KYB Ultra SR damping rates vs Koni adjustable inserts
07 August 2019, 09:51 PM
#1
KYB Ultra SR damping rates vs Koni adjustable inserts
Can anyone tell me the comparative damping rates of the KYB Ultra SR dampers compared so standard STi rates are please? I read 180% above standard STi somewhere but cant find any official readings
Koni state that their adjustable inserts start at 50% above the standard rate, as they are only sold as fitment to the WRX the I assume its 50% above the WRX rate... which is what on the STi scale?
Koni state that their adjustable inserts start at 50% above the standard rate, as they are only sold as fitment to the WRX the I assume its 50% above the WRX rate... which is what on the STi scale?
09 August 2019, 12:47 PM
#2
You might also consider, the ratio of rebound damping, to bump damping - this will dictate how much time you spend on the bump stops.
The RB320 Bilstein struts had a bias toward compression (bump) damping (too much?). They used linear, as opposed to digressive, pistons.
More rebound damping, in relation to bump damping, will pull the car onto its bump stops.
The length and durometer of the bump stops is, therefore, very important.
A stiffer rear stop, than oem, can reduce understeer, without increasing rear bar size.
A shorter, softer, front stop will reduce understeer on undulating/uneven roads - the inverted ultra sr and inverted sti struts both use the same 60mm, rock-hard, front stop, as a form of pitch control.
OEM bump stops are generally tuned to create understeer, which is safe, particularly in poor road conditions.
The inverted Ultra SR are highly gas pressurised - which acts as an additional dynamic spring. As your car has struts front and rear (1:1 motion ratio), excessive gas pressures can adversely affect ride/handling and increase ride height. Non-inverted ultra sr have much lower gas pressures.
Age-related sagging of the rear springs/falling inverted gas pressures, significantly reduce the rear ride height, which creates more understeer. In my experience, this low rear ride height is considered normal. OEM STI rear ride height - wheel centre to arch is 363-366mm, with a full fuel tank. Or, add 50kg to the boot, if the tank is empty.
The RB320 Bilstein struts had a bias toward compression (bump) damping (too much?). They used linear, as opposed to digressive, pistons.
More rebound damping, in relation to bump damping, will pull the car onto its bump stops.
The length and durometer of the bump stops is, therefore, very important.
A stiffer rear stop, than oem, can reduce understeer, without increasing rear bar size.
A shorter, softer, front stop will reduce understeer on undulating/uneven roads - the inverted ultra sr and inverted sti struts both use the same 60mm, rock-hard, front stop, as a form of pitch control.
OEM bump stops are generally tuned to create understeer, which is safe, particularly in poor road conditions.
The inverted Ultra SR are highly gas pressurised - which acts as an additional dynamic spring. As your car has struts front and rear (1:1 motion ratio), excessive gas pressures can adversely affect ride/handling and increase ride height. Non-inverted ultra sr have much lower gas pressures.
Age-related sagging of the rear springs/falling inverted gas pressures, significantly reduce the rear ride height, which creates more understeer. In my experience, this low rear ride height is considered normal. OEM STI rear ride height - wheel centre to arch is 363-366mm, with a full fuel tank. Or, add 50kg to the boot, if the tank is empty.
Last edited by 2pot; 09 August 2019 at 01:03 PM.
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20 May 2013 09:47 AM