QUOTE(zeng @ Dec 31 2021, 11:41 AM)
Yea, that's what I was thinking too along the lines of lower tyre pressure gives relatively higher grip than higher tyre pressure, everything else being equal.
Having said this, it bases purely on 'tyre engineering' or properties.
Could the writer approach this subject of over-steer/under-steer corrections from the perspective of
vehicle suspension dynamics (which we ignore totally) during turning/cornering, which may cancel, neutralise or over-run grip effects of lower/higher tyre pressure?
For all we know, the writer could be right ?
Btw, does higher tyre pressure results in higher spring rate of a car suspension spring system whilst lower tyre pressure results in lower spring rate of said suspension system?
i dont know much about vehicle suspension dynamics or motion ratio, maybe you should email the writer to get your answer why he will put higher pressure at front to overcome understeer
from my experience going through different kind of road including track, too much pressure will cause the tyre not being grippy at corner and at straight it will be bumpy as well, and you will risk the tyre burst when it get higher than the designed air pressure, higher pressure do get you lower rolling resistance though
running lower pressure will allow more part of the tyres in contact thus more grip, but pressure too low will cause the wheel spinning on tyre sidewall while cornering and you will risk your tyre ripping itself off the wheel, on normal driving you might experience bouncy ride because of pressure and soft tyre sidewall
i have experiment with both and i use 33-35psi hot pressure for track day and 40psi front and 37-38psi warm pressure for normal/high driving, and it doesn't really help much in solving understeer or oversteer issue, or maybe a very minor effect, but from the perspective comfort,
tyre pressure doesn't affect spring rate, spring rate is the properties of the spring, unless you change the spring or the spring worn out/damaged, the spring rate will remain constant regardless your tyre pressure
personally i refer to this post
https://www.pistonheads.com/gassing/topic.asp?t=1110130 for more precise fine tuning, at the end of 3rd post there is the explanation on entry, mid-corner and exit understeer/oversteer and ways to overcome it, which i find it quite accurate since i can play around with the damper settings on track
but all these tuning and adjustment can only help you to a certain extent, if you did everything as told and your car still under/oversteer then that is the limit of your car/tyres and you are driving above limit, is time to look at your driving style instead
This post has been edited by amduser: Dec 31 2021, 08:08 PM