[quote=“fairgentleman Z,post:244,topic:27647"”]
Yeah, lowering rear tire pressure will make it even more loose.
I hope that people read this, learn from your unfortunate mistake, and understand tire pressures more. Lowering pressure in the rear does not increase grip by increasing the contact patch, it makes the sidewalls softer = oversteer.
Think of it this way:
two flat tires up front = big push
two flat tires out back = big rotation
[/quote]
I respectfully disagree.
There is an optimum point of traction in relation to pressure. Going above OR below that pressure point will reduce the available traction at that end of the car. The traction/pressure curve is more gradual on the soft side, and more abrupt on the hard side. It’s very unlikely that going from 41 to 39PSI caused the spin.
I’m not sure what type of tires were being used in this case, but assuming that they were decent street tires with reasonably firm sidewalls the range of goodness on the back of a WRX should be anywhere between 30 and 45 PSI. On both my WRX and my first EVO, running on good streets (Azenis|Advans), when running at Valeo (bumpy surface) that didn’t like high pressures, I would have to run down into the 25PSI range on the rear to get decent rotation.
Didn’t want to jump in on this, but I’d hate for someone with less experience to be afraid of adjusting their pressures for fear of spinning off into a curb.
George M (AS 91)