Enzo
and Mclaren
Chassis Set-Up
Weight Distribution
Weight distribution plays an important part in handling. Batteries are the heaviest
part of the car, and plays a large role in weight distribution. On X-Mods, you
can move the battery housing forward and back for weight distribution, but on
mini-z, it is fixed. The only way to change weight distribution is to change
the chassis length and using different motor mounts. Either MM mount that place
the motor ahead of the rear axel, the HM mount that place the motor on top of
the axel or the RM mount that place the motor behind the rear axel.
Enzo
and Mclaren
A standard 98mm chassis like the Mclaren has very close to 50/50 weight distribution. The Enzo has a slightly heavier nose due to the larger over hang in front of the car. The Enzo is a popular car for the modified class. With the long wheelbase and wide track, it is very stable, and goes where it is pointed with no deviation. However, during acceleration out of corner, the Enzo and Mclaren can spin out on a slippery track.
94mm
Ferarri 360 GTC
This is where a 94mm chassis comes in. With the shorter chassis, the rear axel is moved close to the battery. Weight distribution is around 47/53 for a 94mm car with a mid motor mount. During acceleration out of corner, the rear wheels are planted to the ground. A 94mm wheel base with a RM mount that place the motor behind the axel has even more traction out of corner. However, with the extra weight hanging back there, car tends to continue to over steer after the initial turn-in. Steering is also much more sensitive. Braking into the corner can easily cause a spin out. Also because the the 94mm chassis requires a shortened motor mount for the MM motor mount, the motor is place higher on the chassis than the normal MM mount to save space. The resulting higher CG would also cause more weight to be transfered to the rear wheel during acceleration.
86mm
Porsche 934 and 935
At the extreme end of the scale is a 86mm wheelbase rear motor mount like the Porsche 934 and 935. Weight distribution is around 44/56. The 934 is very twitchy. The rear loves to come around when entering a corner, but has good traction out of the corner. The 935 has longer overhang on both ends of the car, so is slightly more stable due to higher moment of inertia. The large tail on the end of the car also puts some aero force on the rear, and is much better handling than the 934.
Choosing a chassis length then depends on the traction condition. On my home track where is kept very clean and flat, traction is very good. Is hard to break traction even under full acceleration out of the corner. The Enzo with its stability and even weight distribution is the hands down winner. It is the fastest car around the track. On a more slippery track at Kenon, the 94mm car is definitely faster than the Enzo. With the Enzo, a slight excess throttle pressure cause a spin out on the track. With the 94mm Lamborghini Jota, the rear is planted to the track. Both cars have +3mm offset in the rear for even comparison.
94mm Jota with +3mm
rear wheel offset.
Pan car bodies made by PN and Atomic use 98mm chassis, so weight distribution is about 50/50. However, due to the downforce generated by both those bodies, they have exceptional traction in and out of corner as well as good stability. They are probably the next best thing to AWD.
Real life example of weight distribution is comparison between the Corvette and Porsche 911. The Corvette with the V8 has much more power advantage over the Porsche. However, the Corvette has the engine in the front while the Porsche has the engine in the rear. In 0-60mph acceleration runs, they are both dead even because the Corvette just can't get the power to the ground like the Porsche which has more weight over the rear wheel. However, in high speed passing from 60 mph on up where power is more important, the Corvette easily beat the Porsche.
The 911 is know for its evil handling with all the weight in the back. Only an expert driver can handle the car effectively. Is common for rookie driver to spin out in a 911. This is similar to mini-z.