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Brake shudder caused by electric steering rack in 2011 GT?

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I have a 2011 GT. I understand how the anti-nibble sw in the 2011 electric steering rack can cause a shudder with aftermarket control arm bushings. Can the same shudder be caused by using track pads?

I have been fighting a consistent shudder under hard braking on track and can't seem to get rid of it. It feels like pad deposits but it never seems to get either better or worse despite what I throw at it. I have replaced front LCA with stock Ford replacements, new inner and outer tie rod ends, Ford Racing hubs with extended studs, struts are good condition coilovers, Vorshlag cc plates. I've been running mostly 305 square RE71 on track. I do swap between stock Ford pads for the street and GLOC R10 on the track, using the same rotors. So I'm suspicious that maybe I am getting inconsistent pad deposits but again, it never changes or improves even if I take the rotor off and sand it all down with 80 grit sandpaper, etc.

I run stock Ford pads in the rear, rear GT500 13.8" rotors. Balance and brake bias feels fine. I'm not usually braking hard enough to trigger ABS. Problem occurs at approx. 7-8/10ths braking on track.

Any ideas? Many thanks.
 
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LMR SVE 19x11, 50 mm offset with 25 mm spacer. But I have same problem with my Apex 18x9.5, 35 mm offset, no spacer.
 
1,128
1,101
In the V6L
I have a 2011 GT. I understand how the anti-nibble sw in the 2011 electric steering rack can cause a shudder with aftermarket control arm bushings. Can the same shudder be caused by using track pads?

I have been fighting a consistent shudder under hard braking on track and can't seem to get rid of it. It feels like pad deposits but it never seems to get either better or worse despite what I throw at it. I have replaced front LCA with stock Ford replacements, new inner and outer tie rod ends, Ford Racing hubs with extended studs, struts are good condition coilovers, Vorshlag cc plates. I've been running mostly 305 square RE71 on track. I do swap between stock Ford pads for the street and GLOC R10 on the track, using the same rotors. So I'm suspicious that maybe I am getting inconsistent pad deposits but again, it never changes or improves even if I take the rotor off and sand it all down with 80 grit sandpaper, etc.

I run stock Ford pads in the rear, rear GT500 13.8" rotors. Balance and brake bias feels fine. I'm not usually braking hard enough to trigger ABS. Problem occurs at approx. 7-8/10ths braking on track.

Any ideas? Many thanks.
It's what EPAS on the 2011 GT's does. I had one with exactly that symptom and went through three different rotor types, multiple pad types and different alignment settings. A set of Stoptech front brakes reduced it a lot. I ultimately solved the problem by getting replacing the EPAS and brakes entirely. The replacements came as part of a package from Ford called the "2014 GT500".
 
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It's what EPAS on the 2011 GT's does. I had one with exactly that symptom and went through three different rotor types, multiple pad types and different alignment settings. A set of Stoptech front brakes reduced it a lot. I ultimately solved the problem by getting replacing the EPAS and brakes entirely. The replacements came as part of a package from Ford called the "2014 GT500".
@JAJ, so if I'm understanding correctly, in your experience the 2011 EPAS feedback loop can be triggered by the track pads alone? Obviously the GLOC pads have a ton more bite on track compared to the stock pads so it makes sense they might trigger the feedback problem? But I'm hoping to hear from those of you with first hand experience of this problem and solution before just throwing parts at my car.

Thanks very much for your help and insight, much appreciated.
 
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@JAJ, so if I'm understanding correctly, in your experience the 2011 EPAS feedback loop can be triggered by the track pads alone? Obviously the GLOC pads have a ton more bite on track compared to the stock pads so it makes sense they might trigger the feedback problem? But I'm hoping to hear from those of you with first hand experience of this problem and solution before just throwing parts at my car.

Thanks very much for your help and insight, much appreciated.
Sadly, I don't remember the details - it was ten years and three track cars ago. It's possible that a less aggressive race pad might work - I settled on Pagid RSL29's a long time ago and that may have been part of the solution. I know I tried Hawks and PFC's and they didn't make it any better.

The Pagid's are relatively pricey for an experiment (good news is that they last forever) but you might try a GLOC compound or maybe Ferodo DS2500's with a mu in the 0.40 to 0.45 range (similar to the RSL29) to try. I'm not sure it'll work, but it might be worth a try.
 
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No worries you've told me enough already. I just bought a used 2014 rack and we'll see if that fixes it. Thanks.
 
@stevebd I remember someone on here mentioned that a "Track tune" disabling Advancetrac completely eliminated their steering nibbles. Not sure if there was a follow up on this

Personally, I haven't experienced the nibbles yet running 18x10's with 285's coupled with a spacer on my 2011 when running my Ortiz performance Track tune at autocross. I'm pretty sure AED is the go to for coyote track tunes though. Will be testing the car with 18x11s and 315's this weekend, fingers crossed the nibbles don't show up

Out of curiosity, which part number 2014 rack did you go with? I've heard their are different racks for different wheel/tire combos from the factory.

Hope it all gets sorted with the rack swap!
-J
 
Very interested in whether you are successful. I've been chasing the same issue with my 2011 GT autocross car across three different pad and rotor sets on standard GT front brakes (not Brembos). This is the first I am hearing of the rack potentially causing it...
 
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Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
Steering shudder on the 2011 and early 2012 cars has been well documented. A number of things contribute to it including more rotating mass (bigger wheels/tires/brakes) and stiffer bushings. I had some before changing front bushings but it was unbearable after. I ended up with the Boss 302R rack from Ford Performance. At the time I couldn't find a suitable used rack and it wasn't any more expensive than a new stock rack from a later model car. It was expensive, but completely fixed the problem.
 
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@stevebd I remember someone on here mentioned that a "Track tune" disabling Advancetrac completely eliminated their steering nibbles. Not sure if there was a follow up on this

Personally, I haven't experienced the nibbles yet running 18x10's with 285's coupled with a spacer on my 2011 when running my Ortiz performance Track tune at autocross. I'm pretty sure AED is the go to for coyote track tunes though. Will be testing the car with 18x11s and 315's this weekend, fingers crossed the nibbles don't show up

Out of curiosity, which part number 2014 rack did you go with? I've heard their are different racks for different wheel/tire combos from the factory.

Hope it all gets sorted with the rack swap!
-J
I got a used 2014 rack off ebay. I focused on the year but not the wheel size. The ad said it fits 2011-2014 with 19" or 20" wheels.

Your post is the first I've heard of getting rid of this problem with ECU tuning. I didn't think that was possible, since the software in the electric rack is separate and distinct from the ECU? But I don't know for sure. I definitely have this problem with AdvanceTrac totally off on track, but my car has its totally stock original tune.
 
I have a tune which disables AdvanceTrac, and does seem to resolve the steering nibble. However, I do have an intermittent shudder under braking as noted above. If the rack fixes yours, I may give it a shot on mine.

I have a 2013 rack on the shelf, but lost motivation to replace it when the tune cured the nibble.
 
I have a 2011 with shudder symptoms that appeared at the track for years. I had always thought the brakes were to blame. I recently installed Boss R front lower control arms with delrin bushings and now the EPAS goes nuts on the freeway. I’ve come to realize it was likely the EPAS the entire time, even with stock LCAs. Boss R rack (M-3200-EPAS) will be installed for a track event next weekend. I will update with results
 
486
428
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
I have a 2011 with shudder symptoms that appeared at the track for years. I had always thought the brakes were to blame. I recently installed Boss R front lower control arms with delrin bushings and now the EPAS goes nuts on the freeway. I’ve come to realize it was likely the EPAS the entire time, even with stock LCAs. Boss R rack (M-3200-EPAS) will be installed for a track event next weekend. I will update with results
You will like the Boss R rack. I went to one after replacing control arm bushings and experiencing the issues on the highway. It eliminated all of the problems I was having.
 
I have a 2011 with shudder symptoms that appeared at the track for years. I had always thought the brakes were to blame. I recently installed Boss R front lower control arms with delrin bushings and now the EPAS goes nuts on the freeway. I’ve come to realize it was likely the EPAS the entire time, even with stock LCAs. Boss R rack (M-3200-EPAS) will be installed for a track event next weekend. I will update with results
Just a follow-up, the Boss R EPAS completely solved the issues I was experiencing regarding steering "jutter". The symptoms were present on the track since I bought the car back in 2014, but I had wrongly diagnosed it as poorly bedded brakes. After installing the Boss R control arms, it became apparent the rack was the culprit. The same sensation I was experiencing under braking and high G maneuvers on track was now present in day-to-day driving. M-3200-EPAS solved the issues I experienced and now track days are much more enjoyable.
 
Coming back to confirm... My 2011 GT had a shudder in the front end under heavy / at the limit braking (CAM-C autocross car). Swapping in the salvage 2013 rack resolved it.

Unfortunately, I went through two sets of pads and rotors last year chasing it before I saw this...
 
486
428
Exp. Type
HPDE
Exp. Level
5-10 Years
Lenoir City TN
Coming back to confirm... My 2011 GT had a shudder in the front end under heavy / at the limit braking (CAM-C autocross car). Swapping in the salvage 2013 rack resolved it.

Unfortunately, I went through two sets of pads and rotors last year chasing it before I saw this...
Don't feel bad, you are not the first to think the shudder was related to the brakes. I put up with it to varying degrees for a couple of seasons until my front bushings were shot and needed replacing. The new bushings made the car almost undrivable on the highway. I didn't realize the shudder I was getting under heavy braking on the track was related to the EPAS until I was forced to swap it out.
 
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These recent posts are inspiring me to install the 2014 rack I picked up late last summer. Thanks all, these are interesting and encouraging updates.
 

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