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Or maybe it's not scary if the racks are tired? And even when the shock absorbers stopped sweating a long time ago, why not continue the trip, if quietly and not far? Together with the Kayaba company, which ate the dog on the dampers, we got the elderly Logan in good condition and went to the Smolensk Ring.
Why exactly this car? Because for almost ten years these workhorses have been riding around the country, winding thousands of runs in private hands and in taxis.
Seriously fearing a coup on unusable shock absorbers, we installed a racing seat and multi-point seat belts
Seriously fearing a coup on unusable shock absorbers, we installed a racing seat and multi-point seat belts. Seriously fearing a coup on unusable shock absorbers, we installed a racing seat and multi-point seat belts.
Our copy was purchased from a caring owner - with a mileage of 70, 000 km, with native shock absorbers. After a series of measurements, he was assigned the role of dummies: salt the oil from them and simulate the situation when the owner completely launched the chassis. And at the other extreme there will be gas-filled KYB Excel-G shock absorbers, just out of the box.
What is good about the Smolensk ring? Bright boxes with electric and water supply, where we will change the suspension and drill racks, liked our technical team. But more importantly, you can complexly load the car at the circuit. Zarulevsky tests for lap times are tests for brakes, chassis, engine … It is worthwhile to find out the weak link in this bunch, and do not expect good results. So let's see how the condition of the shock absorbers will affect the time the route passes, all other things being equal.
To simulate the situation when the shock absorbers became completely unusable, we drilled holes in suitable racks and drained working fluid from them
To simulate the situation when the shock absorbers became completely unusable, we drilled holes in suitable racks and drained working fluid from them. To simulate the situation when the shock absorbers became completely unusable, we drilled holes in suitable racks and drained working fluid from them.
In addition, the race track is smooth asphalt, on which we simulate emergency braking on an intercity highway. And we’ll try to stop with a ride on the curb - a concrete "Christmas tree", which limits the working track of the circuit. It is more slippery and with a pronounced relief - we’ll check how the car behaves without shock absorbers when braking on bumps.
RUNNING AROUND
First, we will carry out races on standard shock absorbers. Frankly speaking, the pleasure of riding on the racing ring on the Logan with a 1.4-liter engine with 75 horsepower is not enough. While it accelerates into straight lines, you can complete the task in the game "Need for Speed"! And in half the turns, where sports cars have to be upset, this Renault can not be slowed down at all. However, the car is harmonious and well balanced, even if the lap time and pensioner's time: 2 minutes 15.4 seconds. Slower in the history of our measurements was only “Lada-114”, tired of serving in the traffic police, and only then for one and a half seconds.
As you know, the suspension consists of guides, elastic and damping elements. If you get rid of the shock absorber, there will be nothing to damp vibrations
As you know, the suspension consists of guides, elastic and damping elements. If you get rid of the shock absorber, there will be nothing to damp vibrations. As you know, the suspension consists of guides, elastic and damping elements. If you get rid of the shock absorber, there will be nothing to damp vibrations.
We change racks to gas-filled "kayaba" - and again to the track. Subjectively, “Logan” became a little more focused, denser and clearer in reactions, but the supercar, of course, did not turn around. The gain on the circle thanks to the new stances is small: exactly a second. We mount empty shock absorbers, roll out of the box … Mom dear! A small difference in coatings when leaving for the pit lane - and "Logan" turns into jellied meat, swaying gradually on the springs. There is nothing to suppress the oscillations!
In the paddock of the Smolensk Ring, it’s spacious enough to place the cones for the “rearrangement” exercise and accelerate to 100 km / h
In the paddock of the Smolensk Ring, it’s spacious enough to place the cones for the “rearrangement” exercise and accelerate to 100 km / h. In the paddock of the Smolensk Ring, it’s spacious enough to place the cones for the “rearrangement” exercise and accelerate to 100 km / h.
The first two laps go cautiously. The Smolensk Ring, which seemed perfectly flat, turned out to be not so. There is a joint invisible to the eye, there is a small wave - and the Renault reacts like jelly to every change in profile. And if the roughness coincided with the movement of the body during braking, acceleration or cornering … At first it’s scary - but how will we turn over? But then we go, dancing, fidgeting in bends with the front axle and the rear, and we laugh stupidly.
All cars are designed to minimize the risk of a coup. Even with empty racks, the Logan performed a glide maneuver, remaining on wheels
All cars are designed to minimize the risk of a coup. Even with empty racks, the Logan performed a glide maneuver, remaining on wheels. All cars are designed to minimize the risk of a coup. Even with empty racks, the Logan performed a glide maneuver, remaining on wheels.
Roller coaster in a children's amusement park, and more! Complained that the Logan’s normal suspension is too bland? So they got entertainment: they didn’t roll over, but they’ve plenty of driving and gas. The lap time is worse, but not radically: 2 minutes 16 seconds, that is, about half a second is inferior to the result with native racks and one and a half - with Kayaba.
Hush and iron
We turn to braking on smooth asphalt. We unroll “Logan” to 105 km / h, turn on “neutral” and, as soon as the display of the measuring complex shows a hundred, we brake to the floor. Briefly groaning the tires to the beat of the anti-lock braking system, after the first three brakes, the car on standard shock absorbers freezes at around 46.3 meters. Then the brakes heat up and the results begin to deteriorate: first by a meter, then by one and a half, two … On the tenth meter, the Logan measured only after 52.5 meters!
Objectively, “Logan” on killed racks overcomes the ring not much more slowly, but the sensations are not pleasant. And if the car was more powerful, it would be impossible to manage it
Objectively, “Logan” on killed racks overcomes the ring not much more slowly, but the sensations are not pleasant. And if the car was more powerful, it would be impossible to manage it. Objectively, “Logan” on killed racks overcomes the ring not much more slowly, but the sensations are not pleasant. And if the car was more powerful, it would be impossible to manage it.
Shock! Scary lot! The braking distance from 60 km / h on the comb of a car without shock absorbers can grow by 10 and 15 meters
But the first stable results already provide a starting point. Will new racks help in this discipline? Not. While the brakes do not overheat, the car slows down at the level of 46.5 meters. And if you put the “leaked” shock absorbers, then the results are stable, but not important - in the first five measurements, “Logan” shows from 50.0 to 50.2 meters to a complete stop. It is obvious that during sudden braking, the weight is intensively redistributed to the front axle, empty shock absorbers during the rebound allow the stern to soar upward - and the anti-lock system reduces the pressure in the line. The car rolls longer, but the brakes are less loaded. So, the loss, even on smooth asphalt with unusable stands - about 4 meters.
RASKOLBAS
When braking from 60 km / h, a working vehicle needs 25–26 meters to stop on the comb. In this place they built a wall of cardboard blocks
When braking from 60 km / h, a working vehicle needs 25–26 meters to stop on the comb. In this place they built a wall of cardboard blocks. When braking from 60 km / h, a working vehicle needs 25–26 meters to stop on the comb. In this place they built a wall of cardboard blocks.
We talked recently about how the anti-lock braking system works on rough roads (ЗР, 2013, No. 8). And they even conducted an experiment to find out how much the braking distance is increased compared with the result on smooth asphalt (ЗР, 2012, No. 12). This time we compare the efficiency of deceleration on the comb on different shock absorbers.
They braked from the “urban” 60 km / h, when the wheels of one side rolled on a flat surface, and the other - galloped on the curb of the circuit. Serviceable shock absorbers, which covered 70, 000 km, coped with the task with dignity. From the side it is seen that the wheels try to snuggle up to the surface after each jump, the anti-lock system does not freeze, the car maintains directional stability with a decent deceleration. Although, of course, it is worse than when braking on a flat surface: there the acceleration was 0.8–0.95 g, and here the limit is lower and the range is wider - from 0.5 to 0.8 g. After all, the hook appears and disappears.
If the shock absorbers are faulty, stopping on time fails. With a thud, the barely braking Logan blows an obstacle
If the shock absorbers are faulty, stopping on time fails. With a thud, the barely braking Logan blows an obstacle. If the shock absorbers are faulty, stopping on time fails. With a thud, the barely braking Logan blows an obstacle.
Surprisingly, the installation of new KYB racks gave only slight improvements: like many of the hard-working native racks, Logan stopped, running 25-26 meters. But when they put empty shock absorbers … Even before the start of braking, it was worth dropping the wheels onto a concrete "Christmas tree", the wheels started to sausage - in other seconds both hung in the air! The slowdown chart jumped from 0.2 to 0.6 g. Accordingly, the braking distance has grown. And the most unpleasant thing is that stability has disappeared: sometimes the Logan had enough 35 meters to stop completely, and sometimes it rolled out beyond the 40-meter mark.
To demonstrate the consequences of the accident due to malfunctioning racks, a mock deer was sent for slaughter - such as archers are used as targets
To demonstrate the consequences of the accident due to malfunctioning racks, a mock deer was sent for slaughter - such as archers are used as targets. To demonstrate the consequences of the accident due to malfunctioning racks, a mock deer was sent for slaughter - such as archers are used as targets.
What does it mean? On an uneven surface, a car with a faulty chassis will assemble a train of two or three cars. Or does not stop before a pedestrian crossing. Moreover, the speed with which he will fly on a zebra, with luck, will be about 30 km / h, and if not, then all 40 km / h! In this case, what happens to the 75 kg mannequins, we checked in ZR, 2012, No. 2. Pedestrians have almost no chance of surviving a collision at this speed.
So driving with dead racks is like carrying a loaded gun with a defective fuse. It may, of course, not fire, but I absolutely do not want to check it.
Before knocking down a mannequin, they tried to go around it. This is real, although a machine without shock absorbers makes special demands on the pilot
Before knocking down a mannequin, they tried to go around it. This is real, although a machine without shock absorbers makes special demands on the pilot. Before knocking down a mannequin, they tried to go around it. This is real, although a machine without shock absorbers makes special demands on the pilot.
BEFORE WARRANTY
According to the major dealer of Renault - the company Mosrent-service, the suspension of the Logans is tenacious. To finish off shock absorbers to 70, 000 km, it is necessary to try very hard. On average, with a mileage of 80, 000–90, 000 km, racks are 70% alive and finally lose their effectiveness closer to a mileage of 150, 000 km. Thus, while the owner is tied to the service with a three-year warranty, it is possible to diagnose a malfunction of the suspension in the early stages. Then, with high mileage, the technical condition of the chassis depends on the vigilance of the driver and the level of service where he is served.
When braking without shock absorbers, it remains only to wait for a poorly controlled car to smash a deer into pieces
When braking without shock absorbers, it remains only to wait for a poorly controlled car to smash a deer into pieces. When braking without shock absorbers, it remains only to wait for a poorly controlled car to smash a deer into pieces.
DEADLINE
At what mileage do you need to change shock absorbers?
The replacement period for shock absorbers largely depends on operating conditions and the condition of other suspension elements. For example, a dead spring more than two and a half times reduces the life of the shock absorber.
Kayaba recommends changing shock absorbers every 70, 000 km in Russia and every 80, 000 km when operating a car in Europe, conducting diagnostics every 20, 000 km.
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How to understand that this moment has come?
Damage to the shock absorber rod, a large number of oil smudges speak for themselves. But even an outwardly working element can be worn out. Have to constantly steer? Are you getting tired of driving more and more at the same distance? Did large peaks appear at start-up and during braking? Increasingly, the car, swaying, dazzles oncoming drivers, and uneven wear on the tires? Urgent diagnosis!
Is it possible to independently determine the effectiveness of shock absorbers?
The old-fashioned way - to rock the car body - will help to determine only two “extreme” states: the damper is completely out of order or it wedges. The resistance of the multi-link suspension elements generally does not allow to determine the condition of the shock absorbers by this method. We must go to the service station, where professionals, turning to the help of stands, test trips and examinations, will reach a verdict.
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Does the life of the shock absorber depend on age?
Slightly. Although the shock-absorbing fluid loses its original properties over time, this does not significantly affect the performance of shock absorbers. Oil seals and silent blocks of shock absorbers are more susceptible to aging.
What can be done to increase the service life?
Do not exceed the carrying capacity, do not expect longevity from standard suspensions in races, try to drive holes at low speeds. In the cold season, the first 500 m after parking, move slowly to bring the shock absorbers into operation.
Change the shock absorbers in pairs and check the condition of the suspension every 20, 000 km.