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Discussion Starter #1 (Edited)
Anyone knows if there is enough clearance to regrease as needed? I am planning to do the RB front bar and use greasable bushings but not sure about the clearance. I know some people use JB greasable bushings so I assume it should be ok but just want to confirm and save me some labor removing the wheel and check.

Also, if you just change out the oe bushings for poly, without the bar, how much improvement in body roll is it? Would it be equivalent to having a couple mm larger bar?

I have Koni/RB springs with Progressive rsb on stiff setting and am still not happy with the body roll. It's more like the initial roll that I am not happy about. The rear seems to follow nicely though. It's also feels like making the right turn is much flatter and more controllable than the left. Maybe driver's weight does help a bit.

For those have RB springs and Progressive on stiff setting (stock end links) there is a bonus. Right after switching to stiff setting, I noticed the bar was no longer parallel with the ground, but pointed down like 15 deegree. After lowered with RB springs it's back to its nature position.

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The bushing Durometer or material used will not increase the effective size of a sway bar.

The harder the Durometer the more apparent the driver feed back will receive during cornering. However this usually comes from comparing different end link types (solid self lubricating rod ends R the best) and bushings. Naturally experience in some form Motorsport TRACK events,i.e. Road Track, Slaloms, even parking lot "cone" chasing.. etc., help to make good choices in suspension upgrades and adjustments.

The type of rear sway bar used on many MAZDA's do not require sway bar pre-loading, so perpendicular alignment to the center axle line is not necessary. But for safety of clearance concerns it should at least be checked.


Something that many forget to think about...the number one choice springs to use and lower cars are PROGRESSIVE. Because of this design unlike fix rate springs it is much harder to achieve consistent driving habits over a range of different conditions. So really all one can do is adjust things first and foremost SAFE and then feel good for individual driving style.
 

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Discussion Starter #3 (Edited)
I was reading about poly suspension bushings and they said switching from soft rubber to harder material will improve body roll like having a larger bar. I am not sure if there is any truth to that but I can understand with soft matetial, the whole bar will flex a little before providing the counter twisting force. Maybe that flex isn't that great unless the bushings are really old.

I think that progressive springs, at least in theory, work great: soft during normal drive and stiff when compressed as in turns. However, my priority is not just performance but also the fun to drive factor which may be even more important to me. I had progressive springs on my 2nd Gen before and I was a bit disappointed with road feel. It feft just like stock which is good for people who just want to lower the car. I have no interested in that and wish there was one that is firmer than stock with the same height. RB is not too low and give me the road feel I was looking for but I am still not satisfied with the roll during fast turns. It's probably the higher center of gravity in the rear of the hatch.

I did my suspension in steps until am happy then hopefully will stop. I started with rsb, increase to stiff setting, FSD and then RB springs. Hopefully fsb will be the last one. All for road feel with minimum compromise on comfort (performance comes naturally I hope). My goal is to have fun without having to push the car.
 

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I was reading about poly suspension bushings and they said switching from soft rubber to harder material will improve body roll like having a larger bar.
I did my suspension in steps until am happy then hopefully will stop. I started with rsb, increase to stiff setting, FSD and then RB springs. Hopefully fsb will be the last one. All for road feel with minimum compromise on comfort (performance comes naturally I hope). My goal is to have fun without having to push the car.
If ride comfort is also on your list DO NOT use any Polyurethane bushings anywhere.

I am glad to read that other do upgrades in small steps...:grin2:

For the most parts the larger percentage of members on this forum even if they dont admit it do exactly what you are doing! :wink2:
 

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Discussion Starter #5
If ride comfort is also on your list DO NOT use any Polyurethane bushings anywhere.

:wink2:
I should have said "my comfort" :smile2: . Poly bushings in sway bars give you the least harsh ride compared to other areas'.
 

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Anyone knows if there is enough clearance to regrease as needed? I am planning to do the RB front bar and use greasable bushings but not sure about the clearance. I know some people use JB greasable bushings so I assume it should be ok but just want to confirm and save me some labor removing the wheel and check.
If you use rubber bushings this won't be an issue. A grease gun generates significant pressure, more than enough to force the grease into where you need it. Poly bushings that are greaseable sometimes have small channels to allow easier greasing too. Actually, you want the bushings tight, just enough to let the bar move. Any more than that and they will rattle and bump.
Edited to add-
Thought about this some more- did you mean is there access to the bushings to grease them as needed? In which case, the answer would be not much. It would make it a lot easier if you installed extension lines on the zerk points and mounted them at an easily accessible spot.

Also, if you just change out the oe bushings for poly, without the bar, how much improvement in body roll is it? Would it be equivalent to having a couple mm larger bar?
Depends on what you use for bushings, but it will feel a bit stiffer. It doesn't really change how the bar works though. The poly is far less compressible then the rubber, so its effectively taking up the slack and not allowing the bar to move as much.
Using poly bushings on just the bar won't be too bad for ride quality, its when you do everything that it goes downhill rapidly.



I have Koni/RB springs with Progressive rsb on stiff setting and am still not happy with the body roll. It's more like the initial roll that I am not happy about. The rear seems to follow nicely though. It's also feels like making the right turn is much flatter and more controllable than the left. Maybe driver's weight does help a bit.
Nothing wrong with a bit of body roll. It helps with the weight transfer and may provide a more predictable breakaway at the limit depending on what tires you have.
If left/right turns feel different, it may be something else other then the bar. Alignment maybe? If you dial out the rear toe to something like .08° on the rear that might help, and check the rear camber too. 1.5° or maybe a bit more seems to work well. Remember that toe and camber are not independent here, you may need adjustable arms to get it right.

The type of rear sway bar used on many MAZDA's do not require sway bar pre-loading, so perpendicular alignment to the center axle line is not necessary. But for safety of clearance concerns it should at least be checked.
This may be another reason for the difference in left/right feel. If the bar has a bit of preload, that's what can happen. When you install a bigger bar, you should use adjustable end links to prevent preload, especially when lowering the car any significant amount. The studs on the endlinks should pass through the hole in the bar freely on both sides without having to bend the bar to get them in.
The bar should be parallel to the chassis for optimum performance. The geometry doesn't work as well if it isn't.
Here is a graphic I found on the web a while back that shows how the position of the bar can affect the suspension geometry-



If its way off you can actually break stuff. See the center picture and the way the force is vectored? The bar is a simple torsion spring. You want the center part to rotate on its axis. The force applied needs to be perpendicular to the lever arm to do this. If it isn't it will pull on the bar instead of turning it and the bar will not be as effective.
This can also tear the mount off the chassis in extreme conditions with a big bar. :surprise:

Have you considered H&R or Vogtland springs? Both are similar progressive type springs that are stiffer than OEM. The H&Rs (# 28821) come in two slightly different specs. The -2 variant is slightly stiffer for diesel cars ( TUV approval says the wire diameter of the -2 version front springs is .5mm thicker and the coils are 2mm shorter, rears are identical), the -1 variant is for gasoline powered cars.
They do ride well, the car handles very well, they aren't too low for daily driving either.
 

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Discussion Starter #7 (Edited)
If you use rubber bushings this won't be an issue. A grease gun generates significant pressure, more than enough to force the grease into where you need it. Poly bushings that are greaseable sometimes have small channels to allow easier greasing too. Actually, you want the bushings tight, just enough to let the bar move. Any more than that and they will rattle and bump.
Edited to add-
Thought about this some more- did you mean is there access to the bushings to grease them as needed? In which case, the answer would be not much. It would make it a lot easier if you installed extension lines on the zerk points and mounted them at an easily accessible spot.
Yes I meant access to grease. I know no way a grease gun alone can do it. I am thinking of using it with a flex tube.


Nothing wrong with a bit of body roll. It helps with the weight transfer and may provide a more predictable breakaway at the limit depending on what tires you have.
If left/right turns feel different, it may be something else other then the bar. Alignment maybe? If you dial out the rear toe to something like .08° on the rear that might help, and check the rear camber too. 1.5° or maybe a bit more seems to work well. Remember that toe and camber are not independent here, you may need adjustable arms to get it right.
I agree. Weight shift is good for traction during shafts turns and flatter turns promote dangerous confidence. So getting better tires in also my plan. I haven't checked alignment until everything is done.




This may be another reason for the difference in left/right feel. If the bar has a bit of preload, that's what can happen. When you install a bigger bar, you should use adjustable end links to prevent preload, especially when lowering the car any significant amount. The studs on the endlinks should pass through the hole in the bar freely on both sides without having to bend the bar to get them in.
The bar should be parallel to the chassis for optimum performance. The geometry doesn't work as well if it isn't.
Here is a graphic I found on the web a while back that shows how the position of the bar can affect the suspension geometry-



If its way off you can actually break stuff. See the center picture and the way the force is vectored? The bar is a simple torsion spring. You want the center part to rotate on its axis. The force applied needs to be perpendicular to the lever arm to do this. If it isn't it will pull on the bar instead of turning it and the bar will not be as effective.
This can also tear the mount off the chassis in extreme conditions with a big bar. :surprise:
This is exactly what I was thinking too. When the weight shift, the force is acted on at the end links and ideally, we only want vertical force. When the bar is at an angle, that force is now acts on the horizontal a little (Fx and Fy of a vector) and put stress on the mounting points. At least that's what I am thinking based on simple physics. Not sure if it works like that in real life.

Oh, there was no preload on the end links during installation. I don't see how since the lca and bar can be moved up and down freely.

Have you considered H&R or Vogtland springs? Both are similar progressive type springs that are stiffer than OEM. The H&Rs (# 28821) come in two slightly different specs. The -2 variant is slightly stiffer for diesel cars ( TUV approval says the wire diameter of the -2 version front springs is .5mm thicker and the coils are 2mm shorter, rears are identical), the -1 variant is for gasoline powered cars.
They do ride well, the car handles very well, they aren't too low for daily driving either.
No but RB is the lowest I can go with.

Thx for the awesome diagrams :thumbup1 1:
 

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This is exactly what I was thinking too. When the weight shift, the force is acted on at the end links and ideally, we only want vertical force. When the bar is at an angle, that force is now acts on the horizontal a little (Fx and Fy of a vector) and put stress on the mounting points. At least that's what I am thinking based on simple physics. Not sure if it works like that in real life.
It does. Older MX-5s for instance had issues with the bar mounts tearing when using stiffer bars, especially the front mounts. Improper mounting made it that much more likely to happen.

Oh, there was no preload on the end links during installation. I don't see how since the lca and bar can be moved up and down freely.
You should do the final setup with the wheels on the ground or up on ramps and the suspension loaded. Assemble the first side, the bar will be able to swing freely as you say to align the hole. Once that side is attached, the other side will either line up or it won't. As the suspension is loaded, you won't be able to move the lower control arm and the bar won't be able to move as its now fixed in place by the opposite endlink. If you have to force it or move something to line up the hole with the stud, there is preload. Sometimes aftermarket bars don't line up as well as they should.
 

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Discussion Starter #9
You should do the final setup with the wheels on the ground or up on ramps and the suspension loaded. Assemble the first side, the bar will be able to swing freely as you say to align the hole. Once that side is attached, the other side will either line up or it won't. As the suspension is loaded, you won't be able to move the lower control arm and the bar won't be able to move as its now fixed in place by the opposite endlink. If you have to force it or move something to line up the hole with the stud, there is preload. Sometimes aftermarket bars don't line up as well as they should.
My feeling is it won't line up both sides perfectly, too many factors involved: beside the bar itself, spring compression on both side not exactly the same or ground is not perfectly level, etc....but it's a good test ro see how far off they are from each other.
 

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My feeling is it won't line up both sides perfectly, too many factors involved: beside the bar itself, spring compression on both side not exactly the same or ground is not perfectly level, etc....but it's a good test ro see how far off they are from each other.
It might or might not. That is the reason for using adjustable endlinks- to ensure that they do line up without preloading the bar. :smile2: And yeah, its best done on a level garage floor.
 
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