Undertray / belly pan build - VW Golf MK3 1.9 Turbo Diesel

[COcyclist]

Originally Posted by redpoint5

Nice work! Looks like a politicians race car now underneath. My question is, how much of a difference did it make? Could a mod like this cut down on road noise too?

It is not scientific since I can't really do back to back testing of the belly pan. But there is a trip I regularly take where my previous best mpg was about 55 with careful driving and I got into the low 60s after the belly pan, on the Scanguage. I didn't really notice any difference in noise though.

[Exalta-STA]

It'd be great if you have a template/trace out of your undertray :-)

[minAirForce]

Where you get your plastic plugs? Those things are expensive in the auto stores

[minAirForce]

Also, be careful about how you fasten your copper tubes. Galvanic corrosion will rust your car.

[COcyclist]

Originally Posted by minAirForce

Where you get your plastic plugs? Those things are expensive in the auto stores

If that question is directed to me, I just drove the roofing screws into existing plugs in the VW underbody, didn't even pre-drill. Make sure the leading edge is fastened securely and no problems with the rest.

[minAirForce]

how you mount these panels? did you have to drill holes in the body?

[COcyclist]

Originally Posted by minAirForce

how you mount these panels? did you have to drill holes in the body?

http://ecomodder.com/forum/member-co...mg-0134sm.html

If you look carefully at this "before" photo you can see a round plastic plug just to the left of the catalytic converter and a couple more on the frame type reinforcements (look where the fuel line snakes around).

This photo shows what I used to attach it. NO new holes were drilled into the sheetmetal.http://ecomodder.com/forum/member-co...-img-0142.html

[sallen]

Hi guys,

Have finally made my way through 87.5 litres of various flavours of diesel (83% Bio 17% Dino) with my undertray on, and I'm showing a 4mpg (uk) increase from 58 to 62mpg. That brings me into the 50's in US mpg.

Initial observations:

• Noise levels seem higher (tho this could be my hard tyres);
  
• I can hear more 'wind noise' around the A pillars (perhaps the road noise has dropped so I can now hear this);
  
• This is only the first full tank with the tray on, and it is pretty roughly built;
  
• I have been driving VERY VERY slowly tho I was doing that last tank too;
  
• Due to the price of fuel in the UK (about $2.28 per litre), the motorway network has slowed down, with many lorries now limited to 50 by their owners; and
  
• I need to tune the exit angle, it is way too steep as it is.

I have also just scored a scrap garage door, so will remake my undertray from Sheet Metal to make it smoother.