It could be S1 data.
However, it appears that many preformance cars have roll centers in the 30 to 70mm range.
Based on my data from the control arm positions, even at stock ride height of 130mm, the formula is giving me a roll center below the ground. I still think there is either a problem with some of my measurements, or the forumula is in error.
I do find it odd that the lower control arms are pointed up, even at stock ride heights. That typically is not good geometry, but thats what my ruler said when I took the measurements.
I remember reading an article somewhere about Lotus having trouble with the Elise oversteering in the design phase, and their solution was to put the instantaneous centers outside the front wheels. That was a while ago I saw that (years) and I wondered if it was true, but it's sounding like it is.
Edit: It would be a relatively easy thing to modify, by making a redesigned steering arm (piece 4) that moves the upper ball joint and outer tie-rod upwards.
2006 Chrome Orange Elise: LSD/TC, Nitron SAs with 425/650 springs, BWR 7/8" ("Hardcore") Front Bar, Eliseparts bumpsteer kit, VF Stage 2, 2bular Header + Sport Cat + 8x24 GT3 Muffler, ECU Tune by Jermaine, Smaay's fuel rail, ACT XT clutch, Saikou Michi dual catch can, Moroso pan, Manly's mount inserts & FF Engine Damper
2000 Black Integra Type R - DD: 231,000 miles!
Last edited by fpitas; 07-29-2009 at 12:56 PM.