Keep it Light
The number one goal in the new design was to keep the Hyper 9 light weight. Reduced weight equals faster acceleration and cornering speed. Smaller 8x14mm bearings have been used throughout the chassis (except for the rear 8x16mm wheel hub bearings). The number of screws was reduced, the plastic was reduced and the amount of aluminum used was reduced. The part count in total has also been reduced.
Chassis Balance
The engine was moved toward the center by using a 40 tooth spur gear and keeping the 13 tooth clutch bell. In doing this, the center drive line angles are also straighter, reducing scrub on the joint pins.
Moving the engine closer to the center drive line did not allow room for the rear brake on the center outdrive, so the disk was moved to the rear pinion shaft. The engine was then angled 25 degrees toward the center for four reasons.
1. Allowed clearance between engine mount flange and center drive shaft.
2. Moved weight toward center of chassis.
3. Lowered center of gravity.
4. Pulled pipe toward center of chassis. All this combined with the asymmetric aluminum chassis plate balances the buggy left to right with a half tank of fuel.
Ground Clearance
Ground clearance has been something overlooked for years by most 1/8 scale designs. The chassis has been shortened for clearance front and rear while keeping the same wheel base as the Hyper 8.5. The bend for the 10 degree kick up in the nose has been moved forward as much as possible to increase clearance. The aluminum chassis plate has been reduced in size, cut on all four corners, and the side guards have been angled up for extra clearance. This is especially important when the chassis leans and squats while exiting a corner.
Gearing
The buggy accelerates and has greater top end speed because of the 11/43 gear combination at the front/rear gear boxes and the 13/40 combination at the center differential. The faster spinning center differential also reduces the torque effect of the engine.
Better Cornering and Better Jumping
Most of the testing for the new Hyper 9 was setting roll center points front and rear for better balance through the corners and better jumping. The new buggy has better matching roll centers that make the buggy more consistent as the track conditions change.
The Hyper 9 runs stiffer front springs, and the front end rides higher. This, combined with the reduced weight, allows the buggy to jump further (chassis does not scrub off speed on face of jump) and recovers from landings faster (chassis does not bottom out as hard).