2nd Gen R56 Cooper S Most liked posts in thread: Street Mods 2011 MCS Hardtop

Kent, for the next important mod go here:

Motoring Alliance :: MINI Cooper Forums - Store

You will need two, M/A, 2nd Generation, retro Bowling Shirts (you and the wife). It is a proven fact that your MINI will drive much better when the driver and passenger are in proper attire.

Jim

 

Good explanation Ben. Makes me want them now! I know the alignment guy was able to get me a bit when he aligned my car a while back. Need to find out how much more I could get with plates and what the downside is, if any.

 

Start your research here: http://www.motoringalliance.com/forums/suspension-brake-modifications/4204-installing-springs.html

I'd try explain camber plates more, but I tend to speak "engineer" too much and I lose people...

 

I love engineers and their language. My son is studying engineering at nc state and I have lots of friends who are engineers!

Don't be bashful!

Btw. I think I know why you said that. Ha ha. All in fun!

 

Ok, here's my attempt at explaining why camber plates give you more traction. Take your hands and hold them out in front of you, fingers up, palms 6" apart and facing each other - like you're describing how long a sandwich is.



Hold your hands there, and lean to the left. Notice how both hands are at an angle to the ground. Ok, bring your lean back to center, and tilt your hands towards each other just a bit so the heels of your hands stay the same distance apart, but your fingertips get closer together. Now lean to the left again. See how your left hand is more perpendicular to the ground?

Now imagine your hands are the wheels on your car. If you're leaning to the left, you must be turning right, and that small adjustment in camber to the outside tire put more rubber on the pavement.

Camber describes the angle that the tires lean towards each other relative to vertical. Negative camber is when the top of the tires lean closer to each other, and positive camber is when the top of the tires lean away from each other. MINIs come stock with about -0.1 to -0.9 degrees of camber, and no adjustment is possible*. Adjustable or fixed camber plates will allow you to change the front upper strut mounting points. Pop the hood and find the three bolts poking up through the sheet metal at the tops of the struts - the camber plates will sit right under that sheet metal.

*Some camber adjustment is possible in R56 cars. The holes are slotted slightly and there's a small plastic button you have to remove. But it's not much.

You basically have two choices for camber plates - fixed and adjustable. And here's where you have to evaluate your goals for the car and make a compromise. Fixed plates only offer a specific camber change (-1.25*), but they usually have a more compliant bushing. The camber plate has to turn when the wheels turn, so there's a bearing up in there, too. The bushing pads the bearing from vibration. Adjustable camber plates allow your alignment shop to dial in a specific camber angle, but they usually have a more robust bearing and no bushing. Lack of a bushing reduces compliance and uncertainty in the steering, but it makes frost heaves and expansion joints very loud when you drive over them. The solid bearings in most adjustable camber plates make them more durable than fixed camber plates, but it all depends on how hard you're gonna drive the car. I can recommend specific brands of plates, but I'd prefer you called your favorite MINI parts vendor and had a chat. Gotta keep those guys in business.

 

Excellent Ben, thanks

How important is it to add negative camber to the rear?

 

Mmmmm.

$5 footlong. I'm getting hungry.

What are we talking about again?

 

Well, adding negative camber to the rear will add traction during cornering, which is equivalent to making the car understeer more. MINIs arrive at the dealership with a lot of understeer, so there's no reason to add negative rear camber to a street car. Different story on a race car, of course.

Most people add lowering springs and discover that they have somewhere around -2.5 degrees of rear camber. Due to suspension geometry, lowering springs will add a little bit of negative camber in the front and a significant amount in the rear. That's why a lot of vendors recommend adjustable rear control arms with lowering springs, so you can reduce the rear negative camber.

A good rule of thumb is about 0.5 to 1.0 degrees less negative camber in the rear than in the front. I run about -2.0 degrees camber in the front and -1.5 in the rear and that seems to work well. And I owe these settings to many people who established them before me on the various internet forums.

 

Thanks Ben, the more I see it written and explained the better I understand it.

 

Did you order your Bowling Shirt Kent? Go to stay on the cutting edge ya know.

Jim

 

Great Post Kent and Great Mods!

 

No problem, Kent. I think I was hungry when I came up with that sandwich explanation. Keep writing about your mods, it gives the rest of us a great story to read. And your perspective as an intelligent and inexperienced modder reminds us all of where we started from. Well, some of us were intelligent once...

 

Ben

Thanks for the very helpful write up. I'm wondering if I only have the camber done by removing the white plastic button, I believe it provides -.5 degrees of negative camber, does that do anything to the tire wear? The MINI is strictly for street use.

 

I was able to get -.7 and -.8 degrees of camber on my 2008 after an alignment by the local expert. Does anyone have a feel for how noticeable a fixed camber solution (-1.25 degrees) would be for me on the track or the dragon?

I am trying to decide if it is worth the upgrade cost. (parts & labor)

How anyone made a similar camber adjustment/upgrade?

 

Nah, camber doesn't do much for tire wear. Just rotate them front to back every 3-5k miles and you'll be fine. Toe has a much bigger effect on tire wear. I can't really comment on that, though, as I haven't had a set of tires that I didn't track with camber plates.

Don't get too hung up on the specific numbers. What's more important is establishing a front-to-back camber bias - more camber in front will decrease understeer. A difference of 0.5 to 1.0 degrees is useful. There are several different ways to dial out understeer - thicker rear sway bar, different spring rates front/rear, different shock rates front/rear... establishing more camber in front is just one more tool to set up your chassis.

 

Thaks for the help!

 

As a footnote to this, the specific camber settings ARE important on the track where ultimate grip is important, along with balancing understeer/ oversteer. Racers use pyrometers to measure the tire temperature on the inside, middle, and outside of each tire. If one side of the tire is doing more work, it will heat up more, so you can adjust the camber to compensate. And if the outsides are doing more work than the middle or vice versa, you can adjust the tire pressures up and down to compensate. By adjusting the camber settings, you can balance the heat and grip across the tire so the whole width is doing work, not just one side of it.

But these concerns aren't relevant to a street-driven car. The understeer/oversteer balance is more important, so moderate negative camber settings with a small difference front to back are safe.

 

Did you mean to say "Due to suspension geometry, lowering springs will add a little bit of negative camber in the front and a significant amount in the rear."

I was curious what would happen if lowering springs are introduced to the suspension

 

Good catch. Yeah, the fronts don't gain much negative camber but the rears do when you lower the car. JCW springs apparently are exempt from this, btw - they don't lower the car enough.