Those blades have a LOT of flex. 4 blade set up will work fine 28ish lbs or less, and yes, they act like a big speed brake if you pull the throttle back. Don't forget to keep power on all the way down. Mine flew at 33# and was a dog. Started re-working the tail, and converting it to two bladejust never finished. Has a 4.2 in it now, plan to run 22x12, maybe a little more, should move right along

I've gone electric on pretty much everything now, and I was eyeing this prop as a future mod. Link might not work, so click on 32I, http://www.ramoser.de/home_e/variopr...rioprop_e.html

Have a pair of their props on a Yellow P-38 that I hope to finish up this winter. Anxious to see how they perform

Lets see some pictures!