hal menarik dari masukan operator lapangan ttg mobil yg baru disuplay
Ada hal menarik dari masukan operator lapangan ttg mobil yg baru disuplay, katanya mobil lama ( no modif – Cuma ganti ban MT ) bebih enak di gunakan – so modifikasi jadinya malah tambah tak enak – goyang – tak lincah ( bumper nongol ) handling jadi aneh. Artinya modifikasi tak ada benefitnya. So harus dicari solusi dari deasin awal. Pemasangan bulbar . berat – tak ada crumple zone ( berbahaya & not airbag compatible ) .saat kecelakaan akan merusak chasis & energy tabrakan di terima penumpang tak ada yg terserap ( bisa sangat berbahaya – mematahkan tulang rusuk & kaki ) > solusinya bulbar harus di buat seramping mungkin & berat tidak lebih 50 kg ( kekuatan di peroleh dari tekuan – bahan besi – proses pemotongan /Lasercut – pengelasan –mig . dudukan winch harus diperkuat dgn braket khusus – harus ada Hilift Jack point di bulbar – 3 antena mounting – dudukan aux lamp, braket untuk memperkuat cumplezone di mobil – penambahan crumplezone di bulbar ( harus bisa menyerap energy tabrakan - , ada dudukan untuk 3 keping skid plate . desain bentuk harus aerodinamis untuk deflect abgin & air secara maksimal & tanpa mengurangi volume udara untuk mendinginkan radiator Jadi pemasangan bullbar ada benefitnya – mobil tetap bisa digunakan pada saat terjadi kecelakaan ringan – dapat meyerap energy tabrakan untuk meminimallan resiko cedera & kerusakan chassis mobil lebih kuat dibanding standart – ada tempat untuk winch /lampu /antenna /skid plate /memperbaiki aprooch agle Hitungan energi tabrakan A car with a mass of 2000 kg drives in 60 km/h (16.7 m/s) before it crashes in a massive concrete wall. The front of the car impacts 0.5 m (slow down distance). The impacting force can be calculated as F = 1/2 (2000 kg) (16.7 m/s)2 / (0.5 m) = 558 kN ( 558000 joule/meter ) Note that the gravitation force acting on the car is Fw = m g = (2000 kg) (9.81 m/s2) = 19.6 kN
Suspensi – apa yg kita mau cari Nyaman dikota ( kecepatan 60km < / nayman di high speed 100-150km/ntyaman di jalan rusak 60km
Mofif mesin untuk HP > No, untuk daya tahan oke
Crumple zones are designed to absorb the energy from the impact during a traffic collision by controlled deformation. This energy is much greater than is commonly realized. A 2,000 kg (4,409 lb) car travelling at 60 km/h (37 mph) (16.7 m/s), before crashing into a thick concrete wall, is subject to the same impact force as a front-down drop from a height of 14.2 m (47 ft) crashing on to a solid concrete surface. Increasing that speed by 50% to 90 km/h (56 mph) (25 m/s) compares to a fall from 32 m (105 ft) - an increase of 125%. This is because the stored kinetic energy (E) is given by E = (1/2) mass × speed squared. It increases by the square of the impact velocity. Typically, crumple zones are located in the front part of the vehicle, in order to absorb the impact of a head-on collision, though they may be found on other parts of the vehicle as well. According to a British Motor Insurance Repair Research Centre study of where on the vehicle impact damage occurs: 65% were front impacts, 25% rear impacts, 5% left side, and 5% right side. Some racing cars use aluminium, composite/carbon fibre honeycomb, or energy absorbing foam to form an impact attenuator that dissipates crash energy using a much smaller volume and lower weight than road car crumple zones. Impact attenuators have also been introduced on highway maintenance vehicles in some countries. An early example of the crumple zone concept was used by the Mercedes-Benz engineer Béla Barényi on the mid 1950s Mercedes-Benz "Ponton". This innovation was first patented by Mercedes-Benz in the early 1950s. The patent 854157, granted in 1952, describes the decisive feature of passive safety. Barényi questioned the opinion prevailing till then, that a safe car had to be rigid. He divided the car body into three sections: the rigid non-deforming passenger compartment and the crumple zones in the front and the rear. They are designed to absorb the energy of an impact (kinetic energy) by deformation during collision.
Crumple zones work by managing crash energy, absorbing it within the outer parts of the vehicle, rather than being directly transmitted to the occupants, while also preventing intrusion into or deformation of the passenger cabin. This better protects car occupants against injury. This is achieved by controlled weakening of sacrificial outer parts of the car, while strengthening and increasing the rigidity of the inner part of the body of the car, making the passenger cabin into a 'safety cell', by using more reinforcing beams and higher strength steels. Impact energy that does reach the 'safety cell' is spread over as wide an area as possible to reduce its deformation. Volvo introduced the side crumple zone with the introduction of the SIPS (Side Impact Protection System) in the early 1990s. When a vehicle and all its contents, including passengers and luggage are travelling at speed, they have inertia / momentum, which means that they will continue forward with that direction and speed (Newton's first law of motion). In the event of a sudden deceleration of a rigid framed vehicle due to impact, unrestrained vehicle contents will continue forwards at their previous speed due to inertia, and impact the vehicle interior, with a force equivalent to many times their normal weight due to gravity. The purpose of crumple zones is to slow down the collision and to absorb energy to reduce the difference in speeds between the vehicle and its occupants. Seatbelts restrain the passengers so they don't fly through the windshield, and are in the correct position for the airbag and also spread the loading of impact on the body. Seat belts also absorb passenger inertial energy by being designed to stretch during an impact, again to reduce the speed differential between the passenger's body and their vehicle interior. In short: a passenger whose body is decelerated more slowly due to the crumple zone (and other devices) over a longer time survives much more often than a passenger whose body indirectly impacts a hard, undamaged metal car body which has come to a halt nearly instantaneously. It is like the difference between slamming someone into a wall headfirst (fracturing their skull) and shoulder-first (bruising their flesh slightly) is that the arm, being softer, has tens of times longer to slow its speed, yielding a little at a time, than the hard skull, which isn't in contact with the wall until it has to deal with extremely high pressures. The stretching of seatbelts while restraining occupants during an impact, means that it is necessary to replace them if a vehicle is repaired and put back on the road after a collision. They should also be replaced if their condition has deteriorated e.g. through fraying or mechanical or belt mounting faults. In New Zealand it is officially mandatory to replace worn inertia reel type seatbelts only with 'webbing grabber' type belts that have less play and are more effective on older cars.Newer cars have electronically fired pre-tension seatbelts that are timed to work with the airbag firing. Buying used seatbelts is not a good idea even in countries where it is legal to do so, because they may have already been stretched in an impact event and may not protect their new users as they should. The final impact after a passenger's body hits the car interior, airbag or seat belts is that of the internal organs hitting the ribcage or skull due to their inertia. The force of this impact is the way by which many car crashes cause disabling or life-threatening injury. Other ways are skeletal damage and blood loss, because of torn blood vessels, or damage caused by sharp fractured bone to organs and/or blood vessels. The sequence of energy-dissipating and speed-reducing technologies—crumple zone — seat belt — airbags — padded interior—are designed to work together as a system to reduce the force of the impact on the outside of the passenger(s)'s body and the final impact of organs inside the body. In a collision, slowing down the deceleration of the human body by even a few tenths of a second drastically reduces the force involved. Force is a simple equation: Force = mass X acceleration. Cutting the deceleration in half also cuts the force in half. Therefore, changing the deceleration time from .2 seconds to .8 seconds will result in a 75 percent reduction in total force.
A US Market Ford Escort that has been involved in an offset head-on collision with a Sport Utility Vehicle - showing the raised point of impact - missing the car crumple zone. A misconception about crumple zones sometimes voiced is that they reduce safety for the occupants of the vehicle by allowing the body to collapse, therefore risking crushing the occupants. In fact, crumple zones are typically located in front of and behind the main body of the car (which forms a rigid 'safety cell'), compacting within the space of the engine compartment or boot/trunk. Modern vehicles using what are commonly termed 'crumple zones' provide far superior protection for their occupants in severe tests against other vehicles with crumple zones and solid static objects than older models or SUVs that use a separate chassis frame and have no crumple zones. They do tend to come off worse when involved in accidents with SUVs without crumple zones because most of the energy of the impact is absorbed by the vehicle with the crumple zone — however, even for the occupants of the 'worse off' car, this will still often be an improvement — as the result of two vehicles without crumple zones colliding will usually be more hazardous to both vehicle's occupants than a collision that is at least partly buffered. Another problem is 'impact incompatibility' where the 'hard points' of the ends of chassis rails of SUVs are higher than the 'hard points' of cars, causing the SUV to 'override' the engine compartment of the car. In order to tackle this problem, recent Volvo SUV/off-roaders incorporate structures below the front bumper designed to engage lower-height car crumple zones.
A DEEPER LOOK AT SPRING VS. AIR Suspension systems contribute to a tractor-trailer’s road handling and ride quality (the vertical acceleration to which a tractor-trailer is exposed). Keeping the tires in contact with the road as much as possible, suspension systems help minimize the amount of jarring (bumps, vibrations) for improved load-carrying ability, protecting the trailer and the freight inside from being damaged.
Untuk offroad malah akan mengurangi traksi LC200 mengguakan KDDS untuk non aktifkan swaybar saat offroad JK Rubicon memiliki fasilitas non aktif front swaybar via switch saat offroad .
Jika diganti ukuran lebih gemuk dengan asumsi berat mobil tetap / tak bertambah sesuai desain pabrik Penggunaan front swaybar lebih gemuk , handling menjadi under steer Pengganti rear swaybar lebih gemuk . handling menjadi over driver
Sway bars This component mst be the least well understood component of suspension . or maybe just the easiest for people who don’t know suspension tunning to want to mess with . more often than not people looking for aftermarket sway bars just assume it’s an upgrade but generally have on idea why or how . often people seem to assume that a stiffer bar at one end of the car will increase traction at that end of the car . it would be a natura; conclusion . after all everyone believes that bigger sway bars increase traction but they really don’t . A stiffer sway bar at one end of the car will reduce traction at that end it is increasing the effective spring rate winch is transferring traction to the other end of the car . add a stiffer front sway bar and the car will become more understeery in the front and less oversteery in the back . if that’s what you want then the sway bar can be a good tuning tool . if you add stiffer sway bars front and rear it will reduce the amount of roll while maintaining similar hadling characteristics . if you cannot change spring rates up the a little bit . peronally if possible I belive one shuld try to get the spring rates asclose as possible then just fine tune with sway bars . It is also good to remember that stiffer sway bars reducse roll but not pitch . so a car with stiffer springs ad softer bars will reduce both pitch and roll whereas slapping big sway bars on stock suspension will reduce roll but still have a lot of pitch . contraty to comments in other articles pitch is not a big thing to shoot for . naturally there is a happy balance and too much or too little of anything will become bad there is a common saying with macpherson suspension tuning and there is somr truth to it . the saying goes something like the best way tu get macpherson suspension to handle well is to keep if from moving . of course this is not litteraly true but it contains seed of truth . mapherson suspension does ot have the best geometry and gig changes in suspension travel tend to take toe , caster . camber , etc curves further from ideal . so while you do want the suspension traveling enough to absorb imperfections on the road and keep the tires as close as possible to optimal grip you don’t want a ton of pitch or roll as you come into a corner because the more your suspension travels the less ideal your geometry will likely become . if someone does find more pitch improves their turn in then it is likely that their suspension geometry was actually improved and that changing thestatic geometry with reduce pitch would probably produce even better results . Another big misconption with sway bars is that they will try to lift the inside tire . often these people will believe that therefore a setup with stiffer springs and no sway bars would put more pressure on that inside tire , it is easy to think of things in that way but that’s just now how it works . Think of it like this . weight distribution is dictated by center of gravity and G forces . so whether you were doing around a corner with zero suspension or with soft suspension and huge sway bar or stiff suspension and no sway bar the weight of the car pushing down on each tire is dictated by COG and cornering force . The sway bar is not pulling the inside tire up . it is reducing roll and keeping the inside of the car lower . it is true that if the car rolls . enough a sway bar will make it more likely for a car to actually lift a tire off the ground but with no sway bar there would still be zero weight on the tire . it might be resting on the ground but it’s ability to trun or accelerate would realy be no better . The stiff . front spring no sway bar setup became very popular in the AW11 scne after a few people found success with it in particular classes of autox . I can’t guarantee I could build a more competitive setup tn that class of racing but that doesn’t change the fact that the threads and discussion of this setup are built on a lot of bad theory and correlation . so if you are looking for a competitive setup for that class of racing don completely dismiss if but if you are looking for proper technical discussion or accurate theory understand that just because someone wins races withy their setup does not mean they understand why or that it couldn’t be improved upon if they did . a lot of rasons given for getting rid of the sway bar in these threads are not true or technically correct and things I addressed above like someone assuming that a sway bar was significantly less ideal because it would reduce weight on the inside tire which is absolutely not true . This C4AG article also recommends running different pads in the front to change braking bias . this is not really suspension related but this is a huge pet peeve of mine so I’ll add it in .