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

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After these first 4 runs (of 1 we take for the weekend), I was inexplicably leading the ESP class - ahead of the 7 car field that included CP Nat'l Champion Todd Farris and 7-time ESP Nat'l Champion Mark Madderash. Huh?! I mean, sure... the car felt quick, but it had all sorts of understeer, no testing, the wrong tires, the rear diff was letting go, and was still just an STX prepped car with a spoiler and Kumhos. Even the heat 1 announcer Andy Hollis was shocked, and sounded incredulous when he made the announcement of who was in the lead after my last run. That was pretty exciting, and we had dozens of racers come by that morning and congratulate us on "finally finding the right class for the Mustang!" I was hooked on grip once again so I doubt we'll ever run this car in STX again - it just fits better here!


Left: ESP class results after round 1 - I was in the lead! Right: ESP results after all 3 rounds, I was in 2nd. Orange line shows Super Challenge cut-off

Official Event Results: http://scca.cdn.racersites.com/prod/...%20Results.pdf
PAX Results: http://www.sccaforums.com/LinkClick....rcedownload=tr

Unfortunately, that was the high point of the weekend, and the rest of the ProSolo event went pretty much downhill for both of us. The car developed some funky "Service AdvanceTrac" fault, the steering feedback jitters were rampant, and the poor stock limited slip devoured itself completely - by Sunday it was an open diff; we never got close to our Saturday morning run times. I was trying everything I had on every run, and my final two Sunday morning runs were .7 to 1.0 sec slower than my Saturday morning left and right side runs. Looking at my 12 class runs I cut five .5xx lights, five .6xx lights, had one .4xx redlight, one in the .7xx range, and a pair of cones. Meh, I never claimed to be a ProSolo expert; in 24 years of autocrossing (I uh... started racing when I was 2!) I've only attended 7 ProSolo events, and it never really suited my driving style (I just don't get much better over the course of 12 runs on the same course).


Left: If you don't show up on 315's in ESP, don't bother. Right: "SERVICE ADVANCETRAC" fault

With the car's performance falling off like it did I was lucky that my Saturday morning times were still good enough to hold onto 2nd in ESP class for the event, and put me at 12th place in PAX standings. That was a bit of a shocker. Madderash slapped on a sticker set of Hoosier R6s Saturday afternoon (I would too, if I had them) and looked faster everywhere, dropping a second per side on his final two Saturday afternoon runs, which were his fastest of the weekend. I ended up .4 / .6 sec off of him per side, so a total of 1.007 sec back for the weekend. He got 2nd in PAX overall for the event, by a mere .002 sec, so he was driving very well. I was still VERY happy with my results and look forward to more battles with Mark and the other ESP racers in the future.


Everyone had a bit of push in this corner, it seems

Amy's Saturday morning times weren't enough to keep her in 2nd in L1, however. After two of her L1 competitors improved dramatically on their 11th and 12th runs of the weekend (with sticker tires Sunday) that bumped her to 4th place out of 9 cars in class on the last Sunday runs. Not unexpected, considering how far off my times she was and how the car was sort of imploding. Here's the video of Amy's Challenge runs - which was the only in-car video we got from her all weekend. She was about 3.5 sec off of her own pace, ugh. My Sat afternoon and Sunday in-car videos contain so much foul language (from me fighting with the car - and losing ) I cannot post them, heh!

Somehow both Amy and I made it into the Challenges - she into the Ladies Challenge and me into the Gumout Super Challenge. Amy's times were way off of her "index times" from Saturday morning and she went out in round one. Mine were similarly "off" from my best, and I was paired up against #1 seed Andy Hollis - oh boy. Still, I gave him a run for his money and cut a .514 light on one side and even beat him back to the line on one of the 2 runs (I think he had a mistake), but he beat me enough on the other side to advance. As I came through the lights on my first pass the AdvanceTrac fault light was on and I had mere seconds to get to the staging lights - not enough time to "reboot" the systems, so run 2 was plagued by a wacky throttle (it kept cutting out and flashing lights). Oh well, just making it into the Challenge was a first for both of us, so that was cool.



I got a quick weight on the Mustang at full ESP prep using the SCCA scales, and it came in at 3467 lbs (car is on the scales backwards so ignore corner weights). The 4th gen F-bodies in class are 3200-3300 and the lone 3rd gen is 3100, so we still have the heavyweight in ESP class - but its nothing like the weight discrepancy we saw in STX class (with 2600 lb RX8s and 2750 lb BMWs). With ESP rules we can lose more weight now, too. After the trophy presentation we helped clean up the site (hauled 20 bags of stinky garbage to the dumpsters) then loaded up and headed home by 7 pm. Thus ended our exhausting 3 day race weekend, which we are still recovering from now as we load up for another race weekend.

Many Upgrades in Store

We have a laundry list of things to fix before our next ESP outing, and our guys here at Vorshlag have already tackled most of them this week including: more rear spring rate, rear differential rebuild (carbon disc upgrade - before we finally pull the trigger on the Torson or Wavetrac), and more. I will show the guts of the original factory diff, which was indeed coming apart. The steering rack has got to be reprogrammed soon, so we're trying to schedule a 2 week window of no events so we can pull it and send it off to Ford. There aren't many 2 week gaps in our schedule for months, so we might bite the bullet and buy a 2nd $1000 electric steering rack to have programmed. Ugh.



So overall it was still a great weekend, I was just a little disappointed at how the car's performance (and our own) peaked early, then fell off quickly. The tires still feel fine, but they are no Hoosiers. We are going to use them for track events from now on, including NASA's Time Trial event this weekend at TWS. Before we run in ESP again the car will be on fresh 315/335 Hoosiers (there's even room out back for 345s). As expected every single car in ESP that weekend was on 315mm tires front and rear, including: four 4th gen Camaros, one 3rd gen, and two S197 Mustangs. I was the lone driver on Kumhos and two driver's were on Goodyears (that were sticker tires Sat morning but wore down to cords after only 25 total runs - these things are way too soft!), with the rest on Hoosier A6s - the default DOT Race Tire in Street Prepared.

Check back next week and I'll talk about the prep for this weekend's NASA event (rear wing uprights, full brake ducting, etc), which is wrapping up this afternoon up as I post this (I need to be on the rode to College Station right NOW). By next week we should be shipping any backorders on S197 Camber Plates, we might actually have a more solid date on the long overdue D-Force Mustang 18x10s (agh!!), and we can work on fitting the Moton Motorsport Pro 2-way shocks on our car with the new VM Camber Plates. We have 3 race weekends in June, including another Optima Challenge event - so that's another set of $1200 street tires (200TW) we need to buy. I might open a used tire store here, since I have like 7 or 8 sets of half-tread 140-200 TW tires from racing the Mustang in STX for so long.

Thanks,

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Project Update for May 1, 2012 - Part 1: The day after the MW ProSolo we got to work on the Mustang prepping it for the NASA Time Trial event at TWS the following weekend. In this two part update I'll show some new mods done to the car for better track worthiness (Part 1) as well as talk about the TWS event (Part 2).

Front Brake Cooling

For a while now there has been one item we've been meaning to design and fabricate for the car, which is the front brake ducting. It is something I highly recommend to all S197 Mustang owners who track their cars. Now Ford Motorsport (FRPP) has a kit that they sell for the 2010-2012 Mustang GTs that is made to work with the optional CS lower fascia we have (pulls air in from the lower foglight holes). The problem with that kit is that the backing plates included have a tubing diameter that is too large to fit inside the common 3" high-temp brake duct hose. Users end up having to hack the hoses to pieces to make them fit. It also requires modification to the inner fender liners to route the hoses they include, which is not legal for STX.



For the longest time we held off making our own front brake ducting because of the STX rule limitation, but I decided - to Hell with it. We change rotors and pads and now rear aero/trunk configurations between autocross and track events. How much harder is it (if necessary) to pull the brake ducting off? So Ryan and AJ built the brake cooling set-up above using some steel tubing we had (in a diameter slightly bigger than the brake hose), welded them to the OEM backing plates, then routed the ducting to the CS lower fascia foglight openings and through the fender liners - without cutting them. We found a gap between two liners we could use legally in ESP and routed them there. We zip-tied them to the swaybar - which moves up and down with the wheel, pointing the ducting to the back of the rotor. We checked it at ride height at full lock with the 18x11's on the front and it just barely cleared.



And man, did that help! Running at TWS you do get some extra brake heat after coming off the banking and bombing into Turn 1 then stabbing the brakes, in excess of 140mph. The brakes felt GREAT and I was very happy with the extra cooling added. If someone sees something here that is not SP compliant, please speak up - but it looks legal to me. And its not like we need brake cooling in an autocross, so we can take it off if need be. We've made similar one-off brake cooling solutions before, so this was fairly easy for us.

High Speed Aero



The rear spoiler (shown above, now painted black and weighing 9.3 lbs) we made for ESP class autocross use really has no business on a proper road course and was only made to be used at sub-70 mph speeds seen in autocross. It was also made to meet the somewhat arcane rules of SCCA Street Prepared. The Wright Brothers had more advanced aerodynamics in 1903 than the SCCA allows in many classes in 2012, but hey - the rules are what they are. So that 10" tall rear spoiler is basically a big parachute that does provide some downforce at low speeds, but at the expense of drag. This style spoiler is not at all efficient above those parking lot speeds. I know they use similar parts in NASCAR... see my comments above about antiquated rule sets.



I had this "3D" APR wing (GTC-300), a 67.5" wide carbon fiber monstrosity that we purchased a while ago (we've been an APR dealer for many years). I think I got it for the E46 TTD car, but we re-did our TTD class points with the current tire size (285mm Hoosier R6) and realized we didn't have enough points to do any aero. Then I talked about sticking it on the E30, then decided that putting a $1200 wing on a $2000 car was nuts. So it was just sitting here.



The 3D wing shape is really made for use with coupes and sedans to sit lower than the roof height, where the greenhouse adds an aero blockage in the middle of the car and the airflow is compromised behind the rear window. So this style wing kicks up in the middle, behind the greenhouse, to try to capture air flow coming off the roof. Mounted 2 to 12 inches off the trunk floor (under the roof height) it is ideal for this type of situation.



When we looked at using it on the Mustang this year, we checked the rules for classes where other S197 Mustangs play - NASA TTS and NASA American Iron (as well as SCCA Street Modified). We noticed that in each of these classed we can stick the rear wing well above the roofline (8" above in AI/TT, 6" in SMOD!) and a 3D wing isn't necessary if you can mount it up that high. But we had this wing on hand, so we made uprights to fit it to the car anyway. This would allow us to see how it would work and to verify the upright design that we had been tinkering with. We have since found out that we can get a flat style CF wing from APR for a good price and will likely go to that style wing at a later date. This 3D wing will be used in the future on another car where it will be mounted below roof height.

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The 2nd trunk we acquired for the ESP spoiler was re-used and can now be quickly switched from spoiler to wing and back. An outside designer who is an aero specialist that has worked on professional road race teams as well as Bonneville record holding cars, helped us with the wing placement and upright design. After making wooden uprights to test the design and verify fore-aft placement (Tuesday), we took the 3D designs and turned them into engineering drawings (Wednesday), then had water jet cut parts made (by Thursday). Our fab team tweaked and welded up the bases and uprights, then shortened some adjustable rod end struts for the wing adjustment, and fitted the wing to the car Thursday afternoon and Friday morning. We trimmed the wing at the lowest angle of attack, loaded it into the trailer for TWS, and we were on the road by 4:45 pm - this made for a hectic few days of drafting and fabrication work in the shop.



We kind of neglected one variable (what's under the base, in the trunk structure?) and so we had to move the mounting bases rearward about 4" from where we had first laid them out. The back of the wing now sits behind the car by more than the amount allowed in AI - but it's still TTS legal. We're even street testing the wing this week - just to see how well the mounting base and uprights hold up to regular use (not that anyone would be crazy enough to drive on the street with something like this). Once we get our hands on another straight style wing (not "3D"), we will modify the mounting uprights for proper height, improve the adjustment range, and tweak the rearward placement of the wing to stay within AI rules. No, this car is never going to AI, but we want the wing to be AI legal as well.

Other Wing Examples

Some people wondered why we simply bolted our wing mount uprights onto the trunk lid, so I shot several examples of other wing mounts at the same NASA TWS event. Many uprights passed through trunks and bolted to frame rails, others bolted to trunks directly, but had supports underneath to the trunk. Like our car, others simply sat right on the trunk lid structure only. This is how we had to do it to not modify the trunk or to add structure underneath it so we can avoid running afoul of ESP rules even with the wing removed. We did see some flex in the rubber bumpers that locate the rear of the trunk (height) at the back, which we will replace with custom Nylon bushings before the next event where we use the wing.



Here's a Corvette with the wing uprights bolted right to the trunk panel, braced underneath. Above right is a G-Stream wing on a factory Boss 302S Mustang race car - also bolts to the trunk.



Above we have a Fulcrum Wing on Mike P's 4th gen F-Body American Iron car, which won both AI races Saturday - handily. It bolts to the frame and passes through the trunk lid. Another wing is shown on a multiple time NASA ST2 winner's SN95 Mustang - this one with a wicker bill/Gurney flap, bolting right to the trunk.

Rear Diff Rebuild

During and after the ProSolo event (and looking back, at some previous events as well), I noted considerable problems with the OEM Limited Slip Differential - the Ford TractionLok, clutch-style diff. After the 30+ runs at the ProSolo with 315mm wide R compounds, it was finally toast. We had a handful of days to get a functional diff in the car before NASA at TWS, so instead of gambling on getting a WaveTrac or Torsen T2R in time, we went with a known fix and ordered the Ford Racing "Carbon Clutch" rebuild kit - M-4700-C. This is one of two kits that FRPP still offers for the 8.8" TractionLok and the "C" version comes with upgraded carbon fricton material and different steel plates for a whopping $108. The non-carbon kit (M-4700-B) retails for for $70 and even comes with the friction modifier, but the Carbon kit is the one to use for best performance. It's even SCCA F-Stock legal, thanks to a TSB from Ford - we installed one of these in a 2007 Mustang Shelby for FStock class autocrossing a month ago.



As soon as they pulled the old diff apart, it was obvious that the clutches were done since the friction material was coming apart. The new discs were soaked in the fluid, then the discs and steel plates went in and the rear end was topped off with fresh 75W140 gear oil and friction modifier. OMFG that stuff stinks something fierce! The shop reeked of gear oil smell for 2 days.



We didn't have time to do much testing on the rebuilt diff, other than a few laps around the parking lot. "Feels good!" I said and onto the trailer it went.

Please check back tomorrow below for Part 2, where I talk about how all of this worked at the TWS Time Trial event...

Thanks,

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Project Update for May 2, 2012 - Part 2: This entry will cover the NASA Time Trial race we attended in the Mustang test mule last weekend. The lap times were somewhat mediocre for most of my sessions with the Mustang only making about a dozen hot laps all day, but we had fun and learned a lot. This entry is sort of long, just so I can keep track of all of my thoughts for a later date. If that unimpressive opening hasn't put you to sleep, then keep reading.


Couldn't find a decent track map of TWS so I made this from a satellite image - click to enlarge

We had planned on only running one day for the NASA 3-day weekend, since we had just done a long and tiring 3-day race weekend the week before and had other plans on Sunday (a non-race event, for once). Originally we planned on bringing two cars: our TTD E46 (for Amy to race - and this car is finally ready for TT use again, after a long hiatus from NASA events!) and the Mustang (for me to race), which was now bumped up to TTS class. This was due to the massive tire, power and aero changes since our last TTB event in 2011. With our little 36' enclosed trailer we cannot fit 2 cars inside, but I found an open trailer to borrow - just not a second truck. We could rent one, then drive 2 trucks and two trailers down... twice the fuel and driving? Nah. Amy has never run the TWS 2.9 mile course and had only run the smaller infield-only TWS course back in 1994? I told her about the speeds she'd see on the 2.9 and she decided to pass on TWS in the E46 and just go along to help drive the trailer and take pictures. So I got a track helper and towing buddy, yay!

Vorshlag picture and video gallery: http://vorshlag.smugmug.com/Racing-E...SA-TWS-042812/

It's now 4 days after the event and they still don't have results posted yet (color me shocked, heh). I can only go by the printed results sheet from session 2 on Saturday that I "liberated" during the event (it was an extra!). I have learned over the years that if you want to ever see class results for a NASA Texas event, you have to take matters into your own hands. For a group that runs such an awesome event, maintains schedule, and has excellent safety, they have crap results. Even after they are eventually posted (via the "MyLaps" site), you won't see all of the info that these results sheets show. I've bemoaned the poor NASA Texas race results before and will continue to do so until it improves, as a sort of Public Service Announcement.

Sat, TT, Session 2 Results: http://vorshlag.smugmug.com/Racing-E...12-ses2-X2.jpg

Amy and I arrived at the track late Friday (after 9 pm), due to leaving late and hitting 5 o'clock traffic in Dallas. I said 'hi' to a few folks, unhooked the trailer, then headed to dinner and the hotel. Saturday morning we got to the track at 7, unloaded the car and had it annual tech'd. Afterwards, I went to an instructor meeting at 7:30, the TT meeting at 8, and HPDE meeting right after. Since I was only there for Saturday, I got switched to a Saturday-only HPDE1 student, who also had a 2011 Mustang GT. Luckily she knew the track well, but not having run with NASA before it was an automatic DE1 placement (I signed her off to HPDE2 after 3 sessions).



Our Mustang had several changes since our last NASA outing, where we ran it in TTB. This time we had the new stupid-high-mega-wing, the LS splitter, new 18x11/18x12 wheels and still-somewhat-fresh 315mm Kumho V710s (that we ran at the ProSolo). It was so far past TTB prep that it moved all the way past TTA and into TTS - which is the first of the "power-to-weight" classes in TT, so at least we don't have to nit-pick every point per modification. There were some other Mustangs in TTS already, including David Armstrong's well prepped Boss302 on AST 5200s and a real Boss302-S race car.

Relearning Texas World Speedway

After seeing the track briefly while riding along with my HPDE student in her first session, I quickly realized that I had forgotten all of my visual cues and lines from past outings at this track. Grass had overgrown the curbing, the surface was very different from my last time on track, and I had forgotten everything. Thinking back I really haven't run this track much in almost... 20 years? I co-drove the E36 Alpha car for 2 sessions with Hanchey back in 2008, where we got check out rides to get our TT Comp licenses. Before that I had run it a bit in the mid-1990s, but it was a completely different track configuration where Turn 3 joined with Turn 10. In the late 1980s/early 1990s I had run this 2.9 mile layout while still in college, but man... that was a LONG time ago.


Allan and Ken's tandem E46 M3's were both fast, equipped with AST 4200s + Vorshlag parts and prep work

I knew it would take a bit to blow out 20+ years of cobwebs, so I gridded up behind AI speed demon Mike, from AST/Moton. HE knew this track very well so I figured I'd follow him for a few laps and... WHOA! He took off like a freagin man on fire, right on the warm up lap. So I got some heat in the tires, look back, and the E46M3 TTB Terror Twins KenO and Allan Page are right on my bumper. OK, OK, you guys go around... I'll follow them for... dang, mirror has more cars behind me, etc. Just trying to get my bearings but these TT guys are ready to RACE, like right NOW. I spent the first few laps of this session letting people go around me as a rolling roadblock and didn't get a single lap in unobstructed from the front or back. By lap 4 the car felt really loose on slow speed turns, and I smelled gear oil smoke and had a traction control fault, so I brought it in. I felt like an idiot out there, fumbling around trying to find some sort of visual cues on each corner. Ran an abysmal 2:01 best lap, which gridded me way back in the pack for session 2. Great.


Here I am - the rolling roadblock, holding up the field

The first TT session was at 8:40 am and the sky was overcast, so the track was still stone cold. Turn 3 had no grip due to a Spec Miata that popped a motor there on the Friday 3 hour enduro, and it never felt good all day. Turn 10 (the carousel) was slippery as always. But the rest of the corners was mostly just... my crappy driving and generally terrible memory. Also, with completely new track set-ups and radical parts changes you inevitably have teething problems, and I quickly found one.

As I pulled into the paddock, the car reeked of gear oil. I jacked the rear end of the car up and it had gear oil all over the right axle tube, fuel tank, right muffler, and right rear tire. A-ha, that's why it felt squirrely and was smoking! We had just rebuilt the TractionLok the day before and the old "loop of hose" that was attached to the OEM axle vent wasn't enough to keep oil from filling the hose and coming out, especially after just topping off the 75W140 the day before and running on the insanely steep banking at TWS. Oil + tires = no grip! Talked to other racers with stick axle cars who had seen similar problems before - "keep driving it and it'll burn off enough fluid eventually!"

Luckily the Session 1 times for TT don't count for anything other than grid spots in Session 2, so I cleaned off the mess as best as I could - managing to get most of the gear oil on me. Ahh, gear oil - the world's worst perfume. I had to burn that shirt. Then I hopped in my student's car for her 2nd session and afterwards I went out in the Mustang again in TT session 2. This time I was gridded 16th out of 28 cars when I went out, and behind cars I know and was faster than before when we ran in TTB on street tires. Ugh, this session was going to be some work. I got some heat in the tires on the out lap and the car was responding better to the increased track heat (10:45 am) and a little better driving. I quickly caught and passed several cars gridded ahead of me (hence faster than me in session 1). My in-car video, a compilation of a few "offs" from other cars + my best lap (lap 4) is shown below.


Video from Session 2

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That lap # 4 in the video above was a 1:56 lap, after which I noted yet another AdvanceTrac fault and came in to reset it and check for more diff oil spewage on the rear tires. A sub-2 min lap was more in-line with what the car should do but still off the pace a bit. For example, KenO ran a 1:55.8 in a TTB car and Allan Page was right behind him, so of course I should have driven faster. David Armstrong managed a 1:53 in a TTS car, so I was still 3 seconds off the TTS pace (which is an eternity). Yes, there are several driving mistakes I made on that lap - but with this being about my 8th lap on this track in 4 years, with an all new aero package and all new grip levels, I wasn't too worried. Excuses... I gots em!

Since that session was cut short, I came in and re-checked the diff leakage - and it was once again wet with fresh diff fluid on the undercarriage and on the RR tire. Crap! I jacked it up, mopped up the mess again, then went out with my student once more. There were several after-session HPDE meetings and instructor/TT meetings and I talked to like 50 people I hadn't seen in forever, so it was a busy day. I wanted to show my student some changes to her driving line, so I took her out for a couple of 8/10ths laps in session 3 (taking a passenger is allowed in TT but it DSQs your times in that session, as does an "off" if you are solo) and we made it two laps before seeing more faults. With the student I ran a 1:59 lap and was hardly pushing it at all - I was working on my braking and line into and through T1 (which is tricky coming off the banking at 140-150 mph) and my apex kept getting closer to where it should have been into T4 and the T7-T9 complex... With more laps under my belt, I quickly realized where I was butchering all sorts of corners earlier. It just took a while to come back to me.


Right: Mike's AI car was putting down 1:55 laps and he walked away from both Saturday AI/CMC races

Most of the TT guys went slower in Sessions 3 (and did again in 4), as the ambient temps climbed up to 90°F, so I wasn't going to find a stellar lap in session 4. By then I was also tired of the continuous computer faults and worried about more oil hitting the back tire (although I didn't see a drop under the car after session 3 - I guess it burned/burped off enough excess), so I let the car cool off, and talked to Amy. I was doing good to not have put a tire in the dirt in the 3 truncated sessions so far, given the oil on the rear tire, so I counted my lucky stars and we called it a day. We had a 4 hour tow back to north Dallas ahead of us and Amy was already bored after taking 200 pics, but not racing in TT herself. We packed up after my student was done (and checked out for solo in HPDE2) and hit the road right as the TT group was going out for their 4th and final session of the day.

Overall it this day at the track was a LOT of fun, and we learned a good bit about the new set-up (its faster than me on this track!). I had forgotten how much more stressful it is to run on the big banked turns at 140+ mph compared to the tighter, more technical, and slower road courses we run elsewhere in Texas - such as ECR, MSR-C, MSR-H, Harris Hill, TMS infield, and GrandSport Speedway. Still, we have VIR in July to contend with so I need to bring my game up at higher speed events pretty darned quick!

How Were the Upgrades?

As I stated in yesterday's update, the extra front brake cooling really worked. The brake ducts we added + the Porterfield R4 track pads Costas and others suggested (thanks!) were spot on. I only caught myself giving it a bit more brake pedal on one lap (lap 4 in session 2 - I'm talking to the damn video camera about it! I don't even know I'm doing this), after a mad dash into T1 at high speed (braking from 140+ to around 70-80). The rebuilt TractionLok just flat worked, even through the tighter/twisty turns like T3 & T4, T7-9, and the other tight turns before the front straight (T11-15). Even so, this car is still getting a better diff before the next big autocross (Spring Nationals) to deal with the tighter turns we see in autocrossing.



Looking at the front camber it seems... barely enough (-3.8°). Gonna add more soon

I never felt the urge to adjust the rear wing angle of attack. We had it trimmed out at the lowest setting and it felt... very balanced. According to the CFD data it can generate 600 pounds at the highest AOA, but we had it trimmed down to much lower settings and it felt fine. This was hardly a proper aero test with barely a dozen hot laps run all day, so I will play with this the next time I have more track time. I really want to get a flat "2D" wing on there before we do any real aero test work though. For now... the wing seems to work, and other than the oil on the rear tires, the car worked fine (like in session 3 when it stopped puking on the rear tire). We had bumped up rear spring rate from 175# to 200# (that's the only stiffer spring we had on hand in this diameter and length).

What should the car have run? Well a 1:53 would have been more in line what several people feel the car was capable of - with a better driver. I tend to agree with them, and I know I was way off the pace for what the car should have been doing. If we had run Sunday and found some cahones ... maybe. I need more seat time at TWS to reach this car's potential, for sure. Put me at a track that I know better and I can get closer to the potential, I think.

Other Updates & Upcoming Events

I just talked to the folks at APR and there is indeed going to be a straight horizontal "2D" carbon fiber airfoil in 61", 67", and 70" widths, with an optional dual element 2D style wing. The pricing will be "more competitive" than the 3D wing (its probably easier to make) and these should be out sometime this year. I told them I want a 70" wide unit and that's what we'll perfect our wing design to use. Until then we'll keep this 3D wing on there with the current uprights for track events, goofy as it looks.

There are several events in May that we plan on taking the Mustang. Going to run the NASA TT event May 19th at Grandsport Speedway, located way south of Houston. This is an unusual "HPDE and TT only" NASA event, which makes sense on this smallish track. This will be the first time NASA has ever run there, so all TT class winners will set new track records. Hopefully I can find a little bit more speed (in the car and in myself!) and tighten the gap to the top TTS finishers. This is a tight little 1.3 mi track that I have run before (more recently than 20 years ago) so power and slippery aerodynamics (ie: Corvettes) won't be as big of a factor as it was at TWS. On May 20th there is another Texas Region SCCA autocross at TMS I'm going to attend, so that makes for a busy double-header weekend with a few hundred miles of towing in between. I plan to run both of those events on the Kumhos, so at least it won't take much prep changes between Saturday and Sunday.

Memorial Day weekend has a massive "Spring Nationals" SCCA Solo double-header weekend in Lincoln, NE. Friday and Saturday is the ProSolo while Sunday and Monday is a National Tour. The ESP class is already chock full of good entrants. We have to go to this one to see where we are, and we need to be on fresh Hoosier A6's by then, hopefully with some extra power and a real diff.

We have to have the updated programming for the steering rack before any of these events, as I'm tired of seeing the same nagging computer errors and steering wheel feedback. Now that we're confident this programming is SCCA legal I'm going to get it done. We will be pulling the rack out of the car this week to send it to Ford Racing, as the replacement $1000+ 2011 GT racks is on national back-order. Apparently there's a 3-4 month build date window where all of the early 2011 GTs are having similar "issues". Ford is not doing a recall yet, but probably will "eventually". If you are seeing this type of steering shudder CALL YOUR FORD DEALER and demand a recall/TSB. If you don't want to wait, call Ford Racing in Detroit. All of the World Challenge and GRAND AM Mustang's run this update programming, and it supposedly fixes the steering feedback loop shudder and related Traction Control system faults. We'll find out and report back soon!

Cheers,

[Fair]

Project Update for May 18, 2012: We've made some additional changes to the car and had an autocross since my last update after the TWS NASA Time Trial event. After we received the new Vorshlag camber-caster plates and the re-valved Moton Club Sports, we scheduled time to install all of it onto the Mustang, then went looking for an event to test the new set-up at...

New Parts for our Mustang

The newly revised Vorshlag camber-caster plates were finally complete at the electro-plater a week ago and after we fulfilled customer back-orders, we built a set for our own S197 Mustang (shown below).



I was looking forward to the much easier camber adjustment these new plates would allow us. Plus we could potentially use the added range of positive caster, if we felt the need to add more than the +6.4° the car came with stock. The next bits that were finally ready to install were the Moton Club Sport 2-way coilover shocks. The AST 4150 prototype coilovers had served us very well the past year, but we were really pushing the envelope on grip levels in an S197 Mustang with 315mm R compounds at all 4 corners. Adding compression adjustment would be a tuning improvement and the additional fluid from the remote reservoirs would also help stabilize performance on longer track stints.



These Motons had been purchased a while ago and were a bit unique in that they were built before the Moton acquisition and were an old design. The front struts had lower mounting flanges with massively slotted upper holes, which are not part of the current Moton S197 spec. I'm not a fan of slotted mounting holes as it reduces wheel/to-strut clearance and can allow the lower setting to slip under hard cornering. So after test fitting the front struts and new VM plates to check the available camber range (more camber travel than before), Ryan filled in the slotted holes.



There was enough range in the camber plates and strut tower opening that we could actually use the stock sized upper strut mounting hole on the Moton struts, so the slot was filled with a steel "slug", fully welded, then ground smooth (on all four slotted holes). Again, this isn't something that needs to be performed on this S197 strut any longer. Moton-USA also installed custom valving and their new DDP digressive pistons for some extra rebound force at low speeds.


Click to see the full sized dyno plots for these. Left = front struts, right = rear shocks

Well, if you know much about dyno plots, those actually make a LOT of extra rebound force at low shaft speeds! That area from 0-2 in/sec shaft velocity is crucial in both autocross & track use, and being able to alter those numbers to this extent with the turn of a knob makes for better racing performance and a much more comfortable street ride after rebound is turned down. These DDP pistons are evil - we had them in the AST 4150s on this car before and loved them! Now with these double adjustables we can adjust low speed compression as well, for more tuning ability.

Vorshlag's Step-By-Step Moton S197 Install Gallery - http://vorshlag.smugmug.com/Instruct...stall-Mustang/



Installing the Motons and their accompanying remote reservoirs, then aligning and corner balancing the Mustang, took the better part of ten hours. About two hours of that was the fabrication work Ryan had to do on the slots, but that's still eight solid hours of install and set-up work. These were far from a "just take it out of the box and bolt them on" affair - just like all remote reservoir shocks, which add their own mounting complications.



The front strut installation was relatively straightforward and didn't require any cutting or surgery since the hoses were long enough to route under the frame rail next to the brake hard lines. This allowed the remotes to mount right up into the engine bay with no fuss. The struts were bolted up to the Vorshlag plates with stiffer 550 #/in Hyperco springs (up from 450 #/in) and went in fairly quickly. Of course we fabricated custom front and rear reservoir mounts, like we've done on some other installs here recently. These brackets bolt to existing factory holes and keep the remote reservoirs away from engine heat, but keep the compression knobs accessible.



The rear shock on this Moton kit is a standard for race cars - an "eye-to-eye" shock. That means it has a spherical eye mount on both ends, unlike the stock shock which used an eye lower and pin upper mount. To make it fit the S197 chassis without modifying the upper mounting hole, we found some "eye-to-pin" adapter mounts made for the S197 from Ford Racing. These mounts bolt to the upper eye mount, along with some bushing adapters from Moton, and then slide into the hole in the stock sheet metal. The lower eye mount also has bushing adapters (included in the Moton kit) to fit the stock lower hole.

We had several options for routing and mounting the rear shocks' reservoirs. I wanted them away from exhaust heat/rocks/rain/debris and since there is no spare tire with this car, I decided we should mount them in the spare tire well inside the trunk. We routed the hoses through sheet metal, so there was some cutting involved with the rear reservoir pass-through hole. This is the first cutting or drilling we've had to do to the chassis, so we took great care (Amy does not want us cutting or drilling on her street car!). We like using these 2-piece "Seals-It" brand grommets for reservoir mounting. They can be unbolted and the entire reservoir can pass through the hole in the chassis when removing the shocks, without having to discharge the nitrogen and remove a hose. Even with "quick connects" (a very costly option) you still have to discharge the nitrogen in a monotube shock with remotes. If installed the way we did them, you don't ever have to discharge the pressure and potentially lose fluid when removing the rear shocks. We tested the fit of these seals at the autocross in the rain and not a drop made it into the trunk. Perfection.

Other New Bits Coming?

While we were doing this Moton CS install, AST Holland was posting Facebook pics of the new and improved but much-delayed AST 4150 coilover strut housing for the S197 Mustang. They let the cat out of the bag (or the wooden shoe out of the closet?), so I am going to repost at least one picture. Now we could be seeing the first 4150 test sets for this S197 chassis, the BMW E36, BMW E46, and the Subaru BRZ at Vorshlag before too long. We will be contacting local Dallas/Ft. Worth testers (so we can install them here, to verify that everything fits perfectly) for all of these cars when we have the first 4150 shocks on hand. Once we've verified these fitments, AST-USA can have AST Holland proceed with full scale production. Don't hold me to any dates, because so far I've been failing miserably on ETAs for these shock models.



Speaking of overshot ETAs on new products, we finally have a gaggle of D-Force 18x10's for the S197 chassis now in hand. There have been a dozen sets sold and shipped so far and I've been seeing pictures on social networks of them on cars - very cool. We only have a few Flat Black sets and plenty of Silver sets in stock - give us a buzz if you are interested. They were 19.5 lbs exactly when weighed here, just as predicted.

continued below

[Fair]

continued from above

Autocross Test - NTAXS Event #3

With the Moton Club Sports and new camber-caster plates finally on the car, it was time to test them out before switching to Hoosiers the following week. With the Moton install completed over Thursday and Friday (May 10th and 11th), the car was loaded onto a trailer and Amy and I autocrossed it on the 12th. This NTAXS event was a non-SCCA club that is run by the SCCA regulars, with the same course designers we see at Texas Region SCCA events. They used the same sealed asphalt "TMS Bus Lot" site we test at often. They do have twice as many runs in a given day (4 morning + 4 afternoon runs), so it's great event for testing.

• Results: http://www.vorshlag.com/documents/NT...results.htm#3R
• Photo and Video Gallery: http://vorshlag.smugmug.com/Racing-E...XS-TMS-051212/

The day started off with a freak rain storm that wasn't on any forecast or radar and caught everyone off guard. Nobody was set-up for wet conditions, including the event organizers, and a small percentage of people left the event after getting soaked during the course walk-through. They delayed the start by 15 minutes and got all of the equipment dried out, while attendees dried off and made adjustments for the rain. The Mustang was still running on the 18x11/18x12 Forgestars mounted with tread-less 315/35/18 Kumho V710s, so we knew we'd be slipping and sliding until it dried out - if it dried out.



Luckily, we worked the first heat when it was totally soaked and continued to sprinkle a bit more, but when we made our four morning runs in the second heat it was beginning to dry. It was so wet somebody still managed to take out a timer at the finish. This club is a bit more informal than SCCA and you can grid up in paddock on your own, with the folks more experienced with this club wisely waiting until the very end of heat 2 to make their runs. Then they take 7-8 cars to the starting area at a time to make all four runs back to back. I wasn't so smart and was one of the first cars to the line, driving in slopping wet conditions. And yes, we left the wing on the rear since this wasn't an SCCA event.

It was wet as can be when I ran and my 4 runs and they were all terribly slow, including a spin on my first run. I have video from these runs, but they aren't worth watching. Amy was smarter and ran a bit later in this heat when it was quite a bit drier - and she was 5 seconds faster than me in our morning runs. The people running at the end of heat 2 were getting an even drier course and were that much faster than her.

Thankfully it was completely dry in the afternoon heats 3 and 4, and we all got some better runs in. Unfortunately Amy left the vidcam on for 2 hours after her final morning run and killed the battery, so all we have are videos from the morning session. In the video below I was riding with Amy on her 4th morning run, and continually admonishing her to PUSH the car harder. She wasn't being aggressive enough with the throttle, but during my morning ride-along she managed to drop another 1.5 seconds.


In-car video on Amy's morning run #4 (she was 7 seconds quicker in the afternoon!)

The afternoon runs were a bit better, but I didn't learn from the morning sessions and ran in the first sub-group again. The course was dry, but now it was dirty from all of the mud that washed onto the course from the nearby construction. There was about one third of the course that was covered in dirt when I ran, which had markedly less grip. Amy wised up and waited until the end of heat 4 to make her runs and was the last car on course at the end of the day. She made her fastest run on her last, beating the entire 3R class, and set the 2nd fastest time of the day. Nice! The only car quicker was a BSP-prepped E46 M3 driven by KenO, who is one AST/Vorshlag's super-testers.


Terry (at left) was sliding around but Amy (right) was doing nothin' but winning.

In the dry afternoon runs Amy punished me by 1.3 seconds, so I was mired back in 4th place behind some SCCA regulars in SS Corvettes. But my placing didn't matter much to me - I was excited that the car was doing this well on a completely untested, new set of Motons. Getting skirted happens when your wife is this fast, and I'm used to it.

Observations from this Event

What good is going to an individual event if you don't learn something? At this NTAXS event we learned a lot about the new parts we had installed (Motons, spring rates), re-learned to never come to an event without proper rain tires (even the 275 Bridgestone RE11s would have been better on my first 4 runs than the bald R compounds), and I learned that if the club has "optional gridding" that you wait for the optimum time to make your runs! I also found out that if I over-pushed the Kumhos on 4 back-to-back runs that the tires can overheat and get very greasy. Again, watching more experienced folks that run with this club, they were pulling out of line to spray their tires with water to cool them off, something I needed to do. Oh well - live and learn.



One thing we could see from the spring rate and shock change was the front brake dive was less than before, as was front bodyroll. The extra 100 #/in front spring rate and increased compression and rebound settings we used (in the afternoon) helped there (ran the compression full soft int he wet session). Also, the new camber setting of -4.0° up front seems to be edging in to the proper amount, after looking at high resolution pictures of the outside front tire under cornering. As you know, a radial tire works best with a little bit of negative camber when fully loaded, so this picture is almost perfect. A tick more and I think we're there. I will keep an eye out at the next event (a week later at the same event site), when we've switched to fresh Hoosiers and see if it ever gets into to positive camber. If it does, we will add more static negative.



We've always run a lot of negative camber on this car, as learned from testing. Even with street tires it responded best with over -3.3° of front camber. Some folks like to argue that S197 Mustang's don't need this much camber, but I disagree. Again - as a camber plate designer, this is one of the only things I really know well. Pyrometer data, pictures showing the tire loaded, and tire wear trump theory and internet wisdom, in my book. The S197 is not magical - it is just another strut car to me. And like many other McStrut cars we've raced and designed suspension parts for, this one needs more static camber the higher the grip levels go. With 315 R compounds up front we're seeing more grip than a GRAND AM or World Challenge race car, and we keep adding more negative camber than those race teams run to keep this big tire as close to vertical when loaded.



Another of the tests we did at this event was to look for any indicator of downforce at speed. I manged to snap the picture above when Amy was hitting over 60 mph on course and as you can see, the trunk was deflecting a good bit even at a low AOA on the rear wing (we can always make a LOT more rear downforce with a wing than a splitter can hope to match up front). We knew the culprit - the factory "trunk bumpers". These little rubber bushings are what set the height of the trunk at the rear when it is latched, and we knew from the TWS event they were deforming at speed.

We had a solution in mind and the day after this NTAXS event Ryan made up a replacement set of bushings from some round Nylon stock I had purchased the week before. Chucked them up in the lathe and made a drilled and tapped hole on the underside to mount them to the mounting plate. After tweaking the length to get the trunk height set properly, they were bolted down and now we have no more deflection there. The wing uprights sit right near the edge of the trunk lid (which has structure underneath) and this should now be a more firm mount, and still stay within the SCCA Street Prepared ruleset (normally you build bracing from the trunk floor to the wing mounts, but that's a no-no for ESP class).

My next update will go over the next week's prep, which included a change to Hoosiers and a gamble on rear tire size choice... using the largest A6 tire that Hoosier makes. I rolled the dice, so check back to see if that choice paid off!

Thanks,