last one for the day
The front pads were very worn after the Road Atlanta event. There was less pad thickness than backing plate thickness, as shown above. The front rotors were also DONE, with massive heat cracking on all of the surfaces. Those were both replaced with fresh Centric rotors and Carbotech XP20 pads and we won't do any more TT events without NEW pads at all four corners, and we'll keep full spares in the trailer (we usually do that already). The rear brakes looked fairly worn and after the first HPDE session at ECR 2 weeks later they were replaced at the track with a new set of spare Carbotech pads. The brake pedal was still mushy as crap after we got the car back from Atlanta, and the fluid looked like coffee. It had gotten HOT and boiled, as simple as that. THAT is what ultimately caused the loss of brakes...
But why did they boil? Two reasons: 1) I was driving longer stints than we designed the car for and 2) the worn and thin brake pad material wasn't thick enough to insulate the brake fluid in the calipers from the 1000+ degree rotors. We have since upgraded the Mustang to Motul RBF660 with a complete fluid flush. The Motul 660 looks light brown right out of the bottle, not clear like the RBF600 does when new. We had just flushed another car (see above pics) with 660 and that's what it looks like, fresh.
And even though these extended driving stints are very atypical for us in NASA TT, we went ahead and upgraded the front brake ducts from 3" to 4" on the front of the car, and plumbed the system with 4" flex tubing.
For 99.5% of you reading this the
3" backing plate + hose kits we already make (we now have the hoses as an option) are more than adequate for HPDE or even TT use. Our shop guys are building the 4" backing plates now (below right), but we ran it with the 4" hoses and front openings at ECR already and saw a 60 degree drop in front caliper temps. This weekend at Hallett will be an even better test.
Safety Gear Upgrades
I already wear an SFI 3-2A/5 driving suit, but its a very heavy material (read: cheap suit) and I'm going to upgrade to a more modern style that is about half the weight, and fitted better to my body than this giant Simpson STD.19. Having a lighter weight suit will make me wear it more often, especially during hot events, and reduce my chances of overheating my body. We're not going to use a cool suit, as that is overkill for our typical 2-3 lap stints. I borrowed a Simpson Hybrid Pro HANS device that I will use this weekend at Hallett, and if it works well I'll buy it for use for the rest of this season. Wearing a HANS device wouldn't have helped with the GTA shunt, which was an unusual force vector going almost straight up/down, but it would obviously help in a head-on or side impact crash.
I'll go with a new Alpinestar, Puma or Sparco suit soon. People might not know this, but we sell driving suits (it would help if they were listed on our website, I know), harnesses and all sorts of other safety gear - but we do. And if a driving suit comes in for local pick-up, our Operations Manager tests them out (see Sofi being a goof, above).
I've got a little bit more written but this post is getting too long, so I'll save that for another post later this week.
What's Next
- More post-Road Atlanta Repairs - Pictures and details of the somewhat simple repairs + a short video showing what worn front S197 hubs sound like
- FSF @ ECR - Track test after the car was repaired, where Amy drove the Mustang
- Gas Monkey Bar & Grill Moto GT Bike Reveal / Car show - Sofi's charity bike build was unveiled at GMBG
- NASA @ Hallett - Amy and I are racing the TT3 Mustang at the Hallett circuit this weekend with NASA and a record 41 TT competitors for this event
More soon,