Toyota to reduce horsepower to improve engine reliability

Toyota to reduce horsepower to improve engine reliability

Toyota Racing Development likely will scale back the horsepower in its engines for this weekend’s race at Pocono Raceway as it tries to determine the source of valve spring issues that have felled three engines in the last two weeks.

Kyle Busch failed to finish the Sprint Cup race at Charlotte two weeks ago; Matt Kenseth and Martin Truex Jr. didn’t get to the end Sunday at Dover.

Those failures, combined with two in the season-opening Daytona 500 and then one to Clint Bowyer in March at California, have soured a season in which Toyota has eight poles and five victories in the first 13 races between Joe Gibbs Racing and Michael Waltrip Racing.

“We know our drivers are capable, we know the cars are as good or better than any other cars in the garage and we believe our engines to be as good or better,” said David Wilson, a TRD senior vice president.

“So we can afford to back it down a notch to make sure that we have our durability.”

The issues have primarily been valve-train related, and that typically is the most fragile part of a Cup engine.

Gibbs Racing switched to Toyota engines in 2012 because of reliability issues as well as the switch to electronic fuel injection, which TRD had extensive experience with while Gibbs did not.

“We wouldn’t have made the switch if we didn’t trust the group, the team that they have over there,” J.D. Gibbs, Gibbs Racing’s president, said.

“We have the faith and confidence those guys will get it all figured out.”

At Dover, Toyota drivers had four of the top five spots in qualifying.

“A big reason why this is such a story is because of how strong our performance has been this year,” Wilson said. “Five races (won), eight poles, leading over 50 percent of the laps — that’s pretty stout and a big part of that performance is a combination of driver, car, team and engine.

“One of the realizations that we’ve had to deal with is that we may have been pushing a little too hard on the engine side.”

Wilson said all performance development has been put on the shelf in order that everyone can focus on durability and reliability efforts.

TRD is still determining what caused the valve springs to fail — was it the materials, the temperatures, the loads, etc. — but obviously the quick fix is to scale back on horsepower.

Approximately how much horsepower TRD plans to give up, Wilson wouldn’t say. Toyota teams also are expected to have some new parts in the engines this weekend at Pocono but it will take time to make sure it has the parts and pieces to sustain the level of performance.

“With the NASCAR scoring system being what it is, a DNF is as much of a penalty as a win is a victory,” Wilson said. “We need to have our equipment go the distance in order to fight for a championship.… To give our teams that peace of mind is to back the performance down just a tad.

“The last thing we want to do is handicap our teams. But we’re dealing with the clock and the calendar and the realities.”

The Charlotte and Dover races were the first two races since Daytona where it was a valve-spring issue that caused the engine failures.

“We went 10 weekends without a race incident with a valve spring,” Wilson said. “Every engine builder will say while you may get through a race without a failure, every one of our competitors, including ourselves, are always walking a fine line and a tightrope in terms of performance versus durability.

“This past two weekends we fell off that tightrope. Despite the fact we went 10 weeks without an issue, our margin just isn’t sufficient.”

The next two races — Pocono and Michigan — can be tough on engines. Even though both races are 400 miles, those tracks require optimal horsepower to maintain pace.

“In a vacuum, six failures across 13 races, any way you measure it, is unacceptable,” Wilson said. “Relative to our competition, it’s too many.… The good news is that we have amazing performance right now.

“We just need to tackle this last 5 percent, which is durability, and we’re on a path to compete for our first championship in the Sprint Cup Series.”