machine-spec

KS-20

-Challenge to evolution-


Powertrain / Drive

Easy to use output characteristics


FOR THE KS-20, WE OPTIMIZED THE FINAL DRIVE RATIO AND POWER CHARACTERISTICS TO SUIT THE NEW COURSE, AND INTRODUCED A NEW LSD, WHICH RESULTED IN A SOLID IMPROVEMENT IN TIME IN THE STRAIGHT SECTION FROM THE EXIT OF THE CORNER TO THE NEXT BRAKING POINT. WE ALSO COMPLETELY REDESIGNED THE FUEL TANK, AND RECONSIDERED THE COOLING TARGET.


・LSD SELECTION

Last year's machine, the KS-19, exhibited very peaky behavior when exiting corners. To address this issue, we worked with IKEYAFORMULA to develop an active LSD compatible LSD exclusively for Student Formula cars, and installed it in the KS-20.
This resulted in stable traction, further improvements to cornering ability for the new course which has a higher proportion of low-speed corners, and improved setting capabilities to handle a variety of road conditions.

Output characteristics suited to the course

After determining the final gear ratio and analyzing the course, we predicted that the normal rotation range of the KS-20 would be 7000rpm to 11000rpm. The power band would be within this range, and we aimed for engine characteristics that would produce power efficiently so that we could reduce times on the straight sections of the course.

- Maximum cooling performance

DESPITE AN ATTEMPT TO IMPROVE COOLING PERFORMANCE BY THICKENING THE RADIATOR CORE ON THE KS-19, THE WATER TEMPERATURE ROSE TO 119°C IN THE LATTER HALF OF THE ENDURANCE RUN AT LAST YEAR'S COMPETITION. CONSIDERING THAT THE NORMAL ROTATION RANGE FOR THE KS-20 HAS RISEN DUE TO A CHANGE IN THE FINAL DRIVE RATIO, AND HEAT GENERATION HAS INCREASED BY 8%, WE AIMED TO IMPROVE COOLING PERFORMANCE BY 20% COMPARED TO THE KS-19 AND KEEP THE MAXIMUM WATER TEMPERATURE AT THE RADIATOR INLET BELOW 100°C. WE APPROACHED THIS BY IMPROVING THE HEAT DISSIPATION CAPACITY OF THE RADIATOR AND INCREASING THE MASS FLOW RATE OF THE AIR PASSING THROUGH THE RADIATOR.

・Stable fuel supply

IN THE KS-19, AIR WAS MIXED INTO THE FUEL IN THE LATTER HALF OF THE ENDURANCE RACE. IN THE KS-20, WE RECONSIDERED THE TANK CAPACITY TO MATCH THE NEW COURSE, THE SHAPE OF THE COLLECTOR TANK, THE LOCATION OF THE FUEL OUTLET FROM THE REGULATOR BACK TO THE TANK, AND THE SHAPE OF THE BAFFLE PLATE, AND DESIGNED IT WITH THE GOAL OF PREVENTING AIR MIXING DURING ENDURANCE RACES.


Frame/Body

Extremely lightweight

The frame accounts for approximately 15% of the total weight and is a part that spans the entire machine, so its weight and rigidity have a large impact on the vehicle.
Therefore, in order to achieve the machine concept, the frame concept was based on reducing weight and ensuring torsional rigidity without affecting the roll rigidity distribution of the suspension.


- Review of layout

By reviewing the mounting positions of each part of the machine, we were able to reduce the number of pipes and the length of each pipe, successfully reducing the weight of the KS-19 to KS-20 by 5.0 kg. In addition, we addressed the loss of rigidity and the reduction in driver space that came with the weight reduction by reviewing the suspension geometry and making the cockpit more compact.

・ADOPTION OF REAR BULKHEAD (RBH) STRUCTURE

The rear section receives a large amount of input from the drive force and suspension. The KS-20 employs a rear bulkhead (RBH) structure to further reduce weight while still ensuring strength and rigidity.

-High rigidity

A cockpit support brace has been installed, and pipes that form a truss structure at the wide opening and suspension input points have been added to ensure greater torsional rigidity.


Aero

Wind for Speed

This year's machine is designed with a focus on improving limit performance by increasing downforce, while also improving powertrain performance through air guidance and enabling settings to be tailored to suit the situation.


・Front wing

The airfoil shape was changed to one that can utilize the ground effect. This enabled us to generate downforce while reducing drag. In addition, to improve separation, the spacing between the multi-element wings was narrowed, and separation on the underside of the wing was suppressed by supplying air to the upper surface of the wing.

・Rear wing

With the goal of improving downforce, the overall width of the flaps was increased, leading to an increase in the pressure generation points. The rods on the underside of the wing were eliminated, eliminating any obstruction to the underside flow and improving flow speed. In addition, the angle of attack of each flap was increased by 5 degrees (compared to the previous year) to increase the pressure difference between the upper and lower surfaces.

Optimized cooling

One of the issues with last year's machine was the lack of airflow through the radiator, despite the thicker radiator core. To solve this issue, we adopted a sidepod shape with a tapered tip to keep the turbulent air away from the rear of the tire and to take in the fast-flowing air passing under the suspension arm.


Suspension

Tractable -Easy to handle-


IN THE SUSPENSION DEPARTMENT, WE AIMED TO CREATE A MACHINE THAT WOULD BE EASY FOR THE DRIVER TO HANDLE AND WOULD BE ABLE TO MAINTAIN SPEED. SINCE IT WAS EXPECTED THAT THE LAP TIME WOULD DECREASE AS THE MACHINE BECAME EASIER TO HANDLE, WE ALSO AIMED TO KEEP THE LAP TIME FROM BEING SLOWER THAN THE KS-19.


- Goal-based layout

The layout was determined based on the results of simulations, with "ease of handling" as the target, in the order of wheelbase and tread, front/rear weight distribution, and center of gravity height.

-The best shoes for your machine

In order to reduce weight and lower the center of gravity, the wheel diameter was narrowed down to 10 inches, and among the tires that would achieve the target time, the tire with the smallest pneumatic trail was selected to minimize steering force as much as possible. In addition, the wheel was decided to be the lightweight "BRAID STURACE Aluminium 10", which is a one-piece wheel that ensures reliability.

-Exploring geometry

To ensure stable maneuverability and high level of settling, each geometry was determined based on the maximum roll angle measured on last year's machine using logger data.

・"Durable" and "light" suspension

By optimizing the diameter and thickness of the pipes for strength and rigidity, and dispersing stress by bringing the angle with the pull rod close to 0°, we have succeeded in reducing the weight by 1,988g while maintaining a safety factor of 3 or more at maximum load, camber change of 0.3° and toe change within 0.1° when driving on the skid pad.

・Unsprung weight

In order to achieve the target of "stable handling," it was important to reduce the unsprung weight. We achieved this by thoroughly selecting the hub bearings, and analyzing the uprights and hubs.

- Control even the most minute movements

To achieve "steady handling," we made the springs stiffer to reduce the amount of roll, and designed the damping force to be optimal in order to minimize changes in vehicle height and ground load.