I purchased a set of four Michelin Pilot Super Sport tires today (205/45/ZR17) and something about the alignment isn't making any sense. The tire in the picture is cupped towards the center, the left rear Camber @1.7 while the right rear is @1.9. What are the factory spec for rear Camber and Toe in?

I'm told that the alignment on the two rear tires is in spec by non-dealer alignment shops, dealer wants too much for an alignment ($140). I do not want my brand new tires to end up cupped like the Pirelli RF. Is this what my Michelin Pilot Super Sport tires are going to look like in 5000 miles? I have 8k on the one pictured, I couldn't get any information from my dealer, they just kept moving around my direct questions.

Appreciate any feedback!

 

I believe that it is correct I have oem rear is -1.75 (.Someone correct me if i'm wrong). It has a huge amount of negative camber in the rear to help drivers into understeer rather then oversteer.

Not sure how it will affect the tire wear but mine is set at -.09 in the front and -1.2 in the rears. -1.75 is a lot for the front for street driving, So I would assume its a lot for the back as well. I would max out the front camber and put the rears at- 1.2.

 

Wait a minute, the alignment shops can't go lower than -1.4 camber in the rear.

 

The pictures are not loading for me I'm on my phone.

What does it say about the rear camber?.
As far as I'm aware my local firestone who did my alignment put it to those specs- there printer was busted the day I went so- I'll call over tomorrow and see if they have a record of it.

 

Per the Bentley Service Manual (page 320-20) for R56
Front Axle Total toe 0 deg 12'+/- 12'
Toe diff between R & L max 12'
Camber -30' +/- 30'


Rear Axle Total toe 0 deg 24' +/- 12'
Camber -1 deg 45' +/- 25'


Max Camber difference between R & L 30'


Cheers,
Greg

 

I just contacted FireStone and they say that the rear Camber should be set at -1.75 on both rear tires, isn't that excessive? I don't understand how you guys set your Camber below -1.0 when the alignment computers don't even go that low, there's got to be something wrong about all this.

 

That's the original rear camber by mini,- 1.75 in the rear .

I had firestone set it to my specifications. Which was the - 1.2 in the rear .

Again - 1.75 rear is excessive and it is like that by the factory to include under steer which is easier to get out of for less experienced drivers.

The -.05 front camber by factory is essentially fixed. If you have Slotted strut mounts you can get it about .09 again that's fixed. The rest is explained in the PM

 

I don't understand this format, I only understand decibels, (ie) -1.7 degrees, don't know what 24' +/- 12' even means? Is this 24 feet by 12 feet?

 

Those are minutes. Like latitude and longitude, each degree has 60 sub-units, called minutes.

So 24' +/- 12' means:

24/60 +/- 12/60 = 0.4 degrees plus or minus 0.2 degrees

 

I found my old sheet when I bought the car over year ago, Camber in both rear tires was -1.4. I drive it like this for many months, then I wanted to check the alignment it showed both rears at -1.4. Thinking I was right seeing that -1.4 was in the red thinking this was bad, I had CarMax put the rear tires in the green (-1.7), that's when the excessive tire wear started happening. Would having the rear wheels set at -1.4 (vs 1.7-1.9) give more even tire wear and if so what does this mean for traction?

 

Probably check this out as a good introduction (if the link doesn't work, just google "tirerack alignment):

http://www.tirerack.com/tires/tirete...e.jsp?techid=4

In general, excessive negative camber will wear the inside of the tire faster (toe setting can cause similar effects). Typically, wear in the center of the tire can be due to overinflation.

The balance between camber in the front and the rear affects, among other things, the balance between understeer and oversteer. As others said, having more rear camber means a car will be more likely to experience understeer (which may be safer for most drivers).

 

I haven't commented on my Michelin Pilot Super Sports (205/45/ZR17), the car definitely feels like I'm glued to the road, is much quieter ride. The bumps are smoother, I like not having to feel every rock or imperfections in the road. How many of you carry a spare tire while driving on non-run flats? I would also need to replace the horribly unsafe OEM jack, it's only safe on perfectly flat surfaces and it's not like we have a patch of road picked out for when we get flat tires?

 

I carry an inflator that I got from tire rack. It has sealant and a compressor built in.

I think that there are plenty of guys that are running stock negative camber with few issues. If you are nervous about the amount of camber, you can swap in a set of adjustable rear control arms and take some of the camber out of the rear.

I'm glad that you enjoy the new tires.

Have fun,
Mike

 

Cupping is not from alignment. It's a crappy shock issue.

 

Excessive tread wear in the center of the tire is an over inflation issue... is it not?

 

The highest I've run the rear runflats is 44 psi, there a hard still tire. Is this too high?

 

Seems high to me. My manual shows 38, 40 psi if driving over 100 mph..

 

I have no personal experience with those Pirelli, but that sounds too high.

 

Here is the print out from an alignment I had done yesterday.

'06 R53 JCW with R113s and Pirelli P-Zero RFTs

Maybe it'll help answer some questions.

https://drive.google.com/file/d/0B-K...it?usp=sharing

 

I never allowed those Pirelli RF's to dip below 42 psi, mostly with 1-2 people in the car. Would a negative Camber of -1.4 be noticeable on tire wear versus a negative Camber of -1.7 if driven moderately with some spirited driving here and there but not hard?

If I ever choose to go lower than -1.4 Camber I'll need H-Sport control arms, I'm just not ready for that at this time, perhaps at a later date. I can tell you this, -1.7 Camber is not for me, it's just too aggressive for my driving style.

Thanks so far for the helpful feedback!

 

Hack - yes!
I run my street PSS's at 35 psi all around, and only pumped them up to 42 psi for autoX runs once (before going with faster dedicated autoX wheels+tires).

Looking at your pictures, there is nothing significantly wrong with the tire wear. Your tires were almost at the wear bars and needed to be replaced regardless, so whatever issues you had did not effect their usable lifespan. Crank the pressures down closer to spec, and your car will handle better, ride better, and the tires will last longer (excessive tire pressure marginally bulges out the center of the tires, accelerating center wear).

Also, your camber is near stock, nothing to worry about.
If you start autoX-ing or DE-ing, you will want to pickup more negative front camber. In that case, take your car to another shop that knows how to properly align cars (the comments about their computer not going high/low enough tells me its a quicky-lube place).

Hope this helps,
a

 

+1.

I carry a pair of these in all my cars (all ex-runflop or doughnut equipped):
1). http://www.tirerack.com/accessories/...nce+and+Safety
2).
#1 is great for adding air, as necessary.

a

 

Or poor wheel balance.

 

I recently got aligned for autocross, and I had the guy max the stock camber. -2.2 in the rear, with 3/32 toe, and -1.2 in the front, with 0 toe. I need way more camber, so I'm going with BC coilovers, since they have the camber plates built-in.

 

Congrats - you are well on your way of having fun with your MINI !!

You can learn an awful lot about driving and going faster with the setup you already have vs. dropping another $1K + labor to install entry-level coilovers. I can guarantee that you can find 5x more time through experience and learning to drive your car as-is, then by throwing money at it.

Take your time, see what other fast guys at your autoX's are running, and understand why!

w.r.t. buying coil-overs - please don't jump at a set just because it has some cheapo camber plates included. Do your homework, and if necessary, buy a set of separate quality camber plates and coil-overs (Koni, KW, Bilstein, JRZ, Ohlins, etc)! You may end up spending a bit more in the end, but both the street and autoX handling will be infinitely better than what you will get from something on clearance sale that has a word "coilover" in the name.

a