Trojan Boat Forum

Does anyone have experience with this DJX style of prop over the Dyna Jet on an F series hull? I' ve been running a 14 x 9 NiBrAl Cupped Dyna Jet for several years and although it puts me into my desired RPM range I'd like a little more thrust, especially at cruising RPM. The Dyna Jet has an E.A.R (Expanded Area Ratio) of 0.56 where the DJX has an E.A.R. of 6.1 which means a greater blade area that I'm told should give me the thrust increase that I'm looking for in exchange for a minor loss in WOT RPM.

Any thoughts? Below is a picture of the DJX that I picked up on Friday.

We've been enjoying a mild winter here which gave me a chance get to the boat and to remove my prop. After cleaning it up and putting it side by side with the old one, you can really see the difference in blade area.

Can't wait to try it out.

Hi Paul, I have a DJX on my F26 and it work great 5.7 MPI Kodiak 330 horse 14x11 NIBRAL LH with a #5 cup 23 mph @ 3100 rpm's there not cheap and i had to wait 6 weeks to have one made.

32pacemaker wrote:Hi Paul, I have a DJX on my F26 and it work great 5.7 MPI Kodiak 330 horse 14x11 NIBRAL LH with a #5 cup 23 mph @ 3100 rpm's there not cheap and i had to wait 6 weeks to have one made.

Are you able to make your full rated rpm at WOT ?


Paul I bet you will be happy with it

Hi Paul,
You'll like it, I've been running one for several years, 14x10 with cup. I'm powered similar to Roger and can reach 5000 rpm at WOT. My old Dyna-jet would hit 5100rpm. The DJX seems to perform better through the whole rpm band, and can stay on plane at a lower rpm.

Thanks for all of the replies gents,

From these replies it looks like I'm on the right track. Although the horsepower of my carburated 350 is about 40 hp less than Roger and Matt, I'm hoping that I'll experience no more than only a 100 rpm loss at WOT as Matt indicated. This should keep me in the correct WOT RPM range. (for my engine it 4400-4800) Being able to stay on plane at a lower RPM will be a real bonus, with the Dyna-Jet the boat currently falls off plane below 3000 rpm. Roger is right on with cost and the long wait for this prop, I ordered it in mid November and took delivery in early January. Glad that I didn't wait until spring to do this.

Hey Paul, I've had the engine to 4800 RPM only briefly and it had more to go I have a medium cup I'm not sure of the cup that Matt has our engines are similar but mine has roller tip rockers, sequential injection and tuned/ported aluminum exhaust manifolds. At that RPM the speed is around 35MPH and the hull didn't feel happy . thats fine it's not a race boat and I'm happy cruising at 23-25 MPH at that speed the boat is fine I do pull out most of the trim with a little trim to level out the boat. i did change the engine from RH to LH and as you said it didn't make any difference even though the engine is offset to the port side by a inch or two.

Finally launched today and took the boat for a short cruise. The new prop boosted my cruising speed by 3 mph at 3600 rpm. Also stayed firmly on plane at 2800 rpm, haven't brought it up to WOT yet but I'll try it next time out. In general the boat feels more responsive, glad I did it.

Hi Paul, what size DJX did you put on

The DJX is 14x9 with a medium cup, same as the Dynajet that it replaced.

Finally took the boat out and did a little testing yesterday. On my first ride a few weeks ago, I thought that my speed had increased by 3mph at 3600rpm however it seems to have increased by only 2mph. Still a 10% increase so I'm happy about that. At WOT I've lost 100rpm and 1/2mph which equated to 4500rpm and 28mph and that's fine since this boat rarely sees WOT. One thing that I did find interesting is that I can now keep the boat on plane as low as 2600rpm at 14mph, any lower and it falls off plane. Ultimately the best cruise still seems to be at 3600rpm but now the speed is 21mph.

Happy with the new prop. Oh yeah, and no more cavitation in a tight turn at speed.

Hey Paul does your boat have Dual exhaust and what Cup did you get in your DJX ?

32pacemaker wrote:Hey Paul does your boat have Dual exhaust and what Cup did you get in your DJX ?

The boat has single exhaust with a Vernatone muffler. The cup on the DJX is medium as recommended by Michigan Wheel.