This is a picture of a friend of mine's pulling truck at the Mt. Pleasant truck pull about a month ago, it's not the highest quality but you can see an 8" flame out the stack behind the cab  A flame like that wouldn't be uncommon for a pulling tractor but there is alot of pipe between his stack and exhaust manifold to carry a flame that far.  The following week at the Eldon pull at the 100' mark when he checked the pyrometer it was aready past 1,600° and still rising even though he had it tuned down a little from the Mt. Pleasant pull.  He hasn't had his truck on a dyno but he can usually put several feet on another truck that's dyno'd 630. 

(Randalls flame-1.JPG)

Randalls flame-1.JPG (78KB - 51 downloads)