Project Update for Oct 11, 2012: We drove both the 2011 and 2013 Mustang GT's at last weekend's NASA Time Trial event at Eagles canyon Raceway (ECR). I had planned to wait after this coming weekend's SCCA Club Race/PDX event but they cancelled it, so I will share what we have learned now instead. I'm still writing the 2013's first post in its own thread, but it is coming soon. We also did some dyno pulls on both Mustangs and the 2013 BRZ yesterday at True Street Motorsports, so I can share those as well.
Pre-Race Prep
As mentioned in my last post the '11 GT needed surprisingly little prep before this NASA race weekend. We had just run it at the Global Time Attack and a local autocross just 2 weeks prior and all of the then newly added Whiteline rear suspension bits were working perfectly - and with two weeks of silent street use we were all smiles. Other than two more new Kumho V710 tires, an oil/filter change, and the swap back to the winged trunk and race tires, it was an easy prep.
That shot above shows all of the Whiteline goodies. These changes + the slight bump in spring rates are all that were different from the car in June when we ran ECR and I knocked off a 1:58.2 lap, using Hanchey's AIM Solo in-car lap timer. We were back to running Kumhos again, and otherwise on the same suspension (Motons + Vorshlag plates) and running the same power level (430 whp) and aero (our custom mega wing + LS splitter).
The black '13 GT, however, needed much more track prep help - but we only had one day to do it, with the sudden change of schdule on our E46 BMW. While the '13 started out life 45 pounds lighter than the '11, it was much less equipped, and missing the much-loved 14" front Brembo brake package - which also includes wider wheels, and different shocks/bars/springs (we think). We had planned on taking our 2001 BMW E46 330Ci to run at ECR in the TTD class, but our painter needed more time so the car wasn't going to be ready, so we hurriedly put the 2013 GT into some sort of track-ready form.
It was still bone stock, with the craptastic 235/50/18 all seasons, 18x8" wheels, stock non-Brembo brakes, stock pads/brake fluid, and stock base GT suspension (which I think is different than the shocks/bars that come on the Brembo equipped cars). I couldn't bare to run this car this stock, as it would shred the tires and be laughably slow, so we threw some parts at it on the Friday before the event. A set of Vorshlag camber plates took the front camber from 0 to -1.7° (with lowering springs the max negative number is closer to -2.8°), threw the old Eibach front bar from the 2011 on, and slapped on a set of our Vorshlag 18x10" wheels and that old set of 295/35/18 Nitto NT-05s that I ran at the Optima Challenge.
As you can see, switching from the skinny 8" wide wheels and 235mm tires to the 10" wide D-Force wheels and 295mm Nittos actually
helped the car lose over 27 pounds of unsprung weight/rotational inertia. That is a huge win, but the +60mm of tire should add more grip, too. The crew here tried to convince me to get a set of track-worthy pads for the '13, but I veto'd the idea, as we are chucking the whole stock brake set-up into the trash very soon and I didn't want to waste $300+ on track-worthy pads for a single event. I said "Hey, they are 13" front brakes, how bad could they be?!" I also blew off flushing out the stock brake fluid with some better Motul RBF600 that we stock and sell. Turns out those were two crucial errors in judgement on my part...
NASA @ ECR, Saturday Oct 6
We loaded up the '11 in the trailer Friday night. JasonM made new number and class graphics for both cars and we applied those at about 6 pm - right as the weather went from 80°F and sunny to COLD and overcast. Uh-oh... the forecast looked bleak but I towed the trailer out to ECR early Saturday morning, with Amy following me in the '13. Had to park in the gravel as the place was
packed with NASA racers (something the SCCA club racers are sorely missing - more on that in a minute). The HPDE groups were loaded up, as was the Time Trial group, and three big W2W race groups. Pretty good, considering the crap weather and late event date in the year (over a month after the NASA Nationals).
We quickly unloaded and fueled up the 2011 and got our butts to grid. Amy was the lucky driver of the 2011 on Saturday and she ran in the TTS class against a very well prepped C5 Z06, an S197 Mustang AI car with big aero on Hoosiers, and many other quick TT racers. I was the unlucky schlub in the 2013 GT for the day, woefully under-prepped for TTB class - running against TTB fiend KenO and his Vorshlag/AST sponsored E46 M3; he already owned the previous TTB ECR track record at a 1:59.8, which he reset this past weekend by over a second - and he drives the car to and from the track, with a full interior. Anything sub-2 minute is QUICK at this track, too.
Let me back up a second - before the Saturday TT event even began I heard about a fellow TT competitor that crashed coming out of Turn 4 on Friday's practice event. A little tank slapper off into a 2000 pound hay bale that pretty much totaled the right side of this EVO X. So that's two totaled cars in two weeks from local Time Trial competitors - the Mustang at GTA and this EVO here. That sucks, but this
is what can happen when you track a car at 10/10ths (or 11/10ths?) Don't forget the potential consequences, and don't short change your own personal safety. Luckily this driver also walked away unharmed, just lighter in the wallet.
Our Previous Lap Times at ECR
So back in early June I ran a 2:03.9 at the Optima Challenge on the 295mm NT-05 street tires, bitching about tires the entire time. The rears would overheat on the '11 within half a lap and I had to baby the throttle everywhere. That was with all of the same aero and the Moton Club Sports but an aftermarket PHB and the softer 450/175# spring rates. Then when we went back in June 23rd at the Five Star Ford track day I ran the big 315mm Kumho V710s, but otherwise the same suspension and aero, and turned a best lap of 1:58.2. Both June events had ambient temps exceeding 100°F. That 1:58 time in June was actually faster than the old track record for NASA TTS class, which was a 1:58.4, set in 2011. So we had thought all either Amy or I had to do was match or better that time from June and we could set a new track record in our street driven Mustang.
continued below...