Project Update for Nov 23, 2011: To our USA friends, Happy Thanksgiving! After over 2 months off from autocrossing in the Mustang (GRM Challenge, a NASA track day, a Hankook Arrive and Drive, plus some other events were jammed in there) Amy and I managed to get it to the last Texas Region SCCA autocross of the year this past Sunday, the 20th. It was run at the Lone Star Park horse track parking lot, my "not so favorite" local autocross site. The site is big, less than an hour from my house, has some cool elevation changes and on-site restroom facilities, so I should love it. It just has a lower grip surface that comes apart badly. It makes for a very narrow "clean line" that you have to stay on at all costs.
Last 2011 Autocross
Overall, it was actually a very fun day, surface degradation notwithstanding. Jarrett Jan laid out a pretty fun course that was technically challenging, plenty long (60 seconds), yet well marked. The hard working SCCA crew spent some serious time cleaning the course surface before the first runs, using brooms and air blowers to move hundreds of pounds of gravel off line. So the first run group has
some clean course runs.
The weather was looking very iffy (high chance of rain), and due to a site-forced re-scheduling, the event was moved a week back from its original date, so we were expecting a very low turn-out - but 82 racers made it out and we had a great event, running in STU and STU-W.
New Tires, Wheels, DDP pistons in AST struts
So yea, if you were paying attention just then we
didn't run in STX. Let me back up a bit to explain why. In July of this year Amy won a random drawing for a free set of Bridgestones at the NSTC event. One of those "fill out this survey" deals. Whatever the reason for the tires, Amy already had a great relationship with Bridgestone for several years, after winning a National Championship (STU-L) on them in 2007 and being sponsored driver in 2008. So we were excited to be running their tires again, no matter how we got them.
They sent us a set of 275/40/18 RE-11s (the biggest 18" size they made, by the way) and a big box of decals, and we mounted them up on the D-Force 18x10" wheels on Friday before the autocross. I gladly put on all of the decals they sent - give me $1400 of free tires and I'll damn sure run your decals!
We've got
pallets of these 18x10" wheels (5x114.3 mm PCD, fits '05-up Mustang and '08+ Subaru Impreza; I'm almost 100% certain it fits the RX8 as well - will know soon!) arriving at Vorshlag right around the end of this year ($300, 19 lbs!) so I really wanted to do an autocross and a track day on the wheels first, and fit them with something wide like these 275s - which fit the 10" wheels perfectly. Sure, a wider tire would work even better, and for a more serious STU effort we would go with a 285mm tire. It was just that the widest RE-11 was this 275, so that's what we asked for and received. We'll use them for street use, drag racing, maybe a random track day, and this last autocross of the year. Good test miles on the D-Force wheels, for sure.
I was really impressed by these RE-11 - I think its just as fast and as competitive as the Dunlop, Hankook, or Yokohama. We drove that day in the cold and later when it warmed up a bit, and it was
ripping up pavement. I think the RE-11's higher price and "lemming effect" of the online community has given this tire a bad rap. I'm going to start keeping the RE-11 on my "go to" list for Street Touring choices. Also street drove on them Monday in the rain and I was able to use
100% full throttle in 1st gear. That's never happened before on this car... the Pirelli's are a joke in the wet. These RE-11s are stupid good in the wet.
These wider/taller tires fit the 10" wide wheels and the car PERFECTLY, with the tall 40 series sidewall making for great ride quality on the street. Filled out the big wheel openings and were only 1/2" shorter than the mammoth 255/40/19 tires it came with. Anything we can do to lessen the effective rear gear ratio (3.31) is a plus, extending 2nd gear speeds even higher - into the mid 70 mph range @ 7800 rpm.
So I was curious if the wider and significantly taller tires would be a significant performance improvement, going from the 18x9" wheel and 265/35/18 Hankook RS-3s to the 18x10" wheel and 275/40/18 RE-11s. The 265 Hankooks had so much shorter and stiffer sidewalls, I
felt the 'Stones would be a big improvement. And I was right.
We also got to try out some brand new shock pistons from AST - their new Double Digressive Pistons, or DDPs, were installed into our 4100 front struts a few weeks ago. We have Moton Clubsport doubles ready to install for this car but have been waiting to try the DDP equipped (and renamed) 4150 AST shocks at both autocross and track events first, before we switch to the Mo's.
I'm glad we waited! These DDP pistons are amazing - they ride
even better on the street than before, but when you turn up the knobs they make some SERIOUS rebound forces. This piston is a game changer, and starting in 2012 all 4000 series ASTs will have these pistons (and a new shock name). Be prepared for a
slight price increase on the AST 4000 series on Jan 1st 2012 - but the added costs will include these DDP pistons, improved top guides, upgraded seals, aluminum shock bodies, and several other innovations - all things learned from racing in GRAND AM in 2011 (where ASTs took 28 of the 30 podium positions in GS for the year!). The new 4150 is coming soon...
(click 2 left images for larger sizes)
This was also our first "normal" autocross event running with the additional ~30 whp from the ARH full length headers. We picked the larger 1-7/8" primary headers with their cat equipped X-pipe, and it added a very noticeable bump in power across the entire RPM range, but strangely added no additional outside noise (as measured in our WOT and drive-by sound tests - see previous thread entries here). The car feels so much quicker, but I was worried it would be even harder to control wheelspin on corner exits.
more below...