I agree...Using a pipe such as the one that Wren developed makes sense as the heated expanding gasses are turned into extra useful thrust...Instead of the heated gasses being choked down until they exit the pipe....I wonder why more kit manufacturers haven't included this type of pipe with the kits...Does Wren have a patent on this???

I'm going to try running with the top of the bypass removed and see if I can tell the difference on my JL L-39...

Thanks for all of the replies!!!...If any of you have more to add, please do so!!![sm=thumbs_up.gif]

Kevin