Could a flame-thrower built into a tailpipe solve tailgating problems once and for all?

Dear Car Talk

Dear Car Talk | May 01, 2002

Dear Tom and Ray:

I have a solution to the tailgating problem. I've heard that you can make flames shoot out of your exhaust pipe by drilling a hole and putting a spark plug a few inches from the end. Then, by connecting it to the battery and a switch, you could make a sort of flamethrower. I would just like to know if this is a bunch of baloney or not, without having to ruin my exhaust to find out. -- Kwong

TOM: It's an interesting idea, Kwong, but unfortunately, it's a bunch of baloney.

RAY: There are two problems. One is that, on modern, fuel-injected cars, by the time the exhaust gets to the end of the tailpipe, there's nothing in it to burn anymore. Cars are so efficient these days that all of the hydrocarbons have long been burned up by then.

TOM: And the second problem is that, even if there was gasoline to burn in the exhaust, the battery wouldn't provide enough power to fire a spark plug. You need about 20,000 volts, which normally come from the coil.

RAY: So I suppose if you really wanted to make this work, you could tap another spark-plug wire off the coil and run it back there.

TOM: And a fuel line, too!

RAY: Unfortunately, Kwong, this really doesn't make sense. So if you really want a flamethrower, skip the auto-parts emporium and drive right to the army-surplus store.

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