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

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Project Update for April 27, 2012 - Part 1: A lot has happened in the past week and a half so this might be a long-ish update. I will break it into two parts - ESP preparation work from a week ago to get the Mustang ready for the ProSolo last weekend. Part 2 will cover the ProSolo results and a list of new issues that cropped up. I posted some of these pictures below on the Vorshlag Facebook page over a week ago - I put previews of upcoming thread/blog posts on FB first, so follow us there!

ESP Rear Spoiler



In my last "quick update" from 4/13/12, I showed a picture of some rear spoiler bracket and element parts we got from a circle track supplier, as well as some machined washers and struts. We didn't use that bracket or the spoiler elements - they were too tall for use on the Mustang trunk. The manufacturer's website didn't have any dimensions so we took a gamble and it didn't pan out. Oh well, the rear support struts and the machined washers were useful. Instead, we made an all new rear spoiler from scratch using some 1/4" thick plexiglass we bought locally and some aluminum sheet we had at the shop. If you haven't been following along, SCCA Street Prepared rules come from pre-historic times and still do not allow a rear wing, only a rear spoiler. It can be as wide as the widest part of the car (excluding side mirrors) and can extend 10" away from the body in any direction.



This spoiler was built to fit a spare red Mustang trunk we located a couple of weeks ago - one we weren't afraid to drill into for the ESP-legal rear spoiler or for the upcoming TTS/AI legal rear wing. The trunk was set up on a bench at the same angle as it sits on the car, so it could be built while it was off the car. Some of the scrap aluminum we had at the time was anodized, which made it a royal b!tch and a half to weld to, so it wasn't the artwork-like welds you typically see coming out of our fab shop. No worries - it was strong, worked great at the ProSolo, and was built to an insane deadline in only a day and a half. It looks pretty good for a prototype made out of scrap, but the next one we make will use some virgin aluminum.

The spoiler bracket bolts to the trunk using four "nutserts" installed into the trunk metal with a special rivet gun. The four points are shown above, where the black lower strut supports are placed. This aluminum spoiler bracket extends past the trunk and covers the width of the rear of the car, to about the edge of the sheetmetal. It could be another 4" wider per side (to extend out to the rear fender lips), but we felt this was wide enough to make plenty of rear downforce to match the Leguna Seca front splitter. The lower sections where it overhangs the rear fenders was later trimmed out so it wouldn't rub the paint and some Xpel paint protection film was added to the fenders "just in case".



Once Ryan had the bracket laid out and tacked up, he and the guys made a cardboard template for the spoiler element itself. It is 10" tall and laid back at about a 65° angle. The next step was transferring the template to the plexiglass sheet and carefully cutting that out. There's a trick to cutting plastic with a saw - too fast and it melts back together behind the blade, too slow and it won't cut cleanly. My cheap "one speed" jigsaw (he had to pulse it on-off-on-off) was a nightmare to work with and it eventually burned up the motor after about 40" of cutting. A trip to Lowe's produced a variable speed Bosch jigsaw that worked like a charm and cut the 1/4" plexiglass sheet like butter. Drilling holes in plastic also takes ... patience. They managed to get everything cut and drilled without cracking the plexiglass. The machined washers are placed on both sides of all bolted joints in the plexi and held up after a weekend of ~30 autocross runs.



The plexiglass spoiler element was simply bolted in place - it was flexible enough that it did not need to be heated and bent to follow the curvature of the trunk or the two "bends" at the edges, where it meets the rear fenders. The struts hold the element well enough, but we might go back and mount two tension rods to the widest points of the spoiler, with the rods attaching at the forward edge of the trunk. A little testing (and video aimed at the spoiler at speed) will tell us if that is needed.



The rear spoiler was finished up minutes before the car was loaded into the trailer Thursday night and it definitely got a lot of looks at the ProSolo. This was the first time we'd made a rear spoiler here at Vorshlag and we learned a lot. The guys were very careful during mock-up and construction (lots of painters tape used!), there were only 4 holes drilled for this part and not a single scratch was added elsewhere in the paint. Good stuff.

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Bigger Wheels



Another new ESP modification we added were 315/35/18 Kumho V710 R compound tires mounted to Forgestar F14 wheels in 18x11" (front) and 18x12" (rear) sizes. We had been eying Forgestar (a division of iForged) for a while now and decided to give these wheels a try for larger widths like these. We called the guys in California there and they knew about Vorshlag and our Mustang, and our propensity for using big wheels. After speaking with them for a bit, they wanted us to become a dealer. So now we are a Forgestar dealer - if you see anything in their catalog you like, we sell at their MAP price.



They did a super-rush build and made these wheels (from flow-formed/semi-forged blanks they keep in stock) in an extremely short time frame for us. These were machined to our 5x114.3 bolt pattern, hub bore, and backspacing. We have done a ton of testing to see how far we can push wheel widths on this car and we sent them our specs... and no, I'm not sharing those with you. If you want wheels that fit like these, call us and we'll be glad to sell you a set. It's the only piece of the puzzle we can hold onto, and we've spent a lot of time and money learning these wheel specs on this chassis.



Even being careful as we measured for backspacing, then calculated offset, we still missed the numbers a hair in the rear and had to add a small spacer. So ... that meant longer wheel studs in the rear were needed. AJ pulled the rear axles out and used our new 30 ton press to remove and install the studs. Now we have ARP long studs on both front and rear axles (and the front/rear studs are different spline diameters and part numbers, so don't just order 20 of one part). All of this final wheel fitting was happening as the spoiler was being built and other race prep work was being performed, all while we had customer cars coming for service and orders were being built and flying out the door. It was a hectic week to say the least.



That final rear spacer tweak got us to this fitment with 11's in the front and 12's in the rear. The front is too tight for 12's under stock contours, hence the 11's, but the rear has the room for a race application (I wouldn't recommend either of the above for a pure street car). I'm very happy with the wheels, which have insane amounts of front brake caliper clearance and a pretty low weight. I will talk more about Forgestar costs and weights in a future post - after we do some more testing on them. They worked flawlessly at the ProSolo and next we'll see how well they do at a banked/high speed track tomorrow - with a NASA time trial at Texas World Speedway.

Delays and Improvements

Now here is the part I hate. Many of you reading these posts have pre-purchased or put your "name in line" for some products we've helped develop on this very Mustang, including D-Force 18x10" wheels and AST 4150 shocks. Both of those products, which Vorshlag ordered in large quantities in 2011, are over 3 months late being built and delivered to us. We have already refunded many of our pre-purchase wheel customers due to the continuous delays. AST stopped giving me dates and we received news this week that the D-Force shipment was delayed yet again. That's after we were told that the container was already here in the USA at port! Now they're saying May 14th. I'm pulling my hair out in chunks! I just want to apologize here to anyone waiting on parts, and I did so publicly in this blog post yesterday.



In that blog post I also talk about several improvements we've made to the Vorshlag branded products that we can better control deliveries on, such as several coating and plating upgrades we've made to various parts in our Vorshlag camber plates. Also, we finally received the machined and laser cut parts for our all-new S197 Mustang camber plates, which went to the electro-plater yesterday. I need these for my own Mustang and we have lots of patient customers waiting for these unique camber plates, so that was exciting. These should finally start shipping next week. So that's some good news to go with the bad.

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Project Update for April 27, 2012 - Part 2: So the update above covered last week's preparation and this update will cover the ProSolo event. We bombed out to the 2012 SCCA ProSolo which was being held at a "local" site on Friday morning - Mineral Wells, TX, only 2 hours away. We arrived at 1 pm so we could help with registration or whatever else the event co-chairmen (Brad and Jen Maxcy) needed. Since we were a sponsor to the Texas Region SCCA for this event (we put up $ for Friday night's welcome party), we got to set-up our trailer and vendor table near the Lincoln Welcome Center trailer/Tech line and next to the giant "shade tent" that was being set-up late Friday. Only had to move our trailer 3 times to make room for everything there, heh. Weather was PERFECT after a brief rain shower Friday at noon, with temps in the 60s-70s all weekend and sunny skies.



Once we got the Mustang unloaded, Amy went to work getting people to sign waivers at the front gate while I got the car prepared for tech. Several sponsor decals later the car passed tech and I got in line for practice starts on the tree. A ProSolo is an unusual autocross format where there are two mirror image courses run simultaneously with a drag race style "Christmas tree" start. You reaction time at the tree does factor into your course times, so "cutting a good light" is critical. The slower your reaction time, the slower your lap time is because the timer starts as soon as the light goes green, not when you cross the start beam like in most autocross events. It's not uncommon to lose 1 or more tenths of a second at the tree, so you strive to cut perfect .500 lights (or at least lights in the .5xx-.6xx range).



I took four practice starts on the new tires and had some pretty blah 60 foot times (2.2-2.4 sec) and reaction times all over the place, but I had one .510 light (a .500 is perfect, but anything .499 or quicker is a red light and you get no time... kind of like a DNF). This was after lowering tire pressures a good bit. Since our car was the only one at the event (160 entrants) on Kumho R compounds, I didn't have much good intel on proper tire pressures to run. I had raced on V710s in the past and remembered that after testing we ran pressures really low... like sub 30 psi, down to 25 even. ESP guru Mark Madderash agreed and said he remembered pressures being that low on this tire, but not many people have run them competitively in Solo in 5+ years.

Vorshlag ProSolo Picture and Video Gallery: http://vorshlag.smugmug.com/Racing-E...roSolo-042012/

Practice time was running out so I went and grabbed Amy so she could take some practice starts, while we continued to play with tire pressures. She was having a helluva time with the tree and kept red lighting, so I bought her more tickets. After 10 practice starts she had the tree down and was popping off some mid-.5xx lights (she has cut perfect .500 lights at Pros before), but still struggling with sixty foot times (2.4-2.8 sec). We talked through the launch, which was quickest for me at 1800 rpm. I guess I have a slight advantage over her with literally thousands of dragstrip starts on R compound and street tires (a bunch of us used to drag race our street/autocross Mustangs in college, using our autocross tires). So I can't give her too much grief for that. I wasn't exactly setting record sixty foot times myself (my best all weekend was only a 2.20 - the best in ESP was a 2.0 seconds and Madderash cut 2.1-2.2).



Friday night we stayed out at the event site late, grilling burgers and hot dogs for 100+ hungry racers for the Welcome Party. I manned the grill for 4 hours and still smell like smoke a week later. I met a lot of new folks from out of state that came in for the Pro, a surprising number of which said that they follow this build thread and loved our little Mustang. Grilling on the open-top little portable grill we brought was no match for this hungry mob, so for Saturday night's party another Texas Region racer brought a 2nd grill, and together we grilled hundreds of chicken, brats, dogs and burgers until 10 pm. We killed 3 kegs of Shiner beer over the weekend, as usual.



Saturday morning many of us hurt - from eating too much food, from so much walking, from excessive beer intake - but we walked the courses one more time and then I headed out to work the course in the first heat. That was when Amy ran in L1 class, so she was on her own for set-up and had no help with tire pressures between runs. The tires crept up almost 10 psi over her 4 runs, so that didn't help. She looked timid behind the wheel, which I kind of expected from her hopping into our STX prepped car just with some big R compounds and a rear spoiler slapped on. It takes her a couple of events on an all-new setup to adjust, but I was hoping 12 runs this weekend would short cut that learning curve.



She was fighting some fast women drivers in L1 and managed to snag 2nd place after her first 4 morning runs (2 left, 2 right). She drove her fastest runs of the weekend that morning, but one of them had a cone penalty - which she cleaned up that afternoon, but she never matched her best raw times from that morning. I don't have a single picture of Amy driving as I was working course when she ran. Unfortunately this was a pattern I mimicked, also running my fastest runs of the weekend in my first Saturday morning race heat (which you can see below in this 6 minute video - my 2nd left and right side runs there were my quickest).


Click here for Terry's 4 runs in heat one

Amy conveyed the tire pressure creep, and since she worked 3rd heat and I ran 2nd, she could help me with tire pressures between runs all weekend (hugely helpful). My first run was on cold tires and was a total throw-away - learning the course, learning the new grip limits of Rs on this car, driving off line in the heavy klag that this site's surface turns to in short order, and having no heat in the tires. By my 2nd left side run the tires had some heat, and the Mustang felt like it was one rails. It had an AWFUL steady state push, but still managed to put down power very well and on the final straight after the giant sweeper it was hitting the rev limiter in 2nd, so that's in the ~75 mph range. Brakes worked well, but it did get into the "funky steering feedback loop" issues towards the end of my last run. I could also feel the limited slip differential starting to slip badly in my 3rd and 4th runs, which I note in the video if you listen.


Left: We have spring rate changes already underway to prevent this! Right: But it happens to others...

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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

continued below