Vorshlag 2011 Mustang 5.0 GT - track/autocross/street Project

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Got this question from an SCCAforums member...

Hello, I was curious to here your opinion on something considering the headache these upper mounts have caused most people. If you were to ignore, just for a moment, any rules in terms of the racing you do with this car would you ever consider running a Torque Arm setup on the S197 since it eliminates the upper mount? What's your opinion on a Torque Arm setup in general on the S197 for a car that would see some small time events, back road shenanigans on the street and normal day to day driving? This is something I have considered pretty hard lately since I have yet to see a good option to get rid of all the problems with the upper link. I hear NVH can be a bit of a challenge with the Torque Arms transmitting rear pumpkin noise into the cabin but some folks haven't thought it was too bad and others thought it sounded kinda Cool

That's actually a very good question, and one I've had with several SCCA autocross racers, various S197 track enthusiasts, and GM guys. I'm going to post this in my S197 Mustang build thread across all forums, since the "Torque Arm in an S197?" question comes up a lot. And there's a lot of bad information out there, I feel.

Sometimes The Aftermarket Sucks

First, let's look at the aftermarket as a whole, and the actual worth of many of the suspension product offerings. Remember what I have said for years about a lot of the bolt-on doo-dads in the aftermarket: some of the stuff out there is made simply because people will buy it. If it is steel, shiny, fabricated, and looks "neat" it often sells. There are so many bolt-on braces and reinforcements, replacement K-members and feeble control arms out there it is hard to wade through the junk and see the small number of helpful, properly designed, quality made parts that improve something. Some of the "I just replaced X" part" stories are soon followed by "This stupid thing broke!" complaints, but most of it gets enough steel thrown at it that they don't break, just don't do anything to improve the car. I had someone ask yesterday at the shop, "Should I get a better strut tower brace for my 2012 Mustang GT?" And I said "If you want a prettier one, sure, why not... but it won't make your car handle better or go any faster. Having any strut brace is usually just about good insurance for long term chassis rigidity... but the stock one works great". I would wager a guess that 75% of the bolt-on crap made for the S197 is mostly blingy steel, only made to lighten your wallet...



"Well, It Worked in The 1970s"... But So Did Bias Ply Tires

A Torque Arm + Panhard Rod rear suspension was first used by GM on the Chevy "Monza" chassis in 1975-80, adopted it to the Cosworth Vega chassis in 1975 (thanks wikipedia!), then was the basis for the all new 3rd gen Camaro/Firebird (F-body) chassis in 1982, and continued through the 4th gen F-body run all the way until 2002. The picture above is a mid 1980's V8 Camaro built for NASA's CMC class, and was in our shop for custom 3" stainless exhaust fabrication. This car has the stock stamped steel torque arm in place, and it bolts to the rear axle assembly - which was made to hold this. The transmissions in these cars had integral front mounts as well.

What's Good For The F-Body...

There are dozens of tubular or square steel fabricated aftermarket torque arms made for the 3rd/4th gen F-body chassis, some are adjustable (pinion angle), some have a front sliding spherical mount, others are "de-coupled" or even have a spring front mount. Most are made for drag racers but there are a few tailored for track racers, which can work for autocrossing. These are not a bad upgrade on these cars, as the stock stamped steel piece if a bit flimsy when loaded up with lots of braking torque and/or tire grip and/or power.

The TA rear suspension was a novel way to package the "upper" rear control arm of a solid axle car while still leaving good back seat room. The long torque arm, stuffed in the driveshaft tunnel, replaced the traditionally short upper control arm(s) in a 3- or 4-link rear suspension. There are some geometry advantages and some disadvantages to the TA, but for the most part it worked in these factory designed cars because it gave better packaging and good enough handling & acceleration. It hurt braking performance, however, and the F-body's dreaded "axle hop" is traced to the geometry and bushing failures of the factory Torque Arm. Still, it was better than most of the crap used in pony cars in the 1980s-1990s, and I've personally installed aftermarket torque arms (plus panhard rods or watts links) onto many Fox and SN95 chassis Mustangs, with good results.

Torque Arms Fit For Foxes



These Fox/SN95 solid axle Mustangs, based on a 1977 Fairmont rear suspension, are a horribly handling messes with the stock "quadralink" rear suspension. These cars had no secondary lateral axle location, and instead the upper control arms are canted inboard at the top to give some lateral control of the axle. When these 4 upper and lower arms swing through their arcs, though, they bind HORRIBLY. To combat this, Ford kept the rear control arm bushings SUPER soft, which covered up this inherent suspension bind. Then, after they put a decent V8 in these cars (1985), Ford engineers slapped 4 shocks on the rear axle - two vertically mounted, two horizontally mounted - to keep it from axle hopping and flopping around under acceleration, because the control arm bushings were all so soft. Truly a terrible OEM solution in every way. Still, they sold a crapload of these cars, and drag racers and other racers changed the rear LCAs quickly. I've owned and raced and worked on many of these Fox Mustangs, too. If you added stiffer polyurethane bushings to the UCAs on a Fox/SN95, you would eventually rip the control arms and upper mounts arms right out of the chassis. Been there, seen that. These added MASSIVE bind as well. We took the rear springs out of a Fox with poly rear bushings and it not only supported the weight of the car, but you could drive it like that! So much bind.

This meant that getting those upper control arms out of the rear suspension was IMPERATIVE, and naturally Mustang guys looked at the F-body TA solution. For the most part (with some notable exceptions), these 3rd/4th gen F-bodies dominated the Fox/SN95 in autocrossing and road racing for nearly 2 decades, and the factory TA + Panhard rod rear suspension was a large part of that handling advantage. So yes, an aftermarket Torque Arm + lateral link is a great solution for 1982-2004 Mustangs. It can work in drag racing or autocrossing, and SCCA rules makers finally relented and allowed the upper arms to be removed when a Torque Arm was installed. Many, many years after allowing TAs.

Why would you keep the UCAs in place with a newly added TA? Bad class rules. If anyone kept the OEM arms in place AND added a Torque Arm to a Fox/SN95, there was so much rear suspension bind that it made things much worse. Tossing the UCAs away when you installed a TA was normal, but not in SCCA circles. You see, the rules makers often don't understand suspension design or the aftermarket solutions, at all, and after writing rules allowing Torque Arms in SP, they "forgot" to also allow removal of the UCAs. Then when this glaring omission was pointed out, they fought the UCA removal for years. SCCA knows best! So autocrossers with these Fox/SN95 cars that wanted the benefits of a torque arm would have to "keep" the stock upper arms in place, so many replaced the UCA bushings with Nerf football foam. This let the UCArms flop around harmlessly, didn't affect the handling and did not add bind. So the upper arms were just there for show, like on a T-rex. RARR!!! This met the letter of the rules, and the SCCA rules makers finally realized their mistake and updated the rules to allow UCA removal. Many. Years. Later.



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A Lot Can Change In 30 Years

Some things never go out of style, but some technologies do become outdated. Brake drums are never used on performance cars anymore, but they were the standard for braking for almost 100 years. Just so, the almighty Torque Arm rear suspension has probably seen its day in the sun. Sure, this was a great aftermarket solution for 23 years of Mustang production, and it also worked well enough for 21 years on the factory F-body chassis. But what about the S197 chassis? The 5th gen Camaro? No, not so much use anymore. Ford found a way on the S197 to package a 3-link and finally added a separate Panhard Bar, and still managed to add high revving 420 hp V8 and kept the price under $29K. They could have used a torque arm, but there are just so many compromises, so they didn't.

But the aftermarket sometimes just keeps doing what it makes money at. Since a lot of what is made and offered for the S197 Mustang is coming from some of the same shops that have been developing parts for the old Fox/SN95 for almost 3 decades, some of them just take the same old solutions and apply them to the newer chassis. This is where I think the mistake lies - in what I call "aftermarket inertia". Dated engineering that doesn't necessarily work well on the latest Mustang chassis is being pushed onto people by some parts makers... that either don't know any better, or just want to make some sales. I say all this with the "In my opinion, your results may vary, blah blah blah" statement at the end.



The new for 2005 Mustang S197 chassis has a pretty decent 3-link/panhard rod rear suspension, that is light years ahead of the Fox/SN95 mess it replaced. This was and is the best handling Pony Car Ford has ever built, and part of why the 2011+ GT and Boss302 is compared in the same breath, and favorably, to $70K BMW M3s by all of the major car magazines. It was the first Mustangs in 2+ decades to not be based on the old 1977 Fairmont suspension technology. Sure, the S197's LCAs and UCA are still chock full of soft rubber bushings to allow for a smooth ride, but the fixes for these are MUCH easier than the Fox/SN95 cars. Just get some good, adjustable length LCAs with better bushings, ignore the UCA, bolt on some LCA relocation brackets, then get proper dampers and springs. Once the car is lowered you need either an adjustable Panhard rod or a Watts Link kit, to control the lateral location and re-center the axle. For 90% of the track/auto-x S197 guys out there, that's a good fit. For the last 10% at the pointy end of the racing grid, add a properly made UCA that has sphericals at both ends. Done.



I think an aftermarket Torque Arm is the wrong suspension solution for the S197 chassis. It could even make the car handle worse than stock, in some instances, possibly... no, very likely adding axle hop under braking. I haven't driven an S197 with a TA yet, so I could be wrong... but I don't think so. I've raced in too many Fox, SN95, 3rd gen and 4th gen F-bodies to believe otherwise. As a suspension designer, I understand the geometry minutiae, the Pros and Cons of a torque arm set-up. I've owned 8 different 3rd or 4th gen F-bodies, 6 Foxes, and worked on many dozens more of them over the past 20 years. So I've witnessed axle hop in these cars first hand, the clanking and banging of the aftermarket TAs, and seen the extremes needed to tame these newly added problems. I've even seen a T56 transmission housings literally EXPLODE at an autocross, after violent axle hop under braking, with the torque arm pounding into the transmission in a 4th gen F-body. BOOM! Gears and fluid and case going everywhere. I have fought with bushings and shocks and tubular Torque Arms on these cars, both my own and customer cars, and know that they make for less than ideal street cars when you "fix" most of the problems. Aftermarket TAs get very noisy, very fast.



So all that being said, I won't recommend a Torque Arm as a good solution for anyone with an S197 Mustang. Except for ONE situation: Serious, ultra-competitive SCCA autocrossers who cannot replace the LCA or use LCA relocation brackets (in ESP and STU class) but otherwise CAN run a torque arm.

Which leads us to where we are now on solid axle rear suspension rules in SCCA Solo. The rules are broken. The solid axle rear suspension rules, as currently written for SP and ST, seem to be penned by people that do not understand suspension design, or the common aftermarket solutions. So we end up where the only way to get the geometry corrected on a lowered S197 is by spending $1000++ adding a janky, last century Torque Arm rear suspension solution to a 21st century car. Again, only on a serious SCCA autocross car built for ESP or STU, that's the only time a Torque Arm on an S197 makes sense. We had even planned on making one for my 2013 GT we were gong to build for ESP, until the SCCA "re-clarified" a rule that made the class less than ideal for us to build around (and kept the rule broken for 2+ years).

For everyone else that autocrosses or tracks their car, not in SCCA's ESP or STU class, don't use this Horse and Buggy solution. That may seem negative towards the SCCA, and harsh to some aftermarket companies, and frankly it is. Because I've had to build cars around SCCA's broken and tortuous rules for 25 years. And I have seen too many useless suspension parts and poor solutions being sold by manufacturers. We go to trade shows and see that roughly 75% of the stuff there is useless CRAP. It frustrates me when I see people waste their time and money on useless crap.

We still design many of our suspension products to meet some SCCA rules, begrudgingly, but it is because some of our customers want that. It drives me nuts when a rule is written so poorly that we have to make something less than ideal to meet it, but they write the rules used by 80% of the autocross clubs in the nation. What do ya do? Until the day that another group supplants the SCCA in autocross attendance and rules making, we're all stuck with their mess of a rulebook.

I write letters to the SEB asking for rules updates and fixes. All. The. Time. It doesn't do much good, but if enough people write in and ask for these common sense updates, over enough years, they.... will.... slow...ly...fix... them. Also, given enough time, many of these old farts die off or leave the sport, and eventually some new blood with a little sense will make it onto these rules boards. I've seen a few bright, upcoming autocrossers make it onto a few committees and rules boards lately, and that is encouraging.

Here's what to ask for, if you are stuck in ESP or STU in an S197 Mustang, and want to see changes:

1. Allow alternate LCAs. Adjustable in length, tubular steel in construction, why not? You're talking under $300 in parts to fix stamped steel, floppy stock arms, all while giving you pinion adjustment.

2. Allow bolt-on, axle-side LCA relocation brackets. This $100 fix is so common and works so well that it hurts me to see them not legal in Solo (we install 2-3 sets of these on S197s per week). These make for significant fixes to rear geometry on virtually ALL solid axle RWD cars that are lowered (other than 1960s-based leaf sprung cars). Allowing these low cost, commonly available-for-every-car-in-ESP brackets that move the pick up points negate the need for $1000+ torque arm "fixes".

Those two allowances are sorely needed, as the current SCCA Solo rules for this area are at least twenty years out of date with the aftermarket and racers.

Before you ask, yes, I know some people will want to know more of the nitty-gritty details. Someone will ask for the geometry breakdown, every pro and cons, somebody else will throw three pages of calculations, another will add some vector graphics, and before you know it this will turn into an internet suspension nerdfest, heh. I think this summarizes the argument quickly: basically everything you do to help forward acceleration by adding a Torque Arm, hurts braking. Just adjusting the squat geometry ($100 LCA brackets) in a lowered S197 helps as much or more as a TA, has no down-sides, doesn't add the clanking and banging that normally comes with an aftermarket TA, and is 1/10th the cost or less. Well, other than the fact that they are not yet legal in some SCCA Solo classes. Also know that a TA is an old 1970s solution that just doesn't necessarily help the 2005-era S197 chassis 3-link rear suspension as much as it did the 1970s opposed 4-links in the Fairmont/Fox/SN95.

Cheers,

[Fair]

Ford EPAS Feedback Failure?

The Electric Power Assist Steering (EPAS) is a potential problem on 2011-14 Mustangs if you modify the suspension in certain ways. We hear from customers weekly so I wrote this. I am not saying that this will happen to your 2011-14 Mustang but it happened to our 2011 GT and we've heard of this on at least 100 more cars, too.

PDF of EPAS document: http://www.vorshlag.com/documents/Ford_EPAS.pdf

The document above talks about EPAS features to fix "Pull Drift Compensation", something most people didn't care about. Ford engineers neglected to see the negative side effects when it sees parameters outside of the OEM suspension/tires/bushings. When you take a 2011-up production Mustang and modify any of these items below you can potentially cause the EPAS to go into an erroneous feedback loop.

Modifications that can cause EPAS Feedback Failure

• Aftermarket Front Control Arms
• Aftermarket Front Control Arm Bushings
• Radical changes to front suspension geometry
• Significant tire/wheel changes (especially R-compound tires or slicks)

Our issues first occurred with lowered ride height + poly LCA bushings, on an autocross car daily driven on 265mm street tires.

This list may be incomplete, but it shows what we've seen that can cause this failure, and what some other suspension manufacturers and racers that have called and talked to us about have seen. It doesn't always happen when you change these parts, especially if you just do the mods and only daily drive the cars. Often it only takes time or circumstances - when these mods are installed, then eventually the car is driven at road course or autocross event, the feedback failure soon follows. And once it begins to happen it only takes a few circumstances (minimum speeds, a certain amount of steering input speed) for it to happen again and again. Watch the video below for how this happened on our 2011 GT after installing Energy Suspensions front LCA bushings.


Vorshlag EPAS feedback loop video.

The video above has been viewed many thousands of times. It has been sent to Ford engineers, but to my knowledge, Ford Motor Company does not have a fix for this, nor do they even acknowledge that there is a problem. The blame is quickly put onto any aftermarket suspension or wheel/tire modifications. Which is true - those changes can kick off this error, and we have not seen this happen on 100% stock Mustangs.

But... there is an error in their programming, for this to happen so frequently with one simple bushing change. This issue cannot be fixed with a new program upload into the EPAS computer (located within the steering rack assembly), either. All attempts to over-write theses "ones and zeros" have been rebuffed or failed. But Ford Racing has a fix...


Vorshlag does not sell the M-3200-EPAS steering rack, but Rehagen Racing does.

We talked to Ford Racing folks, who knew all about the problem. They developed the "race rack" above for the Boss 302-R/302-S race cars, which all come with this M-3200-EPAS rack installed. It has the same hardware as the production 2011-14 racks, but just has the "auto nibble" or "Pull Drift Compensation" programming turned off. It is a simple $999 fix. They will not over-write this programming onto a used steering rack - they will only sell you a new one. We asked many times while the M-3200-EPAS unit was on backorder for several months.



So, if you have a 2011-14 Mustang and plan on doing a lot of suspension modifications, either AVOID touching the front LCA bushings or using an aftermarket control arm (or even the Boss 302-R LCA) or PLAN for this rack upgrade. The LCA bushing or arm replacement are the two most common causes of EPAS feedback failure, and doing either is almost a 100% guarantee you will see this feedback failure. But if you run a production 2011-14 Mustang in any serious track or autocross competition, you pretty much HAVE to replace these bushings, so plan on the M-3200-EPAS upgrade at the same time.



Why are these bushings imperative to replace? See for yourself. The rear-most lower bushing in the front Lower Control Arm is a HUGE chunk of soft rubber. It is the size of a 8 oz beer can. And if the rubber wasn't bad enough, it isn't even solid - there are channels or voids cast into the bushing, which are filled with hydraulic fluid. This does not make for a stable platform to mount the control arm, through which a majority of the suspension loads pass through.

Bushing Deflection Test

Do this visual bushing deflection test, as it is a real eye opener. Go in a parking lot with your S197 Mustang. Have someone prepared to drive the car while you watch. Stand a few feet beside the car and watch the front wheel. Have them reverse briskly then stop firmly. Watch the front wheel move fore-aft relative to the chassis. It will move a LOT. This is unwanted wheel movement and suspension geometry change in action, and it is very evident. The S197 Mustang is not the only car that suffers from super soft front suspension bushing deflection, as you can do this test on virtually any BMW or Subaru and any number of modern cars and see the same thing happen.



Now imagine the car braking from 100+ mph, on a road course, while turning, and the car is equipped with wider and much grippier R-compound race tires. With the stock Beer Can-sized rubber & hydraulic bushings in place there would be a LOT of front control arm bushing deflection, which results in unwanted toe change to the front geometry. This will make the car unstable under braking. This is undesirable, of course. The fix is upgrading to firmer (polyurethane) front control arm bushings. These parts are low cost, with a less than fun installation, but they do work to control toe change under braking. But once installed... steering rack feedback will most certainly occur. And believe me, when this Feedback Failure happens on the street it is disturbing enough, but on a road course it is downright scary. We found that the only way to stop it once it happened on a road course was to come into the pits, cycle the ignition key, reset the Traction Control system (turning it 100% off), then going back out. After about a few months of this nonsense (while waiting on the M-3200-EPAS to come off of backorder), we finally replaced the rack with the Ford Racing unit and it has never happened again. There were zero other changes or benefits to this $999 steering rack.



I'm not trying to sell folks on some bushing upgrade, or scare you into buying a steering rack we don't sell. Just warning you of a potential recipe for problems if you have one of these cars and do these mods. I don't want people reading our forum posts, buying Mustangs and mimicking our S197 suspension mods, to then blindly fall into the EPAS Feedback Failure. And overall these 2011-14 Mustang GT/Boss302 cars are the Performance Bargain of the Decade, and I highly recommend them to anyone that wants a super reliable 420+ hp V8, RWD sports coupe with outstanding brakes (optional Brembos), and a good basis to build upon - all for a really low price. Heck yes you should drive one, and you might end up buying one, just know that this is one of those potential Achilles heels, and the fix is fairly straight-forward, if a tick costly.

Note: This issue does not affect other S197 Mustangs, like the 2005-2010 models with traditional hydraulic assist power steering, and might not even affect other cars made by other car makers with electric assist steering. More and more automakers are moving from hydraulic to electric steering assist systems, and this technology has MANY benefits (costs, weight, power savings, tunable power assist). I do think these electric racks will become the norm for OEM and racing vehicles alike. Ford just has a glitch here that I think they could fix with a little programming, and they have in the $999 Ford Racing version.

Cheers,

[Fair]

Project Update for August 6th, 2013: My last two posts in this thread were not specific to our 2011 or 2013 GT builds, but needed to be covered: the Torque Arm discussion followed by the EPAS warning. I will get back to our project cars in this post, I promise. Where were we....well back in June we hit several events. After we got back from the NASA weekend at Hallett in the TT3 Mustang, it was time for another Five Star Ford track day at ECR. In preparation for this event, we developed and installed our 14" Brembo BBK as well as a new Vorshlag brake ducting kit for the 2013 GT and performed our typical race prep on the 2011 GT and tweaked a few other things. The 2013 GT is now for sale as well (see this link or the details at the end of this post).

Three Track Tests in the 2013 GT

If you have been reading this thread for a while you know that I had purchased a 2013 Mustang GT last September for use in SCCA autocross use, for a dedicated ESP build. Long story but that plan was scrapped, so we decided to keep the car long enough to develop some new parts and move it to make room for an all new 2015 Mustang (that's still happening). We tracked it twice before and planned one more track event with this car, and each time out on track was a test. Each time I drove the car, at ECR, on the same set of 295/35/18 Nitto NT05 tires, to try to keep the variables minimized.

Test 1: NASA at ECR, Oct 6th, 2012 - This was when the car had 500 miles on it, stock brake pads, the base GT's smaller 13.2" front brakes, even stock brake fluid. The car had our lightweight 18x10" wheels, the 200 treadwear 295 Nittos (that were purchased to run at the Optima Challenge in July 2012), a big Eibach front sway bar, and Vorshlag camber plates. I ran it in NASA TTB class (got killed, of course) and ran it for two sessions on October 6th. Even with stock suspension, power, and brakes, I managed a best lap of a 2:07.315, a solid 9 seconds slower than TTB winner KenO, but we stuck it in TTB just for testing purposes. I was only able to take about 3 hot laps, as the brakes would go to the floor on my 2nd hot lap, and it took several cool down laps to get them under control. During my 2nd session the front pads melted, fell apart, and it went to the backing plates. No brakes. The car was a big floaty mess and pushed like mad, but it could still boil the 295mm rear tires on any corner exit, easily.



The ambient temps were in the 50°F range and the weather was clear. I drove two cars that weekend: our '13 GT and the '11 GT in TTS class, turning a 1:56.343 in the red '11 Mustang on Sunday - my new personal best lap at this track. Driving the '13 Mustang GT was a big hot mess, and braking with the small stock brakes was downright scary. The fluid got so hot that we melted some seals in the master cylinder (took us a while to figure that one out). I will never... EVER do another track event on OEM brake fluid or pads. Never.

Test 2: Toy Run at ECR, Dec 8, 2012 - Now we had installed about $5000 worth of suspension upgrades and the handling on the 2013 GT was a LOT better. The suspension mods included a lowered ride height via AST double adjustable coilovers with remote reservoirs, 400#/200# spring rates (still relatively soft, but stiffer than lowering springs), and the same camber plates, wheels, tires and front sway bar.



We also upgraded the brakes to Carbotech pads and Motul 600 fluid + Vorshlag SS brake lines. Massive improvement in stopping, but it would still only do about 1-2 laps and didn't stop much, if any harder. It kept the fluid from boiling, but the pedal was still mush (we hadn't found the master cylinder seal issue yet). The ambient temps were again 50°F and clear - almost exactly matching the NASA event two months prior. My best lap was a 2:03.7, so we dropped 4 seconds with coilovers and brake pads. That's a solid lap time that most S197 owners would kill for, and yet we had bone stock rear suspension parts, bone stock power, and still were on the small diameter brakes.

I drove a staggering four cars that day (2013 GT, ChumpCar, BRZ, and 2011 GT) so my slate was very full. Needless to say I didn't get in a lot of testing/tweaking. With some more time and testing we might have found a little more time, but the brakes were still a limiting factor - they still had almost no endurance, and the mushy pedal did not instill confidence. I could take one hot lap followed by a cool down, rinse and repeat. Two hot laps in a row wasn't possible, due to the brakes overheating.

Test 3: Five Star Ford at ECR, June 29, 2013 - So our third and final track test with this 2013 GT was the ECR event in June. I will go over the test results, then I'll back up and show the work. Same tires, and suspension, just one improvement to the car. However, this event was brutally hot and we saw ambient temperature creep up to 99°F by day's end - when I ran my best laps in the 2013 GT. People and bodies were overheating, and brakes were a nightmare on this day for most (see my event write-up below for more), but not this car.



This event was a lot more crowded than either of the previous two tests, and since we were sharing the AIM Solo (GPS lap timer) between our two Mustangs, I ran in intermediate while Amy ran the 2011 GT in Advanced. This made getting a clear lap utterly impossible for me in the 2013 GT. I ran four sessions in the 2013 GT, one session in the 2011 GT, and another session in a friend's GTS3 BMW, for a total of six sessions. I caught cars on almost every single lap. At the end of the day I finally took the 2013 GT out in the Red group and got one - count em - one clear lap. I finally ran a 2:03.3 lap with clear track, in the hottest part of the day. It was MUCH easier to drive to that time on that lap than back in December, when it was almost 60 degrees cooler, too. And for reference, the best Amy or I could get in the 2011 GT was a 2:00 flat lap on this hot June day, nearly 4 seconds off that car's pace from October or December. So this brake upgrade did much more than the ~1/2 second improvement in lap times show.

Making the 14" Brembo "Vorshlag" Brake Upgrade and Brake Cooling Kits

The brakes are all we changed on the 2013 GT for this June track test. The brake system improvements made the car both faster and EASIER to drive. I could also push the car hard, lap after lap, without losing stopping power. Huge, massive, immense improvement.



The upgrades included jumping up from the 13.2" OEM rotors to 14" Centric rotors, and from the 2 piston sliding calipers to the fixed Brembo 4 piston calipers. We went with Carbotech XP20 pads up front and XP12 rears, and had front brake ducting as well. The car could stop at 10/10ths every lap for 5-6 laps in a row (that was usually the length of the session). I was abusing the brakes as hard as I could and they just didn't care. We also had replaced the old Master Cylinder, so the pedal was finally rock solid.

The Vorshlag S197 14" Brembo brake upgrade kit we came up with is based on the OEM 14" front brakes used on the GT500, Boss302, and 2011-14 "Brembo" GT's and Track Pack cars. We get the new calipers from Ford, the rotors from Centric, the pads from Carbotech, Vorshlag stainless braided lines (BrakeQuip), and it comes with all of the Brembo hardware. We make the kit option-able with any of the Carbotech pads, with or w/o the Vorshlag lines, and even w/o the brake backing plate dust shields - if you want to upgrade to a brake ducting kit. The prices are very competitive and we've already sold a few of these to track drivers in 2005-2013 Mustangs that came with the smaller front brakes. It is immensely more affordable than an aftermarket BBK, as it uses $99 replacement rotors and a common brake pad profile.

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The funniest part is that the massive aluminum 4 piston Brembo caliper is lighter than the aluminum 2 piston OEM caliper, due to the steel sliding mount that the 2-pot works with. The 14" rotor is a tick heavier, of course, but that's mass you want for soaking up and shedding heat. We upgraded the front rotor to Centric's best option; this rotor comes with black coated hats, which won't be rusty looking in a week like the stockers.



We are still finalizing our brake ducting kit, which will have a specific grill and grill ducts for the '13-14 GT's and will be made to work with the CS Lower Fascia on the '10-12 GTs. I'll post up more about that kit later, when it is ready, but needless to say for serious braking on track you have got to duct the front rotors. Our '13-14 duct kit will pull air from an unused portion of the lower center grill area rather than the outboard fog light openings like some other kits (including the '13 Boss302). This inboard spot gets cleaner, higher pressure air and has a straighter shot with the brake duct hose routing when you pull from the location we did. Again - when I have more pictures and details I will share them - those two pictures above are only from my phone.

Event write-up Five Star Ford at ECR, June 29, 2013

In the section above I talk about the 2013 GT Tests 1 through 3, with the 3rd test being done at a June 29th 2013 event. I drove two other cars that day, and we worked on many more, so I will do a quick event write-up. As I've said before, the 2.7 mile course at ECR is a brake killer, and when it is approaching 100 degrees it only gets worse. But we love ECR as a test track on Mustangs because it has a lot of tight corners, bumpy surfaces, and these brutal braking zones. There are also some decently long straights to take advantage of power.


We had both our 2011 GT (Amy in the red) and 2013 GT (Terry in the black) out running at this event. We took riders all day.

I noticed several things after driving both the '11 and '13 GT's that day. One, while the extra 50 whp from the modified exhaust/tune/cold air on the 2011 GT makes the car a little louder and more fun, the added power isn't a HUGE improvement. The stock powered '13 GT 5.0 could hold its own on the straights with virtually any car out there. Both cars had very high end monotube adjustable coilover dampers (Moton doubles with remotes on the '11, AST doubles with remotes on the '13), so the bumpy nature of this track upset neither car. And after adding the same 14" Brembo front brakes, ducting and Carbotech XP20 front pads to the '13 GT as the '11 GT, they both braked VERY well, lap after lap after lap.

No, the biggest difference between the cars was grip.

Obviously, the '11 GT has wider wheels (12" vs 10" wide) and tires (315/30/18 R-compounds vs 295/35/18 streets), and a much softer tire compound (Hoosier R6 vs Nitto NT-05) than the '13 GT. This made for different driving lines and speeds in corners, but almost identical brake marker choices. The Turn 3-4-5 complex as well as the Turn 7-8-9-10 sequence were MUCH slower in the black '13 GT on 200 treadwear street tires than in the '11 GT on big sticky Hoosiers. In the end we only saw about 4 seconds difference in the fastest lap times from each car that day, and it was all in the turns. But, and this is important, the '13 GT could only do one TOP SPEED 10/10ths lap in a row, due to rear tire overheating. The brakes could go all session, finally, but the street tires would only make it for one very hard lap before they got so hot the rears would start slipping and sliding like mad. And this is even with +60mm more tire than stock at each corner.


Video from the Eagles Canyon Track Day ~ Hosted by Sam Pack Ford. Video by Ben Freedman

Again, I'm kinda hard on tires and brakes, and aggressively use the throttle, so I might be more prone to rear tire overheating than some in Mustangs. The '11 GT could just pound out lap after lap at the 2 minute mark or quicker, with the Hoosier R6 tires. It was easy to keep going and going at full tilt, as long as you didn't get stuck in traffic.

ECR Photo Gallery: http://vorshlag.smugmug.com/Racing-E...rd-ECR-062913/

I did notice the '13 GT run a bit on the warm side, late in the day. We haven't seen overheating in our 2011 GT at all, even running it for the past three years in all sorts of hot weather events (up to 105°F). But last weekend in my 2013 GT it got up past mid-way on the stock temp gauge, to 3/4 and almost to the "H"... first time we noticed that. This was after 6-7 hard laps (15 minutes) in the last session of the day when it crept up to 99°F. The only difference in our two Mustangs is the grill... the '11 GT has no foglights and the '13 GT still has them in place. Both have completely stock cooling systems, and none of the extra coolers that come on the Boss302 or Track Pack cars. Strange. Only did it once, and after half a lap it cooled off back to normal. Never had a check engine light or loss in power, just saw it creeping up and I cooled it off. I dunno... if I was going to keep this car the fog lights would come out next to hopefully improve radiator air flow.

I had a blast driving Dave B's GTS3 BMW, too (below, right). This was formerly the gold 4-door 325i called "Goldmember" back in the day, which I helped him flare and stick 18x10" wheels with 285mm tires onto. Dave worked on the GRM E30 for a year as well. This car has come a long way and it is now gutted, caged, with an S50 motor, and he's raced in NASA GTS several times with some wins. The car was built on a tight budget, but is still fast and fun. He wanted me to take a session in it, so I climbed in, knees hitting the dash, and managed about 6 laps before I brought it in. Lots of grip, no, mountains of grip! Those 285mm R compounds on a sub 2500 pound car WORK.

We tracked down a few issues and I told Dave I'd come out and help him debug some things at another ECR test, which I did on July 13th. I got out there with all of my test gear, sitting on pit wall, timers going, 7:30 am, he's making a warm up lap... and of course the car broke (camshaft) on his first test lap - dumb luck. Oh well, we'll do it again soon and help him get more speed out of this car. It should run 2 minute flat times once it is sorted; he played lead-follow with me in the 2013 GT and he could keep up.



I've still never driven a '11-up GT on track with the base model 18x8" wheels and 235mm All Season tires (above left). I suspect it would be quite hilarious, but probably very frustrating after a lap or two. These tall 18" all seasons are nice for the street, but you can NOT use the gas pedal much or the rear will spin for days. I've tried in our 2013 GT on the street, but they are devoid of any usable grip. These particular wheels no longer fit over the 14" front brakes, so they are of no use to me on the 2013 GT. I'm still amazed that Ford would put a 420 hp motor in these cars and allow the base model GT to come with such skinny, crappy, low grip tires. The 13.2" brakes are also pretty much crap, and won't last two laps of hard use on a track like ECR. As I tell anyone that will listen, the MOST important option to get when ordering or looking for a '11-14 GT is the BREMBO BRAKE OPTION. This is the best bang-per-buck option on the best bang-per-buck model Mustang ever made. It only only takes you from a 13.2" front rotor with craptastic sliding 2-piston calipers to the 4-piston fixed Bembos and 14" rotors, but it nets you a one inch wider wheel as well. True, it is a 19" wheel, which is really only done for styling purposes, but at least it comes with a 255mm tire.

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[Fair]

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Again, if you purchased a '11-14 GT with the smaller brakes, we've got that covered plus more in our Vorshlag 14" Brembo Upgrade Kit. Hugely important if you ever track your '05-14 Mustang and it came with the small stuff. I mention this again because we had some good examples of how bad the smaller 13.2" Mustang brakes are that weekend at ECR, with one fellow getting all of ONE hot lap before he called it a day. It took one lap for the fluid to boil, the brake pedal went to the floor, and off the track they went. Weee! We've since hooked him up with some proper fluid and Carbotech pads, and he's heading back out on track, but the 14" Brembo front brakes are on his wish list, and brake ducting won't be far behind.


The base GT's 13.2" front brakes are better suited to drag racing or autocross, not track use.

Ryan was there at this ECR event with me and Amy and he worked his butt off all day long. There were a lot of noobs at this event, driving new but mostly bone stock Mustangs, and some EVO and BMW guys, too. Even with instructors slowing them down, several of the new guys ran out of brakes in one or two sessions. Luckily we brought a lot of tools, a generator and an air compressor. We ended up doing full Motul RBF600 brake fluid flushes on several cars, one guy fried his pads, swapped some wheels for people, changed camber on multiple cars, diagnosed weird sounds and shimmies in half a dozen cars, and basically Ryan was wrenching all day long - he never even made it to pit wall to work on our two cars. Most of the work was on brakes.



In the first session of the day, a student asked one of the experienced instructors to take a few laps in his 2012 Mustang GT (non-Brembo car). The instructor took a warm up lap (driving 5/10ths), then sped it up a little on the beginning of lap 2 (7/10ths) and drove right off the end of the hardest braking zone corner. He was shocked - "Man, I was barely pushing the car, didn't have two laps on it yet. It just lost the brakes completely!!! Pedal went to mush, I was pumping the brakes but nothing was happening."

Been there, done that. We looked at the car and both the fluid was boiled and the front pads were gone, turned to goo. Luckily no damage was done other than to ego. Student was really bummed, as he got ZERO laps himself (they gave him credit for a track day the next weekend). We brought spare track pads for S197s, but didn't have them for the non-Brembo front calipers in our trailer, so he called it a day very early. Amy saw him in the paddock later, all bummed out with no brakes left, and she stuck him in the passenger seat of our 2011 GT. After a session riding with me in the 2011 GT we turned his frown upside down. He was so pumped when he got out of the passenger seat - hooked for life! He came by later the next week, picked up some Carbotechs and Motul from us, and I gave him some barely used 13.2" front rotors, and he was back at the track the next weekend - with no problems.

So the moral is - don't underestimate the basics. S197 Mustangs come with "low rent" brake consumables from the factory: the stock brake fluid and stock brake pads are really for street use ONLY. Even noobs can ruin the old/stock fluid quickly. Sure, some new students are rolling around so slowly that their brakes might make it the day, totally depends on how hard they push it. I seem to find the weak link in any cars' braking systems very quickly, and apparently so do some other instructors. It doesn't take much to really need front brake ducting on these cars, too.

Time To Sell The 2013 GT

As much as it pains me to do this, it is time to let this car go to a new home, and it is now for sale. We recently saw the extremely delayed ruling on the Watts Link/Diff Cover change for SCCA ESP class (a simple rule tweak took 8 months to write + 1 or maybe even 2 more years to implement?) and now it might not take effect until 2015? Basically this demonstrates that they don't care about Mustang owners with these needlessly slow rulings - delaying the "rules fix" to make the majority of the off-the-shelf Watts Link systems legal until after 2015. Progress within this club is painfully SLOW and frustrating. I'm not sitting on this 2013 GT for another year or TWO just so the rules makers pull their heads out of their back sides, so the dedicated ESP build we originally purchased this car has been aborted.


Vorshlag 2013 GT is FOR SALE. See more here.

Still, buying this car wasn't a waste. We got some testing done, logging good track data in wheel/tire changes, camber plates, shock/spring upgrades and brake upgrades. We developed a few unique to '13-14 parts, and made somebody a really cool track/street car, but for the most part I lost a lot of time and money on this car purchase. I won't forget this one for a while, and will think very hard about it before I build another car around SCCA Solo class rules again. Lesson learned.


Left: This is the lightest stock 2011-14 GT we have ever weighed. Right: Not much room left in my home garage to park this one

We have added a few more mods to the car since the 3rd track test day in June. We had previously installed a Spohn "Del-sphere" Adjustable Panhard Bar to this car but it just made too much noise on the street, so I had the guys yank that piece out and install a Whiteline Adjustable Panhard Bar instead. Ahh.... quiet and effective. While they were under there, I had them add Whiteline LCA Relocation Brackets too. These brackets improve the rear geometry for cars lowered like this, and makes it better for street, track and dragstrip use. This black on black 6-spd car is absolutely spotless inside and out and has 5100 miles.



It has AST double adjustable coilovers with remotes ($5000), WL Panhard Bar and LCA brackets, Vorshlag camber plates, D-Force 18x10" wheels, 295mm Nitto NT05's, 14" Brembos, Vorshlag brake ducting and SS brake lines, all synthetic fluids, and plenty of custom care done by the Vorshlag techs. Details like the Seals-It 2-piece grommets in the trunk for the reservoir pass-throughs, custom reservoir mounts, and more. A lot of car for the price - see the For Sale page for more details (please don't post questions in this thread - PM me or e-mail us at [email protected]).



If the price is still shown on the linked for sale page, then this car is still for sale. If not, it is sold. Somebody is going to get a killer street/track car for a great price. We showed it at the last Dallas Cars and Coffee event and had some bites, and I suspect it won't last long. Again - I'm losing a lot selling it at this price, but having two track S197s right now doesn't make sense. We've got so many project cars being built and this 2013 GT is now just a distraction. If you want to come by and look at the car, please call Vorshlag a day before, so I can bring it to the shop from my home garage.

Cheers,

[Fair]

Project Update for August 14th, 2013: I am still playing catch up on the event coverage in an "STU prepped" 2012 Mustang GT I co-drove in July, some changes in SCCA classing that affect the S197 (both good and bad), and some major aero work on our 2011 Mustang GT that we are attempting before NASA Nationals in a few weeks. Let's get to it.

Since the bulk of this post has to do with a test we did in an STU prepared Mustang, I will give some background on the many SCCA autocross classes that an S197 Mustang can be raced in, with my personal views on each. I've raced in every single one of these classes at some point in the past 25 years, and many of those times were in an SN95, Fox body, or S197 Mustang. Or a Camaro, Subaru, BMW or EVO.

SCCA Solo Classing - Many Choices, None of Them Great

I have been fairly vocal about my disdain for some of the rules and rules makers in SCCA Solo (autocrossing), but it is still the biggest club doing these lower speed events in the country and it cannot be ignored. Many other clubs just adopt the SCCA rules, letter and verse, so this big book of rules is the one most people go by (346 pages in the 2013 Solo Rule Book, plus another 28 pages for supplemental event regulations and tire clarifications). Honestly I try to get S197 racers to NOT build around SCCA rules, as it will likely only cause you frustration and pain, but if your goal is to become a competitive autocrosser and nothing else, then this is the series to build around. If you are a casual autocrosser, just know the basics below, build what you want, and "run what ya brung" at local events in the class that is the closest to your car.

Let's examine the basics of each of the optional SCCA Solo classes for the S197 Mustang:

F Stock - Aftermarket shocks are allowed (up to custom double adjustables with remote reservoirs), aftermarket front OR rear sway bar, R compound tires (which goes away in 2014 with Street class), but stock sized wheels, stock springs, and very few cars can have any additional camber adjustment (and virtually all stock cars need it). If you don't have a 2007-08 Shelby GT (which is essentially an "ESP-Lite" car from Shelby/Ford), then you're wallowing around on stock spring rates, super tall ride heights, and hating life.



I really dislike the Stock category due to the excruciating restrictions in some areas, yet wide open rules for tires and shocks (which can really drive up costs), and calling it the "entry level" autocross class is a bit of a misnomer. The super sticky tires needed at the top levels to compete puts the costs of this "entry level" class far out of the reach of the average autocrosser, and the restrictions on modifications keep just about every car's suspension tuned so poorly that they handle for crap AND eat tires too rapidly. There were a lot of good, proposed changes to fix this category for 2014 (camber addition, banning crazy custom shocks, sway bars open, 200 TW street tires, +/-1" of wheel diameter), but the rules makers backed down and in the end only really got one change through - the switch to 140 treadwear street tires for next year. It is still going to be a painful class for the typical (non-Shelby GT) Mustang S197. It will still have too much pitch, roll and brake dive and it will handle like the images shown above.

Street Touring (STX -> STU) - For most of the ST category's existence, the S197 5.0L cars were able to run in either STX (on a max 265mm street tire and 9" wheel) or STU (on a max 285mm tire, unlimited wheel width). In 2012, they locked this car into STX which I felt was a slight mistake. We raced our 2011 GT in STX for two painful years, where it sucked badly, then stepped up to a 275mm tire on a wider wheel and ran in STU twice. The handling and fun was a lot better for such a modest increase in tire size. Suspension options are mostly unlimited shock, spring, camber, and (non-metal) bushing choices, with some out of date rear suspension restrictions. Motor has to stay stock from throttle body to exhaust port, with headers, full exhaust (with catalytic converters) and a cold air intake being open.



You can tune the engine (EFI) to your heart's content, which essentially allows for unlimited boost on factory turbo cars (there is no policing of boost controls - nor any scheme to ever do this). We pushed hard to start a letter writing campaign in early 2013 to get the V8 S197 Mustang moved to STU, and it seems to have worked. Supposedly this is going to happen starting 1/1/2014 (or 2015 depending on how you read the confusing rules update). Will this car do any better in STU relative to STX? Probably not a WHOLE lot better, but the added tire is badly needed on these heavy, powerful cars - we tested this theory in the event described below. Even as uncompetitive as it seems on paper, I feel STU is the class that 90% of the casual Mustang autocrossers would end up in.

E Street Prepared - If you've been reading this build thread for a while you know that we left STX/STU and went to ESP in our 2011 GT in late 2012. We had limited success there (4th at Nationals), due to a lack of testing time, excessive weight of our car relative to the top ESP car (a hybrid Firebird build of a drivetrain/chassis combination only allowed in this class), and some other mods we had not explored yet. This class allows the same weirdly restrictive yet expensive suspension mods as Street Touring, plus unlimited wheel and tire width, and super sticky R compound tires (with treadwear ratings approaching 0 and slick tread, yet still "DOT" certified). Again, some weird aero mods are allowed (circa 1960), plus unlimited intake manifold, no emissions regulations, some obscure amounts of port matching, unlimited EFI, and unlimited boost (which is explicitly allowed in this category).



This is still a "good" class to build for, if you can stomach the tire bills, and with enough time/money/testing a fully built S197 could win this class. An expensive tire budget is a key issue. The Hoosier A6s start to fall off after about 20 runs (usually 60 sec in length), and are probably corded after 40-60 runs. If you want anything more than local competitiveness, you will be building a purpose built race car, sans A/C, radio, emissions, and more. But it will still have the stock camshaft, heads, internal engine parts, and the funky rear suspension issues are likely to be in-curable without extraordinary measures.

Street Mod - This class takes Street Prepared rules, then adds a good bit more. Cars in this class must have four seats (from the factory) so that puts your Mustang up against a lot of AWD turbo cars, lighter BMWs and several other four seat RWD cars.



Winning SM in an S197 can happen locally (we've done that a few times), but at the National level you will be hard pressed to get the car down to minimum weight and still be fast enough to beat the other cars here. Still, the relatively unrestricted nature of the rules - unlimited engine mods, metal bushings allowed everywhere, big wings and splitters - will attract a limited few S197 folks to this category.

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