Hankook AutoX R-comps!!!!!!!!!!!!
Originally Posted by betamotorsports
One thing to keep in mind when discussing handling and tire sidewall height is compliance. A tire is a spring just like a coil spring. Being a spring, a tire has a spring rate that comes from the air pressure and sidewall stiffness - with most coming from the air pressure. Typical tire spring "rates" are around 1,200 to 1,500 lb. in.
A siffer sidewall reduces how responsive the tire is to small bumps that are not big enough to move the suspension due to friction and inertia in the suspension itself. Taken to an extreme with very short sidewalls and high air pressures a tire stops gripping as it should and becomes skatey. It feels responsive but ultimate grip is reduced. Once way race engineers reduce this effect is to reduce friction and intertia in the suspension itself with the most effective methods being unsprung weight reduction and high dollar, multi-adjustable shocks.
A siffer sidewall reduces how responsive the tire is to small bumps that are not big enough to move the suspension due to friction and inertia in the suspension itself. Taken to an extreme with very short sidewalls and high air pressures a tire stops gripping as it should and becomes skatey. It feels responsive but ultimate grip is reduced. Once way race engineers reduce this effect is to reduce friction and intertia in the suspension itself with the most effective methods being unsprung weight reduction and high dollar, multi-adjustable shocks.
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From: NewCastle, WA
Originally Posted by betamotorsports
One thing to keep in mind when discussing handling and tire sidewall height is compliance. A tire is a spring just like a coil spring. Being a spring, a tire has a spring rate that comes from the air pressure and sidewall stiffness - with most coming from the air pressure. Typical tire spring "rates" are around 1,200 to 1,500 lb. in.
A siffer sidewall reduces how responsive the tire is to small bumps that are not big enough to move the suspension due to friction and inertia in the suspension itself. Taken to an extreme with very short sidewalls and high air pressures a tire stops gripping as it should and becomes skatey. It feels responsive but ultimate grip is reduced. Once way race engineers reduce this effect is to reduce friction and intertia in the suspension itself with the most effective methods being unsprung weight reduction and high dollar, multi-adjustable shocks.
A siffer sidewall reduces how responsive the tire is to small bumps that are not big enough to move the suspension due to friction and inertia in the suspension itself. Taken to an extreme with very short sidewalls and high air pressures a tire stops gripping as it should and becomes skatey. It feels responsive but ultimate grip is reduced. Once way race engineers reduce this effect is to reduce friction and intertia in the suspension itself with the most effective methods being unsprung weight reduction and high dollar, multi-adjustable shocks.
great info!
People reading this shouldn't initially freak out over this.
Originally Posted by DavesZ#3
In what gear, 1st? 
I know from talking to different people that some clubs run huge courses that allow for higher speeds. In those cases I can see where hitting it in 2nd would be more common.
I know from talking to different people that some clubs run huge courses that allow for higher speeds. In those cases I can see where hitting it in 2nd would be more common.
Heh... my co-driver is still not used to the Z and often hits it in 1st right before the shift. Actually on our average courses which run 40 - 50 seconds (DC region as well as AI events) I can usually find a section where I can tap it two or three times before the corner.
I was at an AutoX in December where I was within 500 rpm of redline in third... now that was a fast autox.
Originally Posted by z-u-later
I've seen the 275/35/18 series tires on a Z and there's too much gap between the tires & fenders (tires are not as tall as 40 series). I know it's about performance but I want them to look good also. 
Which is why I'm looking closely at getting the Tom Motorsports coilover springs (adjustable) so I can lower my Z when I swap my street setup for these track rims for auto-x/HPDE.
Which is why I'm looking closely at getting the Tom Motorsports coilover springs (adjustable) so I can lower my Z when I swap my street setup for these track rims for auto-x/HPDE.
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