The sky is falling, the sky is falling.

I dare say if you hit a pedestrian with or without this splitter, it would make very little difference to the victim.

 

Composites are the norm on with all these things not the exception, even my966's front lip is a composite.
The front of every F1 car out there is composite yet they are not worried about it breaking into hundreds of pieces and killing anyone. The fronts of most of the cars in the link you provided are made from some form of composite (Not Aluminum). Let’s say you or some other driver does have a wreck and the lip comes off.... The next car by kicks this bent but intact 8 lb piece of alum up into the air and the next guy behind him eats it... Or it shreds his tire going who knows how fast....
There is a reason why race cars do not have such items bolted on to them.
If you are not digging the composite idea then consider a UHMW type plastic.
Homo-Polymer Acetals (Delrin), nylon or polyethylene are a great substrates for such an item in terms of durability and forgiveness. I still think it would be too much mass and to structurally sound but it is a whole lot better than Alum. http://www.professionalplastics.com/...-POMSHEET-RODS
The nice thing about the Delrin or some other structure plastic is you could start with a 1/2" sheet and machine it thinner in the front and you could concave the middle slightly with some diffuser ridges and shape right at the back.

You do not like the foam and fiber idea the shape the foam and then get it sprayed with a spray on low texture plastic similar to a bed liner plastic. Good structure, light and yet sacrificial in an accident.
And BTW I did not call your mounting points into question, just your alum plate. Bend or rip that thing off and you will do structure damage to that belly pan.

 

Tried the source you just posted long time ago... they will not make the dimensions you need to make a 1 piece board. Trust me I searched, this project is 2 years old. We even researched a material that is super light that is made for boats, super strong. Than again we run into the problem of being too strong and when it breaks away its really sharp and harmful. While the aluminum will just flex and bend, it will not tear away like others...Cutting CF also causes cancer when cut on a water jet...theirs pros and cons to any material you use. We believed aluminum is the best solution. Yes its heavier but it will stay in piece and bend down or flex before pieces start flying off and destroying things.

By your own summary of F1, cmon have you seen how dangerous carbon pieces are when they break away ? CF breaks easy if its not molded in that shape to retain the shape. Any hit from the point of the splitter will shatter the CF piece and create extremely sharp pieces that will puncture tires or as you would say "kill" someone. CF is no joke when it breaks off. If you use just a layer of CF with fiberglass under, than its not a true CF piece, w the price tag of full CF..makes no sense. Either do it all in CF or don't do it at all and accept the con's that come with it. To make 1 pice splitter in CF is very expensive for a project that was design for VERY few people whom would use it. Not worth the cost. Race teams have basically unlimited budget and competing for money. Very different application. DE / enjoy mtn roads vs. Race.

 

I can get the UHMW plastc in 4x8 sheets, if you want my source feel free to let me know.

The prepreg carbon graphite autoclaved materials do splinter. But a single or dual layer hand laid material would crumble and turn back to fabric before it would form killer shards. If your so worried about that then use a knitted e-glass, a biaxial double bias fiberglass cloth. Cheap, strong and readyly avaliable too. I would rather run over a piece of broken composite then I would a +8 lb Vorpal Sword <-- that one is for the old D&D geeks on the forum.

 

If you use Delrin or UHMWPE, like you want, it will warp when machined due the surface stress so it will weaken the material. Also it would be 5 times the volume of a thin aluminum sheet, it would be double the weight. Derlin shatters when hit so it would be very sharp....again back to square one. We took what TopSpeed Motorsports.... every material has its pros and cons TopSpeed Motorsports did one for the GT2 Lee competed in, and it was made out of aluminum from what I can tell... it's for a reason. Low volume, low cost, best solution for street and track. You want only track, cost no option, harming anyone not in the books, go CF. Even local track rats whom saw my prototype at the track and they were using ABS plastic thought my aluminum sheet was great vs their plastic. It's easy to talk, rather than do the walk. Do the walk then come tell me what you learned.

 

I agree Larry, not sure why this is even in the books of being a concern for this product. If you run over someone, a splitter is the least of your worries. Than again if you are very concern of running someone over, you should really watch how you drive and be more careful.

 

The haters should go to teemspeed that is what they do best there.

I for one am happy that F1 spent his time and money to make this product. If it works one will be on my car before long. Let me know when your is in Landjet

 

c32AMG,
One thing that I don't worry is the splitter coming off while driving because it is VERY secured. The only concern I have is while the car is parked and some pedestrian is using the front of my car as a shortcut crossing the street; s/he might get a cut that way.

 

Hey Guys, I am posting this via this account so you guys know who I am. My name is Ben and I am the one who designed the splitter, cut it out, and helped with the testing/modeling of the final products. I want to settle some of the concerns out there about the integrity of the splitter and safety to other cars. It seems to me that there are a couple key concerns.

1. What happens if you hit something? Will it damage the underbody of the car? What about cars behind you?

2. What about pedestrian safety? Will it hurt somebody if you hit them?

3. Why use the aluminum sheet over plastic or some other composite? What about machined delrin/UHMWPE like "Engine Guy" suggested.

For the first question:
If you hit something, you will damage he splitter and likely the lip, that is a given. The aluminum we have been using is a 0.09" thick part which, while very stiff, is quite flexible as we discovered during our original testing. We were having problems with the lip flexing down at very high speed and in one case, it bent completely under the car when it hit a large bump in the road. We discovered that the solution to the flexing was to use more robust mounting hardware which would keep the splitter overall more rigid. We also attached the splitter to the bottom part of the front lip which made it almost unbelievably strong. It now is able to support the full weight of a 150lb person on the front part. What this means for you, is if you hit a object on the road (which would have to be quite substantial to begin with), the splitter will first tear away from the lip and then flex under the car. The hardware used to mount it to the car is incredibly strong and is all mounted to very thick steel brackets on the front radiator support. We also removed some of the mounting points that we originally were using that did not attach directly to a metal part on the car.

You would have to hit something very hard to actually cause the splitter to physically come off the car. I don't know what exactly this would be, but in the case that it does come off the car, there is a potential for it to fly out and hit another car. This risk though is the exact same with other materials that have been suggested. The use of plastic for the splitter would not be ideal because to have strength even close to what the aluminum has, you would be using very thick material. The Delrin that was suggested would weigh 21.19lbs (Caculated with Solidworks) in our 2" version of the splitter. Compare that to the 8.45lbs for the aluminum. Additionally, the plastic does not flex, it shatters, this means that it would not fail in the same manner as the aluminum, but rather it would break away much easier, while at the same time, not being anywhere near as functional as the aluminum version.

We have looked into several different composite materials and while there are some viable alternatives, they are either not as economical, not as strong, not as safe, or not practical to work with. The aluminum is reasonably priced, looks decent, works well, and is very very strong.

For the second question:
I think this is kind of a flawed question. If you hit somebody with your car, you are going to hurt them, you are going to hurt them regardless of the splitter being there or not. The front edge of the splitter is about 2-3" off the ground depending on the height of the car. This means it would hit somebody around the ankle. Not to mention, the splitter, on our longest version (2 inches) only sticks out about 1" further than the front nose of the car.

I think people are also envisioning it as a knife or some super sharp edge. It is not really that sharp. I have kicked it twice being the clumsy person I am, and neither of the times have I gotten cut.

I think the big deal here is weather insurance would pay for the additional injuries somebody would sustain. I am not sure of the policies, but keep in mind that even lowering your car increases the hazard to pedestrians. There is a reason why modern cars are designed with higher front ends. It is for pedestrian safety, that is why the new M5 looks so hideous. If you are really worried about hitting somebody, you shouldn't use this in a busy place with lots of pedestrians.

For the third question:
We looked into many different materials to make the splitter out of. Our first prototype was particle board, it worked, but it looked like a 4 year old made it. We settled on aluminum because it was the best material we looked at for strength vs weight with cost taken into account. It would be great to offer a molded carbon fiber splitter with proper grain directions and directional vanes, but that is not practical for 99% of the people who would want this product. Plus that would cost well over $1500 for us to have made and if you damaged it a little, you can't repair it. If you damage the aluminum, it can be bent back if it is minor or a new one can be purchased for much cheaper. Plastic was one of the options we looked at, but after seeing the amount of force this makes we decided against it. For similar strength to the aluminum, we would have to use 0.5" UHMWPE. This weighs more than double the aluminum, costs much more, doesn't look as good, and lowered the front edge of the car by half an inch. Sure you can do it, but it is not the ideal material. I do not believe foam with fiberglass on it will even begin to work. Once you see the loads we have been dealing with, you will understand why.


Finally I want to say, if you are not happy with the design, that is perfectly fine, please don't call us out and tell us that we did not do our homework on this project because we did. We have spent over 2 months testing this splitter including a track day and many hours of testing on back-roads and this is the solution we came up with. We put function before form and designed a part with the primary goal of helping make the car much more manageable. In this aspect, we believe that we have succeeded completely.

Below I have attached some of the stress models we used to simulate different materials. While these do not perfectly simulate the exact stresses and loads in the car, they do a good job of showing the differences.

Lowest factor of safety:
Delrin: 14.723
Aluminum: 22.955

You will also notices that on the plastic model, the same deformation happens with much lower stress levels. The plastic is modeled with 0.5" thickness, and the aluminum modeled with 0.09" thickness. Loads applied are 400lbs (the approx load we see at 160mph) on the front edge of the splitter in both cases. The deformation is exaggerated by the software so you can see where it flexes.

Aluminum:

Plastic:


If anybody still has any questions or concerns, please feel free to either ask here or PM and I will answer them for you.

 

Ok, I was the first one to comment on getting my ankles sliced off...........I was joking!

 

As has been said. If your gonna run someone over its gonna f them up whether you have a splitter or not. If you are worried about it just dropping off on a track and hurting someone then what is stopping anything else just dropping off and hurting someone?? It appears to be bolted up securely! If you like it, get one. If you dont, carry on posting hate! Its funny.

 

Knew you were joking Nikolas.