Originally posted by Eric Ford:
best place to order is tirerack.com
they seem to have it all covered when
it comes to heat cycling
shaving etc...

Qbert, maybe my theory is wrong,
but I've read that you lower the pressure
on the end of the car thats sliding out
so if you have problems with understeer
lowering a little can help.

Think of this, more air in tire the harder it is.
thats why its able to slide out in the rear.

Now with our cars with the 4 link in the rear
and "passive" rear steering you want some play
in the suspension, so it can travel and make
all those cool geometric changes

Really i've set my car up both ways firm front, loose
rear, and vice-versa... and alot of combinations in between..
I can tell you this.. alot has to do with the type of course
I'm on.

When in Peru I ran opposite setup as the SVT tour, and
we were within .2 of each other, now driver skill has to
have some factor. And when I ran the T&T I ran times so
close to each other with both set ups... I can't say for
sure which works better, heck I'm not sure which I like
better..

Well..back to the garage gotta fix this beast... :P



You're not wrong, I should have phrased my other statement differently. You can definitely dial in oversteer by increasing the rear pressures, but this does it by taking away traction. Your rear tires will probably never heat up if you have them up that high. 36psi in the rears isn't even low enough to cause them to scuff the sides.

Basically driving technique has more of a role to play as you stated. Drivers who like to go into corners fairly fast and trailbrake through them probably will benefit from higher rear pressures. I don't like doing this though, too much room for error and not the quickest way through the corner, well not with the Contour anyway. Doing it this way does not allow you to get back on throttle soon enough. I go into corners fairly slow with light trail braking just after turn in to get the rear end to move slightly. No later then mid corner I'm already rolling back onto the throttle. With the lower tire pressure in the rear the tires have the ability to heat up ultimately creating the most traction.

Try a drastic change one day. Drop your rear pressures a lot, possibly down to the 32psi range. Not saying it will work for your driving style, but you may be surprised to find what the car feels like. I think you are correct on the course design playing a big role in tire pressures also. Sweeper course, like I run a lot, require me to run lower rear pressures. Transition courses should probably be run at a higher rear pressure.

2004 Focus PZEV 2.3L - KW sport suspension, SP camber plates, Eibach front swaybar, FS intake, FS Stealth exhaust, 3.82 Final, Torsen ATB, Prothane MM insert, E1 CSVT wheels 1/4 mile - 15.201@89.4mph