Hi Everyone, I should change the lower control arm bushings. I was looking for the Powerflex control arm bushings as people said it is better than the OEM part. Than I found the Positive Steering Response System which has good features. So do you folks recommend this item to me also, is there a chance this item to be broken in advance use track etc?

Thanks from now.

 

I have them waiting to go on this week.There is a much larger thread else where in this section that has nothing but praise in it and not one failure.

 

I have had mine for 5k miles and HIGHLY suggest them. They 'creak' every now and again, but nothing major or something to be concerned with IMO.

Even with Poly you WILL have to replace them in the future. THe PSRS seems to be a one time purchase.

 

I like the quicker steering but has anyone notice the car getting squirrely when you throw it into a corner at high speeds after the install?

I also consistently had issues with the set screws coming out and Alta was super great with there customer service, but I just welded them to the control arm and took out the set screws. Fixed.

 

I've had the poly - Powerflex - on my car for over 100,000 miles and these units are not worn out. I do feel they need to be re-lubricated every year especially if you drive in snow. The Alta unit would have been my choice but I do drive in snow and I'm not sure anyone knows what salt and ice jammed in these will do. Even though I do not have personal experience with the Alta unit I would try it if your car is a weekend warrior and if you live in weather that is salt free in winter...or experiment...

 

i have a slightly different take on the alta psrs. i don't find the steering any "quicker". in fact, i would say turn in is slightly less sharp. it took away the "twitchyness" that i had induced w/ other mods and alignment. at sebring's bishop's bend (a long sweeping left-hander), i turn in at about 95mph, don't have to make any steering correction inputs, keep my right foot firmly planted to the floor and brake at about 110-113 mph. definitely not squirrely.

in which orientation did you install your psrs? i went for max caster gain.

 

I went to the conservative setting. I'm thinking I better do an alignment check...

 

You have to get an alignment after installing these!

Anytime you drop the front sub-frame it can change stuff.

 

Adding caster will increase steering effort...the more caster the more effort. More effort is not necessarily a good thing...and at higher values caster will absolutely dilute the affects of returnability built in at the SAI.

Caster is one of those tuning conceits established at some level from the lack of development elsewhere. It comes with hidden trade-offs and really isn't necessary at some level.

Small doses!

EDIT: also, caster can overwhelm steering feel and preserving steering feel ought to be a primary goal. When the castering force is so strong it overtones feel, it is too much. There are other ways to provide a stable plateform.

 

What does the PSRS actually DO?? What does it look like? anyone got a pic? I just can't figure out exactly what this thing is.

 

It very precisely locates the rear stud of the control during all movements...as does the Powerflex poly bushing. The PF bushing does have some bind.

The stock oil filled bushing has a fair amount of compliance and although some of this is good, some of it is bad from a pure driving perspective...and these wear fairly quickly.

 

Ok, I learned absolutely nothing from that (no offense)

How does precisely locating the rear stud of the control arm increase caster? does it move the stud forward/back/up/down?

I guess it really doesn't matter since I'm not a trackie and I won't be buying it. And I'm sure your explanation will be slightly over my head anyway. That's ok, there's lots of things over my head I just like to know what's out there and learn along the way.

 

the PSRS moves the contact point (rotation axis) of the back of the control arm off center. Alta suggests two possible locations, on that maximized change in caster, on that just tweaks the change a part of that... Anyway, because the rotation axis is moved, you get differences in the steering geometry.

I have them and love them, but did have to do the welding as mentioned earlier.

FWIW, BavarianAuto used to sell (don't know if they still do) two versions of bushing replacement: One with the rotation axis in the stock location, one offset so you could do the same geometry changes. The units were urethane.

There used to be no options here, then there were tons..... Lots of ways to skin the cat..... Anyway, the stock part sucks and it's a great place to improve the handling performance of the car.

Matt

 

The caster adjustments available with the PSRS is a choice of an additional .75 or 1.5 degrees of neg caster........not much at all.

 

Looks like this...



Replace the OEM #8 in this image...

 

Matt, I might have to disagree with this. Rotational axis is the same in stock as it is in the Alta. The movement is the same in both, but just more precise in the alta.

To note, I just removed a suspension with the offset poly bushings, and I will tell you that I would never use these things, The binding is just to prevalent.

I've just completed a whole new front lower and will be offering them for sale at some point. Testing will be next week.

 

...though unwanted, the binding is near the extremes in travel - bump and droop. But also, these do require periodic librication or they will indeed bind thru the entire arc. Just and FYI They are not perfect, but are perhap an alternative for those of us the the salty-snowy regions who drive too much on public roads . Soon however...very soon...

 

Thanks! very informative. I'm not 100% there, but now I understand more than I did. Thanks

 

BUMP to the thread for a question ---

1.5* sounds like a healthy caster increase to me.

But what position are people installing these in? I am lowered 1-1.5", and it's my understanding I lost some caster as a result. I was interested in getting some caster back and then some. But are the "anti-lift" properties still applicable in the 1.5* setting? Why offer the lesser caster setting? Enlighten me.

 

I am at the point where i need to replace my front arm bushing. I have 2 options of going for Urethane or PSRS. PSRS, on top of its handling adv over urethane, is abt 100 bucks more expensive but its seems to be one time change which is good because its not exactly the easiest thing to do (I dont have the tools and skills to do it) and my local shop here charges $325 to put it on.
as far as the nvh is concerned, how severe will it transform the ride which IMO my mini has already a stiff ride right now with the factory web spoke wheel comparing to say a nissan 350z with Factory sport setup. My friends has that and whenever i ride with him i can tell the diff. nissan rides smoother. I am really ok with the harsh ride that mini has, only thing i have to do is slow down when i drive on rough road. I have even drived and ride on a 03 911 Turbo S with 19" and 20" inch wheels setup. That car i think rides harder than the mini but I am still ok with it if it were my daily drive, the only thing i cant stand is the exhaust noise on the freeway. So if PSRS will make my MINI rides like that porsche then I will go for PSRS. what do you guys think?

 

I have had it on my Mini for a bit over a year now. I dont trust the set screws so I TIGed mine one and all has been well. I went with the Anti-lift / Caster option with my setup. I have never heard a rattle out of mine and the brake control is awesome, no wandering.