I believe (the FF guys can correct me if I’m wrong) that dropping pressures in the rear should help with your understeer. When I ran my wife’s Prizm in one event when the Fiero was dead I think I settled on 42F/25R to get some good rotation out of her 1.6liters of 3 speed auto fury.
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I’ve said this before…
[quote=“fairgentleman Z,post:124,topic:27647"”]
Nah all that does is reduce the contact patch, be brave, less tire pressure in the rear = lower cornering stiffness in the rear:
Cfa - Crb > 0 = oversteer
Cfa - Crb = 0 = nuetral steer
Cfa - Crb < 0 = understeer
For FWD car a is small…
For example a FWD car with 63/37 weight dist a would = 37 and b = 63. Therefore to approach neutral steer the cornering stiffness of the rear should be lower (achieved by running a lower tire pressure).
It’s just that overpressurizing the rear is prefered as it is much easier to control.
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[quote=“fairgentleman Z,post:131,topic:27647"”]
And just because something works on paper doesn’t mean that is what everyone is going to do it.
Did you check them before and immediately after every run and write down the behavior of the car as you made adjustments?
Pressure goes up during the day how weird… goes total against anything they teach in thermodynamics.
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I will be sure and do that next time. It never occurred to me to try that yesterday.
I’m not surprised that the pressure went up. My car had been sitting for a while when I checked them, so I guess I don’t have a feel for how long they take to cool and lose a few psi. I’ll have to hook up a thermocouple and pressure transducer to an analog data monitor then graph their time-based rate of change to determine the time constant of a cooling tire. :tspry:
I’ll crack a beer and do some reading tonight to see if I can’t figure out this whole real world horse shit. :tdown:
Haha thanks for the input guys.
Ya know, with the wedding coming up and not wanting to kill my new tires in 1 season, I had planned on just going to like one event and the novice school and that’s all I’d go to this summer. :mamoru: So much for that nonsense.
haha, im gonna have to lay out an arm and a leg for tires soon. since i beat the piss out of my gf’s tires yesterday im gonna end up having to replace those, then im gonna need to invest in wheels and tires on my own car soon…fuckin aye
I’m not surprised that the pressure went up. My car had been sitting for a while when I checked them, so I guess I don’t have a feel for how long they take to cool and lose a few psi. I’ll have to hook up a thermocouple and pressure transducer to an analog data monitor then graph their time-based rate of change to determine the time constant of a cooling tire. :tspry:
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You’ll have to run three per tire so you can log the effects of camber across the section width of the tire.
[quote=“BikerFry,post:163,topic:28538"”]
I’ll crack a beer and do some reading tonight to see if I can’t figure out this whole real world horse shit. :tdown:
haha, im gonna have to lay out an arm and a leg for tires soon. since i beat the piss out of my gf’s tires yesterday im gonna end up having to replace those, then im gonna need to invest in wheels and tires on my own car soon…fuckin aye
Looks like I’ve got my father in law coming to the next event, but only as a spectator. :tdown: He just got a new ///M Roadster but (understandably) he plans on babying that car for about 10 years. So my plan is to get him in on a couple of ride alongs with instructors (spectators are allowed right?) and he’ll go home, pick up the paper, and grab the cheapest Miata in it. Which is actually quite possible. He had a 2004 G35C before the BMW, and his summer car before the G35 was a Miata and he hasn’t stopped talking about wanting to grab a cheap Miata for a toy he doesn’t have to worry about ever since he sold his last one. :tup:
“Beemers” were the original BMW bikes, where BMW really got it’s start. They used to run against the BSA bikes in track comps, which were refered to as “beasers.”
