Tikt C7 Z06 X³ssive

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Im US Forum war das Fehlen von Ladedruck beim Motortrend Test in Laguna Seca auch Thema und fuehrte zu einer Anfrage an Corvette's Chief Engineer Tadge Juechter:

https://www.corvetteforum.com/forums/ask...1590701044

Default [ANSWERED] Z06 @ MT's BDC
Original question is here.
Quote:
four0nefive asked:
I think many people want an answer to this question. I'm not sure if you are aware, but the Z06 that was supplied to Motor Trend for their Best Drivers Car competition finished as a DNF (last place). They noted that the car was supplied with worn brake pads and that the supercharger refused to make boost. We would like to know whether these press cars are checked to make sure if they are in proper condition before they are sent out? It seems like they haven't been checked considering that this is the 2nd time a car was sent to MT and didn't perform properly. To add to this, is it possible that Jim or someone from the racing team will do a hot lap at Laguna Seca since MT will most likely not retest the Z06 at LS?
Quote:
Tadge answered:
The short answer to this question is, yes, we check our press cars before we send them out. However, you are probably looking for the full story and how to reconcile how a Z06, actually the exact same Z06, could do so well in Car and Driver's hands for the Lightning Lap and be such a disappointment weeks later in Motor Trend's Best Driver's car issue.

First a little background: Corvettes are highly sought after test cars for media around the world. The number of requests we get to evaluate cars is well beyond our ability to accommodate them. We have to pick and choose and set priorities. The natural question might be: "You are the manufacturer. Why don't you just make more cars and have a bigger press fleet?" The truth is we have limited resources to manage such fleets and since we are capacity-constrained in production at Bowling Green, every car we put into the press fleet is a car we take away from a paying customer. That means people who have had orders placed for a long time have to wait even longer. We try to accommodate as many media requests as we can and that means there is enormous pressure to minimize the prep time for cars between media loans. Media deadlines are absolute, just like race start times, if you aren't ready when the green flag drops, you don't run. The goal for media prep is always the same: Make the car like-new for each loan. Sometimes this is easy, sometimes there is a lot of work to be done. Magazines and other media rightly expect the cars to be perfect, both mechanically and aesthetically. They usually use the same car for photography and track testing. It would be great to send two cars for every loan, so we would have a back-up, but then we would have to double the size of our fleet (see above). Bottom line is that the Car and Driver loan and Motor Trend loan were scheduled back to back. What could go wrong, right?

A lot, as it turns out. During testing at C and D the car went off track into a tire wall. Stuff happens. It wasn't the first time this has happened and I'm certain it won't be the last. Fortunately, the damage to the car was cosmetic (rear fascia, supports and the energy absorption assembly). It didn't have any fundamental structural or chassis damage. The alignment was fine. Basically, zip ties and some duct tape was all it took to make it track-worthy. The car then went out and ran the second fastest Lightening Lap they have ever recorded.

Any time there is an incident like that, we have to tear the car down, replace broken parts and make it like-new again. In the few days we had to prep the car for Motor Trend, we did a tremendous amount of work to make sure the car was safe, capable and pretty. In our haste, two things were missed. We always replace brake pads before delivering a car, but this was missed. I can’t remember this ever happening before, but it did. We have since changed our pre-test check procedure so this can never happen again. Although Motor Trend made it a point in the article, they did not notice any issue with braking performance during their spirited street drives. Our engineer on-site noticed the linings were worn, and they were immediately replaced and burnished. This was done the day before the Z06 was run on track by Randy Pobst and had absolutely no bearing on the results of the test.

The second unfortunate occurrence related to the intercooler circuit. One of our pre-loan checks is to bleed the intercooler circuit to make sure there is no air in it. Some customer complaints about over heating Z06s have been traced to improperly bled intercoolers. The technician doing the work plugged in the electrical connector for the intercooler pump and it seemed to seat and "click" into position, but the secondary latching mechanism did not fully lock into position leading to intermittent operation. Without the pump running there is no coolant flow, no intake charge cooling and the engine pulls spark to protect itself. That is what Motor Trend experienced at random times during their testing. Unfortunately, the connector was seated enough that the pump and engine worked fine in all the pre-test driving done before trucking the car across the country to Motor Trend in California. Remember this is the same car that performed flawlessly a few weeks prior in sweltering heat during Car and Driver's Lightning Lap. The possibility of bad fuel was discussed because it was clear there was an abundant amount of spark retard, but we didn't discover the true root cause until the car had returned to the Milford Proving Grounds after the test. We have modified our procedure to run the pump remotely during the bleed process so this issue can be avoided in the future.

Bottom line is that like any team we have good days and we have bad days. We showed well at Car and Driver Lightning Lap and stumbled at Motor Trend. We engineers and technicians on the team are even more disappointed than any in the Corvette community. We are reviewing our prep processes, which loans we prioritize and even the size of our media fleet. We will get better. We will live to fight another day. Motor Trend is planning another test at Laguna Seca in a few months with some very, very capable competitors. We intend to be ready.