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

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Project update for Nov 22, 2010: I'll start with some replies to questions, some requests for ideas/advice on upcoming mods, then I'll move on to the wheel test I did yesterday on the 18x9 and 18x10 test wheels.

Originally Posted by Tob Either allow headers or don't. I don't see how they picked the number 6. Why not 7, 10, or 14? Floorpan stampings and engine combinations can leave plenty or no room at all. Why not use a number that allows most any effort the same opportunity in fitting a long tube header?

Agreed. At least the STX and STU classes can do away with 4 cats and replace them with 2, of any type (not OE/CARB stamped units of the same number as stock, like in ST/STR/STS classes). There are rumbles of making STX/STU adopt the lame cat rules in these lower classes, but that's not until 2012, at the soonest. I hope.

Originally Posted by Tob You might consider whether any (muffler) choice greatly increases drone. There are plenty that don't. There are also plenty that do. Maybe I'm getting older, but I much prefer a quieter system that emits a simple, deep, burble, as opposed to an all-out wail. Yup. I'm old.

Agreed. I've owned many Mustangs over the years that had oppressive exhaust drone, and I'm also getting old. And my wife daily drive's the Mustang (but she's pretty a dedicated racer, so she has mucho tolerance). When I worked at a Mustang tuner shop over a decade ago for a short stint the head tuner there (Sen-Roy, who used to post here a lot) would do tricks with varying the muffler case size on each side of a dual exhaust Mustang. It usually killed the drone. If it gets bad I'll swap out one muffler and try that.

Originally Posted by Shortcutsleeping A quick word on coatings....if you coat, don't wrap. (his coater) said it would not help and would not be good longterm for the coating. Check with your coater and see what they say. Costas cars and such...

Yea, I think coating and wrapping a stainless header is probably overkill. Now I'm leaning towards just using header wrap on the stainless headers only, and not blowing $250-350 (and weeks of time!) on coating.


http://www.summitracing.com/parts/DEI-010130/

I have this 100' x 2" roll of DEI header wrap in my "shopping cart" as well as stainless steel zip ties, DEI exhaust wrap (for wiring), some long front wheel studs (for potential wheel spacer use up front - see more below), and a pair of these mufflers:


http://www.summitracing.com/parts/FLO-843048/

I did some searching and found, for the first time, real stainless steel chambered Flowmaster Series 44 mufflers. There isn't room for a small/resonator style muffler before the axle, so I might as well go with a "real" chambered muffler out at the rear bumper (these don't have packing that burns/wears out). I don't want this car stupid loud with $600 worth of Burns mufflers and dumps before the axle, either. Sure, it'll cost us a few more pounds to go with a chambered style muffler and full length tail pipes, but these FM 44's are shown to be only 7-8 pounds each (not 13 pounds like the much larger case sized Flowmaster Series 50 I used on my E36 M3). We'll see how they sound, test the sound levels, test the performance hit with and without them on the dyno, and weigh the mufflers before they even go on. These 3" type 44's are smaller than the stock mufflers so they should easily fit in the stock locations. The stock over-the-axle pipes are so compromised and crimped down to clear the panhard support (by inches) that we should hopefully see some small gains here, as well.


Stock muffler case is 15.5" long. The FM type 44 muffler case is 13" long


http://www.summitracing.com/parts/ARP-100-7722/

If anyone has experience with these wheel studs, please chime in. These ARP 1/2-20 x 3.3" long studs show to be made for 2005-2010 Mustangs ("front only"), so its a gamble if they'll fit the 2011. And at $11.36/each they are just a wee bit pricey. Probably not enough market to make it worthwhile to make our on wheel studs, though. We might need these long studs for use with the 18x10" track wheels (see below).

Originally Posted by Tob Terry, I really enjoy your perspective. You stated your goals, continue to research, make sound and logical choices, then verify results. Keep up the good work and I hope the car is capable of meeting your demands. Tob

Thanks - we are always trying new stuff here, and I'm sure some of it won't work and we'll have to back up and try again. I like having the input from lots of experienced racers, because it limits the "dead ends" a good bit.

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Originally Posted by SoftBatch To save some weight you may be able to get away with just the cats. When I had the '05 GT I had a muffler delete exhaust with stock headers and cats and was never above 93dB at the local autocross course. I know it's a different engine and exhaust configuration but there is also a big difference between 93 and 100 dB.

Yea, I have heard a "muffler delete" exhaust on Kent's ESP-prepped S197. Its still pretty loud. With full length headers and a 7500 rpm redline on this Coyote motor, it might get a bit too loud. I don't want to be "that annoying guy with the loud car" at events.

Originally Posted by Leo_DOHC_GTS We have been spinning our car past 7500 with a 8000 rpm limit. The car only picks up power beyond 7000 with a good CAI (we have a JLT) and just an off road H-pipe we see over 400 SAE on the cars we have tuned. The shop car has; CAI - ported heads - long tube AR headers - X-pipe - resonator delete - flowmaster mufflers - 1 peice DS - RST clutch and flywheel. With SCT software we have gotten as much as 435 RWHP SAE.

Ahh, some real power numbers from an S197 tuner. Thanks for replying. I noticed when we dyno'd the car it wasn't really losing power yet at 6800 rpm, so I could see it gaining a bit more up top with the right tweaks. I'm still planning on an eventual 7500 rpm redline. With the right tire choice (we've been looking at so many) in STX it could mean a 73 mph 2nd gear speed. Virtually assured to never have to shift.

We cannot do the 1-piece driveshaft (the stock unit is a huge 2-piece unit that looks very heavy), ported heads, or the lightweight clutch/flywheel, but the rest is fair game. We need to look at the CAI offerings soon, as I'm getting tired of how quiet, stock and slow this car is already. If anyone has experience with a Cold Air Intake on a 2011 GT, especially with before/after dyno numbers, please chime in. I saw a couple at SEMA already, but many weren't ready yet.



OK, onto the latest round of wheel testing.



The two Enkei test wheels arrived Friday but I didn't get a chance to test them on the GT until Sunday. The 18x9" ET45 FP01 fit fine. This wheel bolted right onto the front and rear, with ample clearance to the caliper and strut (front) and to the inner sheet metal (rear). Even without any camber and this 4x4 ride height the outer lip of the 18x9 wheel fit within the stock fender confines.



As they should - they are almost the same width/offset as the stock 19x9 ET42 wheel. In fact these Enkei 18x9's will be 3mm more inboard than stock, which is good - I like to run narrow track widths for autocross cars when I can, to make slaloms that much easier to navigate. Its worth a little time, as we've seen in testing where we time a car through a set gate length slalom, then again with wider cone offsets by just a few inches. You can see the big end link stud that interferes with some wheel/tire clearance when you push the wheel inboard. If it comes down to it we'll just cut/shorten this stud.



So the 18x10" ET38 Enkei RPF1 wasn't quite as easy to fit. The flatter spokes of the RPF1 didn't clear the caliper on the front, as we kind of expected, and some of you warned about.



Not a huge shock - so I tried it on the rear and it looked good. There's a good 1.5" more inboard room, too.



So back to the front with the RPF1 18x10". I didn't have any 5x4.5" wheel spacers, so I started stacking washers to get the proper clearance. Turned out about 7mm of spacer is all that's needed to clear the caliper with the spokes on the RPF1 up front. Then I counted turns on the lug nuts and had just a hair over 10 threads of engagement... which equates to 1/2" (which is 1 diameter). That's just barely enough, and still only afforded about .040" of clearance at the caliper (but the stock wheel only has about .050" clearance here). Hmm.



Then there was the outer fender clearance. With the already wide 18x10" and now a 7mm spacer. It looks... well, its damn hard to tell if it will clear at full droop and with no camber, even hard to show in pictures. With the stock ride height and stock camber, I'd guess no. But we're going to be lowering the car a LOT (2-3"), which will inherently add negative camber and tire clearance. And then with some more camber adjusted in at the plates, that's more outer wheel clearance we'd be adding.

So for now we'll punt on the 18x10" wheels, and retest this wheel again once we have the car lowered and a 285mm tire mounted to it (I've got plenty of dead Hoosiers in this size we can mount and test with). It looks like we'd need a spacer of some sort, which I can draw up and machine easily enough if it comes to it. So I'll get the longer wheel studs installed, just in case. We'll also get the remaining 3 wheels in the 18x9" set, then order the tires (I'll discuss the size and model in an upcoming post). I'll be buying all of the stuff mentioned in this post in the next 24-48 hours, so if you have suggestions/alternatives, speak up now.

Thanks,

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Project update for Jan 6, 2011: Crap, more than a month since my last update?! Well we've been busy and have done all sorts of testing and multiple camber plate and spring installs on the Mustang since then. Plus we installed the long wheel studs and some other bits. I was going to break this into 3 smaller posts, but I'm so far behind on so many threads I'll do one big brain dump to catch up here


Initial check of the stock alignment - click to enlarge

First, on December 10th, 2010, we got a "snap shot alignment" at COBB Tuning Plano to check the stock alignment specs. See the pic above. These guys were super fast and efficient - its THE place to get a performance alignment in north Dallas. Anyway, the front had about -0.5° camber and +6.7° caster, as delivered from the factory. Not too shabby; that's a lot more caster than I thought it might have, and about all I suspect it will need.



Next we installed the 3rd version of the S197 Vorshlag camber plates and some OEM style upper spring perches (one of our existing BMW-based perches works perfectly, and this allows us to use the double row radial bearing on an OEM style spring - win!) onto the stock struts and springs, to verify that the ride height was unaffected (it didn't alter it even 1/16" of an inch from stock), and the car got down to -2° camber up front.



We could easily add more caster (I didn't feel the need) and a tick more negative camber at this ride height (maybe 1/2 a degree more). To reach the extra camber range we'd needed a smaller "normal" height and diameter M14-2.0 (goofy thread pitch we don't already stock) locking nylock nut, as the stock nut limits inboard camber travel. I've got them on order and will offer these for use on OEM struts with our plates, like we do for most others. The stock strut top nut is a MASSIVE thing that takes up extra room.



Next we put the brand new 2011-specific Eibach Pro Kit lowering springs on the car on December 20th, and man... what a difference that made. This dropped the Mustang a hair over 1" at both ends, and the drop naturally bumped the front camber 1/2 a degree more negative (to -2.5°), with the same camber plate top setting as before. We rated the stock rear springs as well as the Eibach rears, and of course the lowering springs were progressive. I need to make a fixture to located the MASSIVE diameter of the bottom of both the stock and Eibach front springs onto our spring rater, in order to hold them secure while rating. But trust me (after compressing both multiple times to do camber plate installs), the fronts are both SUPER soft. I'll post up the stock & Eibach spring rates/weights/length numbers when I get caught up.



Of course the Mustang looks a LOT better with this lower ride height... duh. But it still rides nicely, too (the rates on these are still pretty soft - your grandmother wouldn't even complain). After driving it around for several weeks my wife says drives almost exactly like stock (it should have been an optional spring set from the factory!), with of course an inch less bump travel. I drove it again today (I almost never see this car) dropping off some late order deliveries, and I was LATE as hell so I was driving it like a complete a-hole. I managed to bottom the rear suspension just once, just slightly, and I was driving over some nasty bumpy roads (not always on 4 wheels). So it was highly unusual conditions, heh. I would recommend these Eibach lowering springs to anyone on a budget with a 2011 GT that wants to get rid of the 4x4 look - you can't spend ~$260 in any other way and make a bigger visual improvement on these cars, period. It won't make the car faster on a race track, other than the lower cg, but it will make it "look right". We sell these springs, so I figured we'd test them before going onto coilovers - and I'm glad we did.



Somewhere in there the longer (and expensive) ARP wheel studs were installed in the front hubs. This is in preparation of installing some ~7mm wheel spacers, to test fit the 18x10 RPF-1s properly. Woo, the first "racey" looking parts!



AJ pulled the hubs off the car and did these the right way, using our hydraulic press. About 45 minutes of work. We've also had the brake lines off the car, twice, getting stainless braided lines built to order. They look so money, and fit perfectly. I had the rear lines made 1" longer than stock, since the stock rear lines were being yanked a bit at full droop, from the factory (facepalm). We will make one more refinement to one bracket and offer them on our website for all 2005-2011 Mustangs, soon. Did I mention they are red and blingy? Pedal feel is of course excellent. I'll post up pics when I've had time to upload the studio shots.


Put those shiny bits on the left.... onto that car on the right... do it now!

The S197 AST 4100 coilovers are going on next. Hanchey at AST-USA is putting the magic valving tweaks on our set (after they get back from Daytona GA testing) and we should have these beauties installed early next week. The Hypercos we're trying out first (somewhat soft, at both ends) are here and ready to go on as well. And our complete set of 18x9" Enkei FP01 wheels and 265/40/18 Yokohama AD08 tires (remember: STX class limits tire and wheel widths) should be here on Monday. Hopefully we'll have time to get everything on, and the car re-aligned, before Costas and I bomb down to Harris Hill Road for the NASA instructor clinic track day event next Saturday.

I'm so excited to get back on track! I haven't raced anything since October 16th - even though I was at the SCCA TMS road course event on the 17th, I didn't get to run the 330 before "someone" blew up the motor - and I'm going INSANE. We'll grab some data via the DL-1 and some in-car video with the new auto-x tires and AST suspension on. I love that little track, even if it is a bit bumpy these days (not that we'll notice much). We'll post up more data and vids shortly after. The first official 2011 NASA Texas track event is in 3 weeks, at MSR-Houston, and there's a Pro Solo and SCCA National Tour in Texas coming up rather quickly. I haven't even bought my "now STX legal?!" giant rear wing & splitter, or nasty full length headers yet, either. Lots to do!

Cheers,

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Project Update for Jan 11, 2011: This is a quick one, and its all about bling (preserving the factory finish and headlight glass). Costas came by last week and installed a full XPEL clear film paint protection kit, since the Mustang was still showroom fresh and unscathed by cone damage or rock chips. He installed the rocker panel kit, the "bikini" hood and front fender kits, the side mirror film, the under door handle film, and the door edge guard film kits.


Me and AJ did some Meguiers Quick Detail clean-up and let Costas take over


Costas is a master of patience, having never installed a film kit to this chassis it all went on and off several times before he locked it down


Once the clear film was on and dried its hard to even see where it starts/stops. Invisible protection.

After finishing the body protection film Costas installed the headlight cover kits.

That are tinted.

...Yellow....





I know its not going to please everyone's tastes... but it will keep the rock chips from the glass housings, and it is distinctive. We had a generally very positive response to the yellow XPEL headlight covers on the EVO X, so I figured... what the hell? And in ALMS the yellow XPEL light covers signified a different class of race cars, which was helpful in night races. So it has... a racing tie-in, sort of.


Amy and I did the headlight install on the EVO, dry, which still took us ~90 minutes. Costas made it look so easy this time

It looks a bit unusual in this indoor/fluorescent lighting, but in person it is more subdued and kinda... neat. I dunno.


Costas said "the red and yellow matches your shirt", so somehow that made it ok?

Just didn't want to distract you guys when you saw pics from this coming weekend's track event, with the yellow headlights... Just get the "Ahh! what have you done!" complaints out now.



Stuart @ AST-USA put the magic valving on our 4100 AST kit today and its being installed tomorrow. The wheels/tires are scheduled to arrive tomorrow also. Next thread update will be much more technical, with 90% less bling.

Thanks,

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Project Update Jan 18, 2011: We got a lot accomplished on the Mustang over the past week, including installing the first set of AST 4100s, our first set of Hyperco springs, another set of Vorshlag camber plates, and the 18x9" Enkeis and 265/40/18 Yokohama ADVAN AD08s. Then we had the car aligned again at COBB and got it ready to take to the track for Saturday Jan 15th, where Costas and I ran it at the NASA Instructor clinic. Busy week... let's catch up.

AST 4100 on S197 install gallery = here



Stuart at AST-USA put the valving mojo on this set of 4100s, based on the spring rates we discussed and experience he has on his own S197 with ASTs. We picked them up Wednesday and AJ started the install on by getting the Mustang on the lift. He quickly removed the stock front struts assemblies (these had the Eibach lowering springs + Vorshlag plates - which we left intact) and then started on the rear, so I could make a spring perch adapter for the back.



Normally this AST 4100 S197 set comes with a machined black Nylon rear spring adapter, but they were out of stock and only had this set of shocks on hand from a previous test set. No worries, I got the measurements and machined two spring adapters on the manual lathe. Took me too long but I finally got the 3" OD Nylon cylinder whittled down to size, and they slide over the alignment cups on the rear axle. The AST adjustable ride height platforms fit over the Nylon adapter pieces, and the 2.5" ID x 8" x 200#/in Hyperco springs fit onto those, and slide inside the upper OEM spring alignment stub.



As convenient as the inverted rear single adjustable shocks are to adjust on the current 4100 S197 sets, we're working on a new set-up with AST-USA that will go to a standard arrangement + the body will get shorter; this all will give us more stroke at a lowered ride height. We set-up the ride height at the rear to 15.5", same as with the Eibach Pro lowering springs, for now.



Up front we went with a 60mm x 7" x 450 #/in Hyperco spring and a set of our camber/caster plates + 60mm double row bearing upper perches, all placed on the standard 4100 S197 strut. We set the ride height at 15", same as before. We're also working with AST-USA on a new 4100 strut arrangement that will keep the same stroke but allow a 1" lower ride height up front, as well as a double adjustable that is completely different. Look for several more AST shock designs to be tested on this car throughout 2011.

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Once the ASTs were on we mounted up we scheduled an alignment check at COBB Tuning Plano for Thursday. I took the car by there and they were amazed that AJ had eyeballed the caster, camber and toe almost spot on. They just had to tweak the toe and we were done in minutes. The car ended up with -2.8° camber, +7.2° caster, and 3/16" total toe out (that was probably a bit excessive, in hindsight, and we'll bring it in to 0" toe for future track events). The ride quality was exceptional, as always, even with radically more front spring rate. We left the rear rates low on purpose, to hopefully help put power down for auto-x use. We might end up with two different spring rates for track and auto-x use - testing different rates at both types of events will show us more, which we'll share.


(click alignment sheet thumbnail above to see larger version)

When I got back from the alignment the tires and wheels had arrived from Tire Rack, and I only had to get one loose tire mounted to the "Test fit" wheel we had ordered earlier. AJ got those mounted up and they looked good.


Click the wheel and tire pics for larger versions

Friday I dropped off dealer orders around town in the Mustang to hopefully get the silicone mold release off the tires, then drove an hour across town at days end to head to Costas' place - they weren't very scrubbed but oh well, we'd get them good and scrubbed in at the track... right?



Wrong - it rained for the next 24 straight hours. It started raining as soon as I arrived at Costas', and we had to load the car onto his borrowed open trailer in the rain. Since we had a simple "in state" tow of only 4 hours, and we weren't bringing much in the way of gear/tires/spares (1 day event), we just used his buddy's open trailer and Costas' truck to tow down with - instead of hauling out my 38' enclosed gooseneck or his 28' enclosed tag trailer for this simple day at the track. Saves a ton on gas and towing with a little 18' open trailer is a total BREEZE compared to either of our big enclosed rigs. We could have driven the car down, but with so many new parts we didn't want to risk some silly failure sidelining us, and we had to be back in Dallas by 6 pm that day.

So we left DFW at 4 am Saturday morning and got down to San Marcos at 7:45am, unloaded, and were ready for the NASA instructor clinic by 8. It rained the entire way down and all day at Harris Hill Road, plus it was cold as balls. We still had fun, even if we didn't get any meaningful testing/data/video on the Mustang, due to the crappy conditions (standing water in most turns, visibility was poor, and grip was non-existent). Costas was an "instructor trainer" and I was there as an instructor trainee, hoping to get signed off for NASA (which could potentially give me a little flexibility at NASA events to take people for ride-thrus). The event was a blast (event write-up located here; picture gallery here) and we both got some good (soaking wet) track time in the Mustang.



Costas took around his trainees in the first 2 of 3 training scenarios in the car while I rode with "mock students" in their cars during the same tests, trying to point out their driving errors (on purpose), proper lines, etc. In the 3rd scenario I drove a "mock student" (Costas) around at 80% speed in my car to show the proper lines, techniques, etc. It was easy and fun, but just not that exciting due to the severely reduced speeds (rain + training). Luckily, after lunch they let us all loose on the track for a fun session, which ended up being about 35 minutes of quicker lapping in the rain. That session made the day!


The Yokohama AD08s were extremely planted in the wet

The Mustang was a blast to drive, even in the wet. 4th gear around the whole track (3rd just caused wheel spin), and with the AD08s and ASTs the car could seemingly pass anything out there. Lots and lots of fun. Big thanks to Costas for towing the car down, shooting so many pictures (430?!) in the rain, and for signing me off on the instructor deal.


There were no fewer than six 2010-2011 Mustangs at H2R that day

So next up - we've got the first real NASA Texas TT/HPDE/race event in 2 weeks (MSR-Houston), which we plan to attend, but the first Dallas area autocross we can make isn't until Feb 27th. We're looking at everyone's schedule and there's literally 4 autocross groups with events the same weekend as the first NASA event - damn it, why does this happen every year??

Anyway, lots more changes are in store for the Mustang. The splitter we're using is supposed to be available in about 2 weeks, and we have several other (STX legal) aero parts planned during the same time frame. Then headers + exhaust + cold air + tuning.

Stay tuned,

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Project Update for Jan 24, 2011: The first NASA Time Trial event we're running in is this weekend at MSR-Houston, so its time to look at TT classing for the Mustang. Of course we had been keeping track of everything in our spreadsheet for this car, but I wanted to share it with everyone, hopefully to help people see how "Easy" it is to class a car with NASA TT. The rules and classing for NASA TT are a bit confusing, some would even say very confusing, but the basic classes go like this (from slowest to fastest): TTF -> TTA. But its nothing at all like SCCA classes/categories. Its.. "simpler"... you just find your base class, add up points for every mod you've done, and figure out where the car goes.

So to start the classing process, we have to know where we begin. Each car is assigned a "base classing", some with penalty points already assessed, and then you can count the additional "points" for any modifications done. Each class has 19 points worth of mods you can do, then you bump up to the next class at +20, and if you keep adding points you might go to the one past it. There's a set power-to-weight ratio limit within each class, and all sorts of modifiers for the power-to-weight number, too. Once you bump out of TTA you go up into the TTS>TTU>TTR classes, which do away with all of the "points" and are strictly power-to-weight ratio based classes. Clear yet?

Let's start out with the base classing for the "S197" chassis (2005-2012+) Mustang GT:

• '05-06 Mustang GT is TTD**
• '07-10 GT is TTC
• '11 GT is TTB

The two asterisks after the TTD class above means the '05-06 GT starts out in TTD class but begins its tally with +14 penalty points (each asterisk are worth +7), so that car can only do +5 worth of mods before going up to TTC.

So the 2011 GT with the new 412hp 5.0L got bumped up a full class from the 2010 GT, and the minimum race weight jumped dramatically to 3770 lbs (with driver). That series of base classing changes, to me, seemed to coincide with the power and suspension updates that the Shelby GT350 had for '07-08, which was an optional package those years. So the full class bump (a huge change) for the '11 GT had to include the power + the Brembo brakes, right?

Wrong. I got the bad news on the NASA forums today about more points assigned to our Mustang. This little tid-bit isn't even in the class rules, but is noted at the bottom of an online form for TTA-TTF classing:

Proceed to calculate your vehicle’s modification points assessment for up-classing purposes. Fill in the blanks with the number of modification points assessed for each item that affects your vehicle. You may leave the lines blank next to modifications that your vehicle does not have. Proceed to Page 2, and calculate all modification points’ assessments, then fill in total points below. ALL Factory Options and Parts Not on the Base Trim Model Must Be Assessed Points!!!

Somehow after 4 years of NASA TT racing I had missed this little note on the classification form about "factory options". This means that the following factory installed but optional bits on my 2011 GT will be assessed "points" for NASA classing - even if they are just cosmetic changes.


Left: The optional Brembo brakes are +2 points. Right: This front grill insert is is +3 points

Factory installed options, not on the "base trim level model", that will now count for mod points

• Rear wing delete = +4
• The optional 4-pedestal factory GT rear wing = +4
• A 71" wide multi-piece CF wing with a huge cord, up to 8" above the hoodline, and 12" tall end plates = also +4?!
• Brembo brake package = +2
• GT500 rear valance (now optional on all GTs) = +1 (planned)
• CS/GT front lower grill insert (now optional on all GTs) = +3 (planned)
• Boss302 LS front splitter = +6 (with the CS grill insert included)

Left: This is the base GT rear "wing". Zero points. Right: Ordering without that is +4!

Here's our current list of what I consider "real modifications:

• 265/40/18 Yokohama AD08 = +2 (for 140-200 treadwear)
• AST 4100s = +3
• Coilover Springs = +2
• Camber plates = +0

But we have many more mods planned, which was pushing us to the limit of TTB. Now add in the cosmetic changes we had planned and we're going to be well into TTA. This new twist is pretty crazy, and I'm pretty disgusted with the NASA TT rules at the moment, but that's the way it is written. Now every time I hear a NASA racer make fun of the SCCA's thick rulebook, I can point out how retarded it is that a factory optional wing delete counts the same number of points as a massive CF race wing.

All of these planned mods are legal for STX class, plus many more - and that class is essentially the slowest of all Street Touring classes (ie: STX cars still get beat by '89 civics with 100 hp). Doing some basic shocks + springs + these "factory option" mods above would kick the car up into TTA... which is home to C5 Z06 Corvettes on Hoosiers, and highly modified cars like supercharged Miatas with giant aero, at least here in Texas. So now at least we know all we need to account for to stay within TTB, right? Oh no, there's more.

There's the set power-to-weight ratio limit for TTB that we have to stay under

• Minimum Competition Weight for 2011 Mustang GT: 3770lbs with driver
• Tested Wheel Horsepower: 367 whp (corrected) It tested 378 uncorrected, but that doesn't matter. It was a chilly day.
• TTB Min Weight/Power Ratio: 10.25 lbs/hp

The Mustang currently weighs 3563 lbs, with zero fuel. Add +200 pounds for me and +50 pounds for fuel, and its around 3813 lbs. That gives me 372 whp before it would have to go up to TTA. Are we done yet? Nope.

Then there's the adjustment factors... see Appendix C (page 52-54)

• For running a smaller tire 275-250 mm DOT = +.4
• For having a competition weight 3800-3899 lbs = +.65
• Total adjustments = -1.05 (they show + when they mean -, but their example calculations show it correctly)
• 10.25 lbs/hp - 1.05 = 9.2 adjusted lbs/hp ratio.
• At 3813 lbs / 9.2 = 414 whp max for TTB for this car

And I assure you, someone will contend something in all of those calculations and rule interpretations in this post. "Its so easy" that it takes spreadsheets and multiple interpretations of rules to even class a car in TT. So now I see why the SCCA ruleset is made by a committee and is very carefully worded. There's less room for interpretation and the try to close these odd loopholes where a giant wind tunnel tested wing counts the same as a stock rear spoiler, or no wing at all. I have a new respect for the SEB today, after seeing this mess. You won't hear me singing their praises often, either.

So we've got some thinking to do. Every single mod we have planned has to be assessed for STX legality, NASA TT points, and if anything lowers the weight or ups the horsepower at all, we have to re-check the power to weight ratios. We know its unlikely that the 3800 pound race weight RWD Mustang is going to burn up the STX class, but TTA? We'd get killed on little 265mm street tires against typical TTA cars. Sure, going to TTA would give us another +19 in mods before we'd kick up to TTS, so we could go to a wider wheel and tire package, like go to giant Hooisers, just for TT use. Two sets of race wheels/tires, one of which is a gumball Hoo$iers? Then we could run a "Real Wing" for NASA and different aero bits for STX. And on and on...

The slippery slope begins. Fun, fun!



I was talking with Stuart from AST-USA today, who has an '06 GT (above, left), and his car starts at TTD** (as does Kent's shown above, right) so he could do a HUGE amount of suspension/wheel/Hoosiers/aero mods to his '06 and still stay in TTC class, whereas I've got to be really careful or my car bumps into TTA - even on street tires. So check your base classing, read the rules, and have the TT director check your classing form. And still, just be ready to have someone to contest it. One of our customers had a car that set some TT track records... never had a competitor protest, until a NASA director saw it and assessed something like +12 points to the front bumper, which was an aftermarket but purely cosmetic piece. All of his records and results were expunged. So sometimes, you never know where you should be classed with NASA.

Sorry to piss and moan so much in this "update", I'm just really frustrated with the TT rules and classing at the moment. I'm seriously looking at other cars to run in TT this year, like the E30 V8 or the E36 M3. The '11 Mustang GT is pretty much boned beyond what we've done now, and this is hardly the final set of mods we had planned for the car.

Cheers,