Review: HKS Hipermax IV SP for 370Z

Originally Posted by Jhill

See this is why I think a lot is all preference. Littlejuanito is running powertrix 12/11 as am I and I wouldn't want it any stiffer (mine is daily) car right now is firm but comfortable but I did notice more understeer vs oem with just stillen bars. It went like this for me: bone stock I feel the car has a lot of understeer and wants to roll over on the front, especially on any down swooping freeway on ramps. OEM + stillen bars set mid/mid the roll was helped a lot (at least didn't feel like my bumper was going to scrap at any minute) and car balance was perfect or near perfect, the rear would get slightly loose before the front indicating to me I was pushing it. Now the roll is greatly reduced and car is planted (for a dual duty car) but now I have a slight flat pushing understeer when getting nearer the limit. So next track day is aug 30th and I'll be trying a softer front setting or a firmer rear setting I think and see if I like the balance difference. But going from stock 7.5k/8.1k and then adding stiffer bars with a greater increase in rear really helped bring the car more neutral to me, now with the stiffer rates but a firmer front bias I feel some of the understeer is back. That said on really tight stuff like autocross the oem with stiff bars was a bit of a handful on the rear end and is now easier but high speed swooping turns the other felt better and now pushes. So these rates as a more track oriented kit makes sense to me.