my headers are 4 in a row tight to gether and i use a coffee can just squished in a bit on the open end nothing to fancy

we use duct tape. works real well and doesnt blow off like a coffee can would in really bad wind and it seals the rain out.

^^^^ lol I use both of those tricks at the same time

I have never had one fly off mine fit kinda tight if i hit the top of the can it wedges on the headers prety tight even trailer my car with them on and never lost one

use a oil filter cover with a nut welded to it and just run wire around the nut and tie it to something

i use antifreeze jugs,duct tape or sometimes both.

Rattle can caps work on mine

I came up with this idea around 2003 when I built my first set of 4 into 1's and have been using them ever since. Heavy PVC pipe with end caps. No more picking up coffee cans in the yard when the wind blows. They're too heavy to blow off when you're going down the road and they don't take up a lot of space in the truck on derby night in the event that it rains (been there & done that many times). The only problem I ran into was when I built my newest 4 into 1's for my small block last year, I switched over to 1 3/4 primary pipes and used an even larger diameter stack. The outside diameter of the chrome stack was the exact same diameter as the inside of the PVC pipe. I ended up having a local machine shop mill the insides of the PVC out just to get them to fit down over the stacks. If you stick with 1 1/2" primary pipes you'll be perfectly fine...

Caps off oxygen tanks for my 4into1's

Been running these for awhile

I run tractor flappers on my Car, you dont have to worry about forgeting to cover your headers up or having them blow off on the road. Also you dont have to take them off during the dreby.  While drinving the car you can see if your car is running because the flaps are up

Got to Lowe's and get a pair of the wing-nut type test plugs in the plumbing section. Just measure your headers and get the correct size test plug. I've never seen anything else look more professional.

I took a piece of 3" channel and welded ends on it..they sit down over my 4 in a rows. Welded a bar across the pipes to keep them together...bungie cord from that over the top and back down.

I tried these just cause they looked COOL but literaly blew them off my headers i tacked the rings to the pipes and blew the little flaps off and tacked them on and still blew them off so i ended up taking them off to much work to keep them on this was all before a single derby i guess the speed and force of the exhaust was too much my headers are 4 in a row so 1 flopper per cylender

I tried the flapped thing aswell and the heat and flames shooting out of my headers literally heated them up and distorted them or just completely blew them apart. I just run four into one now with semi stacks on them and ducktape just remember don't put it on when they are hot and take it off before startup.

1/8th inch metal door straping welded to match the turnouts on the heades and have made a square set for my other set

x2 duct tape on my 4 in a row and flappers on my 4 into 1's

Personally out of every way weve tried, coffee cans, duct tape, or creating a cover the PVC pipe sound like the best. Were gonna have to build a set if you don't mind lol