The Virtual Mk4

[Robert Scott]

Good Afternoon all. Im sure a few folks have seen me wandering around the forum. I have spoken to a few of the usual suspects around here and got to know some of you. I am not exactly sure where this project is going to take me. For right this moment, the design is going to live in my head and on the computer. Will I build it someday? Time will tell.

A few things to know about me. Most importantly, I cant spell! My background. I am an engineer (I do maths and stuff) and I have previously built 2 airplanes. Have wanted to build a car for years but flying always getting in the way. I was not all that interested in a Mk1 or Mk2. Then I discovered the Mk4. I happen to have access to a real one and fell in love. It seems its not a popular build and at one time or another there was kits to be had out there but not looks like a scratch build if you really want one. I have been doing some significant research on the car and have probably 60 hours or so into my model. I thought I would show it off. I am calling it the virtual Mk4 for now. Someday maybe it won't be virtual.

Anyway! Here it is so far.

I shortened the wheelbase a bit to make things fit. Sporting 25 inch tires in the front and 28 inch out back. 15X8 in the front and 15X12 wheels. The car has a 55 inch symmetrical track with a 93.5 inch wheel base. The car is 171 inches long and I opted for 40 inch tall. I gave myself an additional 1.5 inches of height for more cabin space if the thing ever does materialize some day.
More to come I hope soon!

 

[Neil]

That is a very nice model. I'm sure that you have put a lot of work into creating it.

Don't be too quick to modify the wheelbase, as that plays an important role in maintaining stability at the speeds that a Mk4 is capable of reaching. Short wheelbase cars are more difficult to stabilize than one with a longer wheelbase. With the center of mass so far to the rear-- a function of the mid-engine topology-- and the aerodynamic center of pressure forward of that, instability is just around the corner.

 

[Robert Scott]

Certainly trying to avoid it. The body is just slightly off by about an inch. Have yet to come up with a way to fix it. I would prefer to keep it 95 inches as the spec says but but not sure I can make the wheels like up in the wheel well correctly. It is driving me a bit crazy. It is a very visually poor sight when the wheels are not centered in the wheel well lol
Thank you for your comments

 

[Michel]

Unless you are using an existing chassis ; there is noreason to shorten the wheel base to have wheel on the rught place ?????

 

[Robert Scott]

Unless you are using an existing chassis ; there is noreason to shorten the wheel base to have wheel on the rught place ?????

Unless you are trying to center your wheel in your wheel wells on a body body that isn’t exactly right.
Why isn’t the body model exactly correct? Well, the answer is simple. There are no good dimensions for the at that I know of. Unless someone can produce a Ford spec. For example

various sources say the cad is 171 inches long , 174, 171, 172 etc
Well? Does that include the rear spoiler? Who knows?

what about height? Different sources say 38.5 or 39.5 or 40.1 well which is it? Did it include the gurney bubble or no? What size tires were on it when that measurement was take? All unknown

thirdly the width? Most agree to 70.5 inches on good but….
70.5 at the widest part , that is hard to tell in 1967 with a tape measure that has a .250 of slop in it.

so my main goal is to take a different approach as I mentioned above. I think you are correct. Don’t mess with the wheel base.

I have left it as 95. This has caused me to have to stretch the body to 172 inches instead of 171. Still within some agreed upon unknown length of the actual car.

With a 95 inch wheel base things fit now. However this leads me into another post I made in the chassis section. I will leave that one there.

 

[Robert Scott]

Do recall above I said I can’t spell lol apologies in advance

 

[Neil]

Don't worry about it- keep the 95 inch wheelbase, put the wheels in the wheel arches and build your a-arms accordingly. Don't over-think your problems. BTW, Merry Christmas. -Neil

 

[Robert Scott]

Don't worry about it- keep the 95 inch wheelbase, put the wheels in the wheel arches and build your a-arms accordingly. Don't over-think your problems. BTW, Merry Christmas. -Neil

Thanks! Merry Christmas you too!

So the car had to grow a tiny bit to 172.1 inches long now. The wheelbase is 95 exactly. Sporting the same tire dimenesions from above.
After looking at some picture of the real car. It looks as if the front wheel has a bit more clearance behind it to the body where it seems to be a bit closer to the body in the front of the tire. So the tire is not EXACTYL center in the wheel well. I wonder why that is? I looked at a model I have and it is that way even in the model as well as the real car I have access to. I .left mine just slightly forward of center to accommodate bigger tires.

But point is, its exactly 95 inches now. I think im satisfied. Now what to do!

 

[Michel]

Front wheel have to move to make the car turn so ; when the tire is doing a circle in elevation view ( say top view) you have the external edge of the tyre which is doing a bigger circle than the middle of the this same tyre so..... this is why -very often- you have little more "room" behind front wheels not to have tyres rubbing onto the composite of wheel arches
Specially also on race cars because when drivers run outside of "normal"used track they stick rubber onto hot tyre gum and wheels are increasing diameter if you are too close to the wheel arch on this case you destroy rapidly your inside bodywork
When you will have your chassis done with uprights and wishbones just do in CAD the test and you will understand why there is space on this area

 

[Robert Scott]

Latest all fixed up.