rigid (not rubber) may be used to fill any gaps between the struts and the seat). Tighten the bolts until very tight. The quantity of spacers must be correct to ensure the composite is not pulled out of its natural shape and to keep the seat in the desired position. Extra seat struts can now be fitted if used. Keep the head of the bolt away from the top edge of the seat to eliminate bruising of the ribs.

When you are completely satisfied with the performance of the kart, record the position, size and shape of the correctly fitted seat. Also record the measurements of the furthest forward edge of the seat to the main chassis rail where your heel would normally rest and from the axle surface up to the top edge of the seat. (see dim. 1) Keep the dimension that the seat shows below the chassis tubes. Prepare the seat for wet weather by drilling two holes for water drainage at the lowest point of the seat. Remember to consider your rain tire may be a different diameter than the dry tire, check that there is sufficient ground clearance when fitting rain tires.

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