Keep these coming! As an engineer but not a hardcore 4x4 guy I’ve always understood what’s happening with these things but NEVER see any of the ‘reputable’ sources talk anything like this with detail and actual facts and proof on the vehicle. I LOVE IT!
As a structural engineer, I am extremely impressed by the level of information and knowledge that is being passed along here. I am glad to have finally found someone that can logically explain why and how to lift our Toyota and Lexus vehicles. Amazing work, I look forward to your videos and the products you will be providing! ( just don't forget about us GX470 drivers)
I have a degree in Automotive engineering, I've worked for Aston Martin and McLaren racing as a design engineer. I also own a Toyota Hilux that I've modified and I want to congratulate your video. You make the points I've been trying to explain for years but you do so more eloquently than I usually do! Maybe I should carry a whiteboard with me... I upgraded my front suspension because the additional weight of a steel winch bumper and winch meant the OEM springs were struggling. I opted for Land Cruiser springs because they were available in the right rate but without lifting the front too much. Every other spring wanted a 2" lift which I didn't want because of driveline issues. It is very much worth mentioning that over lifting IFS usually gives the CV joints such a hard life at extreme angles then when a large torque spike is experienced (such as grabbing a rock off road after spinning in the air) that they usually fail way before a non lifted vehicle. Then whatever small advantage that clearance gave you is lost and more because you're now on a 3 wheel drive vehicle in a remote location! Hence why my ride height is back to near standard. 1“ higher than OEM. 1/2" from slightly larger tyres and 1/2" from the springs.... Its a close as I could get!
Really appreciate it and it's my honor to get validation from an actual automotive engineer! My career is mechanical engineering for product design, but I love to apply the fundamental principles to my passion in 4X4. Great point on CV angles. Now I want to ask you a technical question I've been pondering. It's regarding CV joint wear over highway driving (no off-road torque spikes). Generally, we relate bearing surfaces wear to pressure velocity (PV) limit. For a lifted full-time 4WD, highway driving will wear the CV because we have both pressure (torque) and velocity. However, what about part time 4WD cars which is only RWD on highway? The front CV joints still get the "velocity" but there is very minimum "pressure". Too much lift still have other concerns, but can part time 4WD owners be less worried about CV wear over highway driving?
@@TinkerersAdventure Hi there. Yes indeed there is less abuse on the front diff when it's free wheeling. It's under load that problems will occur. The only issue I can think of with prolonged high speed running with high CV angles is that grease will tend to be shoved to one extreme of the tripod slider rather than being more evenly spread. I can't see that causing many issues as the first time you hit decent compression it'll get relocated pretty fast. In a perfectly designed system all the driveline components should be in line or within the angles specified. Another issue is tail shaft angles round the centre bearing when the rear is lifted. You'll usually feel this, usually around a certain resonance period and particularly when lifting off as the driveline will react to make the tailshaft angle more severe. I've not known any to break because of this but my mechanical sympathy kicks in... Things aren't meant to vibrate like that!
@@daveg4963 Baja trucks and Humvees are all IFS. They're pretty handy off road. But I agree with Matt here... What's the point in the comment? Edit: I've owned a Jeep and two Defenders and managed to break suspension and steering components off road. Solid axle is cheap, easier to lift and gives great articulation hence rock crawlers use it. Doesn't make it indestructible.
Please make more content like this regarding suspension geometry and limits. This single video cleared up nearly a year’s worth of misconceptions I’ve accumulated on the forums while deciding on a lift kit. Thank you so much for making this.
When he said, “Don’t worry if you haven’t viewed part 1.” I thought he was going to say , “Click on the link to view part 2” next. Instead he summarised and integrated part 1 into the video. Great job!
I think the most important measurement of articulation here is YOUR ability to articulate these tests and measurements. So great! Thanks for all your work.
As a female, I was never taught about cars/trucks and basic information one should know about them, let alone anything beyond the basics. Anything related to vehicle modifications is intimidating to me, but as a 3rd Gen Tacoma owner, I’m trying to learn how to give my truck its best life, and to do the work on my own as often as I can. THANK YOU, so much for your videos. I feel like you break everything down in a way I can easily comprehend (even though I may need to rewind and listen again haha). I appreciate you and your videos so much!! 🙌🏼
What an awesome video. Had to subscribe after watching. As a solid axle guy I think there’s a lot to be learned in this video not only for IFS guys but for solid axle guys too, I wish half the guys in the Jeep groups I’m in would watch this video and learn something from it. A really cool and controversial topic that this reminds me of is whether or not wheel spacers alone add stability, after watching this video I think you could do a great job at proving or disproving this theory in a way that guys would understand. Another idea is the benefits of running an offroad swaybar as apposed to no swaybar and how the presence of a swaybar improves not only stability but traction as well.
Thank you and I really appreciate those technical topics. I had actually reasoned through the effect of wheel spacers and swaybars in my mind before. I can see where you're going and I think we share similar ideas. I will definitely try to get something together in an easy to digest presentation. The bottle neck of most internet discussions is that many think only the first layer and isolate a single component. It is also common to have black & white binary reasoning (this is good, that is bad). The reality often has more nuances and requires looking at the system as a whole.
I’ve never seen this explained! Excellent! I have lived and 4 wheeled the Rocky Mountains for nearly 50 years. I’ve only been doing it in Toyotas with IFS for the last 20 using skinny 235/85R16s. No more than a 1.6” lift. It has worked well for my purposes.
This content is gold. I wish I had access to your content before I started building out my truck but it literally didn’t exist yet 😅. I have learned these lessons the hard way and now you’re actually helping me to fully understand the why and how I encountered these problems along the way.
This is my first TA video. Stumbled here looking for answers about lift vs down travel for my IFS Frontier/Navara. Absolutely top shelf, gold plated, twin-locked, perfectly tuned content! From one engineer to another, I love it when the guy that paid attention in school starts playing with cars! 😀 Subscribed.
VERY nicely done! Refreshing to see actual technical content in the off road community, backed up by science. Too many channels focus on what "looks sick", which unfortunately is what most bros are capable of digesting...
Amazing to see the effort and detail in all of your videos. Great job my friend. As a FJ owner myself, seeking knowledge in all set ups off road, finding factual data is even harder to find. You have a fulltime subscriber in me. Cheers!
Much appreciate it! Yeah I am very much a data driven person. Opinions are only opinions. I always like to strive for quantitative fact based information.
@@TinkerersAdventure What do you think of the wescott designs pre load collar lift kit for the trd pro 4Runner. Says it maintains factory ride. I want lift my pro but don't want to sacrifice my factory fox shocks for newer ones.
Good info. I'm in the process of fitting 35's without adding any additional lift to what I already have. This video helps! I'm a firm believer of "Lift as much as needed but as little as possible" (~Roger Brown)
this is my thought process. i have a 2019 tundra with about a 2.75" preload collar lift and 285/75R18 tiree. just under 35" tires and didnt have to do any type of BMC or wheel spacers or anything. i can turn full lock and have no rub at all. no need to go any higher cuz its absolutely pointless!
Great video. I wish the ARB USA customer service would watch this. They told me I can make my BP-51 coil overs softer by reducing preload. That’s one of the reasons I ditched them and went to King coilovers. Easy to modify, tune, and rebuild at home. But then I switched entirely to a Jeep and can lift 6” and fit 42” tires and retain my full travel.
These must be some of the best videos on the TH-cams about suspension. Especially for Toyota fans. No BS. Just facts. Explained in a clear and simple way that most people can understand, too.
Keep making these. Your hit count WILL go up. These are some of the best technical videos on the subject out there. Don't stop! Thank you for these. If you did 4Runner and Tacoma videos I promise you. Views will SOAR!!!!!
Well done. Two notes. 1) Wheel rate is the spring rate times the motion ratio squared. kwheel=kspring*(mr^2) mr=xspring/xwheel 2) Suspension does necessarily rebound past ride height into droop after bump travel. It can but doesn't have to. A lot of the harshness comes from the lift causing steeper control arm angles resulting in wheel loads being transferred directly into the chassis through the control arms.
Another (former) automotive engineer here. You nailed it. Nice job. I've seen even some of the prominent/respected off-road guys get a lot of these details wrong. To your question about the effect of lift on the CV's on the highway, since they're not under load, a couple considerations (I'm not sure the answer). The higher angle means the CV balls are sliding back and forth in the cup splines a further distance with every revolution. From essentially nothing if the CV is straight, to quite a lot at high displacements. This leads to more shearing of the grease, which will break it down faster. Also, I would wager that even though the shafts have no torsional load, there's quite a lot of force required to rotate the joint. ie: Take a CV, hold it straight, how much torque does it take to rotate? Now bend the joint 30 degress and rotate it. It should take a lot more force to rotate. And at high speed, keep in mind the balls are oscillating very fast, which is also doing work. Which requires force, that is not required when the joint is straight. Does it really matter? I don't know for sure, but it's something.
Kai is soo legit straight forward not only was he fact based and technically concise and well delivered it’s about the most perfect kinda tech video that I have ever seen, soo visually well demonstrated,reminds me of the old tech videos of the 70-80s thank you soo much Kai I could not have seen your videos at a better time as I was about to make mod purchase for my 4Runner 😂
It's funny (but not really surprising) how many of us commenting here are engineers (me too...). And I absolutely LOVE your videos and the no b.s. information you provide. Many thanks!
You are the suspension professor! I'm very impressed with your practical (physical), and graphic depictions of these suspension scenarios! Brilliant and very helpful!
This is excellent and well done, thanks for putting this out there! I think suspension is the most misunderstood part of autos much less 4x4s. I see so many people only look at $$ => inches of lift without considering quality.
Love this series. I’ve been rewatching the preload section multiple times to grasp whether swapping my 14” 700lbs to 16” 700lbs was a good idea to my 2024 Tundra TRD PRO with ICONS suspension.
You have a wonderfully easy way of explaining this complicated topic while at the same time giving plenty of detail. That’s a great skill to have - keep it up and thank you :)
Well, like many of us I subscribed to some YT 4x4 or car addicted channels but I've never seen before such a technical complete explanation. Everything discussed with a cristal clear ease. Hope You'll find the time to propose further videos. You made my day!
Your videos are terrific! Just got a new (to me ) Tacoma and want to lift it but want to be as smart about it as possible. I really appreciate your clear, evidence based information.
The only thing you missed* (or purposely ignored) is that with the full lift not hitting the bump stop at static articulation is weight shift and momentum. If I am going quicker down a dirt road, not hitting the bump stop will mean less stress and smoother ride. I may want a bit more travel to put more energy into the spring. I also may touch the bump stop articulating as I go down hill and may wish to have that extra energy before I touch the bump stop if I am moving quickly. But you nailed it. Keep it up
This is the most informative lift explanation video I've ever seen! The quality of the content is superb, with clear graphics and narration. I can't wait to see the 5th gen 4runner video you teased!
Every couple years i want to lift my wife tacoma. Already at 31"s with stock ride height due to fab fours front bumper. Eventually i get to this dudes video and decide i'm not messing with IFS.
I had a 2012 4Runner that my parents gave me when i was 16 years old.. Now I own a 2019 5th gen 4Runner TRD Off Road, with KDSS option.. The difference, off road, is night and day.. The 2012 use to wheel lift a lot more and was a bit scary.. My current 4Runner (with the KDSS) articulates like a sick Giraffe's neck, and suspension is stock as a rock lol.
It's also amazing that this and many Toyotas are fantastic off roaders and they don't have enough flex to go all the way up these ramps with all wheels on the ground. It means that tremendous flex isn't necessarily required to have a great off roader and that 7-10 inches of travel is usually pretty good. The stock spec on my Cherokee Trailhawk is 6.5 inches in the front, 7.5 in the rear. With the shock extensions I still get 7.5 or better in the rear even with 2 inch spacer lift but it points out that the shock extensions ARE important. Teraflex did a good job. The thing is , it's almost always the BACK tires that come off the ground when I test which shows the importance of having adequate weight relative to spring stiffness. You have to remember that this Jeep is rated to tow 4500 lbs though so the rear springs are pretty stiff. You can't have it all... That said , when doing CTI tests I found that it was VERY important to make sure that the rear tires are aired down enough , it's far more important than airing down the front tires in terms of total system flex : tires , shocks , springs etc. It doesn't add much CTI but it does add some. Rear at 22, PSI , front at 26 gave the best result you could get with higher pressures. Sure if you put all 4 tires at 18 psi you'll get the same result or better. 26 front and 22 rear is the highest pressure I could use to get decent total flex. I lose about 1/4 - 1/2 inches of ride height when airing down - another item to consider.
I agree with all the comments. As a Tacoma owner, it was an eye-opener. I was thinking to go 3" and now everything changes. I have to rethink my options. My Tacoma is also my dairy driver, so it is a new game. Thanks @Thinker's Adventure
A huge amount of work was done here, thank u sir! I really like you methods and visual demonstration of each point. One more point that i can add - i really like your english, diction and pronanse - for me, as for a not a native speaker - it's quite easy to understand what are u talking about. So thanks for that point too. The only thing i can dream about it's your research and exploration about MCferson and multilink suspension lift limits and and possible suspension travel increasing.
This was the most "Asian" breakdown of an IFS I've ever seen, and yes, I'm Asian too lol! Well done! Glad I didn't waste my money chasing all the common "upgrades" for my Tundra.
Are you planning on doing a video about portal axles? I’m sure your audience would love to hear your analysis on them. Thanks for always producing great content!
When adding a steel front bumper and winch to a 2.5” lift, it will obviously lose some lift. Would you recommend adding more preload or change the springs to a “heavier” load springs?
a definite answer would require looking at some numbers and your preference on ride characteristics. But on a high level, with enough weight you'll NEED a higher spring rate for a few reasons. Possibly heavier valved shocks too. The dynamic ride characteristics depend on the combination of spring, mass and damper.
Just started watching your videos and really love the content. Have been contemplating multiple upgrades and mods after my GX 460 lift 3 years ago and realized it's perfect the way it is. Your videos just supported that notion with science so I really do appreciate your research. One question though, what front bumper/skid plate combo is that on the GX and where can I find it?
We recently had a customer with a Chevy truck break a UCA because it was lifted to high. The customer had turned up the torsion bars to the max and the UCA was resting on the bump stops while stationary. The customer drove through a dip at speed and the control arm snapped because of the excessive pressure against the bump stops combined with extended shocks that were not needed since addition travel modifications were not performed.
I drive a solid axle chevy and I found this video very interesting to watch. Very well put together, no unnecessary bullshit or fucking around, just straight to the facts with "why and how" just like you said!
My man you're such a great presenter, wish you the best. Your videos are pretty easy to understand and many things you explained here and in the part 1 are knowledge I know but really doesn't understand at all, like a 1" suspension spacer lift the car 2" in toyota IFS. I was wondering if you can make a video explaining for every inch of lift how many I space the the wheels shall move outwards with different wheel offset or spacer to mantain the driveability and stability. Keep the good work going on!
Imagine a 12" ruler. Lift one end off the table, leaving the other end touching the table top. If the lifted end is 2" off the table, the 6" mark on the ruler should be 1" off the table. For the same reason, a spacer creates more lift than its physical size since the spacer is placed in between the spindle (the part the holds the wheel) and the control arm pivot points. The Part 1 video explains this in more detail. Hope this helps
Sheess!!! Another awesome video! Keep making them don't stop! I absolutely love watching all your vidoes. Its funny after watching the previous ones, now makes me not wanna lift my truck lol🤣 unless i have the pocket to spend on a long travel setup. These videos are very basic but yet overlooked until we realize we are basically just sacrificing our vehicles performance for looks. Can't wait to see the upcoming video on the sway bars!
Just found your videos this morning. Very well said and informative. As a fellow FJ owner and adventurer, this video has me wondering if my 5100s are set too high to be helpful. My rig is "leveled" if not a little nose high after installing a set of 5100s that were taken off of a 2020 4runner. I did not set them up personally, but am assuming they were set at 2.1" (max) lift. I do carry an 8500 lbs winch with steel cable in an all aluminium bumper, so my front end weight is more than stock by quite a bit. Exact specs for the 4runner springs vs. FJ springs was hard to find, but the 4 runner is slightly heavier so I assume they are heavier springs. I'll be looking closely at my bump stops after watching this and possibly pulling out my coil-overs to see where the snap ring is setup. Thanks for making these, you've got a new subscriber today!
I drive a 2015 silverado with a 2” spacer under the shock, I also added a zone upper control arm that gives me 4” of additional droop, I measured it and am very happy with it, lots more suspension travel, I wish I had a Jeep rubicon…
This is your second video of yours I've watched, and the first was the differential relocation video. If I understand correctly, you are demonstrating that the shift in suspension geometry from the lift is reducing droop on the lower wheel, reducing articulation. Would lowering the differential, bringing suspension geometry closer to factory, restore some articulation? It seems to me that it must as a differential drop is essentially a body lift for IFS.
Can’t wait to see your video on sway bars. So many people misunderstand the benefits of KDSS vs the standard bendy sway bars. In my opinion it’s one of the best features of the GX460. Sometimes it is a pain to get that front sway bar back together though 😆
Boy it was a fight to get them in haha. I was jacking left and right to get things lined up. And yeah I was like many who didn't even bother look into KDSS. I thought it was just another gimmick. But after working on this GX I was genuinely impressed.
KDSS, no thought required to disconnect. Way better in my opinion than selectable like Jeep, its troublesome to reconnect the stabilizer and requires flat ground.
from one mech eng. to another amazing video very well explained most people don''t understand vehicule dynamics and suspension geometry contrinue the amazing work
Thx for the great video! This is by far the most thorough explanation of the issues you discussed. I was already aware of the tire fitment issue and it really bothers me to see lift kit companies saying "get this kit to fit bigger tires" when there aren't changing the travel path, so basically lying to potential buyers. You're also the first I've seen to post actual travel #s of stock toyota suspension as well as the increase from extended travel shocks. This is great info for those considering different options like long travel kits, etc. Great work, Thx! 🤙👍
Hi Kai, thanks for making these videos, they are fantastic and beneficial! Do the measurement figures of wheel articulation in the video apply to FJ? It looks like a 2-inch lift is a great choice for me being conservative and wanting to have some down travels.
Can you do a thing on how air suspension +I4S figures in all this? Given that even vehicles like the new LR "Defender" has that, LR3/LR4 have it, my Gen 1 Cayenne has it (along with a center & rear locker, low range and a 6MT mind you!), etc. One thought is changing the air suspension ride height is kinda like changing the preload, since what's actually changing is the air spring height/"thickness"? But I guess as opposed to a coil spring, increasing an air spring's preload involves raising the ride height not lowering it as in a compressed coil spring...so that's why raising air suspension means increased harshness, because the spring compression isn't taking up as much force upon maxing out downtravel, then hitting the next bump. What about when you then do a body lift? In this case, you're not actually increasing the pressure inside the air spring (preloading) to raise the car. It also doesn't seem like you are pre-extending the shock either- you're just adding material above or below it to compensate for the body lift. However you are still trading down travel for up- because the various joints on the suspension are already closer to maximum droop (unless you do a subframe drop as well?)- but this wouldn't affect ride quality per se right?
Keep these coming! As an engineer but not a hardcore 4x4 guy I’ve always understood what’s happening with these things but NEVER see any of the ‘reputable’ sources talk anything like this with detail and actual facts and proof on the vehicle. I LOVE IT!
As a structural engineer, I am extremely impressed by the level of information and knowledge that is being passed along here. I am glad to have finally found someone that can logically explain why and how to lift our Toyota and Lexus vehicles. Amazing work, I look forward to your videos and the products you will be providing! ( just don't forget about us GX470 drivers)
I have a degree in Automotive engineering, I've worked for Aston Martin and McLaren racing as a design engineer. I also own a Toyota Hilux that I've modified and I want to congratulate your video. You make the points I've been trying to explain for years but you do so more eloquently than I usually do! Maybe I should carry a whiteboard with me...
I upgraded my front suspension because the additional weight of a steel winch bumper and winch meant the OEM springs were struggling. I opted for Land Cruiser springs because they were available in the right rate but without lifting the front too much. Every other spring wanted a 2" lift which I didn't want because of driveline issues.
It is very much worth mentioning that over lifting IFS usually gives the CV joints such a hard life at extreme angles then when a large torque spike is experienced (such as grabbing a rock off road after spinning in the air) that they usually fail way before a non lifted vehicle. Then whatever small advantage that clearance gave you is lost and more because you're now on a 3 wheel drive vehicle in a remote location!
Hence why my ride height is back to near standard. 1“ higher than OEM. 1/2" from slightly larger tyres and 1/2" from the springs.... Its a close as I could get!
Really appreciate it and it's my honor to get validation from an actual automotive engineer! My career is mechanical engineering for product design, but I love to apply the fundamental principles to my passion in 4X4. Great point on CV angles. Now I want to ask you a technical question I've been pondering. It's regarding CV joint wear over highway driving (no off-road torque spikes). Generally, we relate bearing surfaces wear to pressure velocity (PV) limit. For a lifted full-time 4WD, highway driving will wear the CV because we have both pressure (torque) and velocity. However, what about part time 4WD cars which is only RWD on highway? The front CV joints still get the "velocity" but there is very minimum "pressure". Too much lift still have other concerns, but can part time 4WD owners be less worried about CV wear over highway driving?
@@TinkerersAdventure Hi there. Yes indeed there is less abuse on the front diff when it's free wheeling. It's under load that problems will occur. The only issue I can think of with prolonged high speed running with high CV angles is that grease will tend to be shoved to one extreme of the tripod slider rather than being more evenly spread. I can't see that causing many issues as the first time you hit decent compression it'll get relocated pretty fast.
In a perfectly designed system all the driveline components should be in line or within the angles specified. Another issue is tail shaft angles round the centre bearing when the rear is lifted. You'll usually feel this, usually around a certain resonance period and particularly when lifting off as the driveline will react to make the tailshaft angle more severe. I've not known any to break because of this but my mechanical sympathy kicks in... Things aren't meant to vibrate like that!
Prove it on the trail. Performance competition rock crawlers are solid axle.
@@daveg4963 Tell me you completely missed the point of the video without actually saying you completely missed the point of the video...
@@daveg4963 Baja trucks and Humvees are all IFS. They're pretty handy off road. But I agree with Matt here... What's the point in the comment?
Edit: I've owned a Jeep and two Defenders and managed to break suspension and steering components off road. Solid axle is cheap, easier to lift and gives great articulation hence rock crawlers use it. Doesn't make it indestructible.
Please make more content like this regarding suspension geometry and limits. This single video cleared up nearly a year’s worth of misconceptions I’ve accumulated on the forums while deciding on a lift kit.
Thank you so much for making this.
Oh wowsers!!! @7:54 is when I solidified my decision to do a 2-inch lift as opposed to a 3-inch. And, I'm staying at a 275 size tire as well. SUBBED!
When he said, “Don’t worry if you haven’t viewed part 1.” I thought he was going to say , “Click on the link to view part 2” next. Instead he summarised and integrated part 1 into the video. Great job!
I think the most important measurement of articulation here is YOUR ability to articulate these tests and measurements. So great! Thanks for all your work.
As a female, I was never taught about cars/trucks and basic information one should know about them, let alone anything beyond the basics. Anything related to vehicle modifications is intimidating to me, but as a 3rd Gen Tacoma owner, I’m trying to learn how to give my truck its best life, and to do the work on my own as often as I can. THANK YOU, so much for your videos. I feel like you break everything down in a way I can easily comprehend (even though I may need to rewind and listen again haha). I appreciate you and your videos so much!! 🙌🏼
What an awesome video. Had to subscribe after watching. As a solid axle guy I think there’s a lot to be learned in this video not only for IFS guys but for solid axle guys too, I wish half the guys in the Jeep groups I’m in would watch this video and learn something from it. A really cool and controversial topic that this reminds me of is whether or not wheel spacers alone add stability, after watching this video I think you could do a great job at proving or disproving this theory in a way that guys would understand. Another idea is the benefits of running an offroad swaybar as apposed to no swaybar and how the presence of a swaybar improves not only stability but traction as well.
Thank you and I really appreciate those technical topics. I had actually reasoned through the effect of wheel spacers and swaybars in my mind before. I can see where you're going and I think we share similar ideas. I will definitely try to get something together in an easy to digest presentation. The bottle neck of most internet discussions is that many think only the first layer and isolate a single component. It is also common to have black & white binary reasoning (this is good, that is bad). The reality often has more nuances and requires looking at the system as a whole.
Yea brother I thought the video was brilliant.
@@TinkerersAdventure Awesome Post brother, and exactly what I was looking for.
Just now subscribed after watching a couple clips.
Me too
I’ve never seen this explained! Excellent! I have lived and 4 wheeled the Rocky Mountains for nearly 50 years. I’ve only been doing it in Toyotas with IFS for the last 20 using skinny 235/85R16s. No more than a 1.6” lift. It has worked well for my purposes.
👍🏽
This content is gold. I wish I had access to your content before I started building out my truck but it literally didn’t exist yet 😅. I have learned these lessons the hard way and now you’re actually helping me to fully understand the why and how I encountered these problems along the way.
This is my first TA video. Stumbled here looking for answers about lift vs down travel for my IFS Frontier/Navara.
Absolutely top shelf, gold plated, twin-locked, perfectly tuned content!
From one engineer to another, I love it when the guy that paid attention in school starts playing with cars! 😀
Subscribed.
Great debunking of all the common bro science that exists in the off-road world! Keep up this content!
Hahahaah "bro science", I love it!
VERY nicely done! Refreshing to see actual technical content in the off road community, backed up by science. Too many channels focus on what "looks sick", which unfortunately is what most bros are capable of digesting...
Amazing to see the effort and detail in all of your videos. Great job my friend. As a FJ owner myself, seeking knowledge in all set ups off road, finding factual data is even harder to find. You have a fulltime subscriber in me. Cheers!
Much appreciate it! Yeah I am very much a data driven person. Opinions are only opinions. I always like to strive for quantitative fact based information.
@@TinkerersAdventure What do you think of the wescott designs pre load collar lift kit for the trd pro 4Runner. Says it maintains factory ride. I want lift my pro but don't want to sacrifice my factory fox shocks for newer ones.
Good info. I'm in the process of fitting 35's without adding any additional lift to what I already have. This video helps! I'm a firm believer of "Lift as much as needed but as little as possible" (~Roger Brown)
Yes I operate with the same philosophy!
this is my thought process. i have a 2019 tundra with about a 2.75" preload collar lift and 285/75R18 tiree. just under 35" tires and didnt have to do any type of BMC or wheel spacers or anything. i can turn full lock and have no rub at all. no need to go any higher cuz its absolutely pointless!
Great video. Too many people throw their lift to its tallest setting without considering how suspension actually works.
Great video. I wish the ARB USA customer service would watch this. They told me I can make my BP-51 coil overs softer by reducing preload. That’s one of the reasons I ditched them and went to King coilovers. Easy to modify, tune, and rebuild at home. But then I switched entirely to a Jeep and can lift 6” and fit 42” tires and retain my full travel.
Bro they need to put you in charge of everything. Best information on the internet. THANK YOU!!!!
These must be some of the best videos on the TH-cams about suspension. Especially for Toyota fans. No BS. Just facts. Explained in a clear and simple way that most people can understand, too.
There are too many vehicle professionals on youtube give opinions but never explain why … these videos are very knowledgeable.
Keep making these. Your hit count WILL go up. These are some of the best technical videos on the subject out there. Don't stop! Thank you for these. If you did 4Runner and Tacoma videos I promise you. Views will SOAR!!!!!
Well done. Two notes.
1) Wheel rate is the spring rate times the motion ratio squared. kwheel=kspring*(mr^2)
mr=xspring/xwheel
2) Suspension does necessarily rebound past ride height into droop after bump travel. It can but doesn't have to. A lot of the harshness comes from the lift causing steeper control arm angles resulting in wheel loads being transferred directly into the chassis through the control arms.
Thank you for pointing them out! You are correct. I will add an annotation in my video!
Another (former) automotive engineer here. You nailed it. Nice job. I've seen even some of the prominent/respected off-road guys get a lot of these details wrong.
To your question about the effect of lift on the CV's on the highway, since they're not under load, a couple considerations (I'm not sure the answer). The higher angle means the CV balls are sliding back and forth in the cup splines a further distance with every revolution. From essentially nothing if the CV is straight, to quite a lot at high displacements. This leads to more shearing of the grease, which will break it down faster. Also, I would wager that even though the shafts have no torsional load, there's quite a lot of force required to rotate the joint. ie: Take a CV, hold it straight, how much torque does it take to rotate? Now bend the joint 30 degress and rotate it. It should take a lot more force to rotate. And at high speed, keep in mind the balls are oscillating very fast, which is also doing work. Which requires force, that is not required when the joint is straight. Does it really matter? I don't know for sure, but it's something.
That makes total sense. Thank you!
Which is why diff drop kits are very popular on 4runners. This also leads to the question of driveshaft angle.
After 22 years of wheeling lifted IFS Toyotas, I agree with all of this. Great explanation and thanks for the video.
dont they sell solid axle toyotas in the u.s?
@@brocksinclair66 Not since like 1997.
My kinda guy, DIY toyota scientist lol. We need more creators focused on hard data and experimentation. Subscribed, keep up the amazing work man!
I’ve watched practically all the Toyota IFS related videos on TH-cam. And this is the best one. Thank you !
Kai is soo legit straight forward not only was he fact based and technically concise and well delivered it’s about the most perfect kinda tech video that I have ever seen, soo visually well demonstrated,reminds me of the old tech videos of the 70-80s thank you soo much Kai I could not have seen your videos at a better time as I was about to make mod purchase for my 4Runner 😂
It's funny (but not really surprising) how many of us commenting here are engineers (me too...). And I absolutely LOVE your videos and the no b.s. information you provide. Many thanks!
You are the suspension professor! I'm very impressed with your practical (physical), and graphic depictions of these suspension scenarios! Brilliant and very helpful!
Thank you very much for the quick reply. Yikes, now I really want to get that spacer lift removed.
As a 4runner owner, thank you for the info and unbiased opinion
This is the most easy to follow detailed and precise information on ifs I have found. Thank you for making this.
That graph for preload made something I never understood quite simple. Great video
This is easily the most informative and educational video on IFS lift suspension geometry I've seen. Thanks for the great info!
This is excellent and well done, thanks for putting this out there! I think suspension is the most misunderstood part of autos much less 4x4s. I see so many people only look at $$ => inches of lift without considering quality.
Just found your channel. GOLD for Toyota builders and modders, like me. Saving me time and money.
Love this series. I’ve been rewatching the preload section multiple times to grasp whether swapping my 14” 700lbs to 16” 700lbs was a good idea to my 2024 Tundra TRD PRO with ICONS suspension.
You have a wonderfully easy way of explaining this complicated topic while at the same time giving plenty of detail. That’s a great skill to have - keep it up and thank you :)
Yo, please keep making these, you're giving information I've been hunting for all over, thank you for your time
Brother I am so happy to see somebody do such a fantastic job of explaining the science behind preload, ifs, and lift kits !! 🤯🤙🏻 keep it up man!
Finally someone who brings quantitative analysis and engineering to the typical forum subjective BS. Keep up the great content!!
what an absolute chad, first time seeing this much technical details when it comes to suspensions
Well, like many of us I subscribed to some YT 4x4 or car addicted channels but I've never seen before such a technical complete explanation. Everything discussed with a cristal clear ease. Hope You'll find the time to propose further videos. You made my day!
I wish you did this for the torsion bar suspension on the 1st gen frontiers/xterras. Great video and thank you for putting out this type of content!
Your videos are terrific!
Just got a new (to me ) Tacoma and want to lift it but want to be as smart about it as possible.
I really appreciate your clear, evidence based information.
The only thing you missed* (or purposely ignored) is that with the full lift not hitting the bump stop at static articulation is weight shift and momentum. If I am going quicker down a dirt road, not hitting the bump stop will mean less stress and smoother ride. I may want a bit more travel to put more energy into the spring. I also may touch the bump stop articulating as I go down hill and may wish to have that extra energy before I touch the bump stop if I am moving quickly.
But you nailed it. Keep it up
Hands down the best information on 4x4 out there. You're the goat bro!
I stumbled across these videos by accident. Took the time to watch them and they are fantastic and informative. Def recommending to my 4wding mates! 🙌
This is the most informative lift explanation video I've ever seen! The quality of the content is superb, with clear graphics and narration. I can't wait to see the 5th gen 4runner video you teased!
This is the most comprehensive explanation of lift, hands down 🙌🏽
People always forget about caster angle. Very informative breakdown.
Every couple years i want to lift my wife tacoma. Already at 31"s with stock ride height due to fab fours front bumper. Eventually i get to this dudes video and decide i'm not messing with IFS.
Awesome video, I'll watch them all before modifying my truck.
I had a 2012 4Runner that my parents gave me when i was 16 years old.. Now I own a 2019 5th gen 4Runner TRD Off Road, with KDSS option.. The difference, off road, is night and day.. The 2012 use to wheel lift a lot more and was a bit scary.. My current 4Runner (with the KDSS) articulates like a sick Giraffe's neck, and suspension is stock as a rock lol.
Yes, I was very impressed by how KDSS actually performed.
Excited for the sway bar episode! I hope you do a test without a sway bar at all to show the increase in flex!
Same I took my front and rear off years ago and not looking back. I bought a rock jock rear but have not installed it yet
It's also amazing that this and many Toyotas are fantastic off roaders and they don't have enough flex to go all the way up these ramps with all wheels on the ground. It means that tremendous flex isn't necessarily required to have a great off roader and that 7-10 inches of travel is usually pretty good. The stock spec on my Cherokee Trailhawk is 6.5 inches in the front, 7.5 in the rear. With the shock extensions I still get 7.5 or better in the rear even with 2 inch spacer lift but it points out that the shock extensions ARE important. Teraflex did a good job. The thing is , it's almost always the BACK tires that come off the ground when I test which shows the importance of having adequate weight relative to spring stiffness. You have to remember that this Jeep is rated to tow 4500 lbs though so the rear springs are pretty stiff. You can't have it all...
That said , when doing CTI tests I found that it was VERY important to make sure that the rear tires are aired down enough , it's far more important than airing down the front tires in terms of total system flex : tires , shocks , springs etc. It doesn't add much CTI but it does add some. Rear at 22, PSI , front at 26 gave the best result you could get with higher pressures. Sure if you put all 4 tires at 18 psi you'll get the same result or better. 26 front and 22 rear is the highest pressure I could use to get decent total flex. I lose about 1/4 - 1/2 inches of ride height when airing down - another item to consider.
This video is so underrated! Awesome video man! Looking forward to seeing more of your videos!
I remember taking a class about Toyota IFS when I was getting my masters. I learned more from this video. Thanks (:
I agree with all the comments. As a Tacoma owner, it was an eye-opener. I was thinking to go 3" and now everything changes. I have to rethink my options. My Tacoma is also my dairy driver, so it is a new game. Thanks @Thinker's Adventure
Incredible explanations with the data to back up the claims
A huge amount of work was done here, thank u sir!
I really like you methods and visual demonstration of each point.
One more point that i can add - i really like your english, diction and pronanse - for me, as for a not a native speaker - it's quite easy to understand what are u talking about. So thanks for that point too.
The only thing i can dream about it's your research and exploration about MCferson and multilink suspension lift limits and and possible suspension travel increasing.
This was the most "Asian" breakdown of an IFS I've ever seen, and yes, I'm Asian too lol! Well done! Glad I didn't waste my money chasing all the common "upgrades" for my Tundra.
This is literally the best explanation I have ever seen.
We need same videos for the rear suspension...
Keep these coming!
Damn dude! You do a lot of work for your channel… Outstanding!
Are you planning on doing a video about portal axles? I’m sure your audience would love to hear your analysis on them. Thanks for always producing great content!
Another clear and educational tutorial. I appreciate the time you put into doing them. Great job.
Best suspension videos on TH-cam.
When adding a steel front bumper and winch to a 2.5” lift, it will obviously lose some lift. Would you recommend adding more preload or change the springs to a “heavier” load springs?
a definite answer would require looking at some numbers and your preference on ride characteristics. But on a high level, with enough weight you'll NEED a higher spring rate for a few reasons. Possibly heavier valved shocks too. The dynamic ride characteristics depend on the combination of spring, mass and damper.
Brilliant. The white board explanation was perfect. Well done sir.
Just started watching your videos and really love the content. Have been contemplating multiple upgrades and mods after my GX 460 lift 3 years ago and realized it's perfect the way it is. Your videos just supported that notion with science so I really do appreciate your research. One question though, what front bumper/skid plate combo is that on the GX and where can I find it?
You are cool. I am blown away by your scientific elaboration of suspension lifting.
As a alignment mechanic I love this dude !!
Very clear explanations for very technical stuff. I love it. Keep them coming.
We recently had a customer with a Chevy truck break a UCA because it was lifted to high. The customer had turned up the torsion bars to the max and the UCA was resting on the bump stops while stationary. The customer drove through a dip at speed and the control arm snapped because of the excessive pressure against the bump stops combined with extended shocks that were not needed since addition travel modifications were not performed.
Wow that’s scary. Good that Toyota doesn’t have a droop bump stop at the UCA. However the 6” drop bracket lifts add that bump stop to the UCA.
I drive a solid axle chevy and I found this video very interesting to watch. Very well put together, no unnecessary bullshit or fucking around, just straight to the facts with "why and how" just like you said!
My man you're such a great presenter, wish you the best. Your videos are pretty easy to understand and many things you explained here and in the part 1 are knowledge I know but really doesn't understand at all, like a 1" suspension spacer lift the car 2" in toyota IFS. I was wondering if you can make a video explaining for every inch of lift how many I space the the wheels shall move outwards with different wheel offset or spacer to mantain the driveability and stability. Keep the good work going on!
Imagine a 12" ruler. Lift one end off the table, leaving the other end touching the table top. If the lifted end is 2" off the table, the 6" mark on the ruler should be 1" off the table. For the same reason, a spacer creates more lift than its physical size since the spacer is placed in between the spindle (the part the holds the wheel) and the control arm pivot points. The Part 1 video explains this in more detail. Hope this helps
I love these technical information videos. Thank you
Nice video, I never knew that about pre load was always told more pre load the stiffer the ride.
Thanks for clearing that up
I had trouble following a few topics, but this videos definitely helped me understand IFS a bit more! Thank you! 👍🏽👍🏽
Sheess!!! Another awesome video! Keep making them don't stop! I absolutely love watching all your vidoes. Its funny after watching the previous ones, now makes me not wanna lift my truck lol🤣 unless i have the pocket to spend on a long travel setup. These videos are very basic but yet overlooked until we realize we are basically just sacrificing our vehicles performance for looks. Can't wait to see the upcoming video on the sway bars!
Ugh...... my life has just dramatically changed 😂 back to the white board I go😢, gawd that was so much fun and fantastic information!! I'm hooked!
One of the best videos I’ve seen on here. Instant subscriber! Going to check out your other videos. Great job!
That graph of lift vs. travel was so good!
People need these detailed videos keep ‘em coming !
Me: *taking notes all the time*
Thank you for sharing such detailed information!
Just found your videos this morning. Very well said and informative. As a fellow FJ owner and adventurer, this video has me wondering if my 5100s are set too high to be helpful. My rig is "leveled" if not a little nose high after installing a set of 5100s that were taken off of a 2020 4runner. I did not set them up personally, but am assuming they were set at 2.1" (max) lift. I do carry an 8500 lbs winch with steel cable in an all aluminium bumper, so my front end weight is more than stock by quite a bit. Exact specs for the 4runner springs vs. FJ springs was hard to find, but the 4 runner is slightly heavier so I assume they are heavier springs. I'll be looking closely at my bump stops after watching this and possibly pulling out my coil-overs to see where the snap ring is setup. Thanks for making these, you've got a new subscriber today!
Good stuff right there I did lot of this as a young guy with a 1986 Toyota truck .
I drive a 2015 silverado with a 2” spacer under the shock, I also added a zone upper control arm that gives me 4” of additional droop, I measured it and am very happy with it, lots more suspension travel, I wish I had a Jeep rubicon…
This is your second video of yours I've watched, and the first was the differential relocation video. If I understand correctly, you are demonstrating that the shift in suspension geometry from the lift is reducing droop on the lower wheel, reducing articulation. Would lowering the differential, bringing suspension geometry closer to factory, restore some articulation? It seems to me that it must as a differential drop is essentially a body lift for IFS.
Can’t wait to see your video on sway bars. So many people misunderstand the benefits of KDSS vs the standard bendy sway bars. In my opinion it’s one of the best features of the GX460. Sometimes it is a pain to get that front sway bar back together though 😆
Boy it was a fight to get them in haha. I was jacking left and right to get things lined up. And yeah I was like many who didn't even bother look into KDSS. I thought it was just another gimmick. But after working on this GX I was genuinely impressed.
KDSS, no thought required to disconnect. Way better in my opinion than selectable like Jeep, its troublesome to reconnect the stabilizer and requires flat ground.
Would you say the kdss system on the GX and 4runner is exactly the same? Or are there a few things different?
I feel you. hahaha
OUSTANDING CONTENT!!! Well done and thank you!! Wow!!
from one mech eng. to another amazing video very well explained
most people don''t understand vehicule dynamics and suspension geometry
contrinue the amazing work
Thx for the great video! This is by far the most thorough explanation of the issues you discussed. I was already aware of the tire fitment issue and it really bothers me to see lift kit companies saying "get this kit to fit bigger tires" when there aren't changing the travel path, so basically lying to potential buyers. You're also the first I've seen to post actual travel #s of stock toyota suspension as well as the increase from extended travel shocks. This is great info for those considering different options like long travel kits, etc. Great work, Thx! 🤙👍
Love this. I am trying to help my friends with their yotas ifs. I have a excursion so solid axles. This helps me a lot thank you
Hi Kai, thanks for making these videos, they are fantastic and beneficial! Do the measurement figures of wheel articulation in the video apply to FJ? It looks like a 2-inch lift is a great choice for me being conservative and wanting to have some down travels.
Very informative video .
Can you make a video of how suspension lift affects down/up travel in solid axle vehicles ? Thank you
Love the engineering technical approach
Can you do a thing on how air suspension +I4S figures in all this? Given that even vehicles like the new LR "Defender" has that, LR3/LR4 have it, my Gen 1 Cayenne has it (along with a center & rear locker, low range and a 6MT mind you!), etc. One thought is changing the air suspension ride height is kinda like changing the preload, since what's actually changing is the air spring height/"thickness"? But I guess as opposed to a coil spring, increasing an air spring's preload involves raising the ride height not lowering it as in a compressed coil spring...so that's why raising air suspension means increased harshness, because the spring compression isn't taking up as much force upon maxing out downtravel, then hitting the next bump. What about when you then do a body lift? In this case, you're not actually increasing the pressure inside the air spring (preloading) to raise the car. It also doesn't seem like you are pre-extending the shock either- you're just adding material above or below it to compensate for the body lift. However you are still trading down travel for up- because the various joints on the suspension are already closer to maximum droop (unless you do a subframe drop as well?)- but this wouldn't affect ride quality per se right?