I have an 07 JCW with JCW 18s, H&R springs, and an adjustable rear sway bar. Does this put me into STX?

 

Yep. It's the springs.

13.8 SUSPENSION
A. Standard, as defined herein, suspension springs must be used. They
may not be cut, shortened, or collapsed. Cars with swing axle suspension
may be lowered sufficiently to achieve no more than two
degrees of negative camber at rest and may use a camber compensator.
Spring perches may not vary from the OE shape within the
working part of the perch.

That's the SCCA language for the Stock class. If the H&R are "standard" in that the rate, length, etc. matches the OEM part exactly then I suppose an argument could be made, but in my experience it might be an uphill discussion.

I had fun in STX, and I bet you will also - unless you are running Nationally no big deal!

Cheers,

Charlie

 

No national's for me or my wife. My wife will be the main autocrosser for the Mini. Just want to make sure before I ordered the magnets. Kind of a bummer. Not worth me tracking down some springs and changing them out.

So any wheel size restrictions other than the tires can't be wider than 245s right?

 

To the best of my knowledge:

The wheel diameter had to be offered on your car. Don't remember if you could order 18's in '07. The offset needs to be close to stock offset. Someone could chime in with the amount it can vary.

The tires can be whatever street tire fits on the above.

 

It came with JCW 18s.

 

Rims cannot be wider than 9" for two wheel drive STX cars.

I used to run 15x8 Enkei out front, and 15x7 out back.

I'd recommend 16x7.5 with a 215 mm tire as an option that balances the risk of a rub against the advantage of a nice well supported and adequately wide contact patch.

38 to 40 mm offset should be pretty good.

There are many options that work well though -- I did just fine on 15x7 Kosei +38 with a 205/50-15. Not at all sure the 15" rims will clear your brakes, but there are two reasons for going to a small diameter wheel for autocross:

1. lightness
2. a higher effective final drive ratio.

Point 2 matters a bit - I used to go from a street setup with a 25" tire diameter to a racing setup at 23.9" for a 4% increase in thrust. That has the same benefit as an eight horsepower gain at the crank.

Cheers,

Charlie

 

Great info! Thanks. I'll have to find out if I can squeeze a 16" wheel. I'm tires are cheaper as well.

 

Unless your car has an LSD then it won't matter if you're in STX or DS as you'll get destroyed...so don't feel bad

If it's got the LSD then spend the time getting the springs and some 17x7 Kosei K1-ts wheels and go to DS.

 

Does the car have to have the factory lsd for d-stock or can you run an aftermarket one.

 

Factory only in ds. Open in stx so an os geiken would rock.

 

Yes the factory LSD is the only one legal in Stock class.

If your going to STX or another class the Quaife or Giken are great investments. If anyone needs help building an AutoX MINI let us know as we have built many and even worked on Craig Wilcox National winning MINI.

 

Is it possible to retrofit the factory LSD. I did my first Autocross this year in my totally stock cooper s and had lots of inside wheel spin coming out of the corners.

 

It depends on the build date of your MCS. If the LSD was an option when yours was built, it'd be legal. It was an option 05-08 as I remember (we had it on an 05 and an 08), and possibly some of 09.