When I see a statement such as "Lowering your MINI "magically" gets rid of torque steer.", I have to ask WHY? Well, I have a theory that I'd like to run by the NAM suspension gurus. But first, I think we're actually talking about 2 different kinds of torque steer:

1. The traditional "grab the wheel out of your hands" feeling you get when accelerating hard in 1st or 2nd gear, especially when turning at the same time. This phenomenon tends to straighten out the steering, even when the alignment is perfect. The term "scrub radius" explains it: http://en.wikipedia.org/wiki/Scrub_radius . I think the R56 probably has a positive scrub radius and the R53 has close to zero, even with stock wheels on both.

Theory: Lowering decreases the scrub radius. I think that lowering probably adds some negative camber in the front (it certainly does in the back.) Adding negative camber moves the average contact patch *inward*, which lowers the scrub radius, hence less torque steer.

2. I think that Ryephile nailed it again when he determined that the R56's wandering and uncertainty at highway speeds is due to too-soft lower control arm bushings. I *think* the geometry & size of the brackets are the same, just the even-softer rubber spider gives the R56 bushings a new part # vs. the R56. I've noticed that at 75mph in 6th gear, adding a little power makes my car ('08MCS w/LSD & Sport Susp.) steer slightly left, and right when backing off. It's this high-speed vagueness that may have been the deal-breaker that's killed more than a few R53-R56 "upgrades".

So, fixing torque steer completely requires 2 different fixes:

#2 would need the Alta PSRS, or at least some way-stiffer control arm bushings. Doing this as a first priority would help the following fixes perform more reliably:

#1 would take some combination of lowering, added positive camber, and higher offset wheels (i.e. more positive).

Now I just have to figure out how to do this on my "family man" budget...

 

I agree with most everything you said, and not just because you gave me props

Lowering the car will lower the roll center. This is a good idea up to a point, after which the roll center will be too low and cause the car to understeer no matter what you do [that's the ultra abbreviated version]. The roll center makes the car understeer because it increase the "road torque" upon the car, giving the suspension more mechanical grip, reducing tire slippage, reducing the difference in torque each wheel has, and thus [breathe] decreasing the difference the front control arm bushings deflect from each other. When the stock front control arm bushings deflect, they cause the caster and toe to become misaligned between front wheels. This misalignment also pivots the CV's slightly, and all this subtle movement adds up to create a faux torque-steer effect.

Let me just clear up a few things before I explain any further. I've had 4 MINI's over the years now, from totally stock to modded to hell and back several times over. My crown achievement in grassroots modding was my R53 single turbo conversion, back in 2006. In peak form it put down 318wHP at 7k RPM and 270wLbFt at 5k RPM. This is far more power and torque than most MINI's are putting down nowadays. The point is, that old R53 had absolutely NO torque steer of any kind. I would let go of the steering wheel as the turbo went from no boost to 20psig and while it would do a burnout in 4th gear, there was seriously, yes honestly, zero torque steer. It was also lowered about 1.5" from stock, wearing 225/40-18 R-compounds with wheel offsets only 5mm different from stock. Ok, back to 2008 and the MINI dealership. I went and test drove a Cooper [not an S], and it was clear there was somthing very different, as it was very easy to induce that faux-torque-steer...in a Cooper, even at part throttle! Clearly engine torque output is not the issue here. Enter my buddy paulsminis, who recently installed ALTA PSRS's in his R56 Cooper S. He was kind enough to let me take his MINI for a drive at this years MOTD. His car felt teriffic...even with the factory clutch-pack LSD! His car with just those ALTA bushings is 95% as precise as my current full-spherical-bearing R53 track-junkie.

Ok, back to the roll center thing. The lower the car is, the more mechanical grip it has and thus the less the tires squirm. A stock ride-height R53 does have some of that faux-torque steer due to the control arm bushings, but it's not nearly as pronounced as the R56 [Cooper or S]. Put a set of lowering springs on an R53 and BAM, it drives like it has slot-car rails under it. Put a set of lowering springs on an R56 and, well, not so much BAM1 as bam. There is a big improvement in steering precision and reducing that kick-back feel, but it's not flat-out gone like in the R53.

Something more is at play.

Ok, what is actually different in the suspensions? Brakes, nope. Wheel offsets and tire sizes? Nope. Front struts and rear shocks....same. Front control arm itself and its outer ball joint, ah, these are different. Rear trailing arms? Weeeel, not really. While the R56 trailing arms are almost identical to R53 GP arms [the only difference is the casting marks], the geometry is the same between later R53's and R56's, so kill that idea. Sideways found the front control arm bushings are different part numbers, even though ALTA and Detroit Tuned [and now everyone else] has found out the bushings themselves are the same diameter. Are the bushings themselves that different? Or are the front control arm outer ball joints that different? I can't answer this because I haven't sat down and actually measured them. That said, they are the only significant difference in suspension setups between the generations.

From my driving comparisions between stock R53's, modded R53's, stock R56's, and modded R56's, my conclusion to date is that the front control arm bushings are a fix to the R56's steering ambiguities and handling wobbles. Changing them out is a horribly annoying and tedious job, but it looks like the front control arm bushings, at least in my mind, has become the "must have mod" of the R56.

Cheers,
Ryan

 

Anybody know if there's a significant difference between the Mini Madness bushings and the Alta PSRS? It's a $150 difference, so just wondering if there's a reason.

 

OK, my head is a complete tailspin as I am overwhelmed with all the tuning options available for my car. I've been contemplating a bunch of options (nearly all of them) but haven't settled on a good, cost-effective solution as of yet. Here's the crux of my problem:

I don't want to invest a huge amount of money on the car. I had a Mazda MX-5 before the MINI that I loved for about 2 years then quickly fell out of fashion with. I had spent a lot of money on tuning for the MX-5 and saw none of that value return on resale. Therefore, I don't want to make the same error on the MINI. Result? Low cost = I don't care if I get the value back or not when I sell it.

[Fhew...]

To my intended question: installation cost. I've heard that these bushings would be very difficult to install. Does anyone know what it would cost to have just front control arm bushings installed? I've read hundreds of posts regarding the effectiveness of certain performance mods and I'm really liking the sound of these bushings.... but not if it is going to cost a grand to install. I'm sure I'm not the only one on this boat...

 

Ryan, did you notice and extra noise or vibration while driving the R56 with the PSRS?

 

Wow, this is a lot of information. But it makes more sense now. good post. I'm confused though because in my case my camber is actually more negative and my front offset is lower (addition of 5mm spacer), rear offset is unchanged. So that still only leaves the lowering as the variable to change the torque steer.

Any ideas on why this could be?

 

Great information!! My MCS is the first front wheel drive car I've owned (except for a very early Honda) and the torque steer is driving me crazy, especially when accelerating in a turn. Maybe as I become more accustomed to this effect I'll get used to it, but for now, at least, I find it VERY annoying.

 

Same boat. How much have people paid to install these?

 

I also would like to know. The more I hear about these, the more I'm wanting a set.

I remember my front control arm bushings crapped out on my R53 from one too many potholes. I don't remember how much it was off the top of my head, but I think it was a pretty costly repair. It was done at employee cost as well, but I remember it still being really expensive.

 

There is a tiny bit of NVH increase with the PSRS, however it's essentially none compared to spherical-bearing rear control arms. It's comparable in harshness to changing your tire size from 215/45-17 to 215/40-17, almost none. Of all the suspension mods I've done over the years, changing the front control arm bushings from spoked rubber to solid spherical brings about the least addition in NVH, surprisingly. Lowering springs are more harsh in comparison.

The difference in cost [and perceived value] between the Madness poly and the ALTA PSRS is completely up to the MINI driver and their intentions. If you want the utmost in precision and want to dial in more caster and/or anti-dive, the PSRS are you only options. If you do not want to risk added much [if any] NVH to your MINI and don't want to bother with changing the front-end geometry, the Madness make perfect sense. The PSRS are more expensive to make, that's why they're more expensive to buy. That's all I have to say about the price difference.

Front control arm bushings are NOT cheap or easy to swap out. The cost of the bushings themselves, no matter which ones you pick, will not make up the full expense. If you are very well versed in the garage and under your MINI expect to take a full day to remove the front end, lower the subframe, wrestle with removing the stock bushings and pressing in the new ones, and then heaving the subframe back up to the car. I've done it a few times and to this day I'd rather pull the engine than lower the subframe. That said, the dealerships have a special tool to remove the bushings and install fresh ones. It would be worth asking your favorite dealer for an install quote.

Cheers,
Ryan