I am running in STX with H&R coil-overs, and Randy's camber plates. The car is significantly lowered, and now running -2+ degrees on the front axle. The lowering adds even more negative camber than stock to the back axle, and the result is very good, but still wants to understeer. I can drive around the problem a bit, and Aaron Shea pointed out that LOW tire pressures in the rear can help a lot (thanks again Aaron), but I am trying for something a bit more elegant.

The Si Hondas that are kicking my butt in NER are running zero camber on the back axle, and so I am contemplating going to -1 or less on the Cooper to see if that will allow greater slip angles without the slight sloppiness of low tire pressures (205/50 15" Azeni 615).

Any comments on this approach folks? Been there, did that, got the tee-shirt? This car is my daily driver, so I have to be cautious about introducing oversteer, as I shouldn't want to swap ends on the street...

Charles Thompson
STX #1 JCW

 

Charles

Definitely get some H-Sport upper and Lower Control arms. This will allow you to adjust toe and Camber. I am currently running -1.0 on both sides with zero toe and no issues on the street, it will make a huge difference for you when autocrossing. You should not have to drive around the understeer, that takes the fun out of it. :-)

Craig

 

I tried everything from 0 to -1.5, in the rear and I like -1. If I need more rotation I adjust the rear bar or add tire pressure in the rear, on my Azenis.

 

Man, I got lucky then when we guessed -1.0 after we knew 1.8 sucked.

Trust Richard, he knows all. He's been running STX for much longer than I.

Craig

 

Ditto the above. I am running -1.0 in the rear with the H-Sport control arms. You can then play with rswaybar and pressures.

John
STX JCW

 

Thanks very much for that prompt advice OasisT - I'll do just that Jul 3, and we shall see - off hand I do not know the next NER event, but I'm sure I'll be looking forward to it.

The feedback loop for me is a slow one, as I'll run 11 of 12 events this year and no test & tune, so the total drive time for the year is in the order of 30-45 minutes. None of my close friends own skidpads....

I have however, the slightly breathless sense that this might be the final piece of the puzzle, and boy is it fun to drive a car that rotates if you get my drift...

 

Mercy mercy, mercy! With 1 degree negative courtesy of Kevin Holmes and the Turner team, the car is perfect. It won't plow, it won't spin, and it wants to turn! Thanks to all for sharing information, and oh my heavans I cannot wait until Sunday! This is what I knew the car was capable of, and to feel it is sweet beyond words!

 

Hey Charles, glad it worked out for you. Are you still running lower pressure on your 615s in the rear? I just signed up for the NE Divisionals, hope to see you there!

Aaron

 

Aaron with the new back end I am starting from scratch on pressures. This Sunday I'll start 37/35 front/rear cold and then go from there. I will look into the timing and logistics on the Divisionals and see if I can make it - it would be great if I could. Hope your season is going well.

 

Five runs yesterday demonstrated that the car still has mid-corner understeer. I started at 38/34 cold, and after the first run (71.4) the fronts were up to 42 and the rears up to 36. over each successive run (and all but the last were within .2 of the opener) I dropped the rear pressure a pound, finally winding up at 42/30 - at which point the car would rotate a bit on quick transitions but on offsets still showed understeer.

The course was mstly two and three cone slaloms chained together, and a generous helping of farily tight offsets, taken low in 2nd.

One of my wise colleagues advised me to slow down on corner entry, and this did help as I tend to overdrive the car, but in addition to the loose nut behind the wheel I am surprised to find that I still have not reached the balance I sought. The fifth run was down into the 70 sec range, and probably was due more to the advice than the tire presure adjustments.

Could anyone comment? Perhaps I should be going in the opposite direction for rear tire pressures?

 

With the Azenis, I start at 35-36 psi in the rear, depending on lot conditions, and go up in 1 psi increments, if I want more rotation. It's possible you may prefer even less negative camber in the rear or if you're at -2.0 to -2.2 in front you may want a little more negative up there.

 

Thank you very much - I will take that advice and run with it!

 

Aaron, looks like you had a good weekend in NY - congrats!

 

I wasn't even close. The car/driver combo of the E30 M3 is just too strong. If it's not for the first rainy day I think my lost would be more embarassing.

It was just like Devens, raining all day on day 1. Conditions in my heat was changing constantly, it was drying up, and a couple more sprinkles, and raining again. Very hard to read the surface. Day 2 was a lot better. I wish I have that kind of site locally in NY to get use to the better pavement and much higher speed. I had a blast.

Can't wait for Phase 2 Evo school next month.....It's definitely a driver issue than the car at the moment...

 

Just posted some still pics at the event. Can't pass the nice long runway for photo ops. Check out my gallery

 

1. a 2nd @ divisionals would not embarass me at all

2. where/when the Evo?