Question- Rear engine/Trans mount structure in the event of a rear end collision.

[C.Plavan]

I'm just curious on the design of the rear of the 818. Did the computers take into the account the ability to "break away" the trans/motor mounts in the event of a big rear end collision.

I know the old 914 had this provision on the trans where the rear mount "Ears" would break, dropping the trans/motor. Last thing I would want is a motor riding shotgun with me (and going through the fuel tank before that) after a big rear ender.
Not trying to be a Debbie Downer- Just a safety question.

[THE ITALIAN]

That's a very good question.
I have two kids, a wife and a possible future hot girlfriend.

They have built in crush zones, but that is a great question
I would plan on a Fuel Cell & fire system for added safety

Thanks for that Debbie

[Frank818]

I would plan on a Fuel Cell & fire system for added safety

Uhm, not sure I understand, are you saying the fuel tank is not as well protected and secured as any fuel tank from a "normal" car?

By normal you know I mean any car coming out of a dealership like Toyota, Honda, VW, BM, MB, Porsche, Cadillac, GM, etc...

[C.Plavan]

The 818 has the gas tank closer to the motor (both mid). A "Normal" cars gas tank is opposite the motor. Porsche rear/mid engine and the tank in the front.

[bigAl]

It seems to me that the engine/transmission is basically a non compressible object - there really isn't much one can do with it in a rear collision. It will go where it is pushed. Any notion that is can be nudged down or something is wishful thinking.

[wleehendrick]

It seems to me that the engine/transmission is basically a non compressible object - there really isn't much one can do with it in a rear collision. It will go where it is pushed. Any notion that is can be nudged down or something is wishful thinking.

Well, Subaru claims that their flat motors are safer as their unibodies are designed so the motor slides under the passenger compartment in a collision

I honestly don't expect any real safety features in this regard from FFR, It's a robust spaceframe, but with the seat so low, as you say, the in a bad rear-ender the motor will likely get pushed into the fuel tank.

[THE ITALIAN]

There are crush zones in my roadster as there is in the 818.
A fuel cell can have a bladder, plastic and foam inserts- designed not to "pour-out" fuel or break.

"""not sure I understand, are you saying the fuel tank is not as well protected and secured as any fuel tank from a "normal" car?"""

No, I don't think so, it is very light "Race car" The 818 does not have tons of metal , subframe or space surrounding the driver like a Normal car, nor is it high off the ground like a normal car.
One advantage it may have in a collision would be "it's weight" compared to what could come in contact on the street, like a watermelon hitting an orange. Even the body panels would break away then the other object would have to deal with a space frame.
Nothing is perfect, but you can purchase more safety-fuel cell- fire sys- "R"

[bromikl]

Safer than a motorcycle - and that's safe enough for me. :-)

[Frank818]

Safer than a motorcycle - and that's safe enough for me. :-)

Yeah, I didn't think about that one. loll

[Goldwing]

I'm pretty much in the camp with bromikl. The 818 is a replacement for my Goldwing, thus the handle, and so I look at any metal surrounding me as safer than a motorcycle. It's also how I funded my 81&, by selling the Goldwing (for medical balance issues) and soon my little Buell Blast. That said, I'm going to look into as many safety items as I can starting with ABS. I'll look into seat belt airbags or just going with 4 or 5 point belts. Bumpers underneath if possible (I need a better understanding of the built-in crumple structures to understand if a bumper will help or hurt. I am looking at being able to tow my kayaks, so a receiver/bumper is pretty much a certainty in back. I didn't fully understand the fuel tank used here, if a bladder will make it safer, then yep, I'll probably do it. That's a great idea!

[metalmaker12]

The actual frame structure around the occupants it very strong from there test and should be as safe as most small open cars like a miata or s2000, the side impact looks to be pretty decent to. I think the motor and tranny would get destroyed in a rear end crash over 15- 20mph. The rear lower frame might take a low hit decently, but at this impact speed most cars will suffer extreme damage, but without airbags and crash test it will not be proven to be as safe as any factory car. it will be safer than a bike lol

[C.Plavan]

I just want to be clear I was not knocking the design. I get it. I just wanted to throw the question out there to see if any computer simulations were done. It in no way is making me second guess my 818R coming- Mine for sure will have a fuel cell since it will strictly be a race car on the track. With the 818R, you just have a few more options where to put the fuel cell.

I cant get mine fast enough. :P

[PhyrraM]

There are crush zones............. in the 818........

Where? We've all seen the frame and there is only the bodywork and what looks to be a simple 3/4" steel tube structure holding the radiator in the front. In the rear there is only a simple support for the rear of the transmission and the bodywork. On both ends the first thing with substance or bracing is the suspension mount points, which are approximately in line with the wheel centerlines. In the front, that's awfully close to where your feet go. In the rear the transmission is already being pushed forward by the time an impact hits real steel.

I'm NOT saying the FFR should have done more (they have done a wonderful job on the chassis), but I would not call what we have seen so far a crush zone. To do so is just calming your own reservations.

[THE ITALIAN]

Dave spoke of them integrated in the early design, as they did in the roadsters. It is in video. it does not show up in the frame as "stickers" or glued on panels, it is part of the design.
We have seen roadsters crashed, and they have pushed frame sections away from the driver as designed.
I don't need to be "calmed", I have been driving my roadster for over 6 years