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wildcat

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wildcat last won the day on September 18 2016

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  1. @desertdude, come on now, if you are going to continue "spouting rubbish" as someone else said, you must expect to be called out on on it, and resorting to personal attacks does not help your credibility at all- it only makes you look stupid. But here is the thing- you demand fact and figures, while you don't supply any of your own to support your claims. Referring people to opinion pieces on the internet means nothing, except to show that you either don't know anything about the topic, or that you expect people to believe anything you say because you've read it on the internet. But to facts and figures. You are of course right that water injection is nothing new, but you are not telling the whole story, and I believe that @hanif will be along shortly to call you out again. Anyway, water injection on competition engines is computer controlled, whereas in your method, there is no control over the amount of water the engine ingests. In a computer controlled system, the amount of distilled and purified water injected amounts to only a few parts per million relative to the total air/fuel mix, and contrary to what you claim, the primary purpose of the water is not to keep inlet temps down, but to partially quench the detonation flame, (just like EGR does) as well as to create small amounts of hydrogen when the water molecules are ionized. If you didn't know, the hydrogen increases combustion pressure when it burns, which then boosts power, but for this to work as intended, the ECU makes adjustments to valve timing, ignition timing, fuel injection timing/pulse width, and other settings whenever water is being injected. If it did not make these adjustments, the engine is likely to not run at all, or shut off when the water is injected. This however only works in high compression engines, which forced induction engines running on petrol typically are not, which is why water injection is mainly used on diesel engines that have higher compression ratios. Moreover, water injection is typically used on new engines that have no carbon, so there is nothing to remove. Get it now? As for your method to remove carbon with water, do you even know why it works? I guess not, so if you are interested, here is what happens, assuming that there is carbon in a petrol engine to remove in the first place... Anyway, if you get the amount of water just right at any given engine speed, the water molecules get broken up, but not enough to create hydrogen because there is not enough heat and pressure. What happens instead, is that the oxygen content of the water is released, which raises the combustion temperature, which if it is high enough, burns off the carbon, or some of it at any rate. If you get the amount of water wrong at any given engine speed, the water quenches the combustion flame, so instead of liberating the oxygen in the water, you create super-heated steam that only loosens the carbon. Some of it may be expelled through the valves, but much of it is turned into sludge that lodges in the rings, where it works as grinding paste. This is particularly true if the engine had been burning oil for a long time, which can cause major carbon deposits, but you knew that, right? But there are another problems if you create steam in the engine, the first being that steam washes the oil film off the cylinder walls, so while you are adding water all day long, as you say can be done, you are removing ALL the lubrication off the cylinder walls, which I am sure even you will agree is NOT a good thing. (If you did not know, during normal combustion, (without water being poured into the engine) the detonation flame never reaches the cylinder walls or the top of the piston, which is why the oil film on the cylinder walls can be maintained.) In addition, some of the steam escapes past the rings to condense in the crankcase, where it forms sulfuric acid when it comes into contact with most types of combustion products. Apart from contact with heat and oxygen, sulfuric acid is one of the main drivers of the process that breaks down oil additives like detergents, anti-foaming agents, and viscosity improvers (you've heard of those, right?). So while you think you are removing carbon, you are actually destroying the oil in the engine, which in all fairness to other members of this forum, you should perhaps have mentioned. So yes, professional mechanics will call you out when you make silly, unfounded, and dangerous claims and statements- not because they don't like you (I'm sure they don't), but because they know a lot more about the topic than you do, or ever will.
  2. Gaurav is right about a lot of the advantages of an automatic, but only as far as petrol engines are concerned. The only real disadvantage of an automatic on either a diesel or petrol engine is that is does not offer the benefit of engine braking when one goes straight down a sand dune unless you have a lock-up torque converter. However, a manual geabox on a diesel engine will beat any automatic anytime, since it develops most of its power at low RPM's, which prevents a lot of wheelspin on loose sand, because a lot of gear changes can be eliminated with a diesel running at about 3000 RPM.
  3. I fully agree with Gaurav, but allow me to share one last bit of irrelevant information here before we call it quits- Apart from rock crawling, which is something I have never done, the fact is that the more you modify a vehicle, the less reliable it becomes. So to perform extensive modifications just to get some performance and handling from a vehicle intended for off road use is a really bad idea. Oh, and there is a lot of sand in Africa too! Thanks guys, it is always interesting to learn about other experiences and ways of doing things.
  4. The strange thing with Pajeros is that while everything you say is true, I have yet to see one complete an African transcontinental trip. I have completed more than 200 000 kms crossing Africa in all directions over the past fifteen years or so, and the only Pajeros we ever see are broken ones. As for the Dakar- you must remember that all teams have massive technical support, which can make anything complete, and even win the event. You mus also remeber that the Pajeros competing in the Dakar bear very little technical resemblance to the production models ordinary peope can buy. Pajeros may be perfect for dune bashing, but all SUV's are useless in serious off roading driving conditions where there is no technical back-up, no spare engines, no spare transmissions, or a dozen mechanics available to repair any break downs. You may want to try some real off-roading on a grade 5 trail- I think you will change you mind about what makes a real off road vehicle. I am also an accredited off road driving instructor, and my experience with Pajeros and other soft roaders have been uniformly bad, and these days I refuse to take any SUV on even grade three trails, simply because they do not have the suspension articulation and flexibility required to cope with seriously uneven terrain. Moreover, they have too many electronics and driver assist systems, and disabling the ABS to make them safe to drive off road is more trouble than it is worth. I should perhaps also mention that you cannot fit a winch to a Pajero without extensive modifications, which makes it useless as a serious off road vehicle. I don't think we are talking about the same thing when we speak of off road driving, but you should perhaps put a Pejero to a real test sometime.
  5. I have a question; Why the insistence on driving on sideslopes deliberately, but more to the point, why the insistence on driving on sideslopes with vehicles that were not designed for it? Worse though, why drive on sideslopes deliberately with softroaders like Pajero's that have very high centres of gravity?
  6. 5 reasons to not use SUV's for off-road In my previous advice I have explained: How to choose a capable off-road car? based on low range, ABS and Diff-locks. In this advice I will explain why SUV’s and crossovers do not make good, capable off road vehicles. The SUV’s / crossovers have serious design flaws (or differences) that make them unsuitable as off road vehicles. Below are the 5 points that will make this class of vehicle unsuitable as off road vehicles. 1) SUV’s have poor suspension articulation Main part of the reason why proper off road vehicles can do what they do is the fact that they have a long suspension travel, otherwise known as “suspension articulation”. What this means in the real world is that these vehicles can cope with uneven terrain because the suspension systems allow the wheels to move for up to 40 inches (1 meter) and more with respect to each other. This means that even on extremely uneven terrain, all the wheels can remain on the ground, thus maximizing the traction. In the case of SUV’s and crossovers, the maximum suspension travel is about 9-10 inches (seldom more), which means that once a wheel has moved as far as the suspension allows it to travel, the part of the vehicle lifts off the ground. When this happens, one or more wheels lose traction and if the vehicle is not fitted with diff locks, the vehicle is stuck, and has to be towed out of the obstacle, or uneven terrain. 2) SUV’s are not flexible enough Proper off road vehicles that have separate, “stepladder” chassis are extremely flexible, which also helps to keep all the wheels on the ground. In combination with their long, built-in suspension travel, this means that a proper off road vehicle can negotiate types of uneven terrain that no SUV or crossover ever can, simply because SUV’s cannot “bend” enough to allow the wheels to remain on the ground. 3) SUV’s do not have enough ground clearance While some SUV’s have about the same ground clearance as many proper off road vehicles, the problem is that their suspension setups do not allow for heavy loads. This load is sometimes made up of up to seven passengers, but in most cases, the load comes from the suspension being too soft. When an SUV goes over, say, a bump, the vehicle drops down too low when the suspension compresses as the vehicle leaves the obstacle, and especially so when the vehicle is travelling too fast. Since the suspension compresses too much, the vehicle’s ground clearance can be reduced to the point where some components like differentials, cross members, and even the engine and transmission can hit obstacles like rocks. Proper off road vehicles do not have this problem, because their hard suspensions do not compress to the point where ground clearance is affected in meaningful ways. Moreover, because proper off-road vehicles have hard suspensions, its ground clearance actually increases when one or more wheels go over an obstacle, since the vehicle’s weight is always fully supported by the firm suspension(s). This is not always the case with SUV’s, since their suspensions were designed to move in such a way that uneven spots are absorbed without excessive body roll or movements. Thus, the vehicle is not lifted off the ground when one or more wheels pass over an obstacle, and if the vehicle is loaded with passengers, it could happen that even small obstacles could hit one or more critical components. 4) SUV’s are overly complicated The ideal off road vehicle has as few components as possible to make it work, with driver and passenger comfort coming a long way behind requirements like reliability, ease of use, and easy repair ability. This is not the case with luxury SUV’s and crossovers that are designed to give the driver and his passengers the most comfortable ride possible on hard, paved roads. While we agree that some SUV’s are able to complete short and easy level 1 off road trails that are designed with SUV’s in mind successfully, the problem is that SUV”s are too complex (complicated) to do anything else reliably. Part of the problem is that the electrical systems of modern SUV’s are not designed to cope with the heat, dust, and vibration that go with serious off road driving. In many cases, the air suspensions of these vehicles are protected by dozens of fuses, relays, and control units that were simply not designed to cope with the demands of off road driving conditions. No vehicle that can be completely disabled when a single fuse blows (such as when the compressor stops working when its fuse blows) can ever be trusted on a long, difficult off road trail, and especially a trail that requires extreme care by an expert driver. 5) SUV’s do not have recovery points It is one thing to clown around on some loose sand, or to drive an easy, level 1 trail when there are plenty of other vehicles around to supply a tow, but it is something else entirely when that vehicle has to be recovered in very difficult terrain. For instance, a vehicle that is stuck in sand up to the depth of the tyre sidewalls, can require a force of up to three times the force required to move it if it were on a hard surface. This force is calculated by using the weight of the vehicle as a base line; therefore if your vehicle weighs say, 1800 kgs, you will need a force that is equal to the vehicle’s weight, plus ten percent of that value to move it on a hard surface. In this instance, you will need a pulling force of at least 1980 kg. However, if as we said, the vehicle is stuck in sand up to its rims, you need at least three times that pulling force, thus, 5940 kg, and that is where the problem comes in. Even if there is a vehicle with a winch available, there is no attachment point on the stuck vehicle that is strong enough to withstand this pulling force, and it is almost certain that the normal towing point or recovery eyelets will tear out from the vehicle- leaving the vehicle stuck in the sand, and probably hurting someone as the winch cable snaps and recoils. Depending on circumstances and local conditions, the required pulling force can be as high as six or even seven times the value of the baseline figure, which should make it obvious that unless the vehicle has properly rated recovery points, it should not be used off road, and most certainly not in conditions where it might have to be towed out with forces that exceed its weight by several times. SUV’s are simply not designed to withstand pulling forces of this type, and any attempt to subject a vehicle to these forces is irresponsible, dangerous, and likely to hurt someone. So, no, SUV’s and crossovers do NOT make good off road vehicles, even if it is only because they cannot always be recovered safely.
  7. You hit the nail right on the head with your comment. Check out the Off Road Advice section for more on this debate.
  8. How to choose a capable off-road car? Off-road driving means different things to different people, and one of the most common, and potentially most expensive mistakes made by novice drivers is to think that SUV’s and Crossovers are off-road vehicles simply because they have some AWD capability or they look very similar in height and width. A current post on this forum is good case in point, since it asks if a Renault Duster is a capable off-road vehicle. The answer is simple; No, it is NOT a capable off road vehicle, and no serious off-road driver will ever see it, and other soft-roaders like it as a capable off-road vehicle. This article is not intended to bash Renault Dusters and other vehicles like it; it is intended to explain why they do not make a capable off-road vehicles. For the purpose of comparison, I will stick to why Renault Duster is not a capable as an off-roader, although the reasons listed here apply to all SUV’s and crossovers from almost all the brands and regions. It should have a low range Having a low range is of critical importance in any capable off-road vehicle. It may be true that a Duster has a specially geared first gear that provides a bit more torque to the driving wheels, but the gearing is not low enough to prevent wheel spin, which is an absolute requirement for driving in desert sand. A proper low range should reduce the gear ratio in first gear to the point where the maximum attainable road speed in first gear does not go over 8 - 10 km/h. The advantages of this should be obvious - the low gearing prevents the wheels from rotating fast enough to start wheel-spinning in sand or mud, so with suitable tyres, all of the rotation of the wheels is converted into traction. Soft-roaders like SUV’s do not have low enough gearing to prevent wheel spin, which is why they get stuck so easily. It should have way to disable ABS brakes ABS brakes can be dangerous in off road driving, since it increases stopping distances. This might sound strange, but the fact is that ABS was designed to work on paved roads, where traction is a lot higher than on even the best off road surfaces. On tarmac, the ABS allows the brakes to work at maximum efficiency because there is enough traction to slow the vehicle down effectively without skidding on any direction. However, in the off-road environment, and especially with tyres that are designed for on-road use, traction is reduced to only a very small fraction of what is available on a paved road. Thus, when a driver applies ABS brake when driving on loose surfaces, the wheels lock almost immediately, and before the vehicle has started to slow down. Moreover, as soon as the wheels lock, the ABS system releases the brakes until the wheels lock again, and so on and so forth. In practice, this means that the vehicle effectively has no brakes, and the vehicle could easily drive over a cliff because it cannot stop in time. Any capable off-road vehicle should not have ABS, or if it has, it must have a means to disable the ABS when it is not being driven on hard, paved roads. The most effective way to stop a vehicle on loose surfaces is to allow the wheels to lock, which causes them to dig into the ground, thereby creating increased rolling resistance, which is what stops a vehicle on any surface. It should have a proper diff locks The only differential locks that work reliably are those that lock mechanically. Almost all soft-roaders with some AWD capability have various kinds of viscous couplings that lock only the transfer case to supply torque to the diff that does not normally drive the vehicle. The problem with this is that viscous couplings can seldom handle high torque values over long periods on the one hand, and that the actual differentials on the driving axles are sometimes not locked. Although the Duster can be retrofitted with a rear differential that locks mechanically, there is no point in locking only the front differential in tricky or difficult driving conditions. With proper diff locks, all the wheels receive the same amount of torque but with soft-roaders, and especially those that do not have a low range, the torque that is supplied to the wheels is delivered at wheel rotation speeds that is too high for the tyres and suspension to maintain traction in deep sand or mud. Moreover, soft-roaders are often fitted with traction control systems that are based on the ABS brakes, which means that the system’s stored energy can run out before the vehicle is out of a sand or mud trap. If this happens, the automatic diff-lock control system cannot control wheel spin on an axle, which in turn means that the driver can lose traction on two or more wheels until the traction control system is recharged. On a proper off-road vehicle with mechanically locked diffs, torque is supplied to all wheels equally all of the time, and since momentum is the off-road driver’s best friend, there are no interruptions in power delivery that can cause the vehicle to sink into soft sand or mud. No diff- lock system that works with viscous couplings, and/or that depends on a brake-based traction control system can ever be effective in deep sand or mud, since it cannot supply torque to all four wheels for long period of time. Read more: 5 reasons to not use SUV's for off-road
  9. The "weird noise" is only the traction control trying to save your friend from himself. Side-sloping is one of the most dangerous things an inexperienced offroad driver can do, and without traction control to keep the vehicle in line, he is very likely to cause serious damage to himself and his vehicle in the very near future. If you really wanted to help your friend, ask him not to deliberately drive on side slopes.
  10. This is a strange problem, but we will do our best to figure it out. The first thing to do is to apply the brakes very lightly when you hear the sound. You only need to bring the pads into contact with the disc. If the sound goes away when you do this, it means that the pads don't fit into the calllipers properly, and that normal vibrations in the vehicle are causing them to "bounce" around in the callipers. This means that you have to have the brakes inspected to see if all the anti-rattle plates are in place, or that nothing is obviously out of place. It is likely that the ABS system is registering this as a fault, which is why the light comes on. However, you need to have a proper OBD II diagnostic check performed to see if there is not some other problem that could cause the ABS, or other system to activate the brakes at the speeds you mention. It could also happen that the ABS is deactivating itself due to a problem it is registering, which is why the light stays on until you turn off the engine. The best advice I can offer you with the amount of information available is to have a diagnostic check done before you do anything such as replacing pads and discs. You may not need to do this, since the problem may not be with the discs and pads- it could be in the ABS (or other) systems.
  11. It depends on what you want to do, because both springs and coils have advantages and disadvantages. If you want to drive on fairly good surfaces, you are better off with coils since the suspension setups that go with coils almost always give a better ride quality than leaf springs do. Moreover, the trailing arms in coil suspensions allow for greater wheel travel, and with some modifications, it is possible to double the amount of wheel travel, which is what you want when you do rock crawling, or cross deep gullies. In addition, trailing arms prevent "axle bounce" that can break differentials and prop shafts under high power at large suspension extensions. On the other hand, leaf springs can cope with point impacts much better than coils ever can, so if you are going to drive on uneven surfaces such as rocks that are all about the same size, you are better off with leaf springs. Leaf springs can also cope with higher vehicle weights than coils can , which is why you never see vehicles with coil spring suspensions on vehicle that do long overland trips. In general, shock absorbers work much harder on coil spring suspensions than on leaf spring setups unless you modify the coils. You can change both the compresion and rebound rates to lessen the loads on the shocks. Also remember that the suspensions on so-called "off-road capable" SUV's and trucks are set up for highway use, which means that in off road conditions, these suspensions will always perform less efficiently than any standard leaf spring system. So it all comes down to what you want to do, but I suggest you talk to the local off-road clubs to see what works best for your local conditions.
  12. I could not agree more, even though the FJC has serious issues with defective torque converters.
  13. The only thing I can add to Danny's comment is that 40-50K kms may a bit too long. I would change the transmision fluid every 30k kms or so, but Danny is right- there is no such thing as a "lifetime" oil fill.
  14. Hi Guys, My response may a bit off-topic, but you should try the off-road conditions in Africa whenever you get the chance. I have been around the African continent twice for a total of about 80 000 km, and like some other things in life, everybody should traverse Africa at least once in their lifetimes. Check out this link if you want to know more about conditions in Africa: http://4x4africa.co.za/overland/africa-overland-expedition-vehicle/
  15. Hi Mark, AES suspension failure is a known and very common problem on some Land Rovers, and especially vehicles with the following VIN numbers: Discovery 3/LR3 - 5A000360 to 9A513325 Discovery 4/LR4 - AA513326 to CA638964 Range Rover Sport - 5A900302 to 9A215622 Replacing the balloons does not work, since the problem involves the Hitachi cmpressor that is known to fail prematurely because of wear to the piston and seals. An additional problem involves the filters on the compressor that clog up, or become saturated with moisture, which causes the compressor to either rust, or be starved of an adequate air flow. Bear in mind that the control system is calibrated to not register fault codes only if the suspension system can be pressurised in a predefined time. If it takes too long because the compressor cannot deliver enough air fast enough, the system will automatically release all the air in the system, and trigger limp mode and the warning light. It is possible to replace the compressor with another brand, but all changes to the compressor must be accompanied by software updates to the AES system to recoqnise the new compressor, or thesystem will not work at all. The updates will depend on the specific replacement compressor, so make sure that the vendor or repair shop has the software for the specific compressor you buy, or that the shop is able to update the system. Many aftermarket parts suppliers have developed software for their replacement compressors, so shop around in your area for a compressor to replace the Hitachi unit.
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