I have been planning to install a set of front control arm bushings a while now. I have done some research and the Powerflex standard issued Street seems to be the no-brainer choice here in North America. If you are in UK there is a UK brand that is very similar.

I care about how the Mini ride when not on the track. For that the OEM bushings seem not so bad even on the track in terms of steering response and tightness (with Swift spring, Koni Yellow, and 22mm RSB). I want a reasonable ride on the street and I can tolerate reasonable NVH and I know there are tradeoffs that I have to make - performance versus comfort. The thing is these tradeoffs are a continuum, and are in many areas. So far I have done quite well to maintain the Mini's NVH for a balance of street and track use. I have been taking the modifications one step a time, and able to experience the incremental changes, especially in the increase of NVH.

For me the Mini is more about handling than drivetrain performance. I would take more handling any day over more HP and torque, within reason. What compelled me to think seriously about the front control arm bushings is braking hard (as hard as one can) from 100+ MPH down to 40s. Even with stock brakes and racing pads, the front end shake is quite unnerving. I know my stock bushings are in reasonable shade, and the ball joints are in good condition. I reason that the front end shake is mostly caused by the deflection of the front control arm bushing which affect every alignment attributes.

My struggle is should I go with the Powerflex standard issued Street (purple PFF5101) version, or the Race (black PFF5101B) version. To give some perspective, some track heave car owner would go as far as putting in machined Delrin bushings. I know that I am no where near that nor crazy stiff springs. I do realize, however, the front control arm bushing is the most important flexible coupling of all the suspension parts - over the upper strut mount, sway bar bushings, and everything in the rear that just come along for the ride. It is the weakest part of the Mini's front suspension.

I have tried to find some quantitative information on the difference on Powerflex's site and there is none. My dilemma is which should I choose.

Street bushings


Race bushings

 

Purple for daily, Black if you track. The feedback on the black for daily is if you can live with it being that tight.

 

I feel as if you're questioning it - you might as well go with purple. It's a big enough job that you don't want to do it twice and to me - unless it's seeing 80% of it's time on the track - better off wanting more after the fact then less in my opinion considering the labor.

I put a set of purple powerflex bushings on a car that had 85k miles after driving it a few thousands miles. The change could not be any more night and day. Right now there's just shy of 140k on the car and I can't feel a difference from when they were installed.

 

Thanks for sharing you experience and you input. It is precisely such a difficult job that I want to get it right once.

I like to hear more from others as well. Please keep them coming.

 

I've used and installed both and I'd say just go with the purple street. They work great and I've even used them for years on the track without issue.
Plus they just went on sale so no better time than now.
https://www.waymotorworks.com/powerf...shing-kit.html

 

After sleeping over the choices, I decided to give Mini the black pill, hoping "he is the one". This goes against my instincts as so far I avoided pillow ball camber plates, crazy stiff racing springs, poly engine and transmission mounts.




Prescription filled and credit card charged. It would be awhile before I get to the installation which I am not looking forward to.

 

I was going to suggest purple, although I think you'll probably be perfectly fine either way.

 

Let us know how it feels after install. Some people like the tighter feel, but I guess its a matter of taste in the end. I know most of the guys I track with liked them

 

I have the Alta PSRS Bushings and I love them, Although I have a high tolerance for NVH.

 

Did you install them with the increased caster? I did some search and strangely this thread from 2010 suggested the PSRS is all metal. There were talks that the only way to install them is to spot weld them in place so they don't rattle.

Yet on Alta site now it is polyurethane. I know it has a steel collar still, in which the orientation dictates the amount of caster added.

 

That was the first version of the bushing with the set screws. That one sucked and got loose over time. I have version 2 with the aluminum body and poly center section. The bushings are indeed offset and I have mine for more positive caster and anti-lift. The only real issue which really I don't care about is a single thump noise when braking in reverse, like getting into a parking space. Other then that. They are fine for my needs. I also have Powerflex Black series for my front sway bar bushings ans steering rack bushings. I recommend you do those too. I did all of the ball joints aswell since the subframe was down. Powerflex do sell offset Black series Front control arm bushings and a cool Ball joint that adds negative camber to the front wheels. WMW sells those I think.

 

I am aware Powerflex's special balljoints that adds negative camber. So many way to lighten our wallets. I have given thought to changing the sway bar bushing. I might do them as they should not be too costly. The problem with the while-you-are-there is limitless too. I am still reluctant to replace the power steering hoses as long as mine aren't sweating.

 

Do all of the bushings in there. Especially since the swaybar bolts go through the control arm bushing mounts anyways. The power steering bushing is cheap and there's only one. Replace that since you're there anyways and not have to worry about the factory rubber one if oil gets on it. Balljoints are up to you. I didn't wanna deal with the hassle if the inner ones boots got torn later down the road.

You can see pics of my subframe build in my car build thread.