Yes they do,if your making a Dragger out of it reve the mechanism's that operate it and lock it closed,I did that to mine with the advise of Vito's performance.Some of the racer's have the valve removed and have the space that it was in opoxyed then smooth out,me I kept the valve,but locked it closed.

 

So you guys dont use the exhaust valve for drag racin? I thot that was the big advantage of the Zilla? Could you explain if you have time? thanx.

 

The way it work's is at low end power it's open,at mid it start's to close,at top it's shut.I removed the innr gut that operat it and locked it closed,kinda like cutting out the middle man.Vito told me it's uneeded in drag racing,cuz your full throttle anyway's so why have it.With it being close it has'nt hendered repsonse at low,mid rage's either.