APC has two 13x4.5 EP props listed in their website:

http://www.apcprop.com/ProductDetails.asp?ProductCode=LP13045EP

and

http://www.apcprop.com/ProductDetails.asp?ProductCode=LP13045EP%28F2B%29


Can any one tell me what is the difference?

Martin

Hello Martin,
The thicker hubbed prop is quieter in the corners due to its stiffness, but as Bill said, you pay a price in weight and maybe power consumption. You might try both. The "WOW" noise in the corners is due to gyroscopics coupling with prop flex trying to vibrate the nose of your airplane apart ... if it happens with your combination. For some planes, the thinner prop does not do this, for others it does.
Regards,
  Dean P.

Hi Martin
The F2B version of the 13x4.5EP needs to run about 9500 RPM - that is some 800 to 1000 RPM slower than the thick version.  If you want to use a thicker/stiffer prop use the 13x5.5EP  It usually runs about the same RPM as the thin 13x4.5EP within +/- 100 RPM.

There are people who have tried them back to back - some folks like the 4.5, some like the 5.5 with no real compelling reason why one is prefered (or not) versus the other!


When the 13x5.5EP (then called WEP) first came out we had several folks try them and give there impressions versus the original thin blade 13x4.5EP (now called the F2B) I charted their impressions - see below.

Ha!  Maybe I should have called the table "Eye Chart"?

Here's a pdf you can download - let me know if that is any better...