I am lucky to have our shop in the suburbs of 'Motor City' and been fortunate enough to get to know some very talented engineers. The particular gentlemen that we hired for the spindle geometry project has over 40 years OEM experience in vehicle dynamics. Everything from family sedans to sports cars, Formula SAE to race cars. When he tells me the tire is everything and getting a wider/usable contact patch on the ground is gold, I do as I'm told and listen.
First we measured the entire front end of the car. All the pickup points, suspension link lengths etc. We already had a lot of this data so not too bad.
Then, using suspension design software we were able to start developing a new spindle that would fit inside a 17" wheel, use our existing control arms AND improve the geometry.
We then had to build an entire CAD model to figure out packaging:
View attachment 877662
We then had to sit down with our suspension engineer and CAD guy to tweak packaging and geometry. Having the geometry and CAD model was one thing but they have to play nice together. This back and forth to figure out the best geometry and what would actually fit took lots of time, many meetings and several years...
View attachment 877664
Once the geometry would fit inside the wheel, we then had to stress test the part through computer simulation. Again, this was another round and round exercise. If a certain area wasn't up to the loads we had to modify the design and if that modification affected the geometry would have to go through the process all over again...
View attachment 877665
My real world testing has shown that as well as fitting the wider tires up front, we are indeed using that extra contact patch. Recent trips to Road America have shown we are using all the contact patch of the 275's on our '66 and not the outer half we used to with the regular height spindles. The car is more balanced, has less understeer and is very fun to drive really
The '66 drives perfectly straight even at 160mph on the race track and the 70 drives just fine around town.
I am very proud of this project. It was a big gamble and took a ton of time and money to figure out.