LocostUSA.com

I think if you're really that concerned about the fuel tank, maybe you ought to switch to diesel, especially since your sig indicates you've got some familiarity with diesel.....

Ok, now that that is out of the way, I think the rear collision aspect should be a big concern for lots of people. These cars are capable of some pretty serious maneuvers, and the rest of the folks out there are
1.) driving things not capable of the same level of braking or handling performance
2.) often paying more attention to anything BUT driving (cell phones, radio, passengers, etc)
3.) going to hit us with something that is alot heavier than a Locost. And likely to be more solidly built.

So, the question is, how do you build it stout enough to survive that kind of beating.

I know the focus on alot of people's minds on here is maximizing performance by building lighter / smaller / lower power, etc (add lightness). In my case, I know I'm willing to put more weight in especially if it's in structural areas that might keep me protected in the event of a collision.

JustDreamin

You don't. Plain and simple. You cannot build to sustain a rear end crash at, say, 30MPH. I am talking from experience. I have been rear ended more times than I can count on with one hand and am almost to the point of needing to count on my toes. There is no space available in a Seven for a crush zone. and the car is 1/2 to 1/3 the weight of your normal sedan, which means your car will absorb 2x-3x the impact force that the other car will.



Consider that if you make a strong tank, then that tank will be slammed into your back. If you let the tank deform, but maintain its contents, then I think you are better off. I think that the idea of a "real" fuel cell is good. Bladder and foam. Figure close to a $1000 for a custom bladder and design to racing requirements. It should hold together better in a crash than the welded up tank that "Uncle Ron" designed and safer than your ~1/8in steel armor. That being said, here I am welding up my second fuel tank. Go figure!

Keeping things safe is a good goal. Anything done to get closer to that is a good step forward. But, it will never be anything approaching SAFE. It "may" be generally safer than a motorcycle though!

If ultimate safety is your goal, look into buying a 2013 Whatever. If fun driving is what you seek, build a Locost.

Sorry if this seems to be a rant. I can't word it any other way without sounding this way.

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Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

Sorry, looking at my post, it isn't clear what "it" I was referring to....

My concern was not exactly the gas tank, or even the rear of the car, but making the passenger compartment surviveable, since that really is the only critical area. Keeping the gas tank from spilling it's contents everywhere is a concern, since I don't really want to be "flambe'd", but if I'm dead already (because the passenger compartment collapsed), the fire will just give me a nice viking funeral.

Anyway, you make a good point about not wanting to have something too solid in the trunk that ends up getting pushed into your back. A tank that deforms but holds it's contents would definitely be preferable. Another possiblility is a tank mounted such that it doesn't deform, but instead gets pushed under the passenger compartment, absorbing energy along the way and going someplace "safe" (under my a$$ instead of through it). Trick with that is to figure out how to get it to dive under when loaded that way.

JustDreamin

In my mind, the best way to walk away from a rear end collision is to avoid it in the first place. This means, for me anyway, the car will be painted a bright color, have a center bright LED brake light (possibly flashing a'la a lot of motorcycles), and have an awesome rear-view mirror so I can dart out of the way if possible.

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Fingers of butter and fists of ham.

If you are really concerned about safety, don't build a Seven. Period. It's marginally more safe than a motorcycle. Use motorcycle type driving habits.
These cars are never going to be "safe". The flashing high mounted brake light is a GREAT idea. Always have an eye behind you. ALWAYS!!! Leave a bit of space in front of you at stops just like a motorcycle. Try and have an out.

I pulled out of work last week (in the M3)and there were no cars near. Pull out and within a few seconds I see woman in a giant SUV on a cell phone going +75mph in the 45 zone barreling behind me. I'm doing 45-50 and there is a car in front of me. I see the SUV bobbing and weaving as she slams the brakes at the last second. Happens all the time on that road. You pull out with no cars in your lane, look up and somebody is right on your ass because they are doing 30-40 over the speed limit. Part of reason I rarely ride motorcycles anymore.

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Volvo 240/P1800 Based Locost
2004 Aprilia Mille Factory
1988 Volvo 240 5 Speed ( For Sale)
2002 Toyota Tacoma
1999 BMW M3

I'm extremely tempted to keep my car on the table to finish the entire build. I have the world's worst back and that will help. The legs are strong enough and so is the top support. If I do this, I'll have to widen and lengthen the top. When the car is done I can hoist it to the ground from the barn beam above or just lift it down with my tractor.

Has anyone done the above?

JDD

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1998 E 300 Turbodiesel
2006 Jetta diesel
1995 C3500 purple diesel bucket truck w/yellow & silver flames

It's not quite a 'build' but my friend totally assembled his Birkin on a 'table' of sorts in his basement. We used a chain hoist (to the roll-bar) and a come-along (to the frame forward) attached to the living room floor joists above to lift the completed car off the table, removed the table, and lowered the car. It juuust rolled through the patio doors (1/4 inch each side) on his walk-out basement. It was nominally totally finished, apart from some mega (micro?) squirt wiring mistakes that stopped it from firing.

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Warren
Isuzu Pickup/SR20DE, +401 COLD frame
Build Log: viewtopic.php?f=35&t=11601

I use saw horses to work on my Formula Ford. Being able to put your car on the workbench will always make for a nice story when you talk to people. It is so much easier, it will become one of your favorite things about the car.

I don't see why you need to make the top bigger. Does the oil pan hang under the frame rails? Just make sure there is some blocking or table under the motor mounts. If the frame is wider at the back then the build table consider some fir 2x4's on their side. That should be enough for oil pan clearance too.

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Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.

A friend of mine has a Formlua Vee that he puts on steel sawhorses to work on. He has a pulley system with steel cables attached to the roof joists and culminating in an electric winch mounted to the header above the door. Just hook some S-hooks over the suspension and press the button to raise or lower the car. He even stores the car over winter up there with his DD parked nicely underneath.

A Vee is lighter than a Seven but the sawhorses work out better than a build table would. You can get right up close to the body. Less reaching that way.

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Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

The cars on the ground. Nothing like tires and wheels to make it look like a car. I have a couple of tire clearance issues in the back. I'll probably run spacers to fix it but I'll wait til the fenders are here. I also made a shift linkage extension to get the shifter close to parallel with the steering wheel.

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1998 E 300 Turbodiesel
2006 Jetta diesel
1995 C3500 purple diesel bucket truck w/yellow & silver flames

more photos

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1998 E 300 Turbodiesel
2006 Jetta diesel
1995 C3500 purple diesel bucket truck w/yellow & silver flames

Even my wife is coming around to this whole Idea!

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1998 E 300 Turbodiesel
2006 Jetta diesel
1995 C3500 purple diesel bucket truck w/yellow & silver flames

Yo, JD-
Cool picture! You know that saying about "If Mama ain't happy..." so having her take a test drive is a very good thing!

Chassis is looking good too. I'm liking the red wire wheels!

Keep up the good work!

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JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom

She looks happy to me. She's even color coordinated with the car. Cool!

Looks excellent, JD, just brilliant. Very inspiring. Can we get a close-up picture of the pedal box/steering column arrangement? I'm really struggling with that.