Roadster and GTM Doors/Crash Safety

[Mechie3]

I think my question got lost in the other thread, so I'll put it here so we can all discuss it some.

From the "My visit to FFR" thread:


10.What impact protection is planned for the door of the 818S?

A doors will be similar to all other Factory 5 kits

Well....consider me a noob, but I don't know what any of the other FFR kits look like when incomplete. Google wasn't too helpful, though I did find one pic of a GTM door without the interior panel. Does anyone know of any other pictures they can share? Does anyone know of a GTM or Roadster that has been involved in an accident? How did it fare? Any after pics or driver writeup?

http://www.gtm-supercar.com/wp-content/uploads/2010/05/IMG_0189.jpg

[RM1SepEx]

It didn't get lost, you just didn't like Dave's answer. The door is metal tubing and has an unstressed skin, just like the other factory five products. I expect that you can easily increase that area's strength by adding tubing

[Xusia]

Personally, I think the issue of side impact protection is being overthought. The frame itself has parts that extend down by the hip, as well as by the legs. There is really only a small "V" shaped opening around the thigh area for ingress/egress. PLUS metal framing in the door. That is WAAAAAAY more solid than any production car I can think of.

[PhyrraM]

Like any other purchase, you choose where your comprimises are.

I completely agree that, at this point in developement, most seem to be WAY overthinking most aspects of the 818. Or is it just that are we are feeling particularly entitled and are unwilling to accept any comprimises?

[Mechie3]

It didn't get lost, you just didn't like Dave's answer. The door is metal tubing and has an unstressed skin, just like the other factory five products. I expect that you can easily increase that area's strength by adding tubing

Well, based on the fact that you don't know what the question was, I'd say it got lost ;).

My question was (after you posted Dave's answer) "what do the doors of the other car look like?" (not what side impact protection will it have, as that got answered). Dave's answer was fine but requires some back history that I don't know. Just looking for help with those more familiar with other FFR cars.

The metal in the doors is what I've been asking about all this time. Prior to that the structure of the door was unknown. The opening to me looks as though much of the driver is exposed as the frame is parallel to the seat edge and doesn't extend forward. The hips seem protected, but I'm more concerned about a car intruding into the compartment during a T-bone, especially if it's not perfectly square to the side of the car. If it hits square, the car wouldn't fit in the opening. If it hits with the front corner, they could almost drive up onto you.

Old go kart pic, only thing I have for reference.

http://grassrootsmotorsports.com/media/img/projectcars/Screen_shot_2012-07-16_at_3.25.21_PM.jpg?js&keepThis=true&TB_iframe=false&height=600&width=700



Yes it is a compromise question. However, it's not a compromise of do I want to build this or not, it's do I want an S or an R.

After you've been in a bad accident (especially when its not your fault) perspective changes. I never worried about safety as I was a good driver. Problem is, of the last 3 accidents my wife and I have had, 2 were people running red lights and hitting us, and one was someone turning into our lane and hitting us. Two were in an SUV that came out fine, one was in my WRX that got totaled. If I had a crappy car, it could've been worse. I can't enjoy my 818 if I'm dead.

I wouldn't say the 818 is stronger than a good production car, but with the bars its on par. My wrx has large metal bars in the doors and nearly indestructible b pillars. The overlap of the door with the frame is also important. Large sturdy bars than only attach to the frame via single point (door latch) and in shear isn't good. Production cars have large overlaps between door frames and car frames to eliminate single points of connection. I don't know what the 818 doors look like.

My intent isn't to be entitled but to plan ahead for an 818s or 818r and what changes and additional cost one has over the other.

[Jacob McCrea]

I will post a few pictures of the Coupe doors' inner structure when I get a chance. It is a rectangular weldment of square 1" x .065 tubing (give or take on the thickness) and is pretty stout.

If you want some ideas about how you might install side impact/door bars in a 818S, if you haven't seen them already, there are some thorough threads in the Coupe and GTM sub-forums which will give you some ideas.

[Mechie3]

I will post a few pictures of the Coupe doors' inner structure when I get a chance. It is a rectangular weldment of square 1" x .065 tubing (give or take on the thickness) and is pretty stout.

Thanks. That's all I was looking to get out of this thread.

[David Hodgkins]

Here's a pic of the MKIV frame from FFR's site that shows the door frame:

http://thefactoryfiveforum.com/attachment.php?attachmentid=13477&d=1353093965

HTH,

:)

[Mechie3]

Thanks Dave,
I feel satisfied that an 818S with similar door structures should be safe enough minus getting hit by a massive SUV or lifted truck.

[jlahl3160]

I, and I would expect others interested in an 818 build have thought about the same questions that Mechie3 has asked... but have not asked because of the responses (like those here) when asking reasonable questions. Why do those of you who do not like the question, feel a need to reply in the negative.. adding nothing to the disussion. If you don't like the question why not just move on to the next thread?

Thank you Michie3 for your question. Thank you David for your answer.

One more item... its one thing to to drive around the track by yourself.. it is a whole different matter to be on the street with your wife / child .. other loved one.

John

[Evan78]

I'm glad this came up as well. I don't think safety can be overthought unless you're building a car that will never be driven. There is a point of diminishing returns and everyone will have a different point that they call "good enough", but I am happy to see some people giving it thought.

Asking what FFR has planed for a given area of the car is not the same as criticism or requesting that it be a certain way. It seems clear to me that Mechie was merely seeking additional detail.

[VD2021]

Does anyone know of a GTM or Roadster that has been involved in an accident? How did it fare? Any after pics or driver writeup?

http://www.ffcars.com/forums/42-factory-five-gtm-forum/273979-gtm-owners-careful-out-there.html

http://www.ffcars.com/forums/42-factory-five-gtm-forum/280810-gtm-crashed-texas-mile.html

[Xusia]

I, and I would expect others interested in an 818 build have thought about the same questions that Mechie3 has asked... but have not asked because of the responses (like those here) when asking reasonable questions. Why do those of you who do not like the question, feel a need to reply in the negative.. adding nothing to the disussion. If you don't like the question why not just move on to the next thread?

Thank you Michie3 for your question. Thank you David for your answer.

One more item... its one thing to to drive around the track by yourself.. it is a whole different matter to be on the street with your wife / child .. other loved one.

John

If you are referring to my post, I didn't feel it was negative at all. In fact, in reading it, I think my tone is neutral.

People have the tendency to obsess over details - sometimes meaningless ones. It's easy to get caught in the weeds, and I was merely trying to be helpful by pointing out it seems to me the existing structure looked more solid than any OEM car I know of. I was trying to ease his mind, not criticize...

[bstuke]

Buy the 818R and forget about it. As an owner of a MKII for a heck of a long time, doors are highly highly overrated. I wish I would have bought a challenge car..

[Jacob McCrea]

Here is the photo of the Type 65 Coupe's door frames that I mentioned above.


13503

[Mechie3]

Buy the 818R and forget about it. As an owner of a MKII for a heck of a long time, doors are highly highly overrated. I wish I would have bought a challenge car..

If it was just me, I'd say yes. I'm a little over 6 foot, so a door that comes up to my knee wouldn't be a problem. Plus, as a car enthusiast and the one who built the car, I wouldn't mind. I'm 50/50 over wanting an interior. My wife on the other hand, is a little over 5 foot and would have more trouble trying to step over a door. As she isn't a car enthusiast she would view that as a PITA. I also already have a dedicated non street legal autocross car, so I'm not looking for a no holds barred race car. I would like an interior. I'm essentially looking for a poor mans Ferrari that I can DD and that the wife won't complain about when I want to drive that somewhere together instead of something else.

There's also the $1000 extra cost to think about, needing to either wear a helmet all the time or cut the bars off (which means more work, not receiving the frame the powdercoating from FFR, etc).

[Turboguy]

One more item... its one thing to to drive around the track by yourself.. it is a whole different matter to be on the street with your wife / child .. other loved one.


Personally- I think if you are buying a car for it's crash worthiness you are looking in the wrong place, and at the wrong car.


An 818R -perhaps- if the correct seats are used, or passenger safety equipment is also worn, AND you're hit by a car of equivalent size, weight and height.

[Evan78]

Personally- I think if you are buying a car for it's crash worthiness you are looking in the wrong place, and at the wrong car.This sounds similar to me to someone saying "Why wear a helmet if you ride a motorcycle?" Just because you're riding/driving something that is more dangerous than the typical commuter vehicle, doesn't mean you stop caring about safety completely.

[Mechie3]

What evan said. I'm not looking for 5 star 22 airbag crash sensing automatic brake super protection. Lol. I just want to make sure if a compact or mid size car t bones me I have a fighting chance. Suvs and trucks? Probably not but a 2 star is better than a no star.

[Xusia]

Great analogy. I agree. I get where Mechie3 is coming from. I am also concerned with safety. But this isn't a fibertub VW kit from the 70s. It's a Factory Five. I've heard of numerous accidents on and off the track and the occupants have fared well in every case. BETTER than people would expect from a "kit" car. From everything I've seen and heard, these are solid cars. Based on that, I think the 818 will be as safe as an 1800 pound, open top sports car can be - which is not as safe as a truck, or a Volvo, or a... you get the picture.

[carbon fiber]

it's never gonna be as safe as a production car, but i'd prefer having as much safety precautions as possible. i made a comment on the rear crash protection issue on another thread. it's ignorant to "not worry" about safety. as far as the 818r for the street, you'd have to have a helmet on all the time for protection against the side bar for safety there.

[Evan78]

I just watched a Wheeler Dealers episode where they bought a Cobra replica (not FFR, I can't remember the brand) and had to get it past the IVA test. They had to add headrests between the roll hoops which seems like an obvious item for all Cobra owners. I'm amazed by the number of people that use seats with no headrests and big steel bars within striking distance of a relatively soft skull.

[PhyrraM]

...... I'm amazed by the number of people that use seats with no headrests and big steel bars within striking distance of a relatively soft skull.

Isn't that how the original Cobras came? I would think that was a styling descion based on how the builder wanted the car to look.

The 818 won't have that issue as it's a fairly original design.

[Evan78]

Isn't that how the original Cobras came? I would think that was a styling descion based on how the builder wanted the car to look.I assume you're correct. I just look at the setup and think instant head and neck injury in a collision. I wouldn't make that particular safety trade-off for aesthetics, but I'm in a pretty small minority it appears.

[skullandbones]

I assume you're correct. I just look at the setup and think instant head and neck injury in a collision. I wouldn't make that particular safety trade-off for aesthetics, but I'm in a pretty small minority it appears.

I am close to getting my roadster on the road and safety is a major concern. Two items have come up: what you mentioned about the roll bars and the angle of the shoulder harnesses. I've mounted cross tubes between the halos to hang the shoulder straps at the correct angle per Simpson disign. Also, the bars are going to be padded on the verticals. On the 818 I think FFR will take the inititive to take those issues into account on the basic design. A lot of people are going to be driving it without helmets don't ya think? I believe those roll bars will always win in a crash! WEK.

[Evan78]

Yeah, I didn't bring it up out of any direct relevance to the 818. I am just surprised by the decisions made by many builders in regard to safety.

[FFRWRX]

You can fool yourself into thinking you are safe from a side hit into the door of an FFR, and you might be depending on what hits you and how hard. Here is the inside of a production car door (1984 Fiero). Corrugated steel beam welded to an inner beam; duplicated higher up on the door too. If you want to add another 50 lbs per door you can make your FFR safer. It's not something that bothers me. Sometimes it's better not to think too much. :)

http://i1280.photobucket.com/albums/a500/carbuilder1/fiberglassing/aac4b383636057cb4e3504433d459a2d_zps69d8bde8.jpg


Rick

[BipDBo]

I've talked about this subject a lot in the past on this forum, all before the recent release of pics and info. After seeing pics of the final chassis, I feel a lot better about the safety, particularly for the 818R. I would like to know, however, what is going to be in the doors of the 818S.

NASCAR puts foam in the sides of their cars. This highly engineered foam is, from what I hear, pretty much indistinguishable from standard styrofoam.
http://www.professionalmotorsport-expo.com/winners_07/safety_winner.html
13549
Foam could be added to the doors and maybe even the front of an 818. It would be particularly easy to add to the doors since there are no roll-up windows.

[jlahl3160]

I believe the 50 lbs may be overstating the weight add to make the point... If you were to add an 1/8" steel plate x 36" x 36" it would weigh 44 lbs . I did not invision armor plating as necessary...:D

Adding steel the right way though can significantly improve structural strength... by replicating the steel in photo you shared can be added with minimal impact, as production cars do so every day, and the weight would not noticable in a DD... except of course you might notice it if you needed it in an accident.

I might have had different experiences than any of you... based on my experience driving, and being blessed to walk away from several wrecks .. all other drivers fault ... including being t-boned by a car running a red light with 4 people in the car, I would add the few pounds that it takes to be safer on the street.

Where I worked there was a sign that said "Safety is a decision" .. I think it is yours to choose.

John


You can fool yourself into thinking you are safe from a side hit into the door of an FFR, and you might be depending on what hits you and how hard. Here is the inside of a production car door (1984 Fiero). Corrugated steel beam welded to an inner beam; duplicated higher up on the door too. If you want to add another 50 lbs per door you can make your FFR safer. It's not something that bothers me. Sometimes it's better not to think too much. :)

http://i1280.photobucket.com/albums/a500/carbuilder1/fiberglassing/aac4b383636057cb4e3504433d459a2d_zps69d8bde8.jpg


Rick

[PhyrraM]

.......Adding steel the right way though can significantly improve structural strength... .................John

This is the key.

Not to take anything away from FFRs capabilities, but does the structure FFR adds to the basic frame do the right things? Does it make it better?....or worse? Does Solidworks have a "crash deformation" module?

Sometimes, trying to solve a problem creates other problems. I'd hate to see something added in the name of safety become a instrument of destruction.

**Not trying to say that FFR isn't capable, or a builder shouldn't attempt improvements...Just saying that there are tons of facets to consider when making descions and comprimises.

[Mechie3]

Solid works does have a drop test simulator. More than likely you'd just determine the impulse load and apply it statically and determine the deformation.

[FFRWRX]

I believe the 50 lbs may be overstating the weight add to make the point... If you were to add an 1/8" steel plate x 36" x 36" it would weigh 44 lbs .

John

I don't know how much I overstated the weight addition, I was going by the Fiero door weighing over 80 lbs; that does include the window and mechanism, but there is certainly a lot of steel in it. Of course you also have to have the hinges, latch, and surrounding structure strong enough to withstand an impact to do it right.

[Turboguy]

I just want to make sure if a compact or mid size car t bones me I have a fighting chance. Suvs and trucks? Probably not but a 2 star is better than a no star.


No offense, but I think you're putting a bit too much faith in some 1/2" x 1/2" mild steel tubing.

I believe the "inner door" structure on the 818 and the other FFR offerings is more to hold up the rest of the door and attach the skin to, as opposed to being for side impact protection.

I could be wrong though.

[Nuul]

Adding steel the right way though can significantly improve structural strength... by replicating the steel in photo you shared can be added with minimal impact, as production cars do so every day, and the weight would not noticable in a DD... except of course you might notice it if you needed it in an accident.

I might have had different experiences than any of you... based on my experience driving, and being blessed to walk away from several wrecks .. all other drivers fault ... including being t-boned by a car running a red light with 4 people in the car, I would add the few pounds that it takes to be safer on the street.

Where I worked there was a sign that said "Safety is a decision" .. I think it is yours to choose.

John

Well said, that's pretty much exactly how I feel. If I feel it's too slow with 200 extra pounds from safety equipment and small comforts like sound deadening I'll add more HP.

[skullandbones]

I thought the addition of foam would be a worthwill effort for the roadster but after checking with my inspection camera, that was a pipe dream. First, the space is very narrow at the bottom and then there is the issue of regulating the foam expansion. I had not looked at it closely (should have known it would not be feasable). However, the 818 door does lend itself more to some sort of reinforcement process (steel and / or foam. If the hinges and latch are solidly mounted, it could mitigate the energy transfer in a 20 to 30 mph crash. For many years, 30 mph has been considered a critical speed for sustaining injury in auto accidents. If the vehicle has enough support to cause it to be pushed to the side (light wt) instead of door penetration, driver or passenger would fair better. Here again there is no process for actual crash testing of such a mechanism for the 818. I don't know if the computer simulations would apply. IMO, WEK.

[flynntuna]

Have you guys seen the video on FFR's site where Dave rolled a roadster during a competition (thunder hill I think) and did some minor repairs ,and went on to win the compitition. I know its not the same as being t- boned but it does say a lot about the structure of the FFR's frames.

[Mechie3]

No offense, but I think you're putting a bit too much faith in some 1/2" x 1/2" mild steel tubing.

.

None taken. Someone else mentioned it was 1" tubing. When I get home from Seattle ill take a pic of the inside of a wrx door. They have excellent crash ratings and don't have much more than a few round beams in the door. Granted the end support of those beams and the door size opening play a big part in overall strength.

[Turboguy]

None taken. Someone else mentioned it was 1" tubing. When I get home from Seattle ill take a pic of the inside of a wrx door. They have excellent crash ratings and don't have much more than a few round beams in the door. Granted the end support of those beams and the door size opening play a big part in overall strength.


The size and encapsulating nature of the A and B-pillars are likely far, far more relevant for side hits than any reinforcement inside the door.

[Turboguy]

I don't know how much I overstated the weight addition, I was going by the Fiero door weighing over 80 lbs; that does include the window and mechanism, but there is certainly a lot of steel in it.


A Fiero door weighs over 80 lbs !?!? HOLY CRAP !!

[Xusia]

Hehe. Might explain it's lackluster performance! <-- Just kidding!!! :D

[Mechie3]

Here are the pics of the inside of a WRX front door. It has two tubular bars that run against the outside skin and are welded to the front and rear end faces of the door.

http://i139.photobucket.com/albums/q291/mechie3/2012-12-02_13-24-39_230.jpg

http://i139.photobucket.com/albums/q291/mechie3/2012-12-02_13-24-17_636.jpg

http://i139.photobucket.com/albums/q291/mechie3/2012-12-02_13-24-05_926.jpg

[jlahl3160]

In addition to the tubes, the obvious surface level changes on the inner door panel add significantly to the section modulus, which adds significantly to the strength & stiffness of the door.. and all welded together adds even more.

I would expect good safety results without being too heavy, based on observation.

John