Davidmgbv8
Supporter
Has anyone used one of these in their GT40? It is similar to the RCR version. What are your thoughts?
4130N will be much easier to find than 4140. Welds better, too.I would have to see how it's mounted at the least. From what is in the picture I wouldn't use it if it was given to me. Remember the brake peddle gives you a mechanical advantage of 6 to one. It is pretty easy to apply 100 pounds to the peddle with a relatively moderately aggressive brake application. Easy 1000 pounds in a panic stop.
At the very least the area between the chassis tubing should be filled in completely with a steel plate in the area where the mount will be attached. I would use 1/8" thick 4140 for that and maybe add a couple of additional chassis members across the area as well.
Then there is the adjustable assembly. If it has any movement in it when "locked" in the desired position then...............well it would not be for me. I also think that the stationary fixed plate on the bottom with slots in it needs to be thicker, 1/4" 4140, and quite a bit larger, at least as wide and long as the peddle mount plate. The top plate that is attached to the peddle box also needs to be as wide and long as the peddle box itself and utilize all the mounting bolts, especially in the corners. Place the slots along the perimeter. That "pin" should be made from a 3/8 grade 8 bolt minimum. If I made one it would be 1/2 inch and I would try to figure out a way to make it redundant (two pins spread out and not in line with one of the pedals). I also don't think they penetrate the fixed plate enough, It looks like a 1/4 inch or so. I would do at least the depth of the chassis rails and shield them from the bottom (roadside) with another plate. I see a lot to be improved here.
That's my free advice.
I tried to use a 1/8 thick 6061 aluminum plate with a series of holes in it to provide adjustability in the same way as this unit does but in a more permanent but adjustable manner. It flexed so much that I took it out immediately and bolted the peddle box through the floor with 2-inch diameter steel heavy washers on the other side with 4 3/8 grade 8 bolts.
My personal opinion is (without seeing it in person and trying it in use) that it's not stiff enough. Especially if it's made out of aluminum. If it's high-grade stiff steel.......... may be safe enough and usable in a street car but not in an extreme-performance high-powered car with sticky tires and big brakes. Then ...............if it fails........where does that put you. In the fence? Think about an emergency full brake effort stop with the car and you or others' lives on the line..............and the locking pin breaks, slips, etc.
This didn't work for me in my car. It felt like cardboard when pushing fairly hard on the brakes.
Adjustable pedals are good idea but they cant be under-engineered. Kinda like seat belt mounts. They must be done right. I call this category of parts itelkillyaparts.
Thanks for the insight, I will mount up and give a test.I would have to see how it's mounted at the least. From what is in the picture I wouldn't use it if it was given to me. Remember the brake peddle gives you a mechanical advantage of 6 to one. It is pretty easy to apply 100 pounds to the peddle with a relatively moderately aggressive brake application. Easy 1000 pounds in a panic stop.
At the very least the area between the chassis tubing should be filled in completely with a steel plate in the area where the mount will be attached. I would use 1/8" thick 4140 for that and maybe add a couple of additional chassis members across the area as well.
Then there is the adjustable assembly. If it has any movement in it when "locked" in the desired position then...............well it would not be for me. I also think that the stationary fixed plate on the bottom with slots in it needs to be thicker, 1/4" 4140, and quite a bit larger, at least as wide and long as the peddle mount plate. The top plate that is attached to the peddle box also needs to be as wide and long as the peddle box itself and utilize all the mounting bolts, especially in the corners. Place the slots along the perimeter. That "pin" should be made from a 3/8 grade 8 bolt minimum. If I made one it would be 1/2 inch and I would try to figure out a way to make it redundant (two pins spread out and not in line with one of the pedals). I also don't think they penetrate the fixed plate enough, It looks like a 1/4 inch or so. I would do at least the depth of the chassis rails and shield them from the bottom (roadside) with another plate. I see a lot to be improved here.
That's my free advice.
I tried to use a 1/8 thick 6061 aluminum plate with a series of holes in it to provide adjustability in the same way as this unit does but in a more permanent but adjustable manner. It flexed so much that I took it out immediately and bolted the peddle box through the floor with 2-inch diameter steel heavy washers on the other side with 4 3/8 grade 8 bolts.
My personal opinion is (without seeing it in person and trying it in use) that it's not stiff enough. Especially if it's made out of aluminum. If it's high-grade stiff steel.......... may be safe enough and usable in a street car but not in an extreme-performance high-powered car with sticky tires and big brakes. Then ...............if it fails........where does that put you. In the fence? Think about an emergency full brake effort stop with the car and you or others' lives on the line..............and the locking pin breaks, slips, etc.
This didn't work for me in my car. It felt like cardboard when pushing fairly hard on the brakes.
Adjustable pedals are good idea but they cant be under-engineered. Kinda like seat belt mounts. They must be done right. I call this category of parts itelkillyaparts.