Head of Technical Department

and climatic tests Alexander BALYKIN,

Alexander LYUBIMOV, head of the braking systems debugging bureau, Sergey MISHIN, test engineer of the special tests department.

I want to equip the Niva with an electric fan for the cooling system. How can this affect the thermal regime of the engine?

It is not for nothing that the Niva has a six-bladed fan impeller. Thus, its efficiency is slightly increased in comparison with the four-blade "Zhiguli". But the technical characteristic of the fan driven by the belt is tied to the engine speed. If the latter operates at low speeds (for example, riding “vnatyag” in top gear at low speed, 40-50 km / h), then the fan is relatively ineffective. Even worse, it idles and stops. But imagine driving in harsh conditions - say, through mud or sand - in low gear! In this case, especially if circumstances force the use of high revolutions, the air flow created by the fan is correspondingly enhanced.

As for the electric fan, its rotation speed is almost constant (about 2700 rpm). This is acceptable for a car operated, for example, in a city - overheating in a traffic jam is excluded. But in heavy modes, the electric fan is sometimes not enough. Given the variety of factors affecting the thermal regime of the engine, two fans are provided on the new Niva (VAZ 2123): mechanical and electric.

Consider the above - and take your time with the experiments. After all, overheating of the engine can result in a very expensive repair.

Can I install a 2103 vacuum brake booster on the VAZ 2121 instead of the 2108?

Such a replacement is possible, but not recommended. Firstly, vacuum amplifiers 2103 and 2108 are designed for different main cylinders (2101 and 2108, respectively), the purchase of which is an additional waste of money. Secondly, the "eight" vacuum amplifier in conjunction with the main brake cylinder 2108 provides less pedal travel with slightly less effort.

What is the purpose of the large hole in the front shield next to the air intake box on the side of the spare wheel covered with a rubber plug?

A wiring harness for the injection system on vehicles 21214 passes through this hole.

Many believe that the "Niva" switchable four-wheel drive. Recently I argued about this with a friend, but could not prove that he was wrong: he believes that the front axle is connected with the lock lever …

Niva has a permanent all-wheel drive or, as they say, permanent all-wheel drive. Why is this done?

First, safety wins. The total traction power of the machine is divided between the axles, the risk of slipping of any of them is approximately half that of the classic "Lada" or front-wheel drive "Samara". This means that the likelihood of demolition of the front axle or skidding of the rear is half as much. If one of the bridges is switchable, then the driver in extreme situations should be equally good at controlling techniques, for example, rear-wheel drive and all-wheel drive cars, and this is not accessible to everyone. If the car is always four-wheel drive, then the driver gets used to the features of his behavior. So, under certain conditions, slipping or sliding of the wheels of one or the other axis is possible. But a well-mastered machine is quite predictable - and therefore safer than with a single-axis drive.

Secondly, four-wheel drive is always a high cross! The driver does not need to consider whether or not to include a “resting” bridge. They often remember this when it’s too late - the car sat down.

Finally, we take into account the possibility of production. When creating the “Niva”, it was required to make maximum use of the already mastered “Zhiguli” parts, in particular the gearboxes of both axles - from a passenger car. But the total mass of the Niva is 1550 kg, while the heaviest of the VAZ 2106 Lada has 1450 kg. In addition, the torque transmitted through the transfer case increases by 1.2 or 2.135 times - with the operation of one bridge it is much larger than that of the Zhiguli. If there were no "sharing" of torque between the axles, the load on the gearbox would be excessive. For those who turn off the front axle, it’s useful to remember that in this case the transmission parts fail much faster - the expensive one is “saving”!