Damond Mount Design
Posted on September 20 2016
We at Damond Motorsports take pride in our parts, and those come from our design process. We thought it was time we shared it with you. This is our design philosophy, and our commitment to the process that made us the go to for some of the fastest Mazdaspeeds in the world.
All of our mount designs start with a transverse bushing, typically one that’s off-the-shelf. Aligning the bushing transversely in a car with a transverse engine means that engine weight and engine torque are is on a thick section of bushing with a large contact area. Side/lateral load is on the bushing flanges where the most vibration is due to minimized bushing thickness. This is a no brainer for us.
Once the stock part is measured and we have an initial design concept, we go to modeling. All components of each mount assembly are modeled, right down to the washers. This allows an easy transition into the next phase of design.
All Damond Motorsports engine mount hard parts are analyzed using Finite Element Analysis to ensure the design is sound, basically a computer telling you how strong a part is. Scroll to the bottom if you want a little more detail on our FEA. Adjustments are made to optimize loading in FEA.
After FEA indicates a design is sound, we rapid prototype for initial fitment. If a part is too difficult to install, has small clearance issues, or doesn’t quite line up, this is where we do the first adjustment. Once we’re happy with the rapid prototypes, parts go to metal.
We pick and choose our welding process for fabricated parts. TIG welding is generally prettier, but MIG welding often drastically increases strength at potential stress concentrators. Any particular fabrication may be a combination of types and sizes of weld, guided by FEA to ensure part strength.
All Damond Motorsports fabricated steel parts designed to be made of high strength steels, typically also having properties that help fight corrosion. The material selection and quality of powder coat have been very successful at avoiding rust. All aluminum parts are made from 6061 or better.
Most metal prototypes are made as full production intent parts. Materials, production processes, and fasteners are generally up to production quality. Of course there are instances of imperfect prototypes, but even those parts are usually fully functional.
Steel fabrications are all powder coated, and steel bolt sleeves are all plated to help fight corrosion and rust. All fasteners are grade 10.9 or better unless unavailable. We don’t use grade 8.8 hardware on mounts unless it’s unavoidable. All welds are made by certified welders.
Then it’s time for testing.
The first metal prototypes are applied to the Alpha test car(s). We spend a lot of our time at this step, as we have had good success getting honest feedback from our Alpha testers. Nothing moves forward until Alpha testers have given their feedback, have gotten to TRACK TEST their car with the part, and have given the go ahead for beta testing. They’re run as hard as they ever will be in this test phase to weed out any issues.
Beta test parts, often the same parts that were made for Alpha testers, go out to many people with different applications. We try to get a broad variety of testers, from those that daily drive their moderate power car, to those that race every chance they get. Adjustments are made to fit and finish as needed, but Alpha testing usually has ensured that these parts do their job well.
To ensure design, production, and quality are all in communication, all of our machined and/or fabricated parts are made 100% in the Midwest region of the USA. All first production run parts are inspected at various stages of the process, and the finished parts are inspected 100% for build quality. Future production runs are spot checked.
Then we let them go free into the world to brighten faces everywhere. None have come back broken.
Warning, some technical stuff below
If you’re down here, you’re looking for some data and facts. Without giving away the farm, typical FEA parameters simulate a load on individual mounts that is higher than the total torque that most engines produce. Use your imagination here for a number. The resulting stresses have to be low enough that you are not in a low cycle fatigue failure scenario. That means, per FEA, any Damond Motorsports engine mount can individually take all the torque or load that most engines produce and deliver to three mounts. We also run FEA at a slight misalignment to ensure it isn’t too sensitive to that, typically 5% of load.
We admit we have never validated FEA by testing a mount to failure. Fortunately, that’s because we can’t break it, even after making test parts thinner, or out of weaker materials.
We believe our parts to be as strong as or stronger than FEA predictions. So when we had a revision of a part that didn’t meet our print because of missing welds (a huge no-no in structural parts), we took the opportunity to test what we believed on a track. The part was sent to one of our sponsored test cars, one of the fastest 1/4 mile Mazdaspeeds in the world. The car ran the fastest times it’s ever run, well into the 10s, and the part held up as expected.
It was a weaker than production part in hardest application possible, and had no issues, as predicted. Despite that performance, the remaining parts were all stripped, and the missing welds were added before the parts went to consumers.
Over kill? Maybe, even likely. It’s just our commitment to what we make.