Project EconoPolo (aeromodding a VW)

[Vekke]

Originally Posted by viio

I managed to get hold of some very large sheets of acrylic thanks to my dad, so I got 4 of them and set to work to create underbody panelling (belly pan). I used two pieces (about 3 feet X 4 feet each) and cut them to shape to fit the suspension components. This stuff is pretty heat resistant so I didn't even need to cut a space for the exhaust.

Are you sure that those were acryl?
You can bend one corner with pliers to see if it will brake. Acryl wont work on underpalenels because they will get hit and they will brake if those were acryl.

I am using abs plastic on my smooth undertray.

Also you would want to check that your brakes arent dragging so lift each tire up and see how easy it is to rotate. On my seat cordoba rear wheels after adjusting the rear wheel bearings it would roll 20 seconds after it stopped. If wheel brakes are dragging it will roll just few seconds. When you get over ten seconds you are in proper range and there is no drag.

If your brakes rotors are twisted you can feel and most cases hear that also. That will slow you down.

[viio]

Good call on the brake rotors - I think my front ones are warped/twisted as the brakes judder when used. I've just replaced the back ones, cos they were a bit uhhh.... spent. See below:


It's breakable - but it needs a hell of a lot of force as it's 4mm thick. I would love to use ABS plastic but haven't found anywhere I can get it in the UK at a reasonable price.

[viio]

I've had a productive weekend going crazy with silicon adhesive sealant. I looked for all the panel gaps on the car and smoothed them out where I could. Here are some of the nasty gaps which I was working with and how those gaps sealed up - some are awful grubby still (the car needs a good wash).











Using the correct tools for the job:


And some other bits I've sealed up, like the gap between the roof and the rear spoiler:


Gap at the side of the bonnet/hood, using a length of rubber vacuum pipe to fill one side has actually shifted the bonnet slightly, thus closing the gap on the other side too!


Even the wing mirrors got the treatment, for what its worth. These gaps are no longer there

[Grant-53]

Have you any plans for the flow from the belly pan out under the bumper?

[viio]

I'm not finished with the belly-pan yet I've just received an 8ft x 4ft abs plastic sheet so I'm gonna re-do the whole undertray. Do you mean at the rear of the car? If you mean a diffuser or anything then no I'm not planning anything like that, however I might fit a couple of side pieces to the back bumper like the Prius has:



That is... if my modelling in CFD proves it's a good idea for my car.

[Grant-53]

Yes, try to optimize flow top and bottom to minimize separation.

[viio]

Just did a little Google reading on flow separation (as I didn't know what it was lol). It sounds like there would be a case for a rear tray that actually extends past the rear of the bumper at the bottom, does that sound right?

[viio]

I've just finished a further section on my grille block on the front bumper. The engine is still running cool so I'm blocking more up to reduce drag.



I used some adhesive sealant called Teroson Terostat to glue the new insert onto the front bumper slats, then duct taped it till it dried. Then a bit of hammerite black paint to disguise its presence!

[Grant-53]

Yes, some of the newer Dodge Caravans have a lip molded into the rear bumper facia.

Look at smoothing the internal ducting to the radiator ala Hucho or Katz pictures.

[viio]

I don't think there is any ducting, just a big space behind the grille there. Do you have a link I could go look through so I can understand what you mean?