This is a test drive of my 4 year old Proton Savvy compact car, 1149cc Renault D4F, 75BHP @ 5500rpm, 105nm @ 4250rpm, Galvanized high tensile steel monoque chassis, front wheel drived, sequencial gearbox (manual gearbox anatomy, no torque-converter), bore x stroke 69mm x 76mm, in-line 4, drive-by-wire throtle body, multi-port fuel injected, SOHC 16Valves. Front suspension is McPherson configuration, lower control arm mounted on square type subframe, rear suspension is programmed deflection torsion axle.
This gearbox is basically anatomically similar to a manual tranmission, having a single clutch plate and 5 foward ratios with reverse. The shifter in the gearbox is controlled by a hydraulic actuator and the clutch is controlled a hydraulic clucth actuator pump. The pressure for the hydraulic system is built by a main electrical pump.
There are some issues with the gearbox hydraulic main electrical pump due to insufficient electrical reservoir resulting in undervoltage during shifts which caused overheating, jamming and premature failure. Critical failure at 36,000 km millage. Replaced the main electrical pump which failed due to undervoltage resulting in loss of pressure for both the hydraulic shifter actuator and the hydraulic clutch pump. Manufacturer refuses to admit design fault. Basically the current ratings between hydraulic system and the cars electrical reservoir were mismatched. After expensive repairs, the same symptoms of rough and jerky gear changes still prevail and occasional overheating and jamming still occurs. Underpressure of actuator oil still results of rough recoil of the pump piston resulting in voilent shifts.
The problem is then rectified using a DIY 0.5 farad voltage condenser as an intermediate electrical reservior with low electrical impedance to account for the large current draw during shifts. The problem is then completely solved. There is no more rough shifts and the clutching action as surprisingly smooth and not jerky. Large current draw no longer affect the healamps as well as sensitive electronic equipments. Frequent, rapid and even arbitrary gearshifts are now permisible.
Other than that, this is a excellent car. High tensile steel compact chassis provides an extremly rigid platform which offers virtually no flex during extreme treshold cornering, the rear torsion axle is surprisingly stable on the straights and gives a 'passive rear wheel steering effect' allowing extremely sharp cornering where the car just sticks like a leech no matter how hard you yank it into and during corners. Recovery from understeer and oversteer is surprisingly easy. Lotus tuned handling evident. Low drag coeficient results in less fuel consumption on highways, and good stability at high speeds. Effective cruising speed is at 140-160 kmh, (90-100mph). Surprisingly stable and agile at high speeds. Very easy to yaw (low yaw angular inertia) into corners making is a excelent queue cutting car.
Understeer is minor due to lighweight engine and gearbox at the front as well as due to compensatory effects of the rear torsion axle.
This is a test drive to show the effect of the voltage condenser here on the shifting dynamics of the gearbox. Suburban test-drive is for increased shifts. Car is four years old and there is virtually no problem with the well built engine and chassis even after few years of very hard riding. The driving in this video is more subtle and does not include threshold cornering and full revving.