LocostUSA.com

First off, thanks to everyone who contributes to this site, its a great resource to have. Been lurking for quite some time and now its time for me to give back (a little bit at least).

The plan is to build a hybrid frame using four curved main frame rails (Atom-ish) but with the F20C engine from a 2001 S2000. Car will be street legal and used for mostly spirited curvey roads, trips to the Dragon, and possibly autocross or track day (never done either). Donor was bought back in '06 and has 45k miles on it. The stock rear subframe will be used along with the spindles, control arms, half shafts, & differential. I am giving up a weight penalty but I know the whole package works and is already done. A custom front subframe will be made with custom control arms, Motive's nifty uprights, and push rod suspension.

Specs: (subject to change)
1200-1400lb dry weight
98in wheel base
59in track
4.5 in ground clearance
205-225/50/R16 (24in diameter)
stock S2000 wheels for now
stock length front steer MG midget steering rack (26in)
minimal body panels
Corbeau Clubman seats (if I recall correctly)
one piece flat floor with sump above frame rails



I have been gathering parts for awhile now and started laying out the main tubes with pvc back in November. Not sure exactly how it's going to look with a front engine in an exoskeleton car, but hopefully I'll find out soon. I imagine an engine cover with probably a bump out for the rather tall F20C (25in) and a rear cover over the rear subframe and fuel tank.






I may modify the front diff mounts so that I can push the seats as far back as possible. I could cut off the bent rear sub tube and put in a straight tube and move the two mounts right above the driveshaft in the tranny tunnel. I would ditch the alum castings and make my own mounts. I'll see how everything lines out.



I started to use the stock front spindles but they are so dang heavy and have the uncommon inverted ball joint setup. That was until I saw Motive's nice uprights; lightweight, independent camber adjustment, double shear rod end mounts, use bolt on hubs. Recieved them and where exactly as described (in defense to Motive, the steer arm tubes look a bit rusty but he said he would buy some new steel to make mine but I told him not to worry about it and use what he had, just light surface rust)




More pics to come

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S2000 powered locost; build log here

What happened to the nice electric power steering rack from the S2000? Was it damaged in the crash, or was that you selling it on ebay a few weeks ago? I was considering buying it...

Based on what appear to be r-comps on the donor, it seems like it had an interesting ending.

Looks like a neat build.

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-Andrew
Build Log
Youtube

Man I wish I had your engine for my build.... Nice to see somebody else is also doing an At-om'esk FR car.

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“People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf.”
-George Orwell

how about the beginning it will have with those tires

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2007 R1 Powered Mid Engine Street & Track Car
Build Log: viewtopic.php?t=4970

That wasn't mine on ebay. I haven't gotten around to selling off any donor parts yet. My rack appears to be in good condition with the exception of possibly a torn bj boot from ...umm, someone's... improper dissassembly procedure. firebat, if interested, PM me.

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S2000 powered locost; build log here

I got some nice tools of the trade for Christmas, wonder how they knew, man I'm lucky. A JD squared tube notcher and the HF tube roller.



Steel was bought and I started on the front subframe construction. I am using 1 OD x .063W ERW. I planned to shorten the MG rack to about 20in to narrow up the front of the car for looks, but when it was built, I used an old sketch that had the stock length rack. Guess now I don't have to cut/weld the rack. Funny how things work out.





A rear brace will be installed between the top rear CA mounts and may have to be removable to install engine and tranny. I'll wait until the engine is in place to figure it out.



I made a jig for the suspension points I settled on using Wishbone. The mounts are made from some reclaimed 2x2x.125W square tubing.




I drilled the pivot bolts holes 1/64in under so they can be reamed to final size later. I also welded on some doubler plates (hole saw cutouts) over the holes to give some more bearing area for the bolt.

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S2000 powered locost; build log here

Yeah, I would say. When deciding to buy it, I wondered if that was a clue to a hard life that it had, but the seller, whether it was true or not, said those wheels and tires came off another S2000 that he was fixing up and pulled the interior out of mine for his. The impact to the front left was hard enough to break off the upper bj mount so I doubt that was the rim on the car or it would be in worse shape. I'll keep the tires around for mockup (unless someone wants them) and get something more suited for the street. I'll need to learn how to drive before I start using those sticky tires.

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S2000 powered locost; build log here

I fully welded the front frame so that all the movement will be done so that I can more accurately locate the suspension brkts. Using the custom uprights requires the rack location to be at the same position as the top CA frame pivot. I had to move the cross tube in the subframe higher so that the steering shaft can line up. I fabbed up some the rack mounts and they will allow some fine tuning with shims for dialing out the bumpsteer. Not shown are gussets to give more strength inline with the rack.




After a lot of fitting and grinding, I have the suspension brackets in place. For now, I have them tacked in place so that I can make sure the main front tubes will not interfere with them. I know they will move around some after final welding and plan to make adjustments later. Some more trimming and gussets are still needed for the brkts but they are basically located. The lower rears brkts won't allow much droop travel but I am planning on just 1in droop and 3in bump. The way I figure, running somewhere around 300lb/in springs on a 1200lb car will only allow 1in droop before the springs go loose anyway, so no need for anymore travel.





I tacked up the parts for the uprights. I added some doubler plates around the holes for the lower rod end just for a little extra area. I am using a 5/8in rodend for the bottom and 1/2in for the top.



Up next will be laying out and bending the main frame rails.

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S2000 powered locost; build log here

Wow, that jig looks great! Did you have it CNCed on a router? Using a jig like this I had an easy time as well getting the mounting points in the right spot. Alot easier than trying to measure a spot floating in space. Besides the adjustment you are planning with the rack you can also shim the steering rod end at the upright so you souldn't have any problems getting rid of any bumpsteer. One thing I learned though when adjusting mine was that with the rack inline with the a-arms is that very small adjustments make dramatic changes. (Didn't Staniforth say something like that in one of his books?) Thanks too for the nice words about my uprights. I hope they work out great for you.

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My Build Log: viewtopic.php?t=5850
CAD Drawings:http://locostusa.com/forums/viewtopic.php?f=26&t=6376&p=62465#p62465

Yeah, I cheated and made the jig on my home made cnc router. That was my last project that I built. It was the first thing that got built on my build table. Down the road I am thinking about cutting out a sweet dash for the car.

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S2000 powered locost; build log here

The 2"OD x .065W DOM tubing showed up and they are right at 18ft so it's going to be a little tricky to squeeze out two 8ft bottom rails and two 10ft top rails. They will be bent using the HF tube roller. I got through bending one tube before the setscrews locking the top die to the shaft stripped out on in the soft die material (others have had same issue). I was able to drill a hole all the way through the die and shaft and replace the set screws with some 1/4" bolts. The head of the bolt just barely fit past the edge of the die and I just fingered tightened the nuts. To try and reduce the spiraling, I tacked on some 1" square tubing on each end and layed a level on it. I then stuck some 3/4" pipe through to try and keep it from twisting.



It was a little tricking trying to get a matching pair, but with enough trial and error, they get pretty close.


After sore arms and some help from a few spare ones, the tubes are bent,
They turned out pretty good. There are a few dents when I changed to a sharper radius on the back third of the tube but overall, I'm happy.

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S2000 powered locost; build log here

Thats a nice "pipedream" router. Looks like alot of Z axis travel which can be a blessing or a curse. If only I had the floorspace... What CAD and CAM are you useing? My brother worked for a company that worked with mostly rapid prototyping and they had to close up shop. Guess who ended up with a solidworks 2009/solidcam 2008 seat? Haven't made any "real" parts yet as I'm still learning solidcam but its capabilities are just amazing. Been playing with the 3D and HSM and it makes me wish I had a router table big enough to do car bodies.

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My Build Log: viewtopic.php?t=5850
CAD Drawings:http://locostusa.com/forums/viewtopic.php?f=26&t=6376&p=62465#p62465

Thanks, doing it over again, I would save up and buy linear bearings and rails instead of the DOM tube and cam followers. It works, but took awhile to align and still sometimes locks up at the ends running high feeds. Over at CNCZone they have lots of good build examples.


Yeah, at the time, I didn't know what sizes I would get into so I left plenty of height under the gantry at the cost of some rigidity. Currently I have the t-slot table shimed up about 3.5in and that still leaves 6in from the table to the bottom of z-carriage. I planned to shorten the legs but haven't done it yet.


I am using SolidEdge which I got from the place I work. I have an illegitimage copy of MasterCam X3 and running Mach3 for the machine control. I'm still teaching myself MasterCam but am getting fairly compentant. Doing car body plugs would take forever on my setup running 30ipm, I did some 2ft x 2ft 3D contoured parts with a .02in stepover and machining time was 8 hours! (could increase step over distance and just sand more)

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S2000 powered locost; build log here

I like how your suspension brackets wrap around the pipe.