If you’re a regular visitor to our blog, you’ll know we’ve interviewed the folks who design and engineer our beloved vehicles. They’ve given us an “insiders” perspective on what they do and how they make some of the world’s best off-road vehicles. When they are not in the office, this group of passionate and hardworking Jeep engineers spends their time on the trails and rocks pushing the Jeep® product lineup to the limit. Last month, we caught up with Phil Jansen, chief engineer on the award winning 2011 Jeep Grand Cherokee and asked him some questions about the role he and his team played in reinventing this iconic SUV.
Q: Tell us little about your background with Chrysler Group LLC.
PJ: I’ve been with the company for almost 27 years in which two-thirds of that time has been associated with the Jeep brand in a number of different programs and areas. I am very passionate about the Jeep brand because it has the elements of freedom, capability and fun which are still the most important from an internal and consumer perspective. The people involved and the proud brand history, create a special internal bond within the team. I’m also a Jeep enthusiast and have attended a number of Jamborees and other off-road events to test the vehicle’s off-road capability. Additionally, I’m a Grand Cherokee fan, not only because I have been involved in the past four generations, but because it’s the vehicle my family and I enjoy the most. It provides the perfect blend of everyday comfort and capability to use in any environment.
Q: Can you give us some details on how the award winning 3.6L Pentastar V6 came about?
PJ: The goal of the Pentastar program was to capture the best attributes of what’s out there in the market place along with consolidating our engine applications to one high-end V6 that meets the customer needs. To be competitive in the market today, you need a world class V6 gas engine that is very efficient in terms of fuel usage, weight, torque, and power. We, as a company, wanted to have a V6 engine that we could use across our line-up and deliver the level of fuel efficiency and performance our customers expect.
Q: The Jeep brand and its patented Quadra-Trac® and Quadra-Drive four-wheel drive systems are legendary. What improvements did your team make to the new Selec-Terrain™ system on the 2011 Grand Cherokee?
PJ: When it comes to the Jeep brand, and specifically the Grand Cherokee, the real focus is on traction capability. The Quadra-Trac I system has an all-new transfer case that is much lighter and more energy efficient. We coupled that with two new open front and rear differentials with brake-locking control software. Quadra-Trac I serves the needs of many of our customers in everyday driving. Quadra-Trac II system takes this system further in regards to capability. We developed a two-speed transfer case with active torque control which was new for the Grand Cherokee. It allowed us to move the engines torque from front to rear seamlessly where the customer doesn’t have to interact with the vehicle. In our Quadra-Drive II system, we utilized the two-speed transfer case with active torque and added an electrical locking slip differential (ELSD) in the rear axle. What that does is move torque right and left independent of the braking. So now you have torque transfer in the middle, torque transfer in the rear differential, and then still have a brake locking differential on the front. These system adjustments increased the level of overall capability and traction.
On top of the four-wheel drive system improvements, we developed a new Selec-Terrain ™system that provides a direct interface for our customers to optimize the vehicle set-up for various road conditions. With just a simple turn of the knob, the system modifies the torque distribution, transmission controls, ESC software, and vehicle height, to optimize the vehicle traction control in various on and off-road situations.
Q: What are the advantages of the new Jeep Quadra-Lift™ systems?
PJ: As you know, the 2011 Grand Cherokee has an independent rear suspension that significantly enhances the ride quality and vehicles dynamics on the road. The best way to enhance off-road capabilities is to put in an air-suspension that gives the vehicle additional ground clearance to clear obstacles . Along with enhanced ground clearance, we also provide improved on-road performance with an aero setting for reduced drag and a lower roll center for sportier handling. One final feature of the system is a “park” mode to lower the vehicle down for easier loading/unloading.
Q: Tell us the about the interior along with acoustical improvements your team made in reducing the interior noise on the 2011 Jeep® Grand Cherokee.
PJ: Our goal was to put the “grand” back into the Grand Cherokee through great execution, premium materials, and the team’s passion to be the best in the luxury SUV segment. The Jeep design team did a great job on the styling and the full team challenged each other every day to execute better and better. With regard to sound isolation, our basic approach was to create a triple wall barrier in all directions. Added sound shielding was used under the driveshaft tunnel, in the wheel wells, front engine compartment, and surrounding trim. We even used acoustic side glass and damped heat shields to reduce interior noise levels.
Q: What are some of the key safety features your team has implemented in the 2011 Grand Cherokee?
PJ: The Jeep as a brand is about safety and security – the structure of the vehicle needed to be strong for on-road dynamics and global safety. We took requirements from across the world and bound them together to create a vehicle that would satisfy standards worldwide. We made most of the 45 safety features standard and are continuing to use emerging technologies to make our vehicles even safer. Examples include roll mitigation, active head-rests, seat air bags, blind spot detection, rear back-up camera, enhanced frontal airbag systems and much more. The expectations of our customers increase every year and we have to rise to the occasion.
Q: Many of our Jeep brand performance fans were excited to learn about the release of the 2012 Grand Cherokee SRT8. Can give us any unique details at this time?
PJ: We’ve created an SRT team to focus on a common set of approaches with all of our SRT vehicles. When taking on the challenge of the new SRT Grand Cherokee, the overall architecture of the vehicle gave the SRT team the freedom they needed to take it to the next level and exceed the enthusiast’s expectations. Fans should anticipate a lot of torque and horsepower coming out of the new 6.4L HEMI and a boatload of luxury performance features.
Q: Are they any updates for the 2012 Grand Cherokee that you can share with our fans?P
PJ: We are always getting feedback from customers and try to take those comments back to the teams and see how they can be implemented on future models.