I'm experiencing an odd rumbling sensation and wonder if anyone has any ideas or similar experiences. It seems fairly innocuous but its bugging me that I can't identify it.
Conditions (all need to be occur for rumble to happen):
- Starting from a stop, AND
- Steering wheel at 90 degrees or further (like making a left at a 4-way stop), AND
- ~1/2 throttle or more
Observation:
- Rumble/scrubbing feeling similar to understeering on a wet road ("judder"?)
- Mostly perceived through seat / steering wheel
- Sensation stops once steering unwound past 90 degrees
- Subtle enough that passengers don't notice
- No tire screeching / marking on the road / odd tire wear
- Fairly reperformable
- Almost as subtle as hitting a rough patch of road
- Feels like coming from the front but hard to tell
- Doesn't seem like tires are rubbing the fender or anything
Other relevant facts:
- Totally stock engine /clutch / dog bone
- Stock wheels w/ Michelin PS4S in stock size (10k miles)
- Using spacers but happens with or without
- GC camber plates, Bilstein coilovers (not very low), aftermarket sway bars and LCA bushings
Any pointers? Thanks!
EDIT: sounds like this might just be Ackerman effect (see below)
Conditions (all need to be occur for rumble to happen):
- Starting from a stop, AND
- Steering wheel at 90 degrees or further (like making a left at a 4-way stop), AND
- ~1/2 throttle or more
Observation:
- Rumble/scrubbing feeling similar to understeering on a wet road ("judder"?)
- Mostly perceived through seat / steering wheel
- Sensation stops once steering unwound past 90 degrees
- Subtle enough that passengers don't notice
- No tire screeching / marking on the road / odd tire wear
- Fairly reperformable
- Almost as subtle as hitting a rough patch of road
- Feels like coming from the front but hard to tell
- Doesn't seem like tires are rubbing the fender or anything
Other relevant facts:
- Totally stock engine /clutch / dog bone
- Stock wheels w/ Michelin PS4S in stock size (10k miles)
- Using spacers but happens with or without
- GC camber plates, Bilstein coilovers (not very low), aftermarket sway bars and LCA bushings
Any pointers? Thanks!
EDIT: sounds like this might just be Ackerman effect (see below)
Last edited: