Sway Bar Tuning and Musings (1 Viewer)

[TeCKis300]

I've been knee deep doing a body lift so here's some quick notes.

- Washers were a quick and dirty way to test a concept. They are large enough cover the witness marks of contact so that's what I went with. It's wet my appetite to chase more. @PerryParts , definitely interested and I'll reach out.
- Adding compliance in this manner is distinct from extending links or repositioning links. Though it could be integrated and compounded with those strategies. The current LC200 sway bar relocation for clearance can change the motion ratio of the sway bar end link, which itself changes the effective spring rate of KDSS. Unless relocating the way to the outside of the LCA, which potentially restores some of the motion ratio?
- Great post @daneo ! Always great to have objective references and see what's going on with other platforms to inform what could be done with the LC.
- I don't believe this is so much plumbing bandwidth, as it is an architectural limitation of the KDSS system. Regardless, loosing up the system (if desired) could have performance benefits if high speed running is a priority and I'm excited where this could go.

 

[TeCKis300]

Now that I have had more time and varied use with the mildly relaxed front sway bar bracket, I'm pretty happy with the results
- Incrementally more flexy front axle. Useful more articulation.
- It just completely eats up rally type running. It always has but it's just so slinky and fun to be mobbing at 60+ MPH.
- More front axle bite on twisty and tight mountain roads, reducing understeer more than I expected.
- Lean and sway on-road is still nicely controlled and I don't feel like I lost any roll stiffness. I did also body-lift somewhat the same time, and I was expecting more roll, but happy to say not much if any additionally roll.

Caveat and still feeling this out
- I did tow coming down the mountains from Julian in raining 30 degree weather. This is a road I'm very familiar with having towed probably 20 times over this, but rarely if ever in rain and cold like this. (It's San Diego after-all) There were a couple moments where it felt like the front axle had less bite and steering went a bit vague, but perhaps the reality is that with such cold, wet, and rain, and towing 8k, the roads were just slick. Trying to understand in my mind if this mod could have lended to that, but in solo driving, there is more front bite?

 

[Willie G]

... There were a couple moments where it felt like the front axle had less bite and steering went a bit vague, but perhaps the reality is that with such cold, wet, and rain, and towing 8k, the roads were just slick. Trying to understand in my mind if this mod could have lended to that, but in solo driving, there is more front bite?

I'm far less learned than you in such matters, but is it possible that the trailer tongue weight was just enough to unload the front end slightly?

 

[TeCKis300]

I'm far less learned than you in such matters, but is it possible that the trailer tongue weight was just enough to unload the front end slightly?

Yes, very possible. I was somewhat trail braking and turning on a downhill section (not the best thing to do when towing), so it could have been my fault. I have heard recommendations to reduce anti-sway friction on weight distribution hitches in low traction environments, but my Equalizer isn't adjustable on the fly like that. Just want to make sure I'm thinking about this right and that my sway bar mod didn't contribute to this and I need to drive within the limitations of conditions.

 

[Boston Mangler]

Yes, very possible. I was somewhat trail braking and turning on a downhill section (not the best thing to do when towing), so it could have been my fault. I have heard recommendations to reduce anti-sway friction on weight distribution hitches in low traction environments, but my Equalizer isn't adjustable on the fly like that. Just want to make sure I'm thinking about this right and that my sway bar mod didn't contribute to this and I need to drive within the limitations of conditions.

“So there I was, trail braking my SUV While towing”
-Legend

#racecarthings

 

[bloc]

Now that I have had more time and varied use with the mildly relaxed front sway bar bracket, I'm pretty happy with the results
- Incrementally more flexy front axle. Useful more articulation.
- It just completely eats up rally type running. It always has but it's just so slinky and fun to be mobbing at 60+ MPH.
- More front axle bite on twisty and tight mountain roads, reducing understeer more than I expected.
- Lean and sway on-road is still nicely controlled and I don't feel like I lost any roll stiffness. I did also body-lift somewhat the same time, and I was expecting more roll, but happy to say not much if any additionally roll.

Caveat and still feeling this out
- I did tow coming down the mountains from Julian in raining 30 degree weather. This is a road I'm very familiar with having towed probably 20 times over this, but rarely if ever in rain and cold like this. (It's San Diego after-all) There were a couple moments where it felt like the front axle had less bite and steering went a bit vague, but perhaps the reality is that with such cold, wet, and rain, and towing 8k, the roads were just slick. Trying to understand in my mind if this mod could have lended to that, but in solo driving, there is more front bite?

With how far you are from stock, and how long it’s been since you were stock, I have to wonder what your on-road impressions of the compromises would be if compared directly to a stock LX.

 

[TeCKis300]

With how far you are from stock, and how long it’s been since you were stock, I have to wonder what your on-road impressions of the compromises would be if compared directly to a stock LX.

That's a good question. It has been awhile. I'd like to think it drives pretty close to stock, except the CG is higher. In the grand scheme of things, the mods that affect daily drivability is a sensor lift (1.75" F / 1.25") and 35s. My wife drives it every now and then and the only difference to her is that it's taller.

In trying to maintain cornering grip, I did choose to go with wider 12.5" tires. Dial in alignment with some negative camber. And this mod. She still corners well enough to be fun in the mountains.

The sway bar tuning should still be relevant, but I do remember the stock setup cornering harder (for such a big bodied on frame truck) with it's lower profile tires and better CG.

 

[TeCKis300]

@PerryParts made up some trick high compliance sway bar bushings for the LX. I got them installed today in about 10 minutes.

Pretty neat that it's flexy and compliance in the Z-axis. Stiff and stable in X-axis. Just what I was looking for to dial in some more compliance on the front sway bar.

I'll do my normal commuting route tomorrow and see how they go.

 

[skrypj]

I was kinda thinking I might go superpro sway bar and end link bushings in the rear to stiffen it up a bit. Combined with this in the front, I bet it really evens out the truck.

 

[TeCKis300]

Got a couple days under my belt with the Perry's bushings. Nicely done! I already relaxed them a bit previously, but this definitely added some more compliance again to the front end. It makes the front end feel very independent. This is most obvious over speedbumps and transitions when taking them diagonally. Less head toss as the front sway bar usually tries to square things up.

All while allowing AHC to maintain plenty of front end stability.

I would highly recommend others give this a whirl and would be interesting in hearing their own impressions.

I would also be intrigued for KDSS guys to get a similar bushing! @PerryParts ?

 

[linuxgod]

I’d be happy to install and test a pair on my LC if someone wants to make a set. I’m far from stock though so my experience may not be representative of a stock vehicle

 

[Boston Mangler]

I’d buy a set also, mine need replacing anyway

 

[CanadianRockyCruiser]

I’d buy a set also, mine need replacing anyway

Are these going to be available from @PerryParts ? I'd buy some too!

 

[bloc]

Have we established that the 200-series implementation of KDSS is limited by the sway bar bushings in any way? Only seems like it would matter if we were hitting the limits of the KDSS cylinder stroke.

 

[linuxgod]

Have we established that the 200-series implementation of KDSS is limited by the sway bar bushings in any way? Only seems like it would matter if we were hitting the limits of the KDSS cylinder stroke.

I would think it could make a difference as the effect of KDSS is that it “locks up” at higher speeds, so if you’re on bouncy pavement at higher speeds it’s not going to give you the articulation and compliance it could. Whether that’s a pro or a con I can’t say though

 

[skrypj]

I would think it could make a difference as the effect of KDSS is that it “locks up” at higher speeds, so if you’re on bouncy pavement at higher speeds it’s not going to give you the articulation and compliance it could. Whether that’s a pro or a con I can’t say though

That’s what I hated about KDSS on my GX460. Faster rougher dirt roads were bad cause the KDSS would lock down. Not sure if the LC is the same

 

[linuxgod]

That’s what I hated about KDSS on my GX460. Faster rougher dirt roads were bad cause the KDSS would lock down. Not sure if the LC is the same

Anecdotally I fell like KDSS is “open” up to 10-12 or maybe 15 mph and then gets stiff. Yeah @bloc I realize that’s not actually how it works, it’s just way I’d describe the effect

Anyway I find on dirt roads it’s fine but the tires and shocks really have to handle the terrain. The BP51s set pretty soft do a nice job soaking up a lot of the bumps provided I’m moving at a good clip.

Where I find KDSS annoys me is actually the pothole moguls in my alley, and similar off-road terrain, where you’re going slow enough for KDSS to “open” and now instead of the shocks trying to soak up the bumps the truck starts rocking back and forth.

 

[PerryParts]

Are these going to be available from @PerryParts ? I'd buy some too!

Yes! provided they give the longevity I'm looking for. I have done some cycle testing on these on my suspension dyno with positive results. I'm considering a "soft launch" of these to get a few more sets out in the wild for people to try out and abuse. Ideally folks who wheel often. If you're reading this, and that sounds like you, please send an email to patrick@perryparts.com

I have a few other products I want to launch first, but provided testing goes well, these might just find their way onto the site!

 

[Boston Mangler]

Yes! provided they give the longevity I'm looking for. I have done some cycle testing on these on my suspension dyno with positive results. I'm considering a "soft launch" of these to get a few more sets out in the wild for people to try out and abuse. Ideally folks who wheel often. If you're reading this, and that sounds like you, please send an email to patrick@perryparts.com

I have a few other products I want to launch first, but provided testing goes well, these might just find their way onto the site!

Kudos to you for wanting to do more testing being releasing something subpar just to make a buck

Bravo

 

[TeCKis300]

Have we established that the 200-series implementation of KDSS is limited by the sway bar bushings in any way? Only seems like it would matter if we were hitting the limits of the KDSS cylinder stroke.

As we're enthusiasts always looking for ways to push things, a compliant sway bar bushing could be another tool in the toolbox to tune with. From my wheeling with LCs and GXs, I do think there's room for improvement with KDSS. Both for Baja type fast running and opening up compliance for larger bumps that use up the built in accumulator travel. I'll say this out loud before anyone thinks I'm trying to cast shade - I'm equal opportunity and always looking to improve upon things including for AHC as well.

I think these seasoned wheelers also do a good job to describing some KDSS trades @14:00. Including other ways to address it.