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Suspension Experts

Posted: Tue Apr 06, 2021 5:15 pm
by Irondog4x4
Do we have any suspension Experts here.
Not "Experts" someone that actually knows something about suspensions... not just a part fitter.

Sorry Manny, i know you dont like overkill...
But this a little overkill kill issue i have and want some advice on.

πŸ™ˆ i had a 4" Diff Drop and lift kit installed on my vehicle...(already a problem child) together with 2" Offroad shocks.
the rear is fine, but the front didnt lift and is nou running 60mm lower then the rear.

my thinking was...

Standard lift gives 2" all round..
The Kit adds 4" all round...
The 4" kit keeps all the angles in the same position, just 4 inches lower. thus by adding the 2" shocks and coils the lift will be the same as a normal 2" lift ( angles and stuff) .. together with the 4" everything will be the same just giving 6" in the end.

The rear worked out fine, the front just went up the 4" and now the Shocks and coils are compressed 50mm more then what it should be.. Making the ride hard/ Unstable and killing tires.

what is keeping the wheels form rising that extra 50mm.

Re: Suspension Experts

Posted: Tue Apr 06, 2021 7:19 pm
by Apocalypse
What vehicle is it?

Do the shocks have sufficient travel ?

Re: Suspension Experts

Posted: Tue Apr 06, 2021 8:54 pm
by Anthony Forgey
what vehicle?

Re: Suspension Experts

Posted: Wed Apr 07, 2021 6:51 am
by Irondog4x4
Apologies,
Its the worst vehicle on the road, Ford Ranger.

Yes the shocks still have enough travel, under normal conditions the shocks are compressed by atleast 50mm.
lifting the vehicle the wheel can travel more then enough.

Re: Suspension Experts

Posted: Wed Apr 07, 2021 11:39 am
by Apocalypse
I'm a bit confused.

I'm not overly familiar with the Ford set up - Springs or torsion bars?

When you say diff drop you are talking about dropping the front (IFS) diff down by 100mm?

And the Front subframe? do all the wish bones go down with it?

then you have 2" longer travel shocks and springs to go with it?

Does the front top shock mount also get moved down by 100mm?

Re: Suspension Experts

Posted: Wed Apr 07, 2021 1:14 pm
by KurtG
This thread reminds me of a saying..... β€œa picture is worth a thousand words”

Re: Suspension Experts

Posted: Wed Apr 07, 2021 9:28 pm
by Irondog4x4
Apocalypse wrote: ↑
Wed Apr 07, 2021 11:39 am
I'm a bit confused.

I'm not overly familiar with the Ford set up - Springs or torsion bars?

When you say diff drop you are talking about dropping the front (IFS) diff down by 100mm?

And the Front subframe? do all the wish bones go down with it?

then you have 2" longer travel shocks and springs to go with it?

Does the front top shock mount also get moved down by 100mm?
All of that yes...
comes with springs.

Re: Suspension Experts

Posted: Thu Apr 08, 2021 2:16 pm
by Apocalypse
gonna need pictures... sounds like one of the joints is necked out and restricting travel

Re: Suspension Experts

Posted: Sun Apr 11, 2021 8:58 am
by david bfreesani
As Apoc said, we need pictures. Year models also change setups.

But off the bat, the 4" diff drop only relocates the diff, and hopefully, ALL the mounting points for the upper and lower control arms and swaybar connects. 2" shocks does nothing for lift, just gives you more travel distance on the shock. It's a longer shock, and that is why yours is now very close to full compression because you don't have the lift with the parameters needed for that shock to work within. That all goes out the window if you are running a coil-over setup, but again, we don't know what the Ranger setup uses. My old Nissan had torsions with a set of coilover's as helpers, so who knows.

Your funky tyre wear tells me that your geometry is all messed up. Maybe your upper and lower control arm mounts are not at their correct positions relative to each other anymore.

Lets look at it this way. If you were just wanting a 4" lift with no additional articulation or wheel travel, you would install a 4" drop kit on the diff, all control arm mounts, sway bar connect points, and coil and shock mounts to get that 4" lift on the original shocks and coils without affecting the geometry. BUT IFS is very limiting, and you will find that you still score no articulation, as you are running between a lower and upper bump stop that prevents your suspension from cycling any further than it did originally. So no need for longer shocks or coils.

So, besides the 4" lift, you have just added some horrible angles between your steering rack/box into your draglink and /or tierods, lifted your COG, and still have no additional articulation. All of these points just make for a vehicle that needs more driver input to stay on the road. Even a Jeep owner with a 4" lift and bigger wheels will tell you that it just does not track like stock. My Nissan with 8" lift and 4' bigger wheels, is way more of a handful than stock.

;)TIC comment ;)
Your solution to big lift and wheel travel on a IFS, can only be SAS.

Re: Suspension Experts

Posted: Sun Apr 11, 2021 9:58 am
by Mad Manny
A lift followed by a diff drop is an expensive way of getting back to where you were whilst affecting various charactaristics of the vehicle negatively along the way....

Re: Suspension Experts

Posted: Sun Apr 11, 2021 10:20 am
by grips
Your best and safest lift will be to go the Raptor way. Get a suspension from a wrecked Ranger Raptor or buy them by OEM part numbers.

Configurating a wishbone suspension with a 4 inch lift with stock components is almost impossible. At one stage in the US there were extended wishbones and modified spindles for the previous generation Ford Rangers. Don't know if it is available for the latest Rangers...

Re: Suspension Experts

Posted: Sun Apr 11, 2021 11:04 am
by david bfreesani
Mad Manny wrote: ↑
Sun Apr 11, 2021 9:58 am
A lift followed by a diff drop is an expensive way of getting back to where you were whilst affecting various charactaristics of the vehicle negatively along the way....
Yip, only place you score, is your breakover angle. Most of the rest of your chassis is still at the same height as it was. Well the bits that really matter which forms part of your approach angle/clearance. That rock that you got hung up on, on your cross member/diff carrier, is still going to pose the same problem.

The only real way to get clearance, is bigger sidewalls. Which is probably also the cheapest option out there. But it does open up a whole new world of problems on IFS, as they are seldom designed to handle the additional weight and forces that are created by the additional leverage the wheels can induce.

2" lift means 4" bigger rubber. Work that up from a 245 tyre at around 13kg, to a 285 at around 25kg, or even a 35" at 30kg. And then we also need to start talking about gearing.

Re: Suspension Experts

Posted: Sun Apr 11, 2021 1:30 pm
by grips
Yet IFS and IS becomes more and more popular in races like King of the hammers.
Also huge lifts is something from the past.
Guys are going 47 inch tyres with lots of downward droop

Sent from my YAL-L21 using Tapatalk


Re: Suspension Experts

Posted: Sun Apr 11, 2021 2:05 pm
by david bfreesani
grips wrote: ↑
Sun Apr 11, 2021 1:30 pm
Yet IFS and IS becomes more and more popular in races like King of the hammers.
Also huge lifts is something from the past.
Guys are going 47 inch tyres with lots of downward droop

Sent from my YAL-L21 using Tapatalk
Yes, IFS is becoming a "standard" in these types of vehicles, but you really can't compare the heavy-duty build quality of those IFS setups to a Ranger or any other IFS. off the showroom floor. And then the guys that are doing a slightly better IFS as standard, are also taking CV angles into account by placing the diffs in the centre of the vehicle, giving them longer, and identical length side shafts on both sides. The H1 Hummer comes to mind, and now lately, the Y62 Patrol.

Very valid point you make about the droop. And I think that is what the OP should probably mostly be aiming for, if he could only get past the IFS bump stop restriction on a standard IFS control arm. Custom control arms would probably make an allowance for that. That setup does require fairly long, and high mounted shocks to operate very high in the stroke range. Probably about 20% - 30% of the top of the range to top bump, with about 70% left for droop. The trick is then to get the wheel to actually want to fall out with enough weight to achieve traction on it. Especially relevant in open diff vehicles.

Re: Suspension Experts

Posted: Sun Apr 11, 2021 5:04 pm
by Mad Manny
Great input Apoc, David & Christo!