At the insistence of Toyota President Akio Toyoda, GR Yaris swept the market with a small rally cannon that could experience pure driving pleasure. This time, dr. Dr, a hard-core automotive media person who is keen to explain the knowledge of automotive machinery, was invited. If, let's discuss and analyze the characteristics and charm of GR Yaris's mechanical structure!
The original factory has laid the foundation of hot-blooded driving
Dr. If believes that gr Yaris's original suspension setting is relatively heavy on handling, because the original factory has set a certain degree of wheel Camber angle for GR Yaris - GR Yaris's front wheel Camber angle is about 1.7 degrees, the rear wheel is about 1.9 degrees, and the beam angle of the front and rear wheels is also set to slight Toe-in, thus providing excellent steering flexibility. Dr. If also believes that because the GR Yaris is a steel gun model with a wheelbase and a short body size, the beam angle setting should not be too aggressive, otherwise it will bring more neurotic and over-sensitive dynamic performance. Therefore, the station manager believes that if you want to increase the grip and limit in the corners in the future, perhaps it will be a good choice to add a Camber angle of about 0.1 to 0.2 degrees according to the original factory setting.
Gr Yaris is a steel gun model with a wheelbase and a short body size, and the beam angle setting should not be too aggressive.
Factory set to Toe-in orientation, can still be fine-tuned according to personal needs.
Incorporate the chassis design of its models
Gr Yaris's chassis structure is quite special, a combination of two different platforms at the front and rear - the front half uses a GA-B platform that is not much different from the regular Yaris, and the shock absorber is a McPherson-style structure, so it may take some effort to add camber angles. At the same time, the fixed position and method of the shock absorber seat are also similar to suzuki Swift and CITRO N Saxo, etc., using a single lock point instead of a multi-lock point design for large cars.
The shock absorber is in the form of a multi-link and has a high limit.
The rear half of the chassis is a GA-C platform similar to the CorollaAltis, Corolla Sport, C-HR and other mid-size models, and the shock absorber adopts a multi-link design to control the movement stroke and trajectory of the rear wheels with four connecting rods, thus providing excellent linear stability and a higher handling limit than the torque beam during intense driving. Another advantage of using multiple linkages is that it can avoid the problem that the torque beam structure is easy to enlarge tire defects and lack stability when using more ordinary tires.
Next, look at the adjustable mechanism in the chassis structure - Toyota original factory designed an adjustable screw with a scale in front of the lower arm, and when the adjustable screw is rotated, the lower arm can move left and right, and the bundle angle and Camber angle are fine-tuned. Unfortunately, the connecting rod in front of the rear wheel is not adjustable, otherwise GR Yaris can provide the owner with more room for beam angle adjustment in the original factory state.
By turning the adjustable screws, the bundle angle and Camber angle can be fine-tuned.
In the swingarm (leg) section, Dr. If believes that gr Yaris's original design is decent, but the internal seat is still made of traditional rubber, and if the owner needs to drive fiercely, he may need to change the hard rubber material.
The internal retaining seat can be changed according to the needs of the owner.
GR-FOUR drivetrain
Gr Yaris is equipped with the "GR-FOUR" four-wheel drivetrain, which was developed exclusively by Toyota's GR division and named after the past WRC car Celica GT-Four, in which the rear wheel differential itself is LSD, and the internal clutch plate structure can be individually assigned different torques to the left and right wheels, allowing the owner to carry out a large, long-distance traverse tail when pulling.
After test driving the GR Yaris last year, Dr. If believes that compared with his honda Civic Type-R FK8, the GR Yaris with a small body and four-wheel drivetrain has a lot more spare space when cornering - it can make up the throttle to accelerate out of the corner, and the route choice is quite free. In contrast, the Civic Type-R FK8, although the cornering performance is also quite strong, but due to the wider body and the inherent limitations of the front-wheel drive form, it requires the grip of the tires and the route choice is relatively limited.
Exclusive drivetrain delivers impressive performance.
Original equipment and detail adjustment
After driving the GR Yaris for the first time on the track, the station manager found that the MICHELIN PS4S, as the original tire, still had a fairly good and uniform wear performance after the station manager adopted the tire pressure setting of "4 psi lower than the original recommended value", and the original shock absorber damping setting could already provide quite sufficient support, so it was successfully avoided by the tire from tilting sharply in the bend, resulting in the wear and tear of the tire shoulder. But after looking at the direction of tire wear marks, the Camber angle of the front wheel may need to be increased a little more to make the steering more flexible and clean.
Dr. If believes that the original GR Yaris brake pad material may not be particularly competitive, because in terms of preliminary naked eye judgment, the metal content is not particularly large. What is more special is that GR Yaris adopts an inner and outer layered floating disc, not only the inner side of the aluminum alloy material can reduce weight, the outer disc can also be independently heated and expanded, without affecting the inside, thereby increasing the heat dissipation efficiency and rigidity.
Dr. If believes that the original brake pads are large, and the strength and area of the brakes have a certain level.
Gr Yaris's original brake pad material is not competitive, and the metal content is not particularly high.
Dr. If found that gr Yaris's disc fin design is quite special, contrary to the common design direction, and the left and right side of the heat fins also have their own design, so that the left and right heat fins can be rotated in the same direction. However, the purpose of Toyota's original design, there seems to be no credible statement and information on the Internet at present, and more research is needed.
Gr Yaris discs are made of aluminium alloy on the inside and general iron on the outside, which can effectively reduce weight.
Discs have different designs for heat sinking fins.
Two performance upgrade directions: Dr. What do you say if?
For owners who are just starting with GR Yaris and intend to drive fiercely and experience the performance and pure fun brought by GR Yaris, Dr.If is divided into two orientations to provide advice - the first is the same as the station manager, the owner of the paved road, track day driving, etc., can first start from the tires, braking system and other aspects of the upgrade, and the performance of the original shock has been quite good, but if there is a need to make the vehicle center of gravity lower, the grip is stronger, naturally have to upgrade the shock absorber again.
For paved roads and rally driving, Dr.If gives two upgrade directions.
Dr. If believes that if track driving is the mainstay, it is possible to upgrade the tires and braking system.
Another orientation is pull driving - Dr. If believes that GR Yaris, which was born for the WRC, has a shock set that is quite suitable for pull driving, and can also naturally and obviously move the load of the vehicle to flick the tail, so the only part that must be changed is the tire and hydraulic hand brake.
If you are oriented to pull driving, the choice of tires is particularly important.
In the power modification part, the intake and exhaust system kit for GR Yaris has mushroomed in the market. The computer part, the more entry-level choice has about 20 to 30 horsepower plug-in computer, and if there is a heavy demand for power improvement, it is natural to consider the full replacement computer produced by SYVECS, MOTEC and other manufacturers, but the full replacement computer is also quite a test of the tuning technology of the modification technician.
The GR Yaris computer section already has a variety of options that owners can modify according to their needs.
Finally, Dr.If also added that the chassis reinforcement is also a category of parts worth choosing - tie rods, adjustable arms and other kits, in fact, domestic manufacturers already have a fairly rich product lineup, which can meet the needs of car owners who want to further strengthen rigidity or increase the adjustable range of Camber angle. The tripod on the front wheel of gr Yaris already has a hard rubber bushing, which basically does not need to be replaced, but the rubber sleeve of the retainer of the swingarm still has room for upgrading.
Power lifting and chassis modification are selected according to individual needs.