Hello Autopians! It feels great to be here with you all in this new venture David and Jason started. I’ve been a longtime reader of both, so when they called to tell me about the new website and ask if I wanted to be part of it I immediately said “No, who do you think I am anyway?” But then they told me about how they were building a place where car nuts would want to hang out, and that they’d let me get as nerdy as I wanted in a weekly blog called “Ask An Engineer.” What kind of engineer turns down a chance to get nerdy in public? So I gave in. So this is the plan: You folks ask questions, and I do my best to answer them. Every week I’ll choose a few questions and give the answers in the blog. I promise that the questions I choose will have nothing whatsoever to do with how easy they are for me to answer. No sir, nope, absolutely not — cross my heart, hope to die. Anyway, if I don’t know the answer then I’ll do some research to find it. It can be about anything, but since this is a car site, let’s keep it car-related. If you ask me what to get your significant other for Valentine’s Day then I can assure you they won’t be your significant other on Feb 15. You can even ask me about weird taillights, but I might let Jason take those. Actually, I don’t have a choice [points to taillight clause in contract]. So, who am I and why should you care about my answers to questions about cars and car-related topics? Well, I have been an automotive engineer for all 31 years of my career. Yes, I’m an old fart, but I’ve been a car nut from the moment I came onto this earth. As a little kid, all I wanted was a new toy car, and anything mechanical was fascinating to me. My favorite toys were Lego and Meccano, and I spent hours building contraptions and anything my mind could imagine. Did you know that you can build a gun with Lego train tracks and a rubber band? For a 13 year old, that’s way cool! As I got older I got into engines, and of course the most accessible engine for a teen kid is a lawn mower. I had several over the years, and I remember one day I decided to take one apart as far as it would go. I wanted to know what made it tick, so I took everything apart — the crank case, the piston from the connecting rod, the valves. I even stripped the carburetor down completely. My mother was convinced it would all end up in the garbage, but then I put it all back together. She never forgot the look on my 14 year-old face as I stood next to the fully assembled and running lawnmower an hour later. A few years later I went off to college where I got my Bachelor’s Degree in Mechanical Engineering from Duke University. A few years after that I went back to school and got my Master’s in Mechanical Engineering from Georgia Institute of Technology. That got me my first job in the auto industry at Ford Motor Co. I spent 19 years there, with the majority of that time in the Chassis design and engineering departments. I learned all about suspension systems, steering systems, and brakes. My mentor, Manfred Rumpel, who had worked at Porsche as a young engineer, taught me well and instilled a passion for design excellence. As is normal in a company like Ford, I worked on many new designs that never got past the prototype stage, but then I became part of the D/EW98 platform, which became the 1999 Lincoln LS and Jaguar S-Type. As part of that project I spent two years in England at Jaguar Cars doing the ride and handling development of the S-Type. I learned all about ride, handling, steering, vehicle dynamics, and about how to make a car comfortable but still fun to drive.
When I came back to Ford in Dearborn, I fell into the opportunity of a lifetime for any engineer — developing the Ford GT’s suspension. Seeing a GT still brings a tear to my eye.
As I mentioned in the first paragraph, in 2009 I got a call from a recruiter at Tesla Motors who wanted to know if I was interested in becoming their Director of Chassis Systems. I took the job, and at the end of that year packed up the family and moved out to California. This was right at the start of Model S development, and with a very small team of engineers we designed a completely new suspension, steering, and brake system from the ground up. Working for a silicon valley company might as well have been working on Mars as compared with a traditional company like Ford, and it took some getting used to (I may elaborate on this in a future blog). But it didn’t take long for my team and me to ditch all the old rules we had lived with for so long and design a world class chassis on a shoestring budget. What we did would have been impossible in Detroit, but we did it anyway. It’s amazing what you can do when your hands are freed from the shackles of too many rules and processes. I left Tesla in 2015 and went to work at Apple, where I stayed for 3 ½ years. After my time at Apple, I became the Director of Chassis Systems at Lucid Motors, where I worked with a stellar team that I still miss today. If anyone can design a Tesla killer, these guys can! For reasons related to family, I left Lucid and went to work for the Mahindra North American Technical Center in Detroit, but right as we were getting ready to move from California back to Michigan COVID hit and everything stopped. We unpacked our things and stayed in California with me working remotely from my home office like almost everyone else in the world. During those two years, changes at Mahindra and also family dynamics led me to decide I needed a change in direction. I decided to retire at the end of September 2021. I loved my 31 years in the auto industry, and there is a lot I look back on with pride. There are many people who taught me so much, and to whom I am eternally grateful. I wouldn’t be here without them. Well, now that I have all this time on my hands, it’s time to bring the things I learned to a wider audience. So fire away! Ask your questions, and I will do my best to answer them. Anything car-related is fair game, so send your queries to askanengineer@autopian.com. Let’s do this! Does the placement (leading edge or trailing edge) of the brake caliper affect the direction of torque from braking to the chassis? I’m no engineer and lack the proper vocabulary, but will attempt to explain my question. IF fore or aft placement DOES affect the torque vector, then it seems to me that placing the front calipers toward the rear, and the rear calipers toward the front ( as Porsche seems to do ) would lift the front of the car and squat the rear while braking which would help mitigate nose-dive and rear-lift due to weight-transfer. Of course, from weight-placement perspective, putting the heavy calipers as close to the center of mass as possible makes sense, but I’ve wondered about the torque vector for a decade or more after seeing a tire ( car on jackstands ) visibly move when brakes were applied while it was spinning.* Given that you noted learning about braking systems while at Ford-and especially that you worked on the GT, I’m betting that you know whether my theory applies even if the force is so negligible that it’s not part of design considerations. I’ve enjoyed your writing here so far, and will be looking for your byline every time I drop in: articles like the GT one feed my inner nerd and sooth my reading compulsion, so I’m very glad you’re here! *iirc, it was an early 90s Camry, and one major issue was the A-arm bushings were about non-existent; it would pull to one side when you braked hard. So scary I loaned her the money for the bushings & installed them for free. She carted 2 young kids around in that heap, and I was willing to do the work for free so they all didn’t die. Part of why I no longer do side-work… Truth. I’m convinced that processes at any sufficiently large company are designed to prevent complete failure, not to foster creativity and new successes. I bought a new car and before I took delivery I told them the alignment was off based on how it drove. They did a “quick check” using the quick check machines and the machine said it was good. I demanded they put it on the rack and the toe was off. So that’s a possibility. Now you can also get an idea based on the tire wear. They could also just be (wrongly) doing it as a “standard”. How To Make Your Car Handle by Fred Puhn is a great free downloadable pdf which I have found to be easily understood, and, though decades old, the basic concepts like weight-transfer, roll-center, corner-weighting, etc. still apply. I think I got the above answer from there. I highly recommend it to any fellow nerd interested enough to be reading the comments in this corner of my new favorite website. Seriously, people; go get it. I bet you learn something! I’ve always wondered how does longevity is designed into vehicles. I’d love to know how Toyota can design the Land Cruiser to go 250k… anywhoo I’m looking forward to more of your insight on the backend of car design.
