Maximising Cornering Speed via Tilt Cornering: Roller Width 105mm, Roller Length 110~125cm Front roller in line with centre of gravity/ car axle. Roller angle should be at minimum ~ 1-3 degrees. Front roller Height < Rear Roller height. 3rd set of rollers (balancing rollers) is optional but should have a smaller diameter than your main rollers. The aim here is to achieve a tilt cornering, ie the outer rims do not touch the track at all during cornering, greatly reducing cornering drag. A narrow wheel base would allow for an easier tilt, though a wider wheel base can achieve a faster cornering if tilt cornering is achieved.

Tech Course: Roller Width 90mm~95mm. Balancing roller preferably placed in front as low as possible (ie having faster reaction time for the car to return to track during a jump). Angle should be 5~10 degrees depending of difficulty of track. O-rings and rubber caps for rollers can be added to help the car stay on track. (Might not be the fastest setting to clear tech tracks, just based on my own experience).
Reducing Resistance:

Resistance is what slows your car down. There are many types of resistance: i) contact friction, ii) weight, iii) aerodynamic drag.

i) Contact Friction- Points of contact for moving parts should have as little resistance as possible. Using ball bearings for all moving parts is essential. Place a spacer (those used for ball race rollers) in between the wheels and chassis help reduce contact friction.

ii) Weight- Contrary to popular belief, a heavier car might not be a more stable car. I'd be using a bit of science here to explain.

For every action there will be an reaction. ie a force that acts in the opposite direction to the forward applied force. All cars have a centre of gravity (CG). This CG remains at rest if the car is at rest. However when the car moves forward the CG will move back. Thus this explains why SFM are very good for tech tracks.

Now we look at the equation F=ma, where F is the resultant force, m is the mass of object and a is the acceleration. If our cars are heavy, this means our m is of a higher value. Given constant acceleration, the heavier car will have a greater momentum when it jumps thus making it fly further.

But what do we have to do in order to let our car remain light yet stable (in terms of weight). The answer is to shift the CG as close to the front as possible. This is why SFM and MS PRO are considered quite stable chassis. Either that or use mass dampers (old school set up of stacking rollers in stabilising pole is an example of this) that can alter the position of CG during jumps. Besides, a lighter car can achieve better acceleration and reach top speed much faster.

iii) Aerodynamic Drag

An aspect I feel many seldom pay attention to. Try using covers that have as little perpendicular surface as possible. This is why covers with low ride height tend to run faster as well. Some good covers would be Strato Vector, Tiger Zap (Super FM, TZ) Astute, Super Avante (Zero, VS) as well as T.Shot Mk II and Veldaga =P (MS PRO)

Having "tunnels" on the covers (air intake > air out-take) will create an area of low pressure inside the tunnel, creating downforce. Secondly the air coming out from the tunnel will also give that extra push to your car.

This effect was tested on my old Boomerang Fury with a ride height of only 2.5cm. The time without cover was 0.5s slower than when I put the cover  . I intend to add this to my currrent ride when I can find clear plastic pla-plates.