Cadillac's 'Red Zone' Failure Caused Bottas's Horrific Crash

Valtteri Bottas has revealed how his horrifying crash during the Mexico City Grand Prix was caused by his Cadillac running in the "red zone" for too long with brake temperatures.

Approaching Turn 1 at top speed at the Autódromo Hermanos Rodríguez, the left-front suspension completely gave out.

It exploded in a way similar to Sébastien Buemi's Toro Rosso in China over a decade ago.

Bottas was left a passenger, powerless to prevent a heavy collision with the barriers.

After a short while in the stricken MAC-26, the Finnish driver gave the thumbs up to indicate he was okay.

He then climbed out of the car.

The 10-time grand prix winner explained the extent of his injuries, which were thankfully significantly less severe than they otherwise might have been.

"[There was a bit of] pain, but it is just a muscle bruise, so nothing damaged, and now it feels completely normal," Bottas began to media, including RacingNews365, in his first public comments on the crash.

"These things shouldn't happen, but it happened."

"The main thing is that we understand why we have certain limits when it comes to temperatures, and we've reviewed those so we could really locate exactly what broke, and why."

Bottas revealed that Cadillac has changed back to some older parts for this weekend's Sao Paulo Grand Prix to alleviate any concerns with the car.

"We've had to revert some parts to the old spec, and we've had to revert the limits on temperatures we can run on those," he explained.

"The heat from the brakes has to go somewhere, and at the moment, part of it is going to the wishbones."

Pushed further on the change, Bottas explained that the MAC-26 was running "in the red zone" for too long, with brake issues a problem that has plagued the American team throughout its maiden campaign.

"It is the wishbone mountings, but we've lowered the limits, which shouldn't be an issue here," he said.

"We understand that we're just running too long in the red zone."

"We thought it was safe, but we never tested it by running it so long at that temperature."

Bottas shunted out of the Mexico race when his front left suspension failed at the first corner, sending the car backwards into the barrier deep into the run-off.

Fortunately, Bottas avoided a heavy enough hit to do significant lasting damage.

He revealed on Thursday in Brazil that his pain immediately afterwards — when he was uncharacteristically loud on the radio, and stayed in the car speaking to the FIA medical team — was because he banged his right leg against the steering wheel when the car made contact with the wall.

That left Bottas with some muscle bruising that he says feels "completely normal already."

He has no issue getting back into the car again this weekend because Cadillac has already identified the cause.

Similar to when Sergio Perez suffered a front suspension failure in Canada due to a leak of hot air from brake ducts, Bottas's problem arose from running heat from the brakes "going to the wishbones."

Bottas tends to run a bit hotter on the brakes with his driving style compared to Perez anyway.

But the primary issue seems to be the Mexico challenge exceeding what Cadillac had set its tolerances to and "running too long a time in the red zone."

This should not be repeated at Interlagos with less of a braking and cooling demand at this track.

Cadillac has taken the necessary corrective action as a precaution anyway before what Bottas said needs to be "good redesigning for the future."

"We did have certain limits when it comes to temperatures, but we've had to review those," Bottas said.

"We've had to revert some parts to older spec."

"And also we've had to revert the limits on temperatures that we can run on those."

Asked by The Race about that spec change, Bottas clarified: "It's just the wishbone mountings, yeah."

"And we've lowered the limits, which shouldn't be an issue here."

"We thought it was safe, but we never tested by running it so long at that temperature."

He added: "Based on the forecast here, I think we should be OK."

"But they're still doing more testing at the factory with the right side of the suspension, that is now back in Silverstone."

"So they're doing some stress testing and trying to get more accurate temperature limits on those."

Turning to the Interlagos weekend, Bottas was optimistic that the lower temperatures forecast, including rain on Sunday, should mean the issue is not a problem.

"Based on the forecast here, I think we should be okay," he said.

"It's going to be quite a bit cooler on Sunday, maybe some rain, so I think here we should be okay, but they are still doing more testing at the factory with the right side of the suspension."

Bottas has had some demoralising race performances in his maiden season with Cadillac, but the team's first season in Formula 1 has been defined by learning curves.

The American outfit entered the grid as a new constructor, bringing a fresh American presence to a sport dominated by European and Asian manufacturers.