Infraction Making the Delta Plastiks Ford FC100 214+ mph body even better

[LibertyMKiii]

It is pretty clear that the Ford FC100 body is really good for speed runs.
We now have several guys guys in the 189 to 204 mph speeds with this body running a Limitless/Infraction. I suspect we will see Raz crack that 200 mph barrier very soon. (perks of having access to an airport runway)

While this body is good in plastic form it could be better if you didn't have the strength/flex issues that plastic has requiring many extra body contours that are not necessary.
In prior vacuum forming projects I learned that plastic requires some hard lines and extra bends to keep its rigidity. Composites like fiberglass and carbon fiber do not have those same issues, but can also benefit from them. Finding a balance is key.

Goal number #1 is to not go crazy. This body is good as is. I only want to make some minor tweaks to improve the airflow and reduce turbulence.

Making a plaster copy of the body is what I have found is best.

Here is the process for this project:
1. Paint the body, no cutting etc. Must leave the protective film on the outside of the body.
2. Mark the borders of the body onto a large stiff board. I used 3/4" mdf
3. Cut a hole smaller than the body and then glue the body to that board with liquid nails. Make sure the majority is going on top of the film on the body.
4. Put the box that this body came with over the body and wood. Then cut some holes in the box and fill the cavity with expanding foam. The foam will lock the body to the board. (the foam keeps the plastic body from flexing under the heavy weight of the plaster.)
5. Flip the entire thing over and wax the inside of the body heavily.
6. Fill the body with plaster in 3+ layers with 1-2 days dry time between.

To my surprise the foam removed from the body quite easily in large chunks:

The plaster body revealed and the film still on the original plastic body.
FYI this took 48 lbs of plaster!!!!!!!!

Plastic film removed from the original body. Tried for a mirror finish but only turned out at a dull chrome. I think I didn't have the body warm enough as I found light layers and heat helped the Spazstix mirror paint turn out better. Overall I think it still looks nice...

This week I'll begin making some small changes/improvements to the plaster copy.
I really love this sort of thing as it feels like art/sculpture work

 

[Tex Koder]

That is Awesome!
Great job Liberty man.

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If you don't mind..

Could you take some dimensions of the front and rear ends?
I want to see if I can design some custom splitters and diffusers for this body.

 

[Doom!]

@LibertyMKiii I love when you go into mad scientist /artist mode!

 

[LibertyMKiii]

That is Awesome!
Great job Liberty man.

*********************

If you don't mind..

Could you take some dimensions of the front and rear ends?
I want to see if I can design some custom splitters and diffusers for this body.

I'll shoot you a PM.
The dimensions would depend on where you cut the body...

 

[Sandracer_NL]

@LibertyMKiii I’m already content with myself if I make my own body panels and mudguards. You take DIY to a whole new level.

 

[LibertyMKiii]

@LibertyMKiii I’m already content with myself if I make my own body panels and mudguards. You take DIY to a whole new level.

Thanks man,
I try to encourage others to make stuff by sharing how I do it. It only takes time and money.... I am honestly not very skilled and don't have much more than some basic hand tools.

 

[LibertyMKiii]

To start things off I have removed the drivers cab. Covered the fake fender louvers on the front and rear.

It is rough right now. The joint compound/sheet rock mud has some shrink to it so I have to over apply and then knock it down to where I want it after it fully dries.

I will need to re-add some smaller version of the drivers canopy as I do no want to alter the front angle of the car at all and this transition from the front to the removed canopy is too abrupt and will disturb the air flow attachment.

What I see:

Yes I need to fill in all the little air bubbles on the sides and ridges.

 

[Velodromed]

This is great, love your projects!

 

[LibertyMKiii]

I hope to post an update picture tomorrow. I have been working on several areas of the body and it is looking pretty good so far!

Something to note if anyone is looking to do this and has never worked with plaster before. It sets up very quickly and cold water works best. I take water bottles and refill them with tap and keep them in my garage fridge when working with plaster.

I just use a big 5 gal. bucket and a mixer that attaches to my drill to mix it. Once mixed and the right consistency (slightly thinner than a milk shake where it is pourable) then I get it into the mold as quick as possible. Within 5-10 mins its hard as a rock.

 

[LibertyMKiii]

Still a work in progress.
I also need to add about 2mm width to each of the sides because this was an inside of the body copy and wont quite have enough width

With above lighting sort of hard to see the details in the center cab section.
The idea was to reduce any abrupt transitions from the front to the center section and streamline where I could. This meant retaining a small drivers cab to keep the airflow attached and smooth.

The shock tops bubbles now resemble sperm

The rear vertical stabilizers are removed because I will bolt on carbon sheet to the sides. With them removed you can really see the kick up on the rear acting as a wing.

Other side with lights off and using camera flash (captures the detail better)

 

[Monster Dork]

Very cool! How much is your car going to weigh with the plaster body? I bet it will stop blowovers on speed runs!

 

[LibertyMKiii]

Very cool! How much is your car going to weigh with the plaster body? I bet it will stop blowovers on speed runs!

LOL!
I have not figured out how to install the electronics and suspension inside the plaster yet either.... Hard times!

 

[Tex Koder]

Still a work in progress.
I also need to add about 2mm width to each of the sides because this was an inside of the body copy and wont quite have enough width

With above lighting sort of hard to see the details in the center cab section.
The idea was to reduce any abrupt transitions from the front to the center section and streamline where I could. This meant retaining a small drivers cab to keep the airflow attached and smooth.

The shock tops bubbles now resemble sperm

The rear vertical stabilizers are removed because I will bolt on carbon sheet to the sides. With them removed you can really see the kick up on the rear acting as a wing.
View attachment 205206

Other side with lights off and using camera flash (captures the detail better)

View attachment 205207

Call it Project SPRM!
(Serious Performance Racing Machine)





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Here's the raw draft of the Front Splitter -

I've sliced the piece in two ,so to allow for easy width adjustments..
The center section will have a 3-5° incline to provide additional downforce.

I'll print a mockup later this afternoon.

 

[LibertyMKiii]

Call it Project SPRM!
(Serious Performance Racing Machine)





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Here's the raw draft of the Front Splitter -

View attachment 205215

I've sliced the piece in two ,so to allow for easy width adjustments..
The center section will have a 3-5° incline to provide additional downforce.

I'll print a mockup later this afternoon.

I think it would be pretty awesome to see a group of 4-10 of these 1/7 scale cars racing a big track at a high school or something like that.
This splitter design would be great for something like that!

 

[Tex Koder]

Printed mockups of the Front Splitters..

.
I don't have any on-road bodies.. So this will have to do for now.
Obviously the Mojave have a more blunted nose so the splitters don't exactly compliment it's contours..
But you get the idea.

 

[LibertyMKiii]

I had started thinking about making a mold and how the composites add thickness from the mold surface inward. Then I remembered that this plaster body is not an outside dimension, but it was an inside copy of the plastic body. This means I needed to add some extra width to the body. I began to think of adding more plaster or sheetrock compound and started to feel stressed out about the time and effort that would take. Then I came up with a better ideal. I took some 1.5mm plastic sheets and this will make the body as if it is normal outside of the body dimensions plus a little extra for the composites thickness.

It looks rather sloppy in this picture as I had just applied the side plastic cut outs and getting them to stick on with the sheetrock mud. After it dries I go back and clean it up...

Getting closer to completing the shape on this one. Lots of apply > Let it dry > Sand it > Re-Apply and smooth > Let it dry > sand it down....

 

[LibertyMKiii]

Dusted this one off and pulled it off the shelf.
Forgot how heavy it was WOW!

I have been running the FC100 body on my Hobao VTE2 and just loving it
I am completed with some other projects and paused on the 200+ project so it seemed like a great time to pick this one back up.

The goal will be to finalize it over the next 30 days and make a mold in September or October.
I am already going to break goal #1 from my first post. (don't go crazy because the body is already good). I just cannot help myself

After looking at new bodies like the Delta plastiks dome and previous carbon body creations regarding what worked well and what has not worked well I wanted to modify this one to be a little slimmer in certain areas. This should reduce aero drag and attempt to maintain that great balance of downforce needed also.

For starters, the front bumper area to hood transition has a less than ideal shape. It is likely there to accommodate the strength needs of plastic bodies. Not a concern of mine making this out of composites!

Day 1:
Smoothed front hood to bumper area

 

[LibertyMKiii]

Worked on this some yesterday evening and this morning.

Part 2 is to remove the bubble for the shock tops. It seems those are not 100% needed.
Also the area between the tire and shock tower has a lot of material that can be removed, again making it more like the dome body here.

(have not done the other side yet with the red scribbles on it)

Other minor mod I am doing is removing some of the rear tire bump up. It just isnt necessary at all compared to where the tire actually is.
Yet another thing there to give plastic extra strength.

The far side still has it (redline above it to highlight the feature I am removing) versus the close side I have removed a majority of the curve there. I may leave some....

 

[autolex]

I admire your work but you my friend need to invest in some pour-foam!
I fill some of my boat hulls with this stuff, it will make things way faster on shaping.

https://www.ebay.com/itm/354064529721

 

[LibertyMKiii]

I admire your work but you my friend need to invest in some pour-foam!
I fill some of my boat hulls with this stuff, it will make things way faster on shaping.

https://www.ebay.com/itm/354064529721

100% agree and I have used foam on other projects.
Plaster is messy and takes a long time but the precision and quality is much better. I love it for this application.

On that note I put in some time yesterday and today and have the front end almost done. I added dots from a red marker to help me see the shape better due to the white out effect that is almost too bright.

Really happy with this final shape it has organically evolved into.