Interesting idea on LA Craigslist

[Grumblebuns]

I'm not an engineer to evaluate just how effective this idea is. At the very least, it has a good place to hang aftermarket seat belts.

https://losangeles.craigslist.org/lac/pts/d/lotus-europa-s2twin-cam/6567248057.html

[BDA]

I first have to say that I can't relate to those who fear falling through their floor. I've never had that fear but maybe I've been blessed with a stouter floor than some (I know the thickness of the original Lotus fiberglass is not very consistent).

Having said that, I think what he's done is pretty interesting. I'm not aware of a problem with old fiberglass and it seems it would just be easier to add a layer of mat or cloth to beef things up. I'm not sure if his firewall braces in the engine compartment would work for me either. I've seen several people replace their firewall with marine plywood and that always seemed like a good way to go.

But I feel I'm being too negative. He's obviously put a lot of thought into it. I would think it would be a very welcome modification to a race or track car!

[Grumblebuns]

The problem with products and ideas like these are not knowing the background and experience of the people putting out their offerings. I don't know if he's a one man operation working out of his garage with limited knowledge of chassis design or an actual experienced race shop.

What he is selling is interesting. The seat point of attachment at the base is connected to the alloy firewall which in turn is braced to the chassis. The question is how effective is it.   

[BDA]

He claims over 45 years of experience - presumably he means Europa experience at least.

The firewall is well braced and since you'll generate far more Gs in braking than accelerating or cornering, that might be useful in a racing or track situation, but the things he says he's seen can be remedied a lot cheaper and simpler for a street car.

Before I bought this, I would ask someone like Richard if he thought it was worthwhile. But then if he did, Richard would probably sell his own version.

[GavinT]

If anyone's considering the engineering, just take a look at image #6 on his site. 

[EuropaTC]

If anyone's considering the engineering, just take a look at image #6 on his site. 

Good spot, I hadn't bothered looking at the others until you mentioned it.  But looking at the way the Y section has been hacked about it does make you wonder what's going on there.

I wonder if it's really a project to fit a bigger engine ?  If so then I would have thought it's back to the drawing board and constructing a space frame section rather than hacking the original chassis which, let's face it, is a minimal concept and designed to be as cheap/light as it can be for the job in hand.

I can see where the guy is going - a stiff firewall with rigid seat belt mounts. But are the original ones that bad ?  OK, the steel in the lower sills had rusted away over 40yrs in my car but in their original form I think the design would have held the seat belts in place in a most situations. Any serious (3-4-5g collision   ?) and it's not going to be the seatbelt that's the main concern, it's the collapsing weather shield all around you     

[GavinT]

Yes, the major cut out in the left hand leg of the Y must impact the torsional rigidity substantially, I reckon.

I can’t see the sacrifice of torsional stiffness is addressed anywhere but he mentions a Suzuki GSXR engine / drive train conversion, so perhaps that’s where he’s going.

But if looking to improve the seat belt mountings, I think there’s many easier ways to do that.

And if major chassis mods were acceptable, I’ve always thought a Subaru 2.2 litre boxer engine would be pretty interesting.
It’s all alloy and would place the engine weight much lower than either a Renault or a TC engine.   

[Rosco5000]

If you look at pictures 7 & 8 it looks like there is an addition subframe bolted in to house the bike motor perhaps I imagine that there will be structure added by that piece but unless you see the completed car who knows how strong it will be.