Enduro IFS Shock Tuning thread

[HumboldtEF]

I thought it might be nice to start a thread where folks can share their thoughts and experience with the Enduro IFS kit and tuning the suspension.


I just picked up the kit and dont have anything to share as of yet. I have heard that the springs are a lot stiffer than usual.



Optional springs from left to right, softest on left hardest on right. ratings are lb/in


Green .71, White .95, Gray 1.49 (stock), Blue 2.09, yellow 2.47, Black 4.75 (IFS springs)

You can see how they've been mostly going in steps of .5 lb/in between the other options then jumping from 2.25 (yellow) to the 4.75 lb/in IFS spring (black), thats a pretty big jump.
I have a feeling a spring a bit softer than the black might be a good place to start tinkering.

I also though it might be worth mentioning to ensure you use the shock relocation brackets included with the kit, it moves the upper mount point down 10.5mm. This step is skipped in the instructions so make sure you do this. Look at the shock towers on gate 12 to see how these go, I assume it uses a 10-12mm button head screw to mount these, 4 in total.



Recently I've been using thicker shock oil but I'm going to try something thinner for the IFS kit. I'm starting with 45 wt in the rear and 30 wt up front. I'm also going to play around with some different spring rates as I think I have most of the optional springs from Element.







So share your findings and setups let us know what you've done and how it did.

 

[soze]

I'll put a thread up soon, but I found that using 2 angled rod ends on the steering links worked out better than having one end use a straight rod-end.

 

[svt923]

The springs included with the IFS are crazy stiff, I don’t know how they are going to work on anything but the heaviest trucks. My IFS 1.9 Wraith had no suspension action with those springs, it couldn’t compress them at all even with the weight of the Wraith cage.

After some trial and error, I ended up with these Venture shocks with the stock Venture lower springs and Axial (red, I think) upper springs.

 

[rkj__]

Steel skid plate for more weight perhaps?


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[mk3jetta]

I run the stiff springs, but a longer rod end on the bottom of the shock and a rear sway bar to compensate. The truck seems to work pretty well that way
_MG_9899 by Kolben Hillbery, on Flickr

 

[B-MOW71]

I'm in the process of building the IFS for my Trailwalker. I too thought the front black springs felt stiff.

After I get mine built and tested I'll post my findings!

Thanks for starting this thread! Nice info on the spring rates!"thumbsup" It should definitely help with getting this IFS tuned up!

 

[OSRC]

Its not so much a matter of tuning the front as it is getting the front and rear in balance with each other. With the IFS kit front springs, the front is super stiff and the rear is very soft. Definitely makes for unbalanced handling, especially on climbs.

I found some unknown Redcat progressive rate springs in my stash that were abut 1/2 way between the IFS kit springs the the solid axle springs. They seem to work very well. True progressive rate springs, they start out soft and stiffen noticeably about 1/2 way through their travel. Seems to keep the front from bottoming out. Still running the stock oil in the front shocks.

Out back, I upped to 50wt oil though kept the stock springs. I added some spacers to the lower mounts to somewhat triangulate the shocks. Trying to avoid adding a swaybar if possible, though I have one handy and may try it later.

Seems to be working well overall, the rear is still a little soft but the front and rear are definitely in the ballpark with each other now.

 

[DukeMinnix]

Tuned in to this. For those of you adding input, a front to rear weight ratio and total weight may come in handy for those checking in.

 

[riverat]

to those that now run the IFS System do any of you climb steep rocks to say the IFS is more of a improvment over the straight axle ?

 

[soze]

to those that now run the IFS System do any of you climb steep rocks to say the IFS is more of a improvment over the straight axle ?

It won't be an improvement. It's just something different.

 

[riverat]

thanks i thought so "thumbsup"

 

[HumboldtEF]

So after running a few packs I can say that it is much easier to upset an IFS rig and that the front suspension doesnt always like to settle. If you put it in a situation (when descending) where opposite corners are teetering (with the other tires floating) its very easy to cross the line and have weight transfer up front and roll over. It seems to me like the front suspension doesn't want to settle under the weight of the rig, so if the rig is sitting at an angle instead of compressing the lower side springs they tend to push back. The suspension at this point seems to want to sit parallel to the ground it sits on rather than to flex. The downsides of IFS seemed to show up much more when descending. This was tested with stock springs and Some Venture springs too, also no body.

Steering also suffers a bit, it seems like the rocks are able to push an IFS rig around more so than a solid axle rig.

I did swap the battery to the back and that was a bit of an improvement but I believe completely overcoming the downsides of IFS wont be possible, you can probably improve the balance but I dont think you can completely eliminate the downsides. Moving the stock battery tray to the rear is very simple, you just remove the battery tray mount from the front and move it to the rear, all the holes line up. Even after this change there is still a front weight bias, just a bit forward of center (with a shorty battery)

I tried out some HPI Venture springs (not sure what the spring rates are) after testing it stock, the fronts were softer than stock and the rears got stiffer. This seemed to be helpful in allowing the suspension to flex a bit more up front rather than mainly transferring the load to the rear like stock did. It has a bit of droop up front but not so much the bulkhead is dragging/getting hung up. These springs need to be mounted upside down as the collar between the upper and lower springs gets hung up on the shock body threads.

 

[rkj__]

So after running a few packs I can say that it is much easier to upset an IFS rig and that the front suspension doesnt always like to settle. If you put it in a situation (when descending) where opposite corners are teetering (with the other tires floating) its very easy to cross the line and have weight transfer up front and roll over. It seems to me like the front suspension doesn't want to settle under the weight of the rig, so if the rig is sitting at an angle instead of compressing the lower side springs they tend to push back. The suspension at this point seems to want to sit parallel to the ground it sits on rather than to flex. The downsides of IFS seemed to show up much more when descending. This was tested with stock springs and Some Venture springs too, also no body.

Steering also suffers a bit, it seems like the rocks are able to push an IFS rig around more so than a solid axle rig.

I did swap the battery to the back and that was a bit of an improvement but I believe completely overcoming the downsides of IFS wont be possible, you can probably improve the balance but I dont think you can completely eliminate the downsides. Moving the stock battery tray to the rear is very simple, you just remove the battery tray mount from the front and move it to the rear, all the holes line up. Even after this change there is still a front weight bias, just a bit forward of center (with a shorty battery)

I tried out some HPI Venture springs (not sure what the spring rates are) after testing it stock, the fronts were softer than stock and the rears got stiffer. This seemed to be helpful in allowing the suspension to flex a bit more up front rather than mainly transferring the load to the rear like stock did. It has a bit of droop up front but not so much the bulkhead is dragging/getting hung up. These springs need to be mounted upside down as the collar between the upper and lower springs gets hung up on the shock body threads.

That is consistent with my experience wheeling my old 1:1 truck with IFS (& front sway bar). The front weight bias and IFS wanted to keep both front wheels on the ground, with as little articulation as possible. The rear would flex to its limit, then lift a tire if it ran out of articulation.

Simulating that experience is part of why the IFS kit appeals to me. But, the truth is, I dreamed of solid axle swapping that truck, so... maybe the Element IFS would be a good choice for my third RC crawler, not my second. (I only have 1 right now)


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[mk3jetta]

So after running a few packs I can say that it is much easier to upset an IFS rig and that the front suspension doesnt always like to settle. If you put it in a situation (when descending) where opposite corners are teetering (with the other tires floating) its very easy to cross the line and have weight transfer up front and roll over. It seems to me like the front suspension doesn't want to settle under the weight of the rig, so if the rig is sitting at an angle instead of compressing the lower side springs they tend to push back. The suspension at this point seems to want to sit parallel to the ground it sits on rather than to flex. The downsides of IFS seemed to show up much more when descending. This was tested with stock springs and Some Venture springs too, also no body.

Steering also suffers a bit, it seems like the rocks are able to push an IFS rig around more so than a solid axle rig.

I did swap the battery to the back and that was a bit of an improvement but I believe completely overcoming the downsides of IFS wont be possible, you can probably improve the balance but I dont think you can completely eliminate the downsides. Moving the stock battery tray to the rear is very simple, you just remove the battery tray mount from the front and move it to the rear, all the holes line up. Even after this change there is still a front weight bias, just a bit forward of center (with a shorty battery)

I tried out some HPI Venture springs (not sure what the spring rates are) after testing it stock, the fronts were softer than stock and the rears got stiffer. This seemed to be helpful in allowing the suspension to flex a bit more up front rather than mainly transferring the load to the rear like stock did. It has a bit of droop up front but not so much the bulkhead is dragging/getting hung up. These springs need to be mounted upside down as the collar between the upper and lower springs gets hung up on the shock body threads.

Care to share more pics of your Trxus mt's? I'm on the fence about buying a set

 

[HumboldtEF]

Care to share more pics of your Trxus mt's? I'm on the fence about buying a set

Here you go http://www.rccrawler.com/forum/tires-wheels/614024-new-pl-tire-3.html#post6024269

 

[Steve g]

What do you think a light sway bar on the front would do to your current issue? Help or harm?

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[mass-hole]

I don't have direct experience with the IFS Element setup, but I did spend a lot of time trying to turn my Losi Rock Rey into a somewhat dedicated crawler and balancing the IFS with the rear axle was one of the toughest things. The rear axle always wanted to do more of the work. I could stiffen up the rear springs and lighten the front, but then the rear axle might stop fully articulating for the sake of making the front articulate. A rear sway bar certainly would help, but again, forcing the rear to not articulate for the sake of making the front. The stock sway bar on the Rock Rey was WAY too stiff and cut the rear articulation in half.

One thing to point out is that the springs function differently on a solid axle vs a independent axle. In a solid axle, the weight of the truck on a flat surface is held 1:1 by the spring force. However, when the axle articulates, the force resisting the articulation is some ratio that is determined by how far the spring/shock is from the tire and the roll point of the axle. Think of the axle like a wrench on a nut. The nut is at the center of the axle, the end of the wrench is the axle tube. If I push on the end of the wrench I get more leverage. If I push on the wrench close to the nut, I get little leverage. Same with the spring. If you mount the spring closer to the tire, the spring will resist articulation more than if its mounted farther from the tire. BUT, regardless of where the spring is mounted on the axle, it doesn't change the springs ability to hold the weight of the truck up.

So, you change where the spring mounts on a solid axle, and you don't change the ride height, but you change how the axle articulates.

On IFS, the spring/shock is mounted somewhere in the middle of the control arm and the control arm pivots around a point. The force the spring exerts is used to both hold the truck up and resist it from articulating. If you were to move the spring outward, the ratio changes. The spring now has more leverage to not only hold the truck up, but also resist articulation. You move the spring inboard and it now has less leverage to hold the truck up but also less resistance to articulation. You cannot change one thing without the other also changing.

The spring on the IFS setup has to be stiff enough to handle the weight of the truck at whatever the leverage ratio is on the control arm. If you have the the spring mounted in the middle of the control arm, the spring probably has to be ~2x as stiff to hold the truck up as what it would need to be on a solid axle.

I guess if I was going to try to make it work, I would get my spring rate for the IFS set so that it will allow for full compression under the weight of the truck. Then I would play with where the shocks are mounted on the rear axle. If the rear axle is doing to much of the work, move the shock out. You don't need to necessarily stiffen the spring. If you cannot make that work then a rear sway bar will act the same as moving the spring/shocks outboard on the axle.

I had my rock rey close to where i wanted but could never quite get there. it would fully articulate, but you can see how much preload i had to run on my front shocks because i had to run such a light spring:

Btw i was running Powerstroke XT’s on extended shock towers in the front of my rock rey. The front end has a stupid amount of travel and the total wheel travel is as much as the rear axle.

 

[rkj__]

One thing to point out is that the springs function differently on a solid axle vs a independent axle. In a solid axle, the weight of the truck on a flat surface is held 1:1 by the spring force. However, when the axle articulates, the force resisting the articulation is some ratio that is determined by how far the spring/shock is from the tire and the roll point of the axle.

On IFS, the spring/shock is mounted somewhere in the middle of the control arm and the control arm pivots around a point. The force the spring exerts is used to both hold the truck up and resist it from articulating. If you were to move the spring outward, the ratio changes. The spring now has more leverage to not only hold the truck up, but also resist articulation. You move the spring inboard and it now has less leverage to hold the truck up but also less resistance to articulation. You cannot change one thing without the other also changing.

I was deep in thought about this topic the other day, and realized the same thing. In hindsight, it's pretty obvious, but I just never had much reason to think about it in the past. Nice informative post"thumbsup"

 

[HumboldtEF]

I picked up some new Enduro springs to test and found a pretty good balance. Yellow in the front Blue in the rear. The front needs some preload so its doesnt sit too low. But with these springs its supportive enough for the IFS and I can actually use all of its travel (remember its limited 6mm or so). Stock hardly used much more than half of its travel and the venture springs had maybe 80% of the travel.

Sitting on flat ground this is how much i can get one front corner to compress before lifting a tire. Though out on the rocks when the rig isnt on flat ground it can compress a front corner fully.

This is about where the front end sits when the suspension has settled.

I guess one other factor I was thinking about in comparison to a solid axle is where the weight is for the axle/IFS. A solid axle is unsprung weight where maybe 50% or more of the IFS is sprung weight. Correct me if I'm wrong.

 

[Phyro]

Tried the following setup tonight:
- Front: 30 wt w/ Yellow
- Rear: 30 wt w/ Grey (Stock)
- Forward Battery (3S 5000mah Stick)


The truck currently has a really heavy bias to the front due to the battery. When I pressed the truck down, it wasn't springing backup afterwards. Might try the battery in the rear position instead tomorrow night. Probably should get a 3S Shorty sometime.