BLOWOUT! 130 mph. Left Rear....
Well, the Porsche-Day is always exciting. My student has an Audi-R8, Pirelli ROSSO tires, NOT Runflats. I checked the tires myself before session one, all OK 70% tread, pressures equal and OE. Decent driver, age 60-ish, but only one prior HPDE school ever. He asked about defeating the driver aids, and our school policy is AIDS ACTIVE for novices. Instructor Discretion. "Leave Em On til we feel them" was my reply, "then we'll talk."
Session 3, higher speeds, I have him at 125-130mph on the front straight, brake-zone for a 40mph chicane is Turn One.
Ka-LUNK!
"Brake Easy, did you hit something?" "Did not see anything" .... Slowing at 50%, not threshold brakes.
"Indicator lites? Any parts fly off or out?" " No lites, nothing flew off..." Car vibrating. "Stay Straight" I say, meaning NOT to turn into T-1 Chicane, but want to enter the safe coned-off area of the chicane short cut, common at many chicanes.
He ASSumes that 'straight" means stay on the course...... so as he tries to turn hard right, 40 mph, I grab the wheel and prevent the turn, and scoot the car thru the cones into No-Mans land. Chunk-clunk slow vibrating.
NOW, and only NOW, does the FLAT TIRE lite illuminate and chime! "Ive got a flat" he says.
{I was tempted to ask if that was his first clue?!?!}
While we wait for the flatbed, and a yellow flag is protecting us, he says..... "A month back I hit a pothole really hard, and had a low-tire warning. The dealer checked it out and rebalanced the wheel. The slight rim-damage can be repaired when I buy new tires." He did NOT remember which side.... so I re-examined the wheels. I bet him it was LEFT, and it was.... NOW, under scrutiny, I could see the small 'rashed' ding mark where the LF tire and wheel hit the pavement. I bet him that the LEFT REAR has also tracked into that same hole? He did not recall, but....
Like a Viper, no spare. Sealer-inflator only.......but tire is pretty shot. WHEEL OK!
Observers included the Dealer's 2 techs..who obsered the blowout and heard the 'strange sound' as we slowed. After the wheel/tire was swapped by the on-site dealer with a mounted spare OE wheel(!) we inspected the blowout. The Left rear DID have a small chunk of rubber out of the INSIDE treaded area, as if it had been gouged by a pothole. That area blew. We re-examimined the LF, and it did look OK.
Thankfully, the All-Wheel-Drive Audi, and its on-board nanny, helped control the car. I think it would have been scarier in a RWD like a Viper.
DAMN. Since 1993, this is the SECOND time that hidden, inner-shoulders of REAR tires I INSPECTED had a problem.
Lesson is: WE NEED TO PAY BETTER ATTENTION TO THE FULL CONTACT PATCHES OF OUR TIRES. Especially tru if you have a performance alignment, which eats inner shoulders faster.
PS PartsRack is back OPEN today..................with fresh undies.
