Or close, within maybe .5 What would it take? Obviously, tires make the biggest difference, so that means R compounds. But, what about street tires? How close can you get? Can you get within .5 with say, a rear sway bar, lowering springs, good ie-Koni struts, an good alignment and maybe speed rated street tires? Or, is that asking too much?

 

well.. if you want within .5 of 1 g... you are already there.

stock cornering abilities of the cooper are certainly above 1/2 a g.

with a good set of tires and even a basic set of lowering springs you would most likely be able to gain another .1

My current setup, which is megan coils with custom rates, a propper alignment and a set of maxxis maz1 tires (215 45 16) netted me 1.04 on the skid pad.

more than enough for my liking.

im sure with a set of r comps and bit more suspension tuning (adjustment tweaking not parts) i could gain another .1 to .15

and to give you and idea.. 1.041 was the g rating of the stock lotus elise from a few years ago.

Greg

 

According to my G2X my Mini pulls 1.22g. That was measured on a track, not a skid pad. Thats on street tires, Hankook Z212's with TSW's AST Sportline Coilovers some other twweks and hella good alignment.

 

Good summer tires like Falken Azenis 615s, plus camber plates and adjustable rear control arms so you can get a real alignment should get you near 1G or so. That assumes a good surface too.

Using GEEZ, I see sustained lateral G readings over 1.1 at every autocross, even at those sites with less than perfect surfaces (translated as dusty lots). On decent concrete, I've seen as high as 1.28 in sweepers.

Those figures have been achieved with a variety of suspension setups (SPAX RSX, Bilstein PSS9s, and PSS9s with different front springs). 22mm rear sway bar, 215/45-16 Azenis on 7.5" Kosei K1-Rs. -2.4deg front camber, -1.8deg rear camber, 4.4deg caster. I suspect, but haven't specifically tested, that the alignment and tires do the lions share of that in steady state cornering. The springs, damping and swaybar help transient behavior.

Scott
90SM

 

I do agree that damping will be transient only, but I disagree about the springs and swaybars; they have everthing to do with load distribution during steady state cornering.

Jason

 

I don't disagree. I just suspect that the alignment (requiring plates and control arms) and tires made a bigger impact than the springs and swaybars did.

I suppose if someone wanted to give me a set of OEM wheels and tires, I could put them on my car and see what the difference is. I'd have to dial the camber back out too. Potentially interesting, but it doesn't sound like much fun.

Stock class cars can get over 1G on DOT Rs alone, with minimal camber options. No springs or swaybars (rear anyway) allowed.

Scott
90SM

 

Agreed!

 

Load distribution is, and will always be, far from perfect with respect to the mini. At some point taming front weight bias via springs and dampers begins to erode mechanical grip. Although selecting a proper set of springs and dampers will help, as will a proper alignment, tire compound is in my opinion the biggest factor. I wouldn't discount altering track width...this will help distribute weight transfer more evenly between inside and outside tires.

I personaly look at suspension tuning this way; springs and dampers should be selected to increase driver control. Swaybars should be used to fine tune this control. Camber and tire selection determine grip. Obviously, reality is much more intertwined and complicated, but that's a sort of big picture approach.

 

I thought it would take a lot more than that. It seems like it dosen't take much to get a Cooper there. I was thinking coilovers, an aggresive alignment, and R compunds were needed. I knew it handled well, but somewhere I read that a stock Cooper only pulls about .79 on the pad. With that as a base number, I thought it would take a lot more.

 

I know very little about how G's are actually measured, but I suspect that has a lot to do with it too.

I think the numbers quoted by manufacturers are for steady state cornering on a skidpad of some uniform size.

I bet you can get a higher number as a spike when doing a transition.

I don't know how much I'd trust the numbers coming out of a consumer grade device.

 

i usually pull just over 1G at the autoX 1.01-1.03G measured by a g-tech. i have very few suspension mods: an S rear bar (didn't get SS+), lighter wheels (rota slipstreams) and goodyear eagle f1 gs-d3 tires. my sig has my other mods

 

You're right. A 200ft diameter skidpad is relatively standard, but not anything official. You absolutely can get a higher number as a spike during a transition. That's why I phrased my post the way I did. I'm also pulling numbers from courses with elements that included sweepers (typically roughly 180 degrees) that were close to skidpad size.

As for measurement devices, technically all you need is a tape measure and a stop watch if you use a 360deg skid pad. The G-cube and GEEZ software I'm using has a 3 axis accelerometer which is routinely recalibrated and is securely mounted very close to the center of the car.

Scott
90SM

 

I think we can all basically agree that cornering power and control have to be balanced and that the balance desired depends on the use. But I think I wrote somewhere, cornering power is something we like when we've lost control, and control is something we like when we've lost grip

 

...like when one mods too much...

 

How could that ever happen?

 

No more mods. I am not worthy, I am not worthy...

 

Dr. Mike's seen ~1.4 on r-comps with his setup. I've seen ~1.2 on Hankook RS-2's at the track.

Tires help - a good suspension and alignment help, too. Add all of them up together and wicked fun ensues...

 

...and, in all seriousness, a good seat is a must! Nothing worse than using the steering wheel to leverage one's own movement in a seat. The standard fare ain't that good...

 

just keep it real simple... like mine.

 

falken azenis rt-615, mini madness rear sway, helix camber plates, h-sport springs and my custom rear triangulated conecting bars similar to what EMRACING sells, got me there