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:
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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!!!
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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,