With the ubiquitous nature of electric power steering in new cars, and the hate/backlash it gets, I think we need a place for those that have figured it out to share that knowledge. Because like it or not, it's not going away.
I can't speak to any other chassis other than the S550 mustang, but I will share what I have learned here. Hopefully those that have ZN6/ZN8 can share their findings as well. I know there's EPS controllers out there for those chassis.
So the S550 mustang uses a "dual pivot" steering system which gives it that feeling that it doesn't want to self steer like older cars do. It's less of an EPS issue as it is a suspension geometry issue. Ford designed these things to be comfortable and easy to drive.
Even the base model has a factory feedback setting with "normal, comfort, sport" and the premium model adds a "track" setting but this only adjusts the ammount of assist the EPS will give you.
In order to make the car drive how you want it to, the real issue is figuring out how to work around the suspension geometry. The cheap fix is to swap out the front suspension arms for aftermarket ones that don't have squishy ass bushings and cut knuckles. There are also steering stops in the rack that you can remove if you take off the inner tie rod boot and the age old tie rod spacer. That will get you by for sure.
But the real key is changing it to a single pivot setup. RTR/Funhaver, FDF, and Scotidi all make kits to make this easy. As soon as you install a drift specific kit and get it aligned, you'll realize EPS wasn't the issue, it was the suspension geometry.
Don't be that old guy that's saying, "carbs are better than fuel injection because all I need is a screwdriver". Learn something new. You'll be glad you did.
Agreed!
It would be great if eventually there’s a controller for each chassis/OEM to fine tune even more, there are none for Mustangs yet. There are simulators for if you are going stand-alone so the rack will still power up and operate, though at least for Mustangs as of today they’re not adjustable.
EPS racks are a bit slower returning than hydraulic as they have more mass in the moving parts, primarily the motor. That said, in my experience with the s550, at least with an angle kit the extra mass of the EPS can mostly be overcome with caster, toe, and Ackerman depending on what you like, combined with a bit more wheel inputs than a typical hydraulic steering rack. The caveat being low caster setups. At least in a mustang if you’re running 4-5* you’ll need you bus driver the wheel. But at 6* or more you just need to exaggerate your initial wheel input.
This is a good example of how the car drives with cut knuckles and a full front suspension setup but with factory mounting points. It's obviously not self steering like an older car, but more reacting like a simulator. If you notice, I'm clutch kicking on transition to slow down the rotation and give myself time to get ahead of the steering. This is also in "comfort" mode, so the most amount of assist from the EPS.
Now that my car is on the RTR kit, I don't have to work the wheel nearly as much, but driving like this for years taught me A LOT.