Questions of Cutting Fuel and Vent Holes in the Body?
 

I assume most US racers cut holes in their bodies according to ROAR rules. I've got a few questions about cutting fuel and venting holes before I go hacking up my new body. I searched the forums and didn't find much clear info on these questions.

1. By my understanding I can cut a 60mm hole in the windshield for fueling. Does it matter if that hole extends up into the roof?

2. Does it matter where and what size the holes are for accessing the HSN and glow plug?

3. What other holes can I cut in the body for venting? One of the most common things I see is two circles in the rear window. Is that a good option for this?

Thanks!

I believe that the 60mm hole can extend intonthe roof.


the entire rear window can be cut out if you want.

Also, the side windows can be cut.

I dont think there is any restriction on holes for glow plugs and the HSN.

Z

1. Yes, you can cut a 60mm hole for cooling. That hole can extend up into the roof. At least half of that hole must be in the windshield. The other option is to cut a 60mm hole entirely in the windshield, then cut another hole directly above the fuel tank filler neck for refueling. The fueling hole cannot be larger than 30mm and must not intersect with any other holes If you do it that way, the 60mm cooling hold must be entirely in the front windshield. Most people cut one 60mm hole that is for cooling and refueling.

2. I could not find any specific rules regarding access to the HSN. It does say you can cut a hole out for access to the glow plug.

3 I could not find it this try, but I know the rules allow the cutting out of both of the front side windows. You are allowed to cut out the entire rear window as well. The two hole cut out in the rear is just so the body does not collapse to easily. Remember with all the air coming in the front, you want it to be able to exit the body as easily as possible. The harder that inrushing air finds it to escape the inside of the body, the more drag and lift is created.

From the ROAR Rule book 2007.

6.1.14.3 ..... Holes for use of the glow igniter and carburetor tuning are allowed.

From what I know from IFMAR/FEMCA rules :

1 refuelling hole max 50mm allowed to extend into the roof
1 additional cooling hole max 55mm only on inside front windshield
1 plug heater hole max 15mm
front side and rear window free for cutting
rear side window must remain clear

Thanks for the feedback guys. Hopefully this thread will come up in future searches.