Design Started

My current design has the wheelbase at 77″, and the track at 39″.  The overall length of the car is 106″ and the body height 37″ (not including the additional height of the windshield or steering wheel).  I hope to keep the overall weight below 300 lbs.

Thunderbolt Design Ideas

The overall size of this beast is awe-inspiring and is one of the characteristics that drew me to this car.  I especially love the blend of metal and wood.  This unique car design will afford me to try several new ideas that excite me in this build.  As such, I expect it will take me longer to build, but I find I love building as much as I do driving.  To me it’s a win-win proposition given that I already have one cyclekart to drive while I’m building this new amazing car.

One of the things I love most about cyclekarts is the freedom to explore new design ideas or incorporating ideas from others into your own custom blended design.  Seeing how they develop and learning the intricacies of each design element really intrigues me and keeps my brain cells invigorated.  While disappointments do happen, it is very thrilling when your ideas work as hoped for.  In any case, the freedom to express oneself through design is an art form I am highly attracted to.  Seeing what others have done and tried is something I also enjoy tremendously.  There are some real geniuses and artists in our cyclekart community, and I love the way everyone is willing to openly share their ideas.  To all those I have borrowed from, thank you!

So here are a list of several design elements I intend to incorporate into this project.

DESIGN ELEMENT #1 – EDWARDIAN SIZE
Given the original car large size, my cyclekart will need to be oversized as well if I am going to keep any resemblance of its original design.  So the first element in this design will be that it fit into the Edwardian classification.  There’s not a lot written about this class except it:

  • Uses 18″ diameter wheels instead of the usual 17″
  • The seat must be a minimum of 4″ above the axle
  • The wheel base can be extended to around 74″
  • The maximum wheel track still stays at 39″

DESIGN ELEMENT #2 – ALUMINUM BODY PANELS
The car will employ 0.040″ thick aluminum body panels as I used in my Bugatti Type 13 cyclekart.  I found this to be the right balance needed to handle every part I needed in my previous build, so it should work well here too. 

DESIGN ELEMENT #3 – WOOD BOAT TAIL CONSTRUCTION
I will remain true to the wood boat tail construction by using Sapele Mahogany as was used in the original Thunderbolt.  I have not done planking style wood working before, but the wood look appeals to me and I love woodworking and learning, so this is a perfect fit for me.
 
DESIGN ELEMENT #4 – CHROME RADIATOR WITH MOVEABLE LOUVERS

The prominent Rolls Royce radiator stands very proudly up front with its beautiful shiny surface.  I want to get a high shine chrome finish and considered all the ways in which I might accomplish this inexpensively.  After exploring a few different avenues, I decided to build it out of thin steel and MIG weld it using my existing flux core Titanium welder.  Once done, I will send it off to be chromed.  It will cost a lot I’m sure, but I think it will be well worth it.

Another aspect I’m seriously considering is to have the vertical radiator louvers adjustable so they can be closed or opened.  I intend to use a push-pull cable to manipulate this from the cockpit.  This will be a cool (pun intended) feature.

DESIGN ELEMENT #5 – HOME MADE LOUVER PUNCH
This car has a lot of louvers on both sides of the engine and also along the top cowling.  So it will therefore be necessary to fabricate my own louver punch.  I considered building this from hardened steel, but one cyclekarter, used hard wood with excellent results using 0.040 thick aluminum.  So I’m going this route and hope it works as well as he made it appear to be.

DESIGN ELEMENT #6 – COMPOSITE FRAME
The car size will be quite large and if I’m not careful will become excessively heavy.  To help overcome this problem, I plan on building the frame out of a composite sandwich consisting of 0.040 aluminum, 1/4″ thick plywood, and multiple layers of carbon fiber.  I believe I will save about 50% to 60% of the weight when compared to the typical 1″ x 3″ steel frame.  I conducted some experiments on my Bugatii last year and found I saved close to 70% weight over the standard frame.  By adding an aluminum face to the composite so that the outward facing parts of the frame give the appearance of an aluminum frame, it will add some weight, but still deliver significant weight savings without any penalty in strength.  This method will also allow me to shine the frame to that same luster as the body cowling which will help with the overall look and appeal.

DESIGN ELEMENT #7 – REAR SUSPENSION
Having ridden my Bugatti for a bone-jarring ten hours now, I want to incorporate rear suspension.  From what I’ve seen others do, you simply hinge the rear car frame behind the seat and use two shock absorbers from the moving rear frame and the forward stationary frame section of the car.  I think this will work well and be simplified given the fact I want to also mount the engine up front.

DESIGN ELEMENT #8 – FRONT LOCATED ENGINE
Now for the more interesting and most challenging part, a front mounted engine.  Given the long nose and ample room under the front cowling, it only makes perfect sense to locate the engine in the front rather than in the rear.  This will give the front end more weight and better stability.  It will also resolve any excessive heating of the wood boat tail which could potentially ruin the wood.  After all the work and expense I expect to incur in building the wooden tail, the last thing I want is for it to catch on fire or dry out and start splitting on me. Finally, with adjustable front radiator louvers, I can also adjust the opening to maximize airflow across the air-cooled engine in the summer and close them up in the unlikely event I drive this car around in winter months.

Driving the wheels can either be accomplished by front wheel drive or by a driveshaft turning a transaxle in the rear.  I am leaning toward the rear end drive as one YouTuber has already shown this can be accomplished.  But the front drive design contest between Kelly Wood and Chuck Kraeuter might show me a better way.   I’ll need to make this decision early on in the design. 

DESIGN ELEMENT #9 – SELF CONSTRUCTED FRONT AXLE
I purchased the standard axle and wheel spindles from Renegade for my Bugatti project, and I’m glad I did.  Now that I know better how to weld, I feel pretty confident on building my own.  I’ll probably stay with Renegades spindles, but I may make my own C-Clamp so I can incorporate some suspension and height adjustment.  We’ll see.