Quote:
Originally Posted by Deepstriker
Oh, my apologies I didn't mean to offend you. Although I don't think we were really arguing since I approached you with a question - which is still left unanswered by the way.
Will the wing hold up the 80 pizza load or not?
I spoke to the driver and he said that he used three 5/16" Grade 8 SAE bolts on each side of the stand. I did some quick calculations and using a safety factor of two, each of those bolts can withstand 3490lbf. Combined strength of 10,470lbf to shear all 3 at once, but of course in reality the bolt closest to the front of the car should shear first.
I would be surprised if his wing is really making that much downforce to create that much force in single shear loads even with a moment about the furthest mounting point. I'm curious if you see something wrong with this calculation. I could provide you with an FEA simulation if needed to show you how I have simulated his wing. It was really bothering me that you seemed alarmed that his wing would fly off so I had to be sure this wouldn't be the case if we ran at the same trackday. Safety first!
The driver did have one comment to make though which was that the car attended the track day and drove home perfectly fine with the wing still attached. The driver also couldn't say the same for you making it home in one piece either though:
After the Driver sent me the photo I noticed that the wing was mounted to the trunk and not chassis mounted either, isn't that more double fail than his setup?!  |
Once again, if you are so proud of what you have created, why not publicly admit that this is your OWN car. You did not speak to the driver. You ARE the driver, the owner, the one who make this wing mount. Although we never meet in person but you should know better that I am within the local track runner circle you hang out with and I have intel of what is happening. Don’t pretend to be the “driver” or “owner” anymore.
You talk about load on the bolts. Have you forgotten there are more than just bolts? Did your simulation factor in the mounting area structural strength? Down force and backward drag load which increase exponentially as speed increase? How about the leverage ratio that will multiply the amount of load and the leverage point factor that will alter the direction of load apply to the different mounting points? Form the number you provide, I don’t think you have consider those factors. Aero is more than just single direction load on single object. You can have bolts made out of adamantium or vibranium but if the surface you mounted to is weak, the aero will still fail at speed. Simple physic. I have my share of aero failure and I almost killed myself. I was as naives as you are today thinking the mountings and bolts that I used to bolt the splitter to the front lip were strong enough and paid no attention to the mountings of the lip itself. Result was half of the front lip got torn off by the down force generated by the splitter. It happened just before turn 1 on Pacific. I was lucky to walk away without any dent on my car and myself. I don’t want the same happen to anyone playing with aero.
You got me on the not able to drive home in once piece. Although 2.5 engine swap was planned for 2014, blowing up my 2.0 was not part of the plan. It ended my 2013 season earlier than I would like.