FJ Mods
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desert_hawk
- Intermediate
- Posts: 0
- Joined: Mon Jan 23, 2012 11:54 am
@ Desert Lizard, very good, knowledgable and informative explanation.
during offroading, we don't only drive in a straight line, we do side sloping, side cresting, etc, all of such manoeuvres will be trickier and more risky if the car is lifted, because of the higher center of gravity, SIMPLE PHYSICS.
Thats why a vehicle with 5" lift kit is more prone to roll over on side sloping or side cresting than another one with 2" lift kit.
Now, what Caprihorse is saying is really sensible, a newbie or intermediate driver is better to learn those manoeuvres in a non lifted car, excel in them, then lift the car, this way it will be much safer for him/her.
Think about it this way, don't lift your car and risk breaking your bumper OR lift it and risk rolling it, you do the math.
Obviously that doesn't apply to drivers who are not interested in those manoeuvres or they like rock crawling were their approach will be with less speed and more controllable manner.
i know many drivers with their long wheel base and heavy LC with no higher lift kit than the stock, they drive on the sand very smoothly, OK, they are more prone to get stuck on a crest, but isn't that why we go out to the desert in convoys, so that we recover each other if someone is stuck.
there is a famous say that I like "if you don't get stuck, you are not trying enough" :P
If someone is worried about breaking the bumper or the underneath structure of the car, he/ she needs to install a steel bumper and a skid plate, it will do a better job.
during offroading, we don't only drive in a straight line, we do side sloping, side cresting, etc, all of such manoeuvres will be trickier and more risky if the car is lifted, because of the higher center of gravity, SIMPLE PHYSICS.
Thats why a vehicle with 5" lift kit is more prone to roll over on side sloping or side cresting than another one with 2" lift kit.
Now, what Caprihorse is saying is really sensible, a newbie or intermediate driver is better to learn those manoeuvres in a non lifted car, excel in them, then lift the car, this way it will be much safer for him/her.
Think about it this way, don't lift your car and risk breaking your bumper OR lift it and risk rolling it, you do the math.
Obviously that doesn't apply to drivers who are not interested in those manoeuvres or they like rock crawling were their approach will be with less speed and more controllable manner.
i know many drivers with their long wheel base and heavy LC with no higher lift kit than the stock, they drive on the sand very smoothly, OK, they are more prone to get stuck on a crest, but isn't that why we go out to the desert in convoys, so that we recover each other if someone is stuck.
there is a famous say that I like "if you don't get stuck, you are not trying enough" :P
If someone is worried about breaking the bumper or the underneath structure of the car, he/ she needs to install a steel bumper and a skid plate, it will do a better job.
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Mosalf
- Newbie
- Posts: 0
- Joined: Fri Sep 28, 2012 4:50 pm
[h=1]Body-Lift or Suspension-Lift?[/h]
Ironman 2" (50mm) Torsion/Coil Suspension Lift
Basic diagram of a car's centre-of-gravity
Body-Lift or Suspension-Lift.
It's a classic question lots of 4wders have. Each one in itself has both it's pros and cons. In this article I will attempt to highlight some of these and hopefully help shed some light on the differences and uses of each.
Firstly Suspension-Lifts. These are the most common modification for 4wder's to gain some clearance underneath their vehicles. This is possible in virtually every single 4WD made. This normally requires new larger, heavier rated springs. This is because the springs your car will come with from the factory eventually lose their tension and start to sag, The new springs (assuming they are coil springs) aren't generally much taller, the extra weight they are able to carry results in less sag from the springs under weight, therefore an increased ride height. An increase in clearance will give you the ability to tackle those tougher tracks at your local 4wd park.
This increased ride height causes a large increase in the vehicles centre of gravity. This increase comes from the combined weight of the chassis, body, engine, transmission and essentially the entire vehicle bar the tyres being raised. A taller centre of gravity will cause a more pronounced swaying through corners, less stability in corners translates to a higher likelihood of a roll-over on those steep rock ledges on your favourite four-wheel-drive track if you push it too hard. However a moderate lift such as 2" (50mm) will provide a decent increase in ground clearance while retaining close to factory cornering characteristics. The stronger-rated, (slightly stiffer) springs will also provide an increase in load carrying ability. Choose a good manufacturer and you can actually improve the handling and/in-cab comfort! If the suspension lift is taken too far however, steering geometry may be affected, causing alignment issues and the possible 'death-wobbles' in solid axle trucks. While there are remedies for these they usually push the cost up substantially for the average diyer. In torsion bar suspended 4wds, owners who crank the bars up to gain maximum lift, subsequently lose up-travel and have a harsh and unsafe ride on rough roads and during cornering.
Another option people take is fitting a body lift. These are quite cheap, and a good body lift kit will only set you back a few hundred dollars. A body-lift will gain you an increase in both approach and departure angle however you won't gain any ramp-over angle due to the chassis rails remaining at the same height. A body lift in it's most basic form is simply some poly (Polyurethane) or alloy blocks fitted in between the body mounts and the body (vehicle shell). This has the edge over a similar height suspension lift in that it only lifts a very small amount of the vehicle's total weight as most of the drive-train and the whole chassis remain at the original height. Due to this, the vehicle's centre of gravity is substantially lower than that of a suspension lifted vehicle of the same height. Better hill angles, approach and departure angles and low centre of mass, what's not to love!
There are downsides to body-lifts however. While you can throw some lift blocks under your 4wd, there are some obvious and major implications that may occur. Radiator fan shrouds that move up with the radiator will foul on the fan itself which is still at the old height. Brake lines may be over extended and possibly stretch or break. Steering columns may rub on the firewall. Bumpers and bullbars which are attached to the chassis rails will not be aligned and leave a gap. Fuel-fillers might need to be extended. Gear stalks will dissapear down a few inches in relation to the lift height. While not all these problems may affect your 4wd, it is not as simple and straight-forward as a suspension lift. Another, not so obvious problem may be presented by the actual size of the blocks themselves. If you are lifting the body from the chassis, you are essentially increasing the leverage on the bolt and it's mounting point. A small amount of movement could fatigue the bolt or mounting point. Be sure to use at a minimum Grade 8.8 High-Tensile bolts, and make sure the blocks are at least the same diameter as the original factory body mount otherwise they may actually punch through the body with large forces or heavy off-roading. Other than these points, a body-lift is a very cost effective and beneficial modification.
SUSPENSION LIFTS
PROS
PROS
[h=2]Copied from the internet for better understanding within the group. Lemme know if this was helpful[/h]
Ironman 2" (50mm) Torsion/Coil Suspension Lift
Basic diagram of a car's centre-of-gravity
Body-Lift or Suspension-Lift.
It's a classic question lots of 4wders have. Each one in itself has both it's pros and cons. In this article I will attempt to highlight some of these and hopefully help shed some light on the differences and uses of each.
Firstly Suspension-Lifts. These are the most common modification for 4wder's to gain some clearance underneath their vehicles. This is possible in virtually every single 4WD made. This normally requires new larger, heavier rated springs. This is because the springs your car will come with from the factory eventually lose their tension and start to sag, The new springs (assuming they are coil springs) aren't generally much taller, the extra weight they are able to carry results in less sag from the springs under weight, therefore an increased ride height. An increase in clearance will give you the ability to tackle those tougher tracks at your local 4wd park.
This increased ride height causes a large increase in the vehicles centre of gravity. This increase comes from the combined weight of the chassis, body, engine, transmission and essentially the entire vehicle bar the tyres being raised. A taller centre of gravity will cause a more pronounced swaying through corners, less stability in corners translates to a higher likelihood of a roll-over on those steep rock ledges on your favourite four-wheel-drive track if you push it too hard. However a moderate lift such as 2" (50mm) will provide a decent increase in ground clearance while retaining close to factory cornering characteristics. The stronger-rated, (slightly stiffer) springs will also provide an increase in load carrying ability. Choose a good manufacturer and you can actually improve the handling and/in-cab comfort! If the suspension lift is taken too far however, steering geometry may be affected, causing alignment issues and the possible 'death-wobbles' in solid axle trucks. While there are remedies for these they usually push the cost up substantially for the average diyer. In torsion bar suspended 4wds, owners who crank the bars up to gain maximum lift, subsequently lose up-travel and have a harsh and unsafe ride on rough roads and during cornering.
Another option people take is fitting a body lift. These are quite cheap, and a good body lift kit will only set you back a few hundred dollars. A body-lift will gain you an increase in both approach and departure angle however you won't gain any ramp-over angle due to the chassis rails remaining at the same height. A body lift in it's most basic form is simply some poly (Polyurethane) or alloy blocks fitted in between the body mounts and the body (vehicle shell). This has the edge over a similar height suspension lift in that it only lifts a very small amount of the vehicle's total weight as most of the drive-train and the whole chassis remain at the original height. Due to this, the vehicle's centre of gravity is substantially lower than that of a suspension lifted vehicle of the same height. Better hill angles, approach and departure angles and low centre of mass, what's not to love!
There are downsides to body-lifts however. While you can throw some lift blocks under your 4wd, there are some obvious and major implications that may occur. Radiator fan shrouds that move up with the radiator will foul on the fan itself which is still at the old height. Brake lines may be over extended and possibly stretch or break. Steering columns may rub on the firewall. Bumpers and bullbars which are attached to the chassis rails will not be aligned and leave a gap. Fuel-fillers might need to be extended. Gear stalks will dissapear down a few inches in relation to the lift height. While not all these problems may affect your 4wd, it is not as simple and straight-forward as a suspension lift. Another, not so obvious problem may be presented by the actual size of the blocks themselves. If you are lifting the body from the chassis, you are essentially increasing the leverage on the bolt and it's mounting point. A small amount of movement could fatigue the bolt or mounting point. Be sure to use at a minimum Grade 8.8 High-Tensile bolts, and make sure the blocks are at least the same diameter as the original factory body mount otherwise they may actually punch through the body with large forces or heavy off-roading. Other than these points, a body-lift is a very cost effective and beneficial modification.
SUSPENSION LIFTS
PROS
- Relatively easy DIY install
- Different spring rates can allow for more flex or load-carrying ability
- Good springs and suspension kits can sharpen up a vehicles general handling
- Better overall ground clearance
- Better articulation possible
- Larger tyres can be fitted
- Large lifts can cause steering problems
- More expensive than body-lifts
- Need to match load and flex to suit your vehicle
- May require other components such as shocks and control arms on large lifts
- Increases the centre of gravity making the 4wd more prone to a roll-over
- Must have springs to fit your vehicle
PROS
- Cheap to install
- Moderate DIY challenge
- Simple in design
- Kits can be purchased to suit your specific vehicle
- Good increases in approach and departure angles
- A raised body allows for a raised driveline if needed for protection (eg low-slung transfer cases)
- Allows for fitment of larger tyres
- Only raises a small portion of the vehicle's total weight
- Swaying in corners is not as prominent as in a similar suspension lift
- Raising the body presents various alignment issues (steering cloumn, radiator shrouds etc.)
- Custom modifications might need to be undertaken, or extra parts bought to account for these issues.
- Bolts must be done up very tight to minimise movement.
- Too small a block can result in it punching through the body and/or damaging the mount.
- No ramp-over angle is benefited.
- Mounting hardware must be of a minimum 8.8 High-Tensile Grade to cope with forces applied.
[h=2]Copied from the internet for better understanding within the group. Lemme know if this was helpful[/h]
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Darshan
- Newbie
- Posts: 0
- Joined: Wed Jan 04, 2012 8:51 am
Lol Capri...i am not challenging you or anyone for that matter. I am merely sharing my experience. Your explanation seems perfectly logical and would have agreed with you completely if i had not experienced it first hand.caprihorse;16863 wrote:Darshan (Newbie Driver), you are not challenging me, but you are challenging, basic physical principles.
Imagine, you take a rod made from metal (simulating aftermarket stiff suspension) and rod made from plastic or rubber (simulating stock, soft suspension). You dig them in sand vertically, equal depth and on top of each you fix a certain weight (simulating engine weight).
After that you push both rods with equal force to the side. Metallic rod will fell down, thanks to gravity and the bottom end will jump out of the sand. Plastic/rubber rod will bent and stay. Off course if pushing further, it will come out of the sand and fell down thanks to gravity. But this little difference is safety just before roll-over.
I went through a lot of research (i am good at that) with some people telling me to lift it and some people telling me not to. I finally decided to buy the best suspension out there for the FJ based on the advise from a veteran who taught me a big chunk of whatever little i know with regards to desert driving. I was skeptical because my logic was telling me just what Capri explained: Your chances of roll over is directly propotional to the increase in centre of gravity. Even though i was skeptical, i made the investment because of my trust on the veteran/friend/teacher!
And in hindsight, that is the best investment that i made to the FJ and the best advice i got (for FREE). The vehicle is waaay more stable now. In my early days in the desert (stock suspension), i have made my share of mistakes and that includes trying to ape someone who was far more experienced and there by getting almost rolled over. I had two wheels in the air and it stayed that way till my mates came and set me back on all fours. My FJ and I escaped without even a scratch!!! (Thank you GOD for appointing a gaurdian angel to take care your foolish son)
Point i am trying to drive here is that i still make mistakes, i am still learning, and some of those mistakes could have resulted in an expesive roll over if it were not for the suspension.
Everyone talks about their perspective. Capri is talking logic and from experience on his pathfinder. Pathfinder stock may have a stiffer suspension when compared to a stock FJ. A stock FJ suspension is very soft. Add to that the fact that it probably has more travel than a pathfinder suspension. This throws experience out of the equation. People who have commented so far against lifting (citing roll over chances) are not people who actually have an FJ and have lifted it (Sans Naser/Wasif and they did not say lifting is bad). And even if someone did, this is MY experience that i am sharing. I'd be glad to be proved wrong, not by logic but from actual experience of lifting an FJ with a quality suspension kit.
This is getting longer than i would want, but let me try my hand at logic to explain this: Imagine we borrow "mini me" and we are trying to roll it (poor mini me) by rocking it from its side in a rythm. Imagine that it has verrrry soft suspension. So you start rocking in a rythm, and you go increasing your rythm as it leans from side to side to a point where the wheels start lifting off the ground. At this point the weight of the car leaning and the soft springs is actually helping us rock the car even more. Now imagine the "mini me" was lifted 2 inches, but has a SUPER stiff suspension. Would the same people who did the above "rocking" be able to rock it easily?? forget taking it to a point where wheels start lifting off the ground.
Capri maybe right with regards to his logic and his experience on the legendary pathfinder, i really dont know. When it comes to the FJ, i know that i am right.
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Darshan
- Newbie
- Posts: 0
- Joined: Wed Jan 04, 2012 8:51 am
I agree with you on all points other than the ones above. LEt me explain.Desert Lizard;16864 wrote:I was expecting Caprihorse to come in with more heat.. but he seems busy
Now the reason why the off-road suspension is stiffer than stock is because off-road is not as smooth as on-road, so the suspension has to react to changes in the contour of the road faster and dampen bigger shocks.
a) Capri coming down with more heat: I respect Capri as a senior offroader, i even bought a montana based on his reccomendation :045: He is usually very straight forward and therefore may appear to be coming down with a lot of heat. He only wants for everyone to be safe, hence he is driving a thought what he thinks is safe. I am trying to do the same thing. I am only saying that FJ is a more stable/safer vehicle with a stiffer suspension than with out it.
b) I partly agree to your last point, but there is more to it. The offroad suspensions are made for different purposes. Though most of them overlap in the ways that it can be used. For example, some supensions like xxxxman is built for carrying more weight than stock over rocks without sagging, bottoming out and dragging your underside all over the rocks. Some like King/icons etc are built to carry a bit more weight but also gives you more stability at speed by offering you features like rebound control, adjustable dampening etc. They are stiffer for stability purposes (I agree) but i do not agree that they are stiffer to dampen bigger shocks. The springs dictate the stiffness and the shocks control the damping.
On the icons (adjustable coilovers) it is designed in such a way that if you adjust it to increase the lift, it also increases the stiffness.
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Darshan
- Newbie
- Posts: 0
- Joined: Wed Jan 04, 2012 8:51 am
Well sorted comments. I especially like the ones above.desert_hawk;16872 wrote:@ Desert Lizard, very good, knowledgable and informative explanation.
Now, what Caprihorse is saying is really sensible, a newbie or intermediate driver is better to learn those manoeuvres in a non lifted car, excel in them, then lift the car, this way it will be much safer for him/her.
Think about it this way, don't lift your car and risk breaking your bumper OR lift it and risk rolling it, you do the math.
there is a famous say that I like "if you don't get stuck, you are not trying enough" :P
While talking about lifts on FJs we are talking about a 2 to 2.5 inch lift that a lot of us have.I think anything over that becomes counter productive. I dont know much physics, but do you think we can negate the effects of higher COG if the springs are stiffer and maybe add more width using spacers? Again we are talking sane amount of lift here.
It is definately better that a newbie learns with the less powerful car without any lift, in the process break a few things (it is all in the game of learning) get up to speed and then mod till mad :011:
Steel bumpers introduce new issues as per some veterans. But Don't want to start another war on something that i don't have experience on.
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desert_hawk
- Intermediate
- Posts: 0
- Joined: Mon Jan 23, 2012 11:54 am
If my understanding is right, Darshan is mainly talking about stiffness giving more stability to the FJ in specific due to the soft FJ stock suspension.
The solution for less experienced FJ drivers is to go for a stiffer springs, but with the same height, obviously that is if your point of view about this SPECIFIC case is accurate.
The lifting of the car has nothing to do with the problem you are mentioning, Darshan, right?!
The solution for less experienced FJ drivers is to go for a stiffer springs, but with the same height, obviously that is if your point of view about this SPECIFIC case is accurate.
The lifting of the car has nothing to do with the problem you are mentioning, Darshan, right?!
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desert_hawk
- Intermediate
- Posts: 0
- Joined: Mon Jan 23, 2012 11:54 am
Physics talk, adding a higher lift and the proportionate spacer should keep things almost the same, but how much is the proportionate spacers?!?!??!!, need a physicist to answer, plus, the FJ cannot accommodate spacers at the front without the well known rubbing issue.Darshan;16879 wrote:I dont know much physics, but do you think we can negate the effects of higher COG if the springs are stiffer and maybe add more width using spacers? Again we are talking sane amount of lift here.
When I started my desert offroading in UAE few years back, I didn't lift the car, I didn't put any mods worth mentioning, and I didn't break anything in the car AT ALL, after I learned some tricks, I started the mods gradually and sensibly.
In my opinion, this is the safer approach, I think.
and if we talk about the cheaper approach, I prefer to spend More money ONLY after I know for sure that I will continue in this sport, many join few trips and then stop because they don't like it or it doesn't CLICK with them.
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Abu Jimmy
- Marshal
- Posts: 135
- Joined: Sat Feb 26, 2011 5:54 pm
- Location: Sharjah
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Dear Darshan ,Darshan;16876 wrote:Lol Capri...i am not challenging you or anyone for that matter. I am merely sharing my experience. Your explanation seems perfectly logical and would have agreed with you completely if i had not experienced it first hand.
I went through a lot of research (i am good at that) with some people telling me to lift it and some people telling me not to. I finally decided to buy the best suspension out there for the FJ based on the advise from a veteran who taught me a big chunk of whatever little i know with regards to desert driving. I was skeptical because my logic was telling me just what Capri explained: Your chances of roll over is directly propotional to the increase in centre of gravity. Even though i was skeptical, i made the investment because of my trust on the veteran/friend/teacher!
And in hindsight, that is the best investment that i made to the FJ and the best advice i got (for FREE). The vehicle is waaay more stable now. In my early days in the desert (stock suspension), i have made my share of mistakes and that includes trying to ape someone who was far more experienced and there by getting almost rolled over. I had two wheels in the air and it stayed that way till my mates came and set me back on all fours. My FJ and I escaped without even a scratch!!! (Thank you GOD for appointing a gaurdian angel to take care your foolish son)
Point i am trying to drive here is that i still make mistakes, i am still learning, and some of those mistakes could have resulted in an expesive roll over if it were not for the suspension.
Everyone talks about their perspective. Capri is talking logic and from experience on his pathfinder. Pathfinder stock may have a stiffer suspension when compared to a stock FJ. A stock FJ suspension is very soft. Add to that the fact that it probably has more travel than a pathfinder suspension. This throws experience out of the equation. People who have commented so far against lifting (citing roll over chances) are not people who actually have an FJ and have lifted it (Sans Naser/Wasif and they did not say lifting is bad). And even if someone did, this is MY experience that i am sharing. I'd be glad to be proved wrong, not by logic but from actual experience of lifting an FJ with a quality suspension kit.
This is getting longer than i would want, but let me try my hand at logic to explain this: Imagine we borrow "mini me" and we are trying to roll it (poor mini me) by rocking it from its side in a rythm. Imagine that it has verrrry soft suspension. So you start rocking in a rythm, and you go increasing your rythm as it leans from side to side to a point where the wheels start lifting off the ground. At this point the weight of the car leaning and the soft springs is actually helping us rock the car even more. Now imagine the "mini me" was lifted 2 inches, but has a SUPER stiff suspension. Would the same people who did the above "rocking" be able to rock it easily?? forget taking it to a point where wheels start lifting off the ground.
Capri maybe right with regards to his logic and his experience on the legendary pathfinder, i really dont know. When it comes to the FJ, i know that i am right.
After all what have been written and said , I would like to dedicate my humble signature to you . GOOD LUCK ...
What goes around , comes around .
