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

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We eventually ended the day a session early due to "some exuberant driving by one individual" (it had to do with one of those "driving Flat Out" people), so they called the event to an end early at 3:30 PM and had a trophy presentation for Costas at our trailers - with 2 photographers, a videographer, and an on-camera interview. That was pretty cool. We then broke down Costas' massive covered paddock structure, loaded up both cars & trailers, and headed out by 5:30 pm... only to sit in Houston traffic for 3+ hours, just trying to make it 60 miles north to my friend's shop to retrieve the Toyos. After stopping for a quick bite hoping traffic would subside, we got there at 9:30 pm, but only 2 tires were delivered. Frantic calls to Matt here at Vorshlag and some investigations on his end showed that 4 tires had indeed delivered, but the genius FedEx driver dropped off 2 at some random address clear across Houston, and they were now closed. This is one more reason why Vorshlag NEVER SHIPS FEDEX.

So we ate a second dinner with our friend then blasted back across Houston with the trailer all the way to Baytown, arriving there around midnight, exhausted from a long day racing, standing in the sun, and Houston traffic.

March 18 - SCCA Test-N-Tune (Mustang)

Friday was the registration / set-up / test day for the National Tour weekend, which included a test session where you could buy laps for about $4 each. We had planned on doing DL-1 data logged runs on the Yokohama AD08s then running out and swapping the wheels to the Toyos, but the second 2 tires were still MIA by mid-day, as was our co-driver and his data logger. So we just made 5 runs each runs on the Yokohamas, testing tire pressures and shock settings, and getting a feel for the new brakes. It felt OK, and the brakes seemed to be a LOT better at this lower speed event. The practice lap times were close to the STX cars I could see, but who knows if they were making good runs on the times I saw? We had set up our vendor table, unpacked the car, and finished our laps by 3:30 pm, when we finally had word that FedEx had picked up and redelivered our missing two Toyo tires, so we dropped everything and raced 70 miles across town again to our friend's shop. We got there by 4:30, then drove to a Discount tire and paid an enormous amount of money to have 4 tires mounted and balanced (grumble... crooks!... grumble). Trying to stay ahead of Friday 5 pm traffic we somehow managed to get back all the way to Baytown by 6:30, and grabbed 5 gallons of 93 octane on the way. The car was on jack stands so we mounted the wheels with the fresh Toyos on them, put in the gasoline, and had the car ready to race by 6:45 pm. The past several hours of frantic driving at 85 mph in Houston traffic behind us.

The welcome party that Vorshlag had sponsored was going until 7 pm, and people were walking the course for tomorrow's event... we showed up in time but they had run out of food literally 5 minutes before we found the caterer. While we were looking all over the paddock for the food, the Saturday autocross course was also quickly taken down. Wait, what??? Well we found out that it was because there was a drag race event that night here at the HRP facility, like every Friday night, and they needed the parking lot for the racers starting to show up. Oh well, at least the concession stands were open and had hot burgers for sale. For cash only - and I had a whopping $2 on me. Amy had pocket change. WTF?! I had like $200 the day before, but somehow burned it all on transponder rentals and track food at Grandsport, and bags of ice and snacks along the way. Our luck was failing miserably today.

So we walked to the SCCA trailer and checked in for the National Tour event, drove the Mustang into town to scrub the new R1R tires in, and got some cash - and dinner. Went back out to HRP, found some friends and saw that several autocrossers were entering the Friday night drag racing...

Friday evening - Houston Raceway Park drag racing (Mustang)

For only another $20 cash we could run down the fastest dragstrip in the USA from now until midnight. Hell yes! I've run down this dragstrip hundreds of times in the past, and always seem to get my best times here (good surface + sea level track = fast). We still needed to scrub in these new 265/35/18 Toyo R1R tires anyway - with burnouts and launches! So I made two quick passes right off the highway drive in from town and cracked off two 12.96 second runs at 109+ mph, and on that 2nd pass I accidentally stayed on the rev limiter in 3rd gear for at least 2-3 tenths of a second. Oh damn, if I could clean up my shifts that would mean that a mid 12 second ET was in store?? I was also checking the on-board data logger I had just picked up - a new G-Tech Pro RR - against the track's clocks. It was spot-on at 60', 1/4 mile ETs and trap speeds. It has g meters and a GPS sensor, graphic LCD display, SD memory, windshield mount, with a built in lap timer, segment timer, and predictive lap timer. Neat little $300 gizmo I'll talk about more in future posts.



Amy wanted to make some passes so she got in and made some 13.5 second runs while me and a dozen of the SCCA entrants for the weekend taunted our fellow autocrossers trying to make 1/4 mile passes. Amy handed the keys back to me and I made 2 more runs, and I left the hood up between them as the staging lane started to get backed up - the locals don't really show up until after 9-10 pm. I cracked off a 13.1 second run and on my last run I was paired up with a 4th gen LS1 Firebird with some work done. I had pushed it to the line hood up for 15 minutes, letting the engine cool all the while. This helped and I got to the line with a nice cool motor. We lined up and the Firebird tree'd me, and in my haste to catch up I spun a little in 1st gear (2.1 sixty), but managed to nail my shifts and ran him down and passed him, and the clocks showed a 110.2 mph trap speed - the best ever in the car. Pretty good for 100% bone stock drivetrain! Gotta take the little victories where I can.

March 19-20 - SCCA Houston National Tour (Mustang)

Saturday and Sunday was the National Tour event, and Amy ran in STXL while Costas and I ran in STX. We started the day with overcast skies and cooler temps, which the Toyos supposedly favor. STX had 7 entrants and I started "off the pace", and in my 3 runs never really strung a good one together. Times were erratic and I ev3en DNF'd; I was driving very poorly. The event was all erratically paced slaloms (and "wall-oms") with one big turn around at the end of the lot, none of which were the strong suit for this car. The brakes at least worked better, but we struggled in the slaloms and the car pushed heavily in the turn-around, costing us time. Acceleration was just an exercise in wheelspin. Strangely we all got a 4th run, which was timed but not scored (a "fun run"), and it was then that I pulled my head out and put a good run together (proper slalom timing), running a solid 1.2 seconds faster and finally closer to the faster cars in STX class. Costas had similar trouble on his first 3, and also a fast 4th. Amy ran later in the day, after the sun was out, and ran times a tick quicker than both of to us, and also much faster in her 4th (unscored) run. The tires felt grippier than the AD08s, but with no data collected on the AD08s Friday we couldn't tell by how much.



Sunday was more of the same (almost identical course, with 2 small changes), but at least we drove better. All 3 of my runs were within a tenth of a second and they all felt a lot smoother - I didn't get so behind on the many slaloms. Costas had prior event he had to help run and couldn't race on Day 2. Amy was about 1 second off my times this day. She was running lower tire pressures than I recommended and it didn't help at all - I was working on course and couldn't help her when she ran, either.



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We learned several things at this event: Don't ship FedEx. Houston traffic sucks no matter the time of day. The Mustang isn't putting power down well. Or turning all that well. Slaloms are a mess. I put the seat to far back for my co-drivers. This car needs much more development. Oh well, this event offered up 28 more autocross runs between us - more testing never hurts with a new car, even if its losing badly at an SCCA National Tour.

• Results: http://www.scca.com/popup/raceresult...7098&file=1278
• Pictures: http://vorshlag.smugmug.com/Racing-E...n-Tour-031811/

So we bombed 300 miles back to Dallas and somehow logged 1000 miles for the weekend - meaning we drove just inside the Houston city limits for a solid 400 miles. Did I mention I hate Houston traffic? Monday we unloaded and prepared for yet another short week and a 3 day weekend of racing, this time at the SCCA ProSolo in Mineral Wells, TX. Before this event we slapped on the rear DTC-60 brake pads that arrived and bled the system with Motul 600 fluid. We had been testing an all new, non-inverted single adjustable rear shocks were found over at AST-USA that we wanted to run, and they had been working great the past week. With some custom machined bushings out back they fit the S197 very well - adding more bump travel. AST now wanted us to try some new super-digressive pistons in the rear shocks that sounded like what we needed to control the excessive brake dive/rear axle rise. We also re-mounted the seat forward 2 inches and it fit Amy and Costas much better - no pillows needed! Since Mineral Wells just chews up race tires and street tires like a meat grinder, I had the still new Toyo R1Rs removed from the 18x9" wheels and mounted the Yokohama AD08s again. Cleaned up everything, reorganized the trailer completely, and loaded up for a Friday morning tow out to the event site 2 hours across Dallas and Ft. Worth (somehow this is still a local event for us).




March 25-27 - Mineral Wells SCCA ProSolo (Mustang)

Amy and I got to MW around 10:30 Friday morning after picking up McCall, who was coming out to the site to help out the local SCCA region set-up for this National ProSolo event. We were soon joined by Costas and the 4 of us pitched in to work the gate, set-up the region trailer stuff, the Vorshlag vendor table, and try to lend a hand wherever needed. Amy and I had entered in the EVO school, which was just some classroom coaching on the event format (its been years since we ran a ProSolo), and then several test starts on the .500 drag race tree.



A ProSolo is a unique event combining a pair of mirror imaged autocross courses and a drag race start, with your best times from each side added together for a total time in class, and we had 6 runs on each side over 2 days to get it right. Reaction times count and you can red light or cut a slow reaction time, which can hurt your run times or DSQ the run (red light). Drag race starts with a nice straight at the beginning of each run. Lots of power... runs 12s stock. Should be a good fit for the Mustang, right?

• Pictures: http://vorshlag.smugmug.com/Racing-E...roSolo-032511/
• Results: http://www.scca.com/popup/raceresult...7167&file=1279

Well, when the straights are a good 1000+ feet long, sure, it helps... But on this course set-up this time the starting straights barely took up 1st gear in the Mustang before the first turn, and we lost out badly to the AWD cars (2.2 sec 60 foot times in the Mustang vs 1.8 sec in the AWD VW in our class) and barely matched the RX8s and BMWs in class. So any hope for advantage was just not there.

We quickly noted a new problem with the brakes on Saturday - ABS Ice Mode. When the brakes were pressed quickly the ABS system freaked out and you lost 50% or more of the braking power, and we all blew many turns on course because of this. We don't know what it was, but the only change since the previous weekend when the brakes worked SO well was a swap to DTC-60 race pads out back and the change back to AD08s, but we had run these tires before. The surface was different as well, but I have run at Mineral Wells dozens of times over the past decade, never seeing anything like this. WTF??



We ended up switching from "drive into the corner on the brakes to load up the front tires, just so it will turn" method of driving this plowing pig, to more of a "momentum/Miata" driving style, trying to reduce the time under braking and maximize lateral grip and slalom speed. Driving into a corner on the brakes is a work-around for a pushy car, and Costas and I have used this on many Pony cars in the past, but it just wasn't possible when the brakes were not there. The momentum method sort of worked, and kept the car out of ABS and Ice Mode, but sure was frustrating as all hell. We were dead slow in the big sweeping corners and we knew it.

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After our 4 dismal runs per side Saturday were over, I put the car on jack stands and yanked off the rear wheels and brakes. The pads looked... weird. Discoloration and weird build-up of material in the grove in the pad, especially strange for a brand new set of pads. The rear pad swap was the one main variable that changed, so I wanted to change back to a more normal street pad out back, hoping it would get the ABS computer out of the Ice Mode tendencies under heavy braking. So I took the pads to a local O'Reily's parts store in town hoping to match up with a set of pads they had in stock. The 2011 was too new for their catalog but they had 2009 Mustang GT listings, and we found a match for pad shape. ThermoQuiet house brand Ceramic/metallic pads, which AJ has used on a dozen cars with no ill-effects, so I gave them a try. I wanted less braking power out back, not more.



I got back to the event site and realized I needed a caliper piston retractor tool and a caliper compression clamp, so back to town I went. By the time I had all of the right tools and the rear pads swapped it was getting dark, so I drove out to a nearby highway and tried to bed the pads in, after many stops. The stopping power was still very diminished, and easily getting into the "ABS freak out mode". WTF? I came back to the site and pulled the pads back off for a look - they weren't bedding in well. Then I took the G-Tech data logger and went out and did some 60-0 mph braking tests, with what looked like poor results (157 feet??). Then I took Paul M's STU-classed and Brembo equipped 2011 GT (stock pads/rotors on 275mm Dunlops), and it was stopping just as poorly. I did some 0-60 mph test in both cars as well, pulling a 4.5 sec time and .65g in 1st gear in my car and 5.3 second run and .58 g in his car. So they were closely matched, even with his car's 3.73 vs my car's 3.31 gearing. By then it was pitch black out, I ate some of the food at the party we sponsored and drank some beer, then we hit the hotel for some shut-eye. Tried to stay awake and watch F1, but my eyes wouldn't have it.



Since I was Impound Chief for the event, on Saturday I managed to get the Mustang on the scales... haven't weighed it in a while. Showed 3479 lbs with 1/8th tank of fuel in the car. Much better than before but still a solid 55% on the front tires.

Sunday's driving was more of the same frustration, even with the new rear pads - no heavy braking possible or it went into Ice Mode. On this day the ambient temps went from sunny and high-70s/low-80s from Friday and Saturday to overcast, mid 40s, with a BRUTAL wind all day. Most racers brought clothes and shorts for Spring weather but were under-dressed for this late winter cold front. A few racers still picked up some time in the last 2 runs per side, but Costas and I only got a tick faster each. Amy was slow in her class as well. At least she and Costas BOTH cut one perfect .500 reaction time each (I was cutting consistent crap lights). Costas and I were 2.6 and 2.9 seconds off the class winners for both sides, ending up in 5-6th out of 11 according to the results on site, but the posted results show a driver ahead of us that DQ'd himself for driving the course during set-up. No matter - the results still stunk, and we were slow.

We couldn't ever get a complete, good run in without hitting Ice Mode or fighting lots of mid-corner understeer. Tire pressures and shock changes were not enough to counter this massive push, and the wheelspin on corner exit was again ridiculous. Did we simply have too much power and weight for a 265mm street tire? Is all hope lost? Help me Obi-Wan Kenobi!



I think not. We keep seeing bad tendencies in the data and the close-up pictures of the tires. I think we've been in the completely wrong ballpark on tire pressures, the rear spring rates need to drop, and the brakes need more attention. We've probably run into some pad compound cross-contamination issues with the rotors, so we've ordered a whole new set of rotors and another set of autocross pads (Hawk HP+). We'll cut the existing rotors and re-bed them with the DTC-60 track pads and swap between the matched sets of pads and rotors from autocross to track events - these pads have VERY different cold bite characteristics, as well as different coef of friction, dusting & noise parameters.

We're also awaiting our initial stocking order from Energy Suspension bushings, with some much needed polyurethane bushings for the Mustang being made to order. The OEM front LCA bushings are the softest I've ever felt on an OEM suspension, and as big around as your fist. Soft - like a Nerf football soft. That bushing is deflecting under load and losing lots of camber in corner, and the rear control arms and panhard bar are just as soft, causing who-knows-what out back. We've also noted a side-offset of the entire axle, also due to the panhard bar's fixed length and lowering of the back. We need to start developing a Watts Link for the car. We also still have the stock, non-adjustable swaybars, so we're getting a set of Eibach adjustable/tubular front swaybar set coming ASAP (the 2011 has been "in development" for far too long and I'm tired of waiting). AST is also working with us on this new rear shock and the front strut is getting a revalve as well - we'll get this thing to carve cones, by damn!



We've tested several more wheels in the past week, including an 18x10.5" Enkei with a 285/30/18 Hoosier mounted, which is more appropriate for NASA TT use. But the 285/30 is too short, so we're looking at the 275/35/18 and a Pirelli 305 race tire as well. Another set of 18x9" wheels is on order to help test the many 265mm tires needed for STX autocross use back-to-back; so many choices available, and we need to test most of them. And power never hurts on track, so the headers + custom exhaust bends are going to be ordered soon, and the Steeda cold air + SCT Tuner is already en route.

The E30 isn't forgotten, either. We've ordered a 2nd aluminum seat and two I/O port seat back braces for this thing, as well as another 6-point harness. We need to adjust the rear control arm mounts for adjustable toe and camber and get that sorted. The wiring issues are also being addressed now. And of course we need to find a transmission that can last more than 2 events (we've broken 2 transmissions in 3 events). We have some home-brew aero tricks up our sleeves as well, mostly for on-track improvement. And the ride heights and fender openings will again be lowered/trimmed further, until they are right. We also need to design and build a low-buck adjustable rear swaybar - from scrap metal and used parts (ugh).

Somewhere in this crazy month of March our lead tech AJ managed to replace the tie rods on the E36 M3, align it, pull the transmission, install the shifter/spring kits, a new clutch/pressure plate/TOB, reinstall the trans, fix the shifter, and tidy up a number of things in the process. The car drives like a DREAM now, and is ready for sale finally. More on that in its own thread soon.

Meanwhile I'm going to take a weekend off in April - this weekend - well, one day at least. Already burned out and the season has just begun. There's a Lemons race at ECR I'm driving in (hopefully not crashing in! I've been at the gym for 2 months trying to get ready) and a NASA track event plus 2 or 3 autocrosses, and a test day at the track scheduled. We're trying to set-up a mid-week autocross test day with the AST-USA folks as well. Lots to do.

More soon,

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Project update for March 30, 2011: The Quest For Wheels!

As you may have noticed in several of my thread updates, we've been fairly well stymied on our search for lightweight wheels on this car. Here's the parameters we've had:

1. They have to clear the stock front 14" Brembo brakes. This means some 18" wheels will fit, but definitely not all.

2. 17" wheels are out, as are 19" wheels. Seventeens won't clear the brakes, nineteen are too heavy and race tire selection/weight/cost sucks.

3. We need two distinctly different sets:

A) A set of 18x9" wheels for STX autocross use

o Something with an ET45 fits easily

o Even an ET38 will fit

o Lightness is important! We've already lost ELEVEN POUNDS PER CORNER but could lose even more

B) A set of 18x10 (or 18x10.5") for track use (when we move up to NASA TTA)

o We've found that there's really not one backspacing that fits properly front and rear (the GRAND AM teams use 18x10's with slightly different offsets front and rear)

o The 18x10.5" ET38 fits on the front with camber, but not the rear

o The 18x10 ET38 Enkei RPF-1 fit the rear "fairly well" but needed 7mm of spacer to clear the brakes

4. As much as I'd love to run 18x9.5" wheels - they are MANY more choices in this size - these aren't legal for STX and are too narrow for my needs on track.

5. Cost matters, too... Something under $400 a wheel would be ideal. Weight matters more than cost

6. Looks matter a very small mount. I don't want hot pink wheels or blingy chrome, but I'm pretty open on the rest. Form follows function.



Right now we've got these 18x9" Enkei FP-01 wheels (see above) in ET45 and they are 19.3 lbs each. They clear the front brakes and front fenders and front struts by a mile - they have fairly curved spokes - and the are tucked inside the fenders a good bit (that's how we were able to fit the 10.5" wheels on the front) With similarly shaped spokes they could go outboard another 10mm and still fit inside the rear fenders.

We need another set of 18x9" wheels to better test the various 265mm "ST" legal tires. I was going to order another set of these and had a set on order, but I'm holding off for now. I want to try something new, and hopefully lighter. Please post more suggestions for 18x9 wheels in 114.3 bolt parttern that are under 19 lbs and under $400 each! Thanks.

As for the wider track wheels... well we've got one each of these:



I love the weight on the 18x10" RPF-1, but it only fits the rear (front needs big spacer to clear the brakes). Love the width of the FP-01 in 10.5" but it only fits the front (sticks out on the rear, and its a bit on the hefty side). Hell, I might just use the 10.5" on front and the RPF-1 10" on the back, and get one more of each. Not pretty, mis-matched, and the rears are less than ideal (they really need an 8" backspacing) but it works... well, poorly. This option kind of sucks, but you can see the fit of this mis-matched set with 285/30/18s below.


18x10.5" ET38 on front... 18x10" ET38 on back

We are eventually going to try to make an 18x10" wheel that fits this car correctly, and clears these brakes, and is even lighter - soon. But I need wheels to race on later this month (NASA @ TWS) and I'm tired of waiting.

The alternative is CCW Classics. $2380 for a set of race 18x10" versions, take at least 4 weeks to make, not exceptionally light (figure they'd be 22-23 lbs) but they look good and are at least serviceable. Again, anyone who thinks a 3-piece 18" wheel are light has never accurately weighed one. Lots of bad data out there. LOTS. Accurate scales don't lie. There are many 1-piece cast wheels that are significantly lighter than the same sized 3-piece. The modularity and customization of a 3-piece wheel is the benefit, not the weight. Yea, your brother had a set of 3-piece wheels that were super light. SHOW THEM ON A DIGITAL SCALE. I only believe wheel weights I can take myself, period.



Hanchey's 17x9.5" CCWs from the E36 (above left) were a staggering 20.4 lbs each and the 18x11" CCWs on the E30 (above right) are much heavier.

Sure, with custom built 3-piece wheels I could then get two different offsets (front and rear), but these Classic centers aren't known for clearing big calipers without adding spacers. So they still might need maybe... 7.5" to 8" backspacing + a big spacer on the front to clear the calipers. That backspacing would fit under the rear fenders better and then with a ~1/2" spacer up front to clear the calipers. Might be the easiest solution for now, but neither affordable, quick to build, nor lightweight. Pretty bad option, really. Already have long wheel studs up front for this very purpose, though.

Alternatives? A 1-piece 18x10" wheel with an ET50 or so and under 19 lbs would be ideal!

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Project Update for April 1, 2011: No April Fools silliness in here, just some thread questions, my answers & the logic behind them.

First off, I don't mean to be argumentative or sound like a know-it-all, because I surely do not. Let me try to explain why I keep saying a wheel that "fits" or "doesn't fit". I strongly believe using as much tire width as you can possibly fit, and sometimes even more (flares), when the class allows it. And to use the proper wheel width for a given tire, if not more. So I go to great lengths to maximize wheel and tire width on my cars.

I have been test fitting, measuring and weighing race wheels for 20+ years, and have amassed a lot of data, so I just cannot believe almost anything I read on the interwebs about wheel and tire data. As we all here know, most of the "facts" posted on most forums are just regurgitated crap someone else read somewhere. You see it enough times and it becomes fact, even when its bunk. Even data published on websites (especially wheel weights) or from wheel retailers is often incorrect. Its shocking to me how few of the population knows how to weigh a freagin wheel accurately. I've sent more than a couple of sets of wheels back for a refund when their published/promised weights were off by 3 or more pounds (I warned them up front and they agreed to that stipulation each time). I'm not prejudicial about my skepticism - I simply don't believe anybody. I have to see it with my own eyes. I might as well be from Missouri... since you have to show me.

So if someone says "this wheel fits" or "this wheel weighs about X", I need to see a picture. Or a dozen. And then measure the wheel for myself to verify width, backspace and weight. Huge skeptic. Then I'll still want to see the car raced (load the suspension up and see if the tire touches) and look at the wheelwells for tire residue or watch for smoke. I've posted about certain tires not fitting a given car and than seen the inevitable "I race on that giant tire and it fits!" posts. Then later see them at an autocross or the track and watch as plumes of tire smoke pour out of their car. Or watch as they crawl around at half speed, so they never load up the suspension or tires. So my definition of "what fits" is probably different from someone else's.

And different racing conditions have different tire clearance requirements. A typical autocross car sees only spikes of G-loading (slaloms and small turns) but on a road course everything happens SOOO SLOOOOWLY... with loooong turns... so you tend to load the suspension up laterally for much longer periods of time, and see higher g loading. If you touch the curbs at all that can load the suspension even further. If a tire rubs a bit on an autocross car, what's the worst that can happen? You're never on course for more than 60 seconds, and you can check for the the tire rubbing and residue after each run when in doubt. On track you are out there for 20+ minutes, and a lot can happen in that time if you have a tire touching a fender...



When we stuffed 18x10" wheels and 265/35/18s on my E46 330 (above) it worked fine on the street and even autocross, but when I ran it at the track in TTD the rears would rub the outboard upper section of the fenders BADLY. It took hours of massaging the rear fenders - and proper tire testing with the shock on the bumpstops without a spring installed - to clearance it fully for track use.

So, let's see some pics...

Originally Posted by blackbolt9 How much better do you want them to fit? JBS Motorsports Boss 302R with the BBS wheel, no spacers on the rear. Photo stolen from Rehagen website, I assume taken by Wes Duenkel

Hmm... OK, from that angle that wheel looks like it fits... its a little close in the rear, but it would probably work. So are you telling me the GA cars use the cast BBS wheel? I've heard (there I go using second hand info!) that there's another 18x10" mesh wheel that BBS makes (at double the cost) for the GA teams that has a different offset for the rear. Of course if you're going to GRAND AM races and working at Rehagen then you'd know this to be true or false better than me, so I will defer to you. What's the skinny - is there indeed a street version of this 18x10" BBS wheel, and a different GA wheel?

And as for the 7.0" backspacing claim I made, I trusted the interwebs and look - its burned me again. The early data I found on Rehagen's website about the cast 18x10" BBS showed that it had a 7" backspacing and weighed 20-21 lbs. I literally cut and pasted that data from the website right into the caption on this picture, last year. And of course there's the $637 cost.

Since then I've tested an 18x10 with 7" backspace on the rear and it stuck out on my car a bit more than I liked. But if its now showing to be a 7.2" B.S. wheel, that would indeed fit better out back (barely), and that is also the most backspacing you can get away with on the front before losing clearance to the strut. So if its now showing as a 7.2" backspacing then that's probably pretty darn good. But did someone say you still have to use a spacer up front to clear the caliper?? That seems like an odd requirement for a $637 wheel...

But If I was going to spend over $600 on a 18x10" wheel it damn sure wouldn't be a heavy-ish cast wheel. CCW monoblocks are only $700 each (ha! only), and can be custom made to your specs. Very strong, might even be light (depending on who you believe - I believe calibrated, digital scales, but have yet to see these wheels pictured atop one). And if I was going to to make a custom set of wheels for this car for track use, I'd make them 10.5" front and rear, and maybe even 11" on the back. If I wasn't running NASA TTA with its imbalanced points penalties for tire width, I'd put as much tire under this fat-assed Mustang as we could fit. Probably 295 fronts and 315 rears. But tire width is heavily penalized in NASA Time Trial... anything more than a 285mm and I'm looking at a class bump up to TTS, so that's not going to work. Since I can only afford the class points for a 285 (grumble) then a 10" wheel is sufficient, therefore its easier to make a single wheel fit front and rear. And therefore not really beneficial to make a custom set of wheels. And hence why I'm spinning around in circles trying to find an 18x10" or 10.5" 1-piece wheel that's off-the-shelf and under $400 each.

And I think my comments were misconstrued (and poorly written) about lightweight wheels - the autocross set I need (18x9) can afford to be very light, as running over cones in a parking lot doesn't take the same strength of wheel as track abuse. But even on track this car isn't raced W2W (only TT + HPDE), so it doesn't see the "fighting for the lead" type of abuse the Continental GA cars would normally, so it can probably afford to be a bit lighter than what the GRAND AM teams use.

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Originally Posted by Thinkkker Its the way to go really..... 18X10.5 in the front: *sorry, best I could find* 18X10.5 in the rear: *there is over 1" or so clearance on the inside* The fronts fits about perfect, and without fender mods, I don't think you will get more. These are 30mm Offset....

Kent - sorry, but those 18x10.5" ET30 Enkei NT01+M's don't fit on either end with anything close to perfection, at least to my standards. The poor lighting and odd angle on those pictures you posted (especially from the back) don't really show the situation clearly. Costas and I looked at your car and those very wheels & tires in person at the National Tour event 2 weeks ago and both the front and rear tires stick out past the fenders. A lot out back. Sure, "it works" for autocrossing and is common for the category, I'll grant you, but its not what I'm looking for. Madderash's F-Body wheels stick out as well.


Left: 18x10.5" ET38 (7.2" backspacing) fits up front - BARELY. Right: Same wheel on back sticks out a ton

As you can see above, we've fit an 18x10.5" ET38 (another 8mm inboard than Kent's) on our car with little 285s and they just barely cleared in front but stuck way out in the rear. These have a measured 7.2" of backspacing and have about 3mm of room inboard to the AST strut. Not any room to be gained up front, so nothing wider would "fit" in my book, without flared fenders.



The rear on this 18x10.5" ET38 wasn't even close to fitting - it stuck out more than 1/2" - and this is why I'm still somewhat curious how an 18x10 with the same 7.2" backspacing would fit really well. The rears need to go inboard another inch, if not 1.5". As you can see in the picture above, right, there's a good "three fingers" of clearance inboard to the unibody with these 10.5" (7.2" B.S.) wheels on back. Using something like an ET60 would be a good place to start (8.1" of backspacing). But then you'd need a good sized spacer up front (nearly an inch thick) to have a set of wheels that rotate easily (and yes, ideally I'd want that - as would most track guys). That's a lot of spacer, so realistically a rotatable set of 18x10.5" wheels isn't possible... but an 18x10" set is.

For a properly fitting 18x10" set, in my eyes, I'd want to have the front end up at 7.2" backspacing, but I'd be happier with 7.5" B.S. on the rear, or a 10.5" with 8.0". So I might (if I have to go custom) build an 18x10" to 7.5" B.S. and use a ~1/4" spacer up front. That's if I have to resort to a custom set (CCW). Don't know yet... still looking at some Porsche rear wheels...

Good news on the 18x9" wheel search, thanks to BRODA's suggestion about the WedSport. Found one of our dealers that had a set in stock and they made us a significant;y better deal than $620 each, so a set is incoming. This will be for autocross use (only) for the 265/35/18 Toyo R1Rs. They claim to be 16.9 lbs but I'll snap a shot on the scale and post it up when they arrive, next week. For reference here's a Speedline C5 Z06 17x9.5" wheel that Costas brought by and we weighed today. Not bad for an OEM wheel, but Speedline is very weight conscious.



Also as you can see above, we have the Mustang torn apart awaiting more parts. New rotors and Hawk HP+ pads are going on and the front struts are being revalved at AST-USA today. Trying some new spring rates and I'll report back how they work in a little over a week (two autocrosses that weekend). Also, we weighed the stock front and rear rotors, which can be seen below.



Wow. The front rotor weighs more than the wheel. That's... just, wow. And no, we're not paying $800 for the 2-piece Girodisc rotors that are on the market, but we will be doing something about that. I bet there's 10 pounds in the front rotors alone that could be lose. The hat section of the stock front rotor is THICK steel.

Originally Posted by altiain You know CCW does a lot of monoblock wheels for Corvettes, Vipers, 911s, etc., right? Maybe they've got something that would work for the Mustang. They list their C10 as 24.3 lbs for an 18x13 on their website.

Yea, the CCWs are definitely on my short list for the 18x10" wheel set that we need for track use.



I've had many sets of the 3-piece CCW Classics ($575) but the 1-piece monoblock CCWs look intriguing as well ($700 each). If I keep striking out on a 1-piece wheel that fits correctly (and hopefully at a lower cost), then I'll call CCW back once again.

More next time...

[Fair]

Project Update for April 11, 2011: We had a lot going on the past 2 weeks (prep on 4 of our cars and very busy Vorshlag business) but we still managed to make several changes to the Mustang and then autocross it this past Sunday. Let's take a look at the latest round of mods in this post and talk about the autocross in a post to follow.

First up was the Steeda Cold Air kit that finally arrived, along with the SCT Tuner. This combo-package from Steeda was chock Full Of WIN.



The stock 2011 GT's air inlet box is pretty typical - lots of restrictive accordion style tubing, a closed-element air box, a flat paper element air filter, and weird sound muffling chambers in the inlet tube. There was also the separate "sound tube" silliness that piped sound from the inlet track into the passenger compartment. The stock car is so quiet (81 dB wide open, as tested at an SCCA event!) that this helps you hear the choked up engine sound. The Steeda cold air kit consisted of an all new aluminum MAF housing, a new air inlet tube/elbow all the way to the throttle body, a heat shield that tied into the lower air inlet scoop, a larger lower air scoop piece, and the conical/open element high flow air filter. The kit came with instructions and everything we needed to install it.



I was impressed with the craftsmanship. I've made most of the "cold air" kits on my own personal race cars in the past 20 years, but this car looked a little more complicated with the integral MAF housing in the OEM plastic tube. And with a new higher flowing MAF comes the need for a tune - this has been the standard for Mustangs since the earliest MAF equipped Mustangs 5.0L Mustangs I raced in back in college (MY1986-up). This Steeda kit was not an inexpensive kit, and I am leery of high priced parts that are heavy on the bling and lacking in performance, but this was money well spent. The inlet bell for the MAF housing was a beautifully machined and welded part, and much nicer than I had expected to see (or than I would have made!), with a smoothly tapered inlet bell that has to help air flow. The aluminum heat shield was also very well made and fit perfectly to the new MAF housing, lower inlet scoop, and to the chassis.



AJ had the stock parts out and the new bits back together fairly quickly, but Matt and I snapped some pics of the parts and the install while it was going together. He cleaned up the stock inner fender section under the OEM airbox while it was out (I like my engine bays uber-clean), and it all fit together perfectly. Since its STX-class legal and holds in a little engine heat we removed the plastic OEM "5.0" engine cover piece as well - then cleaned up the hoses and looms underneath. Looks good under there and has less clutter. We did not re-install the OEM inlet air "sound tube"; I consider that part of the OEM cold air system, so its STX-class legal to modify/remove it, in my eyes. That stupid tube weighed less than 1 pound and is more of a marketing gimmick than performance anything. Plugged the hole in the Steeda inlet tube with a a big rubber plug and hose clamp. Again - less clutter under the hood.

Will it be too quiet now without the sound tube artificially pumping engine sound into the cabin? Not hardly! This car SOUNDS GOOD now, and external sound testing shows about a 9dB increase in sound at the SCCA Pro Solo (between my Mustang with OEM airbox and Paul M's identical Mustang with this Steeda cold air) 2 weeks back. See the in-car autocross video below for sounds. We'll plug the 30mm hole in the firewall with some grommet plugs, that Paul found and ordered online, when they arrive.



The SCT Tuner was loaded with a custom Tune Steeda developed for Paul's car as well, which has a more linear throttle response for the drive-by-wire throttle body. Paul was the guinea pig on this mod - he bought this same package and had Steeda tweak the tune a couple of times and we just had them load the same tune for our SCT programmer, as I had driven his car with the same cold air and SCT tune and REALLY liked the improvement. Uploading the tune via the OBD-II port was easy, if not a bit time consuming the first time around (its not nearly as quick as say... a COBB AccessPORT upload, but it has a few more customer-tweakable settings, too). The adjustable speedometer feature (for gearing and/or tire height changes) is a nice feature on this programmer, as is the adjustable rev limit. The OEM limiter is around 6800 rpm and I raised it to 7400 for autocross use (quick bursts up to that limit to avoid a 2-3 shift on some courses), which is plenty safe (the new Boss302 has a 7500 limit). Lots of '11 "Coyote 5.0" Mustang racers are revving stock motors higher than that, but I won't push it further. This ain't no M54.



We then put on a heavier part up front - an Eibach 2005-2010 Mustang GT adjustable, hollow swaybar. They supposedly have had a 2011 GT swaybar kit (with 1mm larger front and an adjustable rear bar) coming out since SEMA 2010, but all we have heard after 6 months of trying to buy one is delays and excuses, and I was tired of waiting, so we ordered the adjustable front '05-'10 bar (but not the matching rear, as it wasn't adjustable; we might make our own rear bar at some point to work with some other mods we have planned). Now this front bar is still 35mm OD, which is the exactly the same as the stock 2011 GT front bar, but as you can see the Eibach tubular unit is 3.4 pounds heavier than the stock non-adjustable front unit, so it has to have thicker wall tubing, which means it should be stiffer at the stiffest settings. And it feels as stiff or stiffer than stock in the "middle" setting we started at - but we need to test this properly and post the numbers up. We'll test the settings on the bar on course at a test-n-tune event later this month. I made sure our tech got the bar installed with no bind in the chassis mounts, which I checked to have "pinky finger effort" to rotate with the end links off. Perfect.... well, almost.

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