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Corvette Boss Explains Why the C7 Z06 Struggled with Motor Trend

Earlier this month we talked about the 2015 Chevrolet Corvette Z06 running into engine problems while participating in Motor Trend’s “Driver’s Car” tests at Laguna Seca Raceway and the Corvette’s chief engineer offered up an explanation on CorvetteForum.com – claiming that the car had been incorrectly prepped by GM for the Motor Trend trials.

In case you missed the Motor Trend piece or our article earlier this month, the 2015 Chevrolet Camaro Z00 ran into engine problems while being tested by Motor Trend at Laguna Seca Raceway as part of their annual top driver’s car list. The car was missing as soon as Randy Pobst hit the track and it was so bad that Pobst – who generally turns excellent lap times in Corvettes – compared it to a 1962 Ford Falcon. Click here for a closer look at that problem in our original article.

Needless to say, the C7 Corvette Z06 failed to impress Motor Trend during their top driver’s car title, but more importantly, it tarnished the image of the most track capable Corvette of all time. That was likely why Corvette chief engineer Tadge Juechter took to the enthusiast website CorvetteForum.com to explain just what happened with the 650hp Corvette during the driver’s car challenge.

The Explanation
While critics of the 2015 Chevrolet Corvette Z06 would like to read about the Motor Trend engine troubles and insist that this was a clear indication of problems with design of the Z06 – it really is not. The new Z06 has proven to be a beast on and off of the track in a long list of tests, including turning down crazy fast laps in the Car & Driver Lightning Lap event. Unfortunately for the Motor Trend team and the Corvette team, the C7 Z06 delivered to Motor Trend at Laguna Seca Raceway didn’t technically have an engine problem…it had a problem caused by human error.

General Motors has found that in many cases of 2015 Corvette Z06 owners having overheating issues, there is air in the cooling circuit of the intercooler unit. These air pockets can cause the intercooler to function less efficiently, so before sending the car off to Motor Trend for the driver’s car testing, the car was fully serviced and the intercooler’s coolant system was checked to be clear of air. However, when the technician hooked everything back up after completing the standard check-up, he or she did not correctly hook up the wiring harness for the intercooler unit. It was connected well enough that the Corvette Z06 ran fine leading up to the Motor Trend track tests, but it was loose enough that it caused the intercooler system to fail at times.

This caused the intercooler system of the new Corvette Z06 to stop functioning correctly and when intake air temperatures climbed through the roof, the LT4’s PCM cut power to protect the engine from the high temperatures. As a result, power was greatly reduced, leading to the decreased performance and Pobst comparing the most track capable Corvette to the 1962 Ford Falcon.

In short, because a technician didn’t plug in a harness correctly, the Corvette team got an unnecessary black eye via the poor performance of the C7 Z06 in the Motor Trend top driver’s car contest.

This Corvette was Wrecked, Had Old Brake Pads
In addition to explaining the issue with the intercooler system, Corvette chief engineer Tadge Juechter explained that this same C7 Z06 had been wrecked during the Car & Driver Lightning Lap tests and the brake pads hadn’t been replaced before sending the car to Motor Trend.

During the early stages of the Car & Driver Lightning Lap tests, the Corvette Z06 got off track and kissed a tire wall. This did nothing but cosmetic damage and after the body damage was shored up with some zip ties, the Corvette went out and turned its record lap time. Clearly, the tire impact didn’t stop the Corvette Z06 from turning in awesome times with C&D, so the “wreck” shouldn’t have been an issue for Motor Trend. (For the record, I am not suggesting that the wreck was an issue, but rather disclosing that this Corvette has had quite an interesting history in its short life.)

Also, Juechter explained that after being worked out by Car & Driver, the Chevrolet Corvette Z06 was prepared for the Motor Trend track time. A normal part of this prepping is to replace the brake pads, but the technician forgot to do so. Fortunately, this problem was caught before the Z06 took the track with Motor Trend so, like the tire impact, the brake pad issue shouldn’t have had an impact on the performance of the Corvette Z06 at Laguna Seca.

Juechter pointed out that both the brake pad process and the intercooler system check process have been altered to prevent this problem from happening in the future – especially with the intercooler system check being something performed by dealers for paying customers.

Fortunately, Motor Trend is likely to get their hands on another Corvette Z06 in the future and should they happen to be joined by Randy Pobst at Laguna Seca – I would expect scorching times.

Source: Corvette Forum

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Comments

"In case you missed the Motor Trend piece or our article earlier this month, the 2015 Chevrolet Camaro Z00 ran into engine problems while being tested by Motor Trend at Laguna Seca Raceway as part of their annual top driver’s car list." Looks like your proofreader took the day off ??
Motor trend was on the money. the bull shit that the harness for the intercooler wasn't plugged in is all made up. I have a 2015 corvette Zo6 with the Z07 package and I cant get 10 min on the track with out it overheating. I brought it back to the dealer 3 times. They changed the coolant and put thicker oil in it and it didn't work. still goes into limp mode. the dealer said that the techs down in the main office said there is nothing wrong and i have to change my driving habits on the track. so what this means to me is i spent greater than $100,000 for a car for the track that they say i have to drive slow. I bought this car for the track as a car that Chevrolet advertises as track ready.. What do I do?
Did you happen to break it in first with a good 1500-2000 miles? I hear the computer will detect mileage and go limp as not to blow the engine. I still have to do the 50 stops from 65-0 for the carbon ceramic brake-in process but after that I'll be seeing how it performs on track. Fingers crossed it doesn't overheat or burst into flames. If it does - may have to go grab a Viper ACR before they're all gone.
Gabs-Yea I went ahead and upgraded my intercooler and tuned the car to run on E85 with new injectors. Now it runs even faster and much cooler. I can run all day at the track.
any way I could talk with you about this engine? 256-694-8880
Hello GM. I previously purchased brand new 1985 & 1998 Vettes. I would like to buy the 2016 Z06 3LZ manual at my local dealership. I enjoy using any car for its designed purpose. This purchase choice is up against a 2010 Ferrari 612 and a 2016 Benz S65 AMG Coupe. Yes, the competition is much higher price. And the S65 AMG Coupe is more GT than the other 2. But I have hoped this was THE Vette that stepped up in ability and quality in all areas. Perhaps this doesn’t mean much to others. But to me and many of my friends, we want a genuine reason to buy American…even if our chosen car company is essentially controlled by the very unions which brought its destruction in the first place. So, GM, PLEASE honestly address this. If I purchase the Z06 I have found, and it has this overheating issue…I will bring it back under the Lemon Law and cause the biggest stink imaginable. I will be checking this site and others over the next 10 days while I make my decision and watch for a reply. Thank you.
Is this guy really comparing cars that cost twice as much and make 100 less HP and weigh 1,000 lbs more. I think I smell a rat,
I have the 2015 Z06, Z07 has the inner cooler recall started?
I finally went to the better buss burl just like it said to to do in the back of the owners manual about my overheating issue on the track w my 2015 Z07. thay put together a binding arbitration w a mediator who after I presented my case made GM buy the car back. They gave me all my $ back and now I am using that money to build a new 3rd generation factory 5 daytona coupe