austin.wranglerMar 20, 09:30 PM

Suspension Geometry: Roll Center Correction vs Bump Steer after 2-inch drop.

Lowered my Evo X by 2 inches on Ohlins DFV. Now experiencing significant bump steer on uneven pavement during high-speed cornering. I installed a roll center correction kit, but it seems to have worsened the tie-rod angle relative to the control arm. Should I run adjustable outer tie rod ends to parallel the linkage, or will that mess up my scrub radius?

Discussion

7 comments

detroit_iron_68Mar 21, 03:03 PM

Ohlins DFV are great, but a 2-inch drop is too low for the Evo X suspension geometry without fully correcting the roll center AND steering linkage geometry

cali_built_brzMar 22, 06:38 PM

Did you get a bump steer gauge? Don't just eye-ball it. You need to measure toe change throughout the suspension travel. Even 1mm of toe-out under compression will make the car feel unstable.

florida_man_garageMar 23, 11:52 PM

Adjustable outer tie rod ends are exactly what you need. You want to adjust the spacer height until the tie rod and lower control arm have matching swing arcs. That will eliminate the bump steer.

kyle_builds_stuffMar 25, 07:50 AM

Scrub radius is unaffected by tie rod adjustments. Scrub radius is determined by wheel offset, kingpin inclination, and wheel center height. Go ahead and fix those tie rod angles.

nyc_taxi_runnerMar 25, 01:41 PM

🔧👨‍🔧

skyler.k10Mar 26, 11:42 AM

When you lower an Evo, you modify the control arm angle, which changes the roll center. The roll center correction kit lowers the ball joint, but if u don't lower the steering rack or tie-rod attachment point tbh correspondingly, you introduce bump steer.

jdm_cody.fdMar 27, 09:34 AM

Keep in mind that lowering the tie rod end will require clearing the inside of the wheel. Some 17-inch wheels will scrape on the corrected tie rod ends.