Thanks for that kieth the uk rep told me someone was writing a review for the next mag shall have a good read. Think i will go with the wren pipe as installed propperly can increase the thrust by at least 1lb they told me which i need. Am going to be using the wren 54mk3 i know it is not the best powerplant for this model (might be slightly under power) but i am not someone who wants unlimited verticals am just a steady flyer. With the boomerang intro i have my first install made a much heavier plane than some and the wren is fine in that so fingers crossed.

Thanks for the help

Rob.