Long Travel Front Suspension?
Hello! I'm new to this forum and I'm glad I've found it cause there seems to be a lot of useful information stored here
Anyway, I have recently bought a 2010 Manual Transmission Pajero TR4 and it's my second TR4. The first one I had was fitted with a 3.5" lift kit, had a subframe drop and 32s, but my new car is stock (for now).
Alright, straight to the point, I've been thinking about the front suspension of the TR4 a lot lately and it seems to me that's one of the biggest limitations of the vehicle when it comes to off roading, since it has such a short travel.
I do understand that MacPherson Struts are naturally limited when it comes to off roading, but I wanna see how far it's possible to stretch it. Have you guys had any experiences with long travel Struts for IOs, Pinins or TR4s? I know the struts aren't the only limiting factor, and it seems to me the passenger side axle might be a huge problem, and maybe even the lower control arm. So has anyone fitted custom axles or control arms? I've seen a guy in Brazil who has changed the CV for a u joint, which probably enhances the resistance, but not necessairly the travel.
What I have in mind, then, is a full front axle/suspension rebuild, with longer axles and control arms and a long travel strut, has anyone done anything like that? If not, any ideas on how I can develop something like that?
I guess I wasn't clear!
Sorry I didn't give enough details, but yeah the 2010 TR4 has the same suspension as the other variations of the Io/pinin and I do understand the geometry of the entire suspension
Let me make myself clear, what I had in mind was keeping the cross member as it is, but widening the vehicle's track, cause it seems that's the only geometry that would allow for longer travel. What that means is new, longer control arms, new longer axles and new sruts (I'm sure keeping the stock strut mounts would be a huge challenge in that case since the knuckles would be further away from the center of the vehicle)
As for the solid axle swap I have no plans to do anything like that, for two reasons: the first one being i absolutely love independent suspensions (hence the fact that I own a 2008 V6 Pajero, which has 4 wheel independent suspension), also, that brings to the table problems I'm not willing to solve like the engine mounts, steering system, the structural integrity of the vehicle and more. A guy in Brazil has been working on a SAS for his TR4 but that has included a whole new subframe all throughout the vehicle, cutting the entire vehicle and an engine swap.
How much ...
Sorry, I still don't see it happening ...
First - very briefly let's look at the rear - will you be widening the rear track to match the front? Will you be widening the bodywork to keep the tires covered?
Back to the front - if you extend the control arms by any appreciable amont whilst keeping the OEM knuckles AND the strut mount in the original location, you'll run into a serious negative camber situation, one option is to extend the "strut ears" (where the strut attaches to the knuckle) outwards by the same amount that you extend the lower arms, this will allow the wheel to have an acceptable camber angle, but only in the straight ahead position - as soon as you start to turn, you'll run into a positive camber situation, you'll also need to source longer steering arms, and the ackermann geometry will be seriously out of whack in a turn.
To get the steering to work properly, you're going to need to move the strut tops outwards by whatever amount you move the ball joint at the end of the control arm (and the same goes for the steering), assuming you can do that, the strut travel is once again going to be the limiting factor, and you're going to be faced with significant camber angle change as the suspension cycles
Long travel IFS typically uses dual wish bones, it's the only way to tame the camber angle changes - maybe you could fabricate some sort of a structure bolting between the strut mount and the crossmember to hold an upper arm pivot, fabricate an upper arm with an upper ball joint, maybe some sort of coil over strut (Toyota Tacoma style)
Nope - I still don't see it happening...
you know what? You're right
Anything involving extending the control arms would lead to a dead end due to the very nature of a MacPherson suspension. Extending the strut ears would be structurally challenging and would make the vehicle steer very poorly.
Now, I gotta say that I have once thought about the possibility of fabricating a double wishbone bolt on kit, but I never really thought about it too much
Is that too crazy of an idea too? I mean, maybe the upper arm pivot could be bolted to the upper part of the subframe, where it's bolted to the vehicle's body (unexpected benefit would be a subframe drop) Do double wishbone suspensions necessarily have two pivot point for each control arm? I mean it does sound necessary in order for the Coilover to go through the middle of the two parts of the upper control arm, but maybe the lower control arm can have a single pivot? But then if I keep the stock pivot point for the lower control arm I'll probably end up with some clearance issues due to the CV shaft being where the Coilover would be and oh god this is really complicated
sounds like a hell of a challenge, but is it impossible? I'm really just letting my mind go crazy right now so I'm sorry if this is too vague of a conversation, I apologize if you feel like I'm wasting your time brainstorming
There was a point.
There was a point in time where I would have considered replacing a macpherson strut front end with a double wishbone setup as a pipe dream, but it has been done. Calmini in California did the kit below for the Suzuki Vitara/Sidekick.
https://www.calmini.com/detail.php?b=2&m=5&t=1&p=1009&n=
Be aware that Calmini doesn't sell the SES as a long travel system, their selling point is that it eliminates the strut as a weak point, I'm just showing you what they did, because they are using the control arm & knuckle from a macpherson strut system.
Full disclosure - I've never used this kit, and I don't think it was successful (in terms of sales numbers), there are a few threads on the Suzuki forums detailing installs, most of which seemed to have minor problems. Calmini, as a company, doesn't have a great reputation for business ethics, you'll find that discussed in the forums also. I have done business with them in the past, and probably wouldn't in the future.
Moving on - I think the upper control arm pivot would need to be well above the frame rails, perhaps slightly above whatever rotating joint you use at the top of the knuckle, so perhaps a fabricated structure that bolts to the frame rail at the bottom and the strut tower at the top, two pivots on the upper arm would be better (more stable) than one, but, there were older vehicles (Morris Minor/Marina) that used a single upper arm that was a part of a lever shock, as I recall, those weren't the most stable of vehicles.
This is the sort of strut I had in mind, way smaller than the original so way easier to fit into the available space.
Make no mistake, a project like this will require quite a bit of custom fabrication, and whoever is going to be doing the work will need to be a good welder/fabricator to pull it off.
On the time wasting - if I didn't want to get involved I would have just not responded to the original post - even if nothing comes out of the discussion, we would both have learned from it.
ok so it's not impossible
honestly that's pretty exciting, but it could use some improvements
I'd probably go for coil overs cause this setup looks too complicated and clumsy
now, something that should be kept in mind is the CV axle and the strut tower are vertically aligned so as it is a double wishbone suspension wouldn't work
which would be harder? moving the diff further to the front or changing the mount for the struts (now coilovers)? Moving the diff does sound complicated cause that would mean fabricating new engine mounts and whatnot, but changing the coilover mount points doesn't sound easy either (I guess using a small coilover as you mentioned would make it a little easier
not sure if you're picturing what I have in mind but the more I think about it the harder it shows to be
.
I'm at a bit of a loss as to why you feel that the strut tower and the CV axle being vertically aligned would prevent a double wishbone adaptation.
Whatever structure you fabricate to fit between the strut mount and the crossmember needs to take the form, so to speak, of an inverted U so the CV axle passes between the legs of the U, the upper control arm would also attach to the legs of the U but above the point where the CV axle passes.
I'm not a suspension geometry expert
for reference, here's a picture of my V6 Pajero, which has a front double wishbone suspension https://photos.app.goo.gl/GaNJaUjbCZrpcWzX9
notice how, from this perspective, the CV axle is in front of the coilover, so that they're not vertically aligned. What that means is the tower is not vertically aligned to the axle.
Now, back to the TR4, could i just bolt the Coilover somewhere else to the lower control arm so that the Coilover is at angle, not coming in contact with the shaft?
.
Why run the strut to the lower arm? Why run a strut at all?
MacPherson strut front suspension systems are very common, and they started out as a cost reduction exercise in which the upper control arm in a double wishbone system was being replaced with a strut.
Essentially your double wishbone system had a coil spring, a shock absorber, a knuckle and two control arms with ball joints - the MacPherson system replaces the shock absorber with the strut which is used as a structural element, and eliminates the upper control arm completely. The compromise in the MacPherson strut system is the constant camber change as the suspension cycles.
You're putting back that upper control arm, so you no longer need a strut - you need a place to mount the coil spring (if you choose to run a coil spring) and a way to "dampen" the oscillatins of the assembly, which is the function of a shock absorber.
Let me explain that "if you chose to run a coil spring" statement - your choices are not limited to leaf or coil springs - those are just the most common methods used on today's vehicles.
I learned to drive on my mother's Morris Marina - the, rear suspension was a live axle on leaf springs, the front was independent, double wishbone with torsion bars attached to the lower wishbones, and the upper arm was a part of what were known as lever arm shock absorbers. My father's car at that time was a Chrysler with all independent suspension, trailing arms at the rear, double wishbone in front, torsion bars & telescopic shocks on all four corners. From those I went to vehicles like the Morris Mini with hydrolastic suspension, trailing arm rear, double wishbone front, and no shocks whatsoever as the damping function was provided by the hydrolastic system.
You're going to be designing an upper arm that must attach to the top of the knuckle with a ball joint and at the other end to some sort of support structure with a pivot arrangement, you have the option of using a coil spring between the existing strut mount and the control arm (if space allows it) and there is nothing forcing you to have whatever shock absorbing/damping device centrally mounted within that coil - you could mount that ahead of or behind the coil, between the upper & lower ams (very common with double wishbone - the top of the shock is attached to the fixed structure near the upper wishbone pivot & the bottom out near the ball joint on the lower arm.
What you're contemplating is going to be quite challenging, among other reasons because you don't have the option of calling Koni or <insert you choice of shock manufacturer here> and saying build me 150,000 units of a shock with this open length, that closed length, etc. - you have to figure out what off the shelf part can be used.
i see
once again, thank you for your patience! These have been really helpful and while there is a bit of a language barrier i think we're getting somewhere
the reason why I mentioned coilovers (that is, the shock absorber centrally mounted withing the coil)is that there are some off the shelf options and, since what I had in mind was getting as much wheel travel as possible, the shock absorber would have to be as long as possible (i know the shock travel/wheel travel ratio isn't 1:1 on these suspensions, but it's close enough so that a long shock would be ultimately a good way to get more travel).
now, back to where the parts would be attached, given that I want a shock as long as possible, ideally the shock would be mounted to the already existent tower and the lower control arm (on that note, is it possible to mount the shock to the upper control arm? it's not a common setup but i don't see why that wouldn't work). So, as it is, the shock would come in contact with the CV axle, but, as you said, there are plenty of ways around that.
adding to the discussion, maybe even some type of pushrod setup would be possible, but it's not clear to me where the springs and shocks would be in the vehicle to be completely honest with you, i don't see myself fabricating something like that in the near future, it's more of a dream right now (for context, I'm a mechanical Engineering student and I'd feel much more confident tackling this kind of problem if I had the knowledge I'm yet to obtain on structures and whatnot) I started this topic to ask if someone had found a way to improve the front suspension of our beloved vehicle, but I have to say I understand why nobody seems to have done something like that
edit: I've done a little research and it is possible to attach the coilover to the upper control arm and that's definitely the way to go! Hell, I could even keep the stock lower control arm and knuckle. Combined with a 3 inch subframe drop, it'd be possible to fit a long enough shock that would allow for longer wheel travel. In that case, the next limiting factor would probably be the axles, and that's a whole other story
conclusion: it'd be necessary to fabricate a part attached to the subframe mounting points. This part would have two pivots. Bolted to the pivots, there would be an upper control arm with a ball joint and some kind of adapter that would allow the ball joint to be attached to the stock knuckle. Also, I'd need a coilover and some other adapter to bolt this coilover to the existing towers.
Research bell crank suspension
It's perhaps more commonly found on open wheeled sports/racing cars, but the concept can be used to mount both the spring & shock (in a coil over format if so desired) with the "direction of compression" very different to that of the actual suspension travel.
This is just a random example off the internet, but you can see the coil overs are mounted more or less length ways in the chassis with a push rod and a bell crank being used to translate the up/down movement of the suspension to a fore/aft movement.
The primary reason for doing this on an open wheeled race car is to reduce drag (the other commonplace for the coil over would have it exposed and in the wind), but the bell crank can also be used to provide mechanical advantage - four inches of vertical movement translated to two inches of horizontal movement.
Regarding your studies. and I mean this in the nicest possible way, it doesn't matter to me if you never turn this discussion into reality, what I do hope is that you will explore it during the course of your studies - you might decide it requires too much custom fabrication for the increase in travel gained, but I hope you do so after you've worked out the possibilities on paper or whatever modelling software you learn to use.
Yeah, that's exactly what I
Yeah, that's exactly what I meant by a pushrod suspension! It's an option, I guess
Yet again, thank you so much! I love learning and I like to spend my time exploring possibilities, I have been obsessed with independent suspensions for quite a while now and it's great to see that I'm not the only one who enjoys using the imagination and discussing this kind of abstract stuff.
I'll let all of you know if I ever end up trying what we've discussed on this topic, and I'll keep an eye on topics regarding suspension mods
Loving this forum so far!
I'm back
In order to bring real closure to this topic I've returned to say that someone has done what I've been dreaming about
A Brazilian guy adapted the entire front suspension of a gen 4 Pajero into his TR4 and it's fantastic! By the way, his car is also on 37s, has 2.72 reduction gears, 4.900 diffs (twin locked) and my mind is absolutely blown
here's one of his last posts:
https://www.instagram.com/p/CgDH6w8O0-8/?igshid=YmMyMTA2M2Y=
Syndicate
I don't know what the suspension on a 2010 TR4 is like
but if it in any way resembles what the earlier production (1998~2005) had, I'm going to suggest that attempting to develop any form of long travel independent front suspension is an exercise in futility.
Harsh maybe, but realistic.
Put the vehicle on jackstands, remove the front wheels, grab yourself a yard stick and get underneath it.
The length of the front control arms is limited by the location of the crossmember and the track of the vehicle, the crossmember also supports the engine, the steering rack & the differential so unless you're willing to fabricate an entirely new front end, starting with the frame rails, you're pretty much stuck, and please bear in mind, that you're working with a monocoque construction vehicle, so it doesn't have a separate frame.
I don't think SAS is an option either