D Modified Project

     Our next project will be to build a Solo 2 prepared D Modified Lotus 7 Clone with a Mazda rotary engine.  This will be done on a shoe-string absent acquiring sponsorship to cover some of the costs.  We will be initially building it as simply as possible to see how fast we can go at the lowest cost possible.  This should be an interesting project...one I've wanted to do for years now.  I should pick up a batch of steel next week and start cutting and burning.  I'll try to document the build here as well with as many photos and as much commentary I can muster.  It will take a while given the lack of finances but should be fun, none-the-less.

Contact Charles Cox if you are interested in discussing
any sponsorship opportunities.

In the meanwhile, I'm planning to take the car from thie current car that weights around 2,200# or so and looks like this:

To something like this weighing around 1,100#:

Using the same engine, transmission, differential and other parts from the old car, I'll be building the frame as well as most of the body panels except the nose and probably the fenders in hope of having it ready for next season.  I have a garage now...should be fun!

Given I'm now about 4-5 seconds a lap slower than the fastest cars here now, it will be interesting to see how much I can improve with a car that weighs half as much and hopefully has another 100hp by porting the engine when I rebuild it!

I'm not using a "kit" but building the whole thing myself from frame to suspension (except some minor body parts like the nose and fenders.)  So far, I'm planning to use my existing engine transmission and differential among other things...I may modify the front struts to use for the front hubs for now too in order to utilize the wheels I already have.  I'd prefer to use a Miata front suspension but for cost reasons as well, may just use what I have.

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Build Log - Just Started 01/2012 | Links and Library

11/31/2011 - I finally bought the MDF build platen Build Platenand have it set up to use in the garage.  Kim made a trip back down South and picked up my 1.5" tubing bender Tubing Benderso I'll be able to make the roll bar/cage.  I've layed out the bottom rails so far but have yet to buy any steel to make the frame but I do have 50' of 1.5" .125 DOM roll bar tubing left from my Miata project to build the roll cage from.

Build PlatenBuild Platen with Layout DrawanHopefully I can pick up some steel this week and start cutting and welding (tack weld) some pieces.  I'm planning on a modified McSorley 442 version using the RX7 as a donor and building it to a DM configuration for both autocrossing and hill climbs.  I'll run DOT tires and will probably build a windshield for later road use and plan on two seats for the same reason as well as training purposes for the track.  Although I hate to take apart the RX7 given it works so well right now, I've always wanted to build one of these and it is now or never...I'm not getting any younger.  I want something easier to work on and modify if I want.   These are about as simple as they get.  The Miata I last built (http://www.miatapower.com) took 3 years to build...I don't have that much patience and am trying to get it done by the start of this season in June.  If not, it will take one more season but that should be plenty as the entire frame is easier to build than the roll cage for the Miata!

Build Bench and Tools Build Bench and Tools Next...get some steel and start cutting and burning!

01/05/2012 Just got the first steel shipment...click here for itemization and cost.  I had to add to the list to make the $200 minimum as their prices were extremely good at Farwest Steel here in Medford!  I already have the 1.5" DOM tubing (50') left over from my Miata roll cage build, I'll use for the roll bar/cage.

Pile of steel to build the frame  Steel ready to cut and burn

Should start my first cut and tack welds today and see if the welder still works after the move...I need to find out if I can actually see the welds with my new helmet and glasses...that was always the problem before!  More photos when I do my first lower frame cuts and lay-out...I also need to get the RX-7 to Rob whom I'm planning to do the engine rebuild but it still works so if I can't get far enough along with this project to justify tearing down the RX-7 donor, I'll wait until next off season to do it and run the car as-is for one more season.

01/06/2012 I can say I have officially started the project.  I cut and weleded my first steel today making the lower portion of the frame.  It needs some more front end work, tunnel and engine mount pieces still installed but won't do those until getting further along with the top frame section, rear and front bulkheads and so forth.  A lot more tedious than I anticipated but going well.  My back doen't allow me to do too much at once and starts hurting after a couple of hours of standing up and doing the work so I need to pace it.  You can see how I've made a pulley setup to lift the build table/platen to put the sawhorses under it and holes drilled to put clamps in strategically.  The MDF is wider than the frame so that's why it looks offset...rather than cut off the side for the proper width, I just left it the original width although anything making it lighter might be a good thing.  I expect to get a lot further on next week as I probably won't have time to work on it over the weekend.

I will need to do a lot of modifications to the book chassis and or the McSorely 442 which I'm basing it on, in order to be satisfied with the triangulation and structure as I feel it needs to be done.  The transmission tunnel and engine will need to be offset to the right at least an inch or so, which is due to the differential being offset in the RX7.  The stock car accommodates this by mounting the engine at an angle to the differential which is probalby fine but given I want better balance and performance, I want the engine as far back and to the right as possible to offset single driver weight.  If I wasn't planning to accommodate a second seat, I'd go even more radical putting the engine into where the passenger compartment would be (within reason) but because we want two seats for rides and training and eventually to make the car a street car, I'll make those compromises.  I'm glad to finally be building something like this after all these years talking about it...doing research, buying books and so forth...hate to use the RX-7 being such a good car as a donor but just the way it is.  As special as the car is, they're a dime a dozen...if I could get enough money for selling it in tact, that might be different but the parts are worth more than the car in total so parts it will become.

01/07/2012 What I did today...main rear bulkhead construction.  Modified it by doubling up on the upper cross member which I will mount the main roll bar hoop to...will plate it first but I think will be better than the book suggestion of a 4" wide plate at each corner connected by 1 tube and a big gap between.  This should be considerably stronger.  I'll probably take a day or two off from working on it. but next will be the side rails and front bulkhead forward of the engine compartment.  New configuration calls for a 15" tall side rail instead of 13".  Should give more depth for the motor and stiffer frame.  Looks like the drive shaft tunnel can be about 1" offset to the right and the seats still fit. Will plan on it and hope for the best.

01/09/2012 Today...adding more tubes.  

01/10/2012 Yet more tubes...at this rate, I'll run out of 1" square which I'd prefer to use for everything instead of the 3/4"

01/16/2012 More tubes doing the rear end now but not welded onto the main chassis yet.  Need to sort where to put the chassis when it gets longer and heavy enough where it is not comfortable for me to try and lift it any more.

01/18/2012 Welded on the rear end frame section.  As with everything, needs a lot of work yet and finish welding but shape is taking place and showing the general structure.  Will probably do the cage next.  I can do that without knowing where the driveline ties in but getting to the point of needing engine, transmission and differential dimensions to do a lot more like the drive-shaft and transmission tunnel.  I need to start ordering other parts like the nose, scuttle, hood (unless making either or both), fenders and some of the weld-on tabs for Dzus fasteners, suspension brackets, tubes and fittings for the control arms and the like.  Then I'll need to sort shocks for this application and springs...that will be a major investment.  Will need a new radiator and design ducting for it and a new oil cooler and fans...as well as fuel cell and so forth.  Doing the most for the least right now.  Also need to sort which steering rack I'll use.  I plan to go ahead and utilize cut down front struts so I don't have to buy any more stuff there...I want to reverse the radiator with ducting out the top behind it like it should be, if I possibly can.  Will probably order the Canadian +4 nose with chin spoiler...$300 Canadian though.