Well, here we are again. I've got another perfect opportunity to share with you all, the results of good sound design.
The attatched images are of our drivers side, lower A-arm and adjoining hardware. On the first lap of the Mint 400 this year, we had a ridiculously hard impact on the drivers front wheel that folded the wheel around the spindle. After returning home, and tearing down the car, I noticed that the lower A-arm on that side was buckled! The impact not only folded the rim and buckled the control arm, it also bent the 1/2" diameter, 180,000 psi tensile strength bolt that attatches the upper arm to the spindle, via a 7/8" uni ball. Notice the wear ring on the shank of the bolt about 1/4" below the beginning of the thread. By design, that is where the shear load is applied to the bolt. NEVER allow the threaded portion of a stressed bolt to fall within the stressed area (i.e. between two tabs for example). If this bolt had less shank, that would have been the case, and the bolt surely would have sheared during this impact. Also notice the nice smooth fillet radius that blends the threaded section of the bolt to the shanked portion. This is an American made, aircraft quality bolt (Bowman, Bowmalloy series) that we used. It too, shares in the success of the joint not failing as a result of the "mother of all impacts" so far to our Monster Mav.
Hardware technology, and the application of it, is crucial in motorsports, especially in desert racing. We again had what should have been a side lining impact to the Monster Mav while racing for the win, and again, the car took the abuse without the need to stop and repair the impacted area, resulting in a second podium in as many races.
The A-arm, by design, has NO internal gusseting of ribbing, with the exception of an internal brace to support the plate where the coil over mounts to, and a basic mild steel, thin-walled tubing (1" x .065"wall) sub structue. Although the arm is a fully welded box, it still can flex under load because of the absence of interior ribbing. If the arm didn't flex or buckle, the impact to the hardware and spindle might have been catastrophic. This is also the same arm that I posted last month from the SF 250 that required a re-sectioning of the end where the welded bung accepts the rod end for the inner pivot point. These arms have over 2,000 miles of abuse on them, and have just about reached what I consider to be the end of their service life.
Notice how the buckled rim hit the steering arm of the spindle hard. So hard, that the tire locked up as a result. Again, a lighter spindle, without the proper fabricating disciplines would surely not have had the chances of surviving the impacts this one did. I used the stock spindles because they offered a strong, practical foundation to build from. Notice the stock casted steering arm on the bottom of the spindle. I used a long, high grade bolt to tie in the new steering arm location to the strength of the original one. That bolt was our savior, because the gusseting alone, without the clamping force of the additional bolt, would not have been adequate to take the load of the rim ramming into the steering arm. There was actually about a 1/8" thick layer of aluminum "swedged" onto the head of the bolt, and the 4130 tab that houses it. I had to literally chisel off the aluminum from the steel!
The lesson shared here is this: Weight is not a penalty in a class as limited to engine mods as ours is IF it is used wisely, and sparingly. Twice, we should have been side lined. Instead, our season is off to a 1-2 finish, and the Monster Mav is now contending with the top teams.
I don't know how I could build an arm from only tubing that would stand up to as much punishment, and for as long as these have.
I must admit that it feels good after a disappointing season last year, and this is as much as a "boast post" as it is an educational one. But still, there are many teams who can benefit from what I am exposing here. It would be a much more interesting race if more than 3 or 4 teams were the only ones contending for the win, and it is my hope that other teams can apply what we are learning to their advantage. We would love to be nerfed, if it is our class that is doing the pushing. Marc races for the competitive side of it, and a win is much sweeter when challenged for it.
So, ask away, or discredit away! Results are results!
The attatched images are of our drivers side, lower A-arm and adjoining hardware. On the first lap of the Mint 400 this year, we had a ridiculously hard impact on the drivers front wheel that folded the wheel around the spindle. After returning home, and tearing down the car, I noticed that the lower A-arm on that side was buckled! The impact not only folded the rim and buckled the control arm, it also bent the 1/2" diameter, 180,000 psi tensile strength bolt that attatches the upper arm to the spindle, via a 7/8" uni ball. Notice the wear ring on the shank of the bolt about 1/4" below the beginning of the thread. By design, that is where the shear load is applied to the bolt. NEVER allow the threaded portion of a stressed bolt to fall within the stressed area (i.e. between two tabs for example). If this bolt had less shank, that would have been the case, and the bolt surely would have sheared during this impact. Also notice the nice smooth fillet radius that blends the threaded section of the bolt to the shanked portion. This is an American made, aircraft quality bolt (Bowman, Bowmalloy series) that we used. It too, shares in the success of the joint not failing as a result of the "mother of all impacts" so far to our Monster Mav.
Hardware technology, and the application of it, is crucial in motorsports, especially in desert racing. We again had what should have been a side lining impact to the Monster Mav while racing for the win, and again, the car took the abuse without the need to stop and repair the impacted area, resulting in a second podium in as many races.
The A-arm, by design, has NO internal gusseting of ribbing, with the exception of an internal brace to support the plate where the coil over mounts to, and a basic mild steel, thin-walled tubing (1" x .065"wall) sub structue. Although the arm is a fully welded box, it still can flex under load because of the absence of interior ribbing. If the arm didn't flex or buckle, the impact to the hardware and spindle might have been catastrophic. This is also the same arm that I posted last month from the SF 250 that required a re-sectioning of the end where the welded bung accepts the rod end for the inner pivot point. These arms have over 2,000 miles of abuse on them, and have just about reached what I consider to be the end of their service life.
Notice how the buckled rim hit the steering arm of the spindle hard. So hard, that the tire locked up as a result. Again, a lighter spindle, without the proper fabricating disciplines would surely not have had the chances of surviving the impacts this one did. I used the stock spindles because they offered a strong, practical foundation to build from. Notice the stock casted steering arm on the bottom of the spindle. I used a long, high grade bolt to tie in the new steering arm location to the strength of the original one. That bolt was our savior, because the gusseting alone, without the clamping force of the additional bolt, would not have been adequate to take the load of the rim ramming into the steering arm. There was actually about a 1/8" thick layer of aluminum "swedged" onto the head of the bolt, and the 4130 tab that houses it. I had to literally chisel off the aluminum from the steel!
The lesson shared here is this: Weight is not a penalty in a class as limited to engine mods as ours is IF it is used wisely, and sparingly. Twice, we should have been side lined. Instead, our season is off to a 1-2 finish, and the Monster Mav is now contending with the top teams.
I don't know how I could build an arm from only tubing that would stand up to as much punishment, and for as long as these have.
I must admit that it feels good after a disappointing season last year, and this is as much as a "boast post" as it is an educational one. But still, there are many teams who can benefit from what I am exposing here. It would be a much more interesting race if more than 3 or 4 teams were the only ones contending for the win, and it is my hope that other teams can apply what we are learning to their advantage. We would love to be nerfed, if it is our class that is doing the pushing. Marc races for the competitive side of it, and a win is much sweeter when challenged for it.
So, ask away, or discredit away! Results are results!
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