Rear IRS LCA Sherical Bearing Upgrade, Is this really worth doing?

[MustangCollector]

been reading up on this past few days and i know lots of folks are saying it helps wheel hop etc and thats fine with me but my car does not have wheel hop anymore. I found the biggest improvement came from the upgraded shock coilovers for the wheel hop issues as i saw little to no improvement with vertical links or toe rods and the other stuff for the cradle. Like us all i tried everything 2 years ago before coilovers came out and low and behold the coilovers fixed it for good.


I notice when you lower these cars the LCA bushing is not centered and seems it has a cocked preload in the lowered suspension state. I always wondered about this being an issue for bind and suspension articulation and how it would affect the oscillations of the IRS on bumpy roads and ride quality.

So my questions to owners who did this and vendors who supply these parts does this LCA bearing upgrade improve suspension travel, articulation and even the effectiveness of the shock and spring dampening.? I am not asking this when the car is being launched but when driven on the street hard or normally,
the labor doesn't seem that hard as i own a press and have the means to do it but im not sure if this is something that would improve things or not on the bumpy streets i drive on daily. My car handles incredible, it could ride better out back and i also wonder if the toe links and vertical links in combination with the offset load on the LCA bushing is actually affecting the IRS movement to absorb bumps without bind. I did test months back with the rear spring removed and a jack under the rear hub the up and down motion with no load wasn't as smooth as i would have expected, it almost seems the IRS wants to turn in and the vertical links prevent this and there is opposing preload on the LCA bushing as well.

technical comments welcomed here, i don't need replies on wheel hop as i am asking specifically for IRS bind and articulation in regards to ride quality.

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[Enzo]

Here's my review of it.

http://www.mustang6g.com/forums/showthread.php?t=73614

 

[MustangCollector]

Here's my review of it.

http://www.mustang6g.com/forums/showthread.php?t=73614

cool i see you also did the FR toe link bearing, does the factory PP come with these already or are the FR parts a huge upgrade over the factory PP stuff? i never bothered to even check my car.

 

[Enzo]

The factory pp does not come with the toe link ones.

 

[BMR Tech]

[MENTION=10530]MustangCollector[/MENTION]

One of the best benefits to the LCA Bearing upgrade, aside from the wheel hop fix that you are not interested in, is the fact that the bearing upgrade will help reduce erratic geometry change. Under cornering loads, WOT straight line blasts, and everything in between. When you are driving your S550, the bushing deflection is causing the LCA to shift in multiple directions. When this shifting happens, you get toe, camber, thrust angle and bump change/inconsistency.

 

[MustangCollector]

[MENTION=10530]MustangCollector[/MENTION]

One of the best benefits to the LCA Bearing upgrade, aside from the wheel hop fix that you are not interested in, is the fact that the bearing upgrade will help reduce erratic geometry change. Under cornering loads, WOT straight line blasts, and everything in between. When you are driving your S550, the bushing deflection is causing the LCA to shift in multiple directions. When this shifting happens, you get toe, camber, thrust angle and bump change/inconsistency.

thanks for this info, do you feel this LCA upgrade is mandatory to also do the toe bearing or they both do different things? id like to correct the suspension bind in the IRS, and if this LCA bearing will do so il def do it in a few weeks time. From your info i would suppose the LCA will aid is the suspension doing its job better and help with erratic behavior on bad roads which i have always experienced

 

[wildcatgoal]

My review: http://www.mustang6g.com/forums/showpost.php?p=1541197&postcount=9

Lots of LCA discussions all with almost exactly the same positive results with little sacrifice. The bounciness you commonly get has been shown to be eliminated by using Steeda's spherical shock mounts with my car, two people I know personally, and other folks on this forum. So that's an option for you, too. If you haven't noticed elsewhere, I tell people now this should be their very first modification. Very first. I also have the toe bearing. It just makes sense to do at the same time since you are already unbolting the tow arm at the knuckle to aid in getting the LCA off of the car for the bearing install.

 

[MustangCollector]

My review: http://www.mustang6g.com/forums/showpost.php?p=1541197&postcount=9

Lots of LCA discussions all with almost exactly the same positive results with little sacrifice. The bounciness you commonly get has been shown to be eliminated by using Steeda's spherical shock mounts with my car, two people I know personally, and other folks on this forum. So that's an option for you, too. If you haven't noticed elsewhere, I tell people now this should be their very first modification. Very first. I also have the toe bearing. It just makes sense to do at the same time since you are already unbolting the tow arm at the knuckle to aid in getting the LCA off of the car for the bearing install.

the upper shock mounts def seems worth doing, i always cringed to see how the factory mount had bind the way the shock geometry gets mounted.

how hard is it to get to the lower control arm bolts for removal, do i need to drop the cradle or remove the exhaust?

 

[West TX GT]

If you care about how the car feels while turning and applying power it is necessary. For me, it is most noticeable when accelerating out of a turn. Everything feels connected and solid and where it should be. Just smooth power delivery out of the turn. Do the toe links at the same time while you are taking things off and using a press. If you aren't paying for install this is a pretty cheap upgrade that feels huge. You won't regret it.

 

[MustangCollector]

If you care about how the car feels while turning and applying power it is necessary. For me, it is most noticeable when accelerating out of a turn. Everything feels connected and solid and where it should be. Just smooth power delivery out of the turn. Do the toe links at the same time while you are taking things off and using a press. If you aren't paying for install this is a pretty cheap upgrade that feels huge. You won't regret it.

yeah im gonna do the LCA and Billet shock Mounts, my car feels awesome no erratic handling but i feel there is bind out back which is affecting ride quality and its making the car very rough to drive locally, highway car feels amazing but when the roads are choppy the back IRS gets a bit out of control.

I have vertical links, toe lines the Steeda IRS and Alignment kit and G tac braces with light wheels and sticky tires the car grips like no other ive driven. lots of my friends have these cars all with various mods but my car does drive the best and handles the best

 

[Rebellion]

A few things:

1. I did the toe knuckle bearing first and the effect, while positive, it doesn't lend itself to be incredibly useful in daily driving. It mainly helps with hard cornering. The LCA, you will feel it all the time, even on straight line driving and low speeds/acceleration.

2. The LCA has several effects: a)it seems to clamp down the car more, maybe due to the shocks working more effectively, b)eats up this hysteresis zone on the up/down transitions, suspension feels like the same rate all the time, c)suspension now it's ON all the time, before it was OFF at low speed and at speed it would turn ON, and d)makes the alignment true and consistent, with the stock rubber, you can't align it accurately, with the LCA bearing, you can align it to the hundredths and it keeps the values very well.

3. Install is not hard if you have the press. For clearance, I did loosen up my axleback clamps and removed the sway bar. The two outer bolts are obviously easy, the inner rear is easy as well...the difficult one is the one with the rubber, the inner front. Had to jack up the knuckle to it's highest position to get tool clearance. This bolt is to be removed last and installed first when remounting.

4. One drawback is that you will feel the road imperfections at low speed, while the suspension seemed to be just mute with the stock rubber. Now it's ON full time, I would gladly trade that little ride comfort for the "light sports car feel" that the LCA gives. Gives a lot of confidence on cornering, for some reason, after a while it seems like it reduces the effective spring rate at the rear or increases damper rate (closer to critical damping). I think this mod is a must for "spirited driving".

 

[MustangCollector]

A few things:

1. I did the toe knuckle bearing first and the effect, while positive, it doesn't lend itself to be incredibly useful in daily driving. It mainly helps with hard cornering. The LCA, you will feel it all the time, even on straight line driving and low speeds/acceleration.

2. The LCA has several effects: a)it seems to clamp down the car more, maybe due to the shocks working more effectively, b)eats up this hysteresis zone on the up/down transitions, suspension feels like the same rate all the time, c)suspension now it's ON all the time, before it was OFF at low speed and at speed it would turn ON, and d)makes the alignment true and consistent, with the stock rubber, you can't align it accurately, with the LCA bearing, you can align it to the hundredths and it keeps the values very well.

3. Install is not hard if you have the press. For clearance, I did loosen up my axleback clamps and removed the sway bar. The two outer bolts are obviously easy, the inner rear is easy as well...the difficult one is the one with the rubber, the inner front. Had to jack up the knuckle to it's highest position to get tool clearance. This bolt is to be removed last and installed first when remounting.

4. One drawback is that you will feel the road imperfections at low speed, while the suspension seemed to be just mute with the stock rubber. Now it's ON full time, I would gladly trade that little ride comfort for the "light sports car feel" that the LCA gives. Gives a lot of confidence on cornering, for some reason, after a while it seems like it reduces the effective spring rate at the rear or increases damper rate (closer to critical damping). I think this mod is a must for "spirited driving".

great points you address, i seem to hear that you feel the road more at low speeds i now wonder if this will affect ride quality and IRS violence more for me on my roads, i still think the rubber bushing being loaded all cocked has to be causing the IRS to be acting weird on choppy roads. my car handles incredible, doesn't have wheel hop but i am primarily interested in trying something to help the IRS become more compliant for daily local driving on bad roads, right now its rough and my car has rock hard recaro seats so you feel everything out back.

 

[Rebellion]

great points you address, i seem to hear that you feel the road more at low speeds i now wonder if this will affect ride quality and IRS violence more for me on my roads, i still think the rubber bushing being loaded all cocked has to be causing the IRS to be acting weird on choppy roads. my car handles incredible, doesn't have wheel hop but i am primarily interested in trying something to help the IRS become more compliant for daily local driving on bad roads, right now its rough and my car has rock hard recaro seats so you feel everything out back.

For pure ride comfort perspective, I wouldn't do it...it does make the car more "racecar-ish", you'll feel the road more at 0-40mph, it clamps down very well. It does get some airtime if you hit steeper transitions.

On the other side, it does make the IRS and spring/dampers work as intended since the movement is now from a solid axis from a fixed location. In that case, it does fix the IRS weirdness, but is that same weirdness that gives you a mute response at low speeds, like a Crown Victoria.

 

[Bluemustang]

I might as well chime in. The first thing you will notice is a different feeling to the car. Yes, it does reduce bind and improve suspension articulation. I think I would benefit from doing the Steeda rear shock mounts and I don't think they equipped to handle it as well once the LCA bearing is in due to the bind in the the stock mounts, which lead to slow speed bounciness as others here have reported.

I recommend doing the toe bearing as well b/c I recall reading from the BMR website that they recommended doing LCA and toe bearings once you install vertical links. I think the two go hand in hand so it does not make sense to do one without the other. Otherwise you're still leaving another area for geometry change to occur.

Everything just feels connected in the rear and no slop. I can take tight corners now with no wheel hop and it now slingshots around the corner. I can accelerate in corners with confidence of knowing the car will go where I want it to. It also helps to know when the car is actually losing grip, eradicating that gray area of uncertainty.

Downsides: you will feel more. Whether you call it NVH or whatever- you will feel more. You will feel the suspension articulating behind you and the wheels moving up and down. Basically it will different than before. I think the Steeda rear shock mounts may help with the ride quality as a few here have suggested so I intend to do that at some point.

Not trying to convince you either way but yes an improvement is real and articulation will improve.

 

[West TX GT]

I don't think it will help restore compliance back into the car. I recommend doing it, but not for softness. It did fix the odd stutter the car would have while turning under acceleration but I do feel minor changes in the road. Though I do think my BMR handling springs and Steeda adjustables set very stiff have a bigger role in that.

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