Warren, what's your email address? I'm wondering if you would like to continue to bring the kit car into the modern era with modern materials.
Warren, what's your email address? I'm wondering if you would like to continue to bring the kit car into the modern era with modern materials.
This just in! Here's a shot of a complete Sport kit with the optional front and rear wing mounts.
Do you guys sell the fenders/mounts separately? If so whats the width and price? These should be perfect for my midlana build, it uses miata suspension
I told my wife I wanted one. She said "fine". Then I told her that I wanted the LS version. 
Just tell her you meant one built from an "LS" trim NB2.
I told her I'd just use my truck motor. The truck isn't scary. It'll be fine.
In reply to bgkast:
Yes. Info@Exomotive.com
+1 on the fenders and mounts----
I've been asked a really good question over and over again recently: "is round tube better than square tube?"
This question popped up on Flyin' Miata's Facebook in light of the Westfield/Exocet side-by-side shots, and I figured it would be nice to show my answer in pretty pictures.
Now, before we look at results, repeat after me: all simulations are wrong, but some are useful. SolidWorks Simulation is a lot better than COSMOS was even a few years ago, but it's still not Abaqus. If anyone wants to throw me $40-60k for an Abaqus or COMSOL license, I'll gladly re-do this experiment.
Anyways, this FEA model is within the scope of the question (comparison), so it should be useful in answering it. The model assumes perfect welds, perfect normalization, and no residual stresses at the tube seams. I put a 3/8" radius on the outer weld surface and a 0.1" radius on the inside. This doesn't reflect real life, but it makes the FEA mesh more valid. We're looking at the behavior of the tube, not the weld itself. In the real world, the square tube will have more residual stresses, a more significant heat affected zone, and the welds are more critical, but we'll assume the best for the square tube. It is a simple model and a simple material, so assuming a linear isotropic behavior should be fine. The loads are 1000lbs down and 100lbs across on the top face of the vertical tube.
Alright, the first step is to find two common tube stock sizes that would be used in a similar manner. Let's go thick wall to make the FEA a little more accurate:
Now let's set them up in a joint and apply a valid mesh (this is the "finite" in Finite Element Analysis):
Ok, now that we have some similar tubes, let's see how much they deflect under the same loading configuration:
Hmm, 15% more deflection is significant under this loading condition. Let's see the stresses:
What does this mean? The red spots are hotspots of stress, and they'll either buckle locally or tear, depending on the loading condition. This is bad for single-event forces and over time. The round tube very obviously spreads out the loads much better, resulting in fewer stress concentrations. Remember, I radiused the outside of each weld to 3/8", so we're not looking at a mesh anomaly here.
Summary: If you are not constrained by the overall tube dimensions, round tube is a better choice for use in a spaceframe. The reason why most kit cars and many racecars use square tube is economics. Mitered joints can be done with any old saw, and manually cutting square tube is many times cheaper than coping round tube. With access to a new-tech diode laser tube cutter, it costs us the same to cut complicated joints as simple ones, so we chose to spend the CAD time and go with round tube just about everywhere. Square tube is used in the Exocet only where it makes mounting things much easier. We even turned a lot of those tubes 45° to give them a complex joint with more of a perimeter. For example, here's the inside of the firewall, right near the passenger's left foot. This area is important, because it helps the transmission and engine deflect downwards in the event of a severe frontal impact:
Warren v wrote: This area is important, because it helps the transmission and engine deflect downwards in the event of a severe frontal impact:
Not that I read a lot on kit cars, but I don't think this is a consideration with 99% of the companies out there. They just want the parts to fit and be cheap to make. Well done sir.
Nice writeup, Warren. It would be interesting to see that test duplicated with the round tube constrained to the same maximum dimension as the square, to see what happens when you're limited by your packaging.
You guys definitely have access to manufacturing capabilities that most kit car manufacturers don't. Even those big arcing main tubes in the Exocet aren't easy things to make. I'm pretty sure Caterham frames are still made exactly the same way the original Lotus Seven Series 1 frames were.
In reply to Keith Tanner:
Generally the stiffness goes up with OD, but so does the weight. Strength is still better with the round tube. Less buckling.
I think I owe the fine folks at Lincoln Electric Atlanta a ride in XP-3 and a hug. This little guy just showed up on our doorstep and asked if he could make some cars for us.
http://www.lincolnelectric.com/en-us/Equipment/Pages/product.aspx?product=K3068-1
For various nefarious reasons, we need two more Exocet jig tables. That means I get to iterate the suface design based on our experience with the first 8 cars. The manufacturing effort required to add a big man-hole, larger corner radii, access holes, and positive alignment features consists of dragging and dropping a DXF file. The future is awesome. 
And yes, the outline of the chassis is laser etched in that top surface.
holy crap...you guys are making these wth Lego men? The future IS awesome!
Yeah, until his little claws break off and his space welding helmet cracks.
Warren v wrote: I think I owe the fine folks at Lincoln Electric Atlanta a ride in XP-3 and a hug. This little guy just showed up on our doorstep and asked if he could make some cars for us.
Nice. I have a 180 that I really like.
Warren v wrote: For various nefarious reasons, we need two more Exocet jig tables. That means I get to iterate the suface design based on our experience with the first 8 cars. The manufacturing effort required to add a big man-hole, larger corner radii, access holes, and positive alignment features consists of dragging and dropping a DXF file. The future is awesome.
What, no cupholder?
;-)
DWNSHFT wrote: What, no cupholder? ;-)
Cupholders? You must be new here.
I love GrabCAD.
In reply to Warren v:
I am Australian based and working with the local supplier to get one of the first Aussie assembled LS1 conversions on the track.
I have a 1997 NA Racecar and I have got it down to 1936 lbs or 880 Kgs just some of the steps needed to achieve that were.
it's quite a bit of effort to do all these little things this kit is another huge leap beyond that for not so much extra effort.
Keep up the good work and don't neglect the non Yanks.
Warren v wrote:
Warrens Lego men run on propane...will wonders never cease?!?!
So have you guys got a fully built, with fluids, Exocet Sport on the scales yet?
XP-3 was 1515lbs when she rolled out on VIR with wings, turbo, and a full tank of gas.
Warren v wrote: XP-3 was 1515lbs when she rolled out on VIR with wings, turbo, and a full tank of gas.
Daauummm!
For the curious, the front weight of XP-3 was 53.6% with a driver positioned far forward. With the front wing taken off, it should be right around 52.3%. In my preferred seating position for my 6'2" self, it should be right at 51.5% to 52%, which is better balanced than a Mazdaspeed Miata. A naturally aspirated Exocet with no intercooler shenanigans, a trunk-mounted battery, and a stock radiator should be quite close to 50/50.
It really, genuinely drives like a distilled Miata. I was drifting XP-3 around like a pro within the first two minutes of driving it (no setup or alignment), and I'm not a particularly good driver.
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