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March 4, 2009 8:11 p.m. Cooper None
Hi all,

I have an '05 Cooper, sport package but not the plus. I plan on running HS in my region...Atlantic Canada. In stock there are 3 particular mods that are allowed but not all 3 at once! I can do only two, I have to take preparation points for these specific changes. Here is my question...which 2?
1. R-compound tires (no points for any regular street tire)
2. Wheel dimension change (16x6.5 on it now)
3. Change/modify front or rear anti-roll bar (larger rear??)
Does any one know how well a Cooper responds to a larger rear bar? A 15x7 wheel going to have enough of an advantage over the stock size? My first thought is R-compound's (just not sure of what size) a lighter 16x6.5 wheel and a larger adjustable rear bar. Alignment, cat-back exhaust, air filter etc all allowed with no points assessed.

Any help on this one would be greatly appreciated, thanks.

Steve
March 4, 2009 8:30 p.m. MCarp22 Reader

My understanding is that the guys in stock class run a larger front bar to keep the camber curves in check, as the strut suspension loses camber/contact patch from bodyroll.

That's really course dependent though, national courses tend to be wide open and favor a car that is neutral.
March 4, 2009 8:40 p.m. scottgib New Reader

To what organization do you belong?

Of those three changes, 1 is far and away the biggest improvement, followed by a rear bar. An adjustable hollow 22mm is a nice handling improvement. A bigger front bar makes it worse by inducing more inside wheel spin. Changing wheel size will make only a small difference. I run a MCS in STX in the States, and I am using 16 x 7 Rota Slipstreams with either 205's or 215's depending on what is hot, available, and cheap. The lower limit on treadwear in STX is 140.

What about camber plates?
March 4, 2009 8:43 p.m. ReverendDexter Reader

What are the locals running?

Seems to me the r-compound is the gimme, as it alone is gonna be worth the most time of the three.

Sway bars will give you some tunability, and maybe allow some time saved as well.

Of the three, it seems like the larger wheels are the least likely to find you some time. I'd certainly take the 15x7 on R-compounds over the 16s and street tires!
March 4, 2009 8:49 p.m. Apexcarver SuperDork

can you do bigger tire size with the different wheels?

go down in diameter if you can and go widdde, the reduction in overall diameter will give the clearance to the fender for the wideness. kinda like this-ish
March 4, 2009 9:06 p.m. Per Schroeder Technical Editor/Advertising Director

Yea, a 15x7 would be a good bump from the stock 15x5.5 or 16x6.5 and that would properly support an R-compound tire. On the other hand, a larger rear bar would be nice.

I'd go with 215/40R16 Kumhos or 205/45R16 Hoosiers with a bigger rear bar. If that doesn't work....well, sell the bar and try bigger wheels the next time you need R compounds.

Per
March 4, 2009 9:24 p.m. mw Reader

I'd see if you can fit some 15x7.5's and 225/45 R comps. That will give you way more grip. Or if you want to tune out some of the understeer, you can run a narrower rear tire to change the balance.

I know miata's in the same rule set are much faster if they leave the stock sways and use 13's.
March 5, 2009 5:41 a.m. TJ Reader

Assuming cost is at least a factor, I would go with wheels and tires. Why? If you are going to R compounds then you will need another set of wheels. So, if you went for the sway bar, you would be buying wheels, tires, and the swaybar anyway, but either still running your heavy stock wheels with sticky tires or sticky tires on a lighter stock sized wheel.

Best bang for the buck: get the tires and wheels. You can do wonders with air pressure to change front/rear balance and you are starting with a good handling platform.
March 5, 2009 9:46 a.m. geowit Reader

Check out this forum for info on H-stock:

NAM H-Stock
March 5, 2009 9:51 a.m. Per Schroeder Technical Editor/Advertising Director

This isn't SCCA H Stock, this is Canadiana's Hstock. Slightly different, hence the slightly different recs.

Per
March 5, 2009 10:54 a.m. G_Stock New Reader

I'd stick my money in some smaller (diameter) wider wheels with the stickiest tires your wallet will accommodate. I hear this is the quickest way to go fast.
March 5, 2009 6:31 p.m. Cooper New Reader

Hmmm...lots of good suggestions. I am a member of the Atlantic Region Motor Sports (ARMS) , http://armsinc.ca/index.html Covers the 4 Atlantic provinces. Some might have heard of our big event Slalom@Slemon held on Prince Edward Island . http://autoslalom.rgisolutions.com/

Anywho, I have been through 3 Miata's now so the Cooper is new to me. Just getting back at this after a couple years off so I'm not sure of any other Coopers running locally other than a JCW (John Cooper Works). Looks like I will be leaning toward a lighter stock size wheel wrapped in 205 Hoosiers and a larger rear bar. At least that what seems to be the average consensus here.

I can't do camber plates or shock/strut tower bars but understand that the rear camber needs to be dialed out a bit with the stock rear bar, anyone think I should go with 0 deg as a starting point with a larger bar? I was thinking I might get away with some negative if I have the larger rear bar.

Many thanks for the suggestions, comments, links...

Steve