The 2015 T25 thread
 

The miata is always well represented in the 25 and this year there are a bunch of ND cup cars running. There are also a handful of NASA's new NP01 sports racers.

Live timing link:
Live Timing NASA 25 Hours of Thunderhill | USAF 25 Hours Of Thunderhill

Live Audio:
Endurance Radio on Livestream.

If anyone knows of in car feeds, or other live content post it up. I would bet mazda will be running live video from their youtube like they did last year but so far I haven't seen any links.

I crewed for the #40 Spec Miata E3 winning team, 12th overall.

The team beat all Mazda cars, including Catfish Jackson Racing Rotrex Supercharged, all 4 NDs, and both MX-5 Cup (NC) Miatas, as well as the rest of the Miata(or any Mazda) contingent.

The #40 qualified at 2.05, but went 2.04 on previous occasion in the same specification.
Weight was 2400lb including driver. Tires Hoosier 205/50x15 R7s.
Typical spec Miata, not a premium professional build but a small enthusiastic team build-effort.

Interesting tid bits, for us who endlessly turn to "tuning" (modifying), this car is slower on 225 and larger tires than on 205, because of its limited power!
Adding power thru NA or turbo/SC tuning, gives modest gains in lap times.

Its interesting how small the difference in laptime is between say Spec Miata and SuperMiata, despite SuperMiata having Aero and tire-size advantange, and power to weight ratio advantage (possibly countered by wider tire drag and aero drag).
Say at Laguna SuperMiata can in ideal conditions do 1.43, and SpecMiata record is 1.44.

It seems that something like PTE Miata and Spec Miata, are quiet an ideal balance of value and performance: in the rain(Which lasted for 1/2 the race) the #40 was often faster than E1, E2, cars, (Bmw M3s 330is, and more).

Laptime difference between a 225/45 RC-1 and a 205/50 R7 is somewhere on the order of 3 seconds a lap on a 2-minute course.

Watched live timing on Race Monitor app. It was very exciting, with the gap at the end of .6 seconds between 4th (my boss) and 5th. Amazing after 25 hours

A few key differences:

SCCA Spec Miata 1:44 runs $165 Hoosier SM7's that are .5s faster during their first 3-4 heat cycles and last about 3hrs vs $125 RC-1's that are fastest just before they cord and last about 7 hrs. We don't count heat cycles on RC-1's, you run out of room on the sidewall.

SCCA lap record car cost about $45k to build with a $7k pro motor. Runs on $8/gallon race gas

SPM lap record is a $1200 junkyard NB2 in a car that cost about $17k to build. Runs on $3.5/ gallon E85 or pump gas.

My SPM on SM7's would run 1:41's at MRLS and probably 1:59 at TRP