Steering Issue at Watkins Glen

[milhouse]

I just got back from Watkins Glen where I had a relatively successful track weekend. I had an issue that I was wondering if anyone else has had, and if so, knows whether a fix is required.


When turning hard on the Outer Loop on the first day, my steering wheel felt "notchy" at one point through the turn. I could certainly steer through it, but I could definitely feel a stop during the turn, such that I had to add additional steering input to get through. At first it was light, and not a huge issue, but as the weekend progressed, the notch became harder to steer through and by the middle of day two I had to add a ton of input, such that when it released the car got completely unbalanced. The weird thing is that it only happened on that turn, and in pretty much the same spot every time.



We removed the wheels and didn't see anything wrong with the stock bushings, tie rods or control arms, and when driving normally (and even on other turns), the issue doesn't happen. In addition, I don't feel anything when the car isn't moving and I turn the wheel.


Anyone have any thoughts? My local shop said its actually normal as the car is driven harder, so I wanted to check here and see if anyone else had the issue and if they were able to resolve it.


Thanks.

[tony_r]

Probably electronic power steering cut. It happens with higher loads on turn in to mid corner. I've only felt it once, and only at the track but I know of others who feel it a lot more.

[Stang70Fastback]

Yeah, I agree that it sounds like power steering cut-out. Especially if it's happening in the same spot. I've had it happen to me on certain autocross courses - always at the exact same spot. Usually a very tight, higher-speed turn, and often where the curve of the road surface causes additional load. There's some sort of load limiter that prevents the electric motor from overheating, and it seems that those combinations can overpower the motor enough for it to very briefly give up to "protect itself." I heard that the refreshed vehicles (2017+) received some adjustments to the power steering programming to resolve that issue.

Either way, it's really annoying and distracting when it happens. You should also be seeing a flashing light on the dash when it occurs, IIRC, albeit only briefly.

[Takumi788]

Yep happens to me while entering turn 7 at the glen. There is a lot of compression making the electric motor work harder than it wants to.

[Icecreamtruk]

Are you guys sure it isnt just the tire hitting the upper part of the fender inside? Have you checked the plastic there to see if there are marks?

[tony_r]

Plastic splash guard is not strong enough to make the steering feel like it does when EPS cuts. Even still there are no witness marks on my car.

There are differences with some cars in terms of caster and end links as well. Running a lot of caster and having endlinks that are less than optimal make this worse.

[kch]

Originally Posted by Takumi788

Yep happens to me while entering turn 7 at the glen. There is a lot of compression making the electric motor work harder than it wants to.

Must be a T7 thing, as it also happened at T7 at Texas World Speedway (rip)

[Fish Eagle]

I have that often. Doesn't worry me any more.

I run 255/40R17 Bridgestone RE11S semi slicks, and it mostly happens with hard trail braking into slower, tighter corners.

Pretend you're a truck driver, and just muscle it.

[milhouse]

Thanks, everyone. While its not ideal, at least it won't cost me anything to fix...

[Molez93]

Clearly I wasn't pushing hard enough as the outer loop for me at the same event didn't produce any weird steering. ;-) ...or in any turn for that matter.

[Joesurf79]

Originally Posted by kch

Must be a T7 thing, as it also happened at T7 at Texas World Speedway (rip)

TWS turn 7 might be the single greatest turn I've ever driven.

It's been bulldozed

[Pat]

Yeah, this is a common issue. I think the sticker the tire the more of an issue it becomes. There are probably other factors at play, too.

[Icecreamtruk]

Originally Posted by tony_r

Plastic splash guard is not strong enough to make the steering feel like it does when EPS cuts. Even still there are no witness marks on my car.

There are differences with some cars in terms of caster and end links as well. Running a lot of caster and having endlinks that are less than optimal make this worse.

Well, I though it was the EPS cutting out for me, until I realised that all the plastic from the fender was gone and it was in fact contacting the strut tower from below (metal). It had already taken all of the paint out and had a nice polish surface on it already

[Pat]

How wide are your tires? What is your wheel offset?