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jima97
12-01-2008, 02:26 PM
Seems all 3900s with the 700 / NXT1 package come with 18x35 CNC Merc props and are running 101 - 102. Has anyone put a 17x36 on one? What were the results?
ThrottleUp Props
12-01-2008, 04:20 PM
It is possible with drives mounted so very high they need the diameter to simply reach the water. What gear ratio are we talking about. We can run the slip and an see if the reduction would be a possibility.

Julie
jima97
12-02-2008, 02:13 PM
1.49:1
NORTECHJ
12-02-2008, 10:57 PM
I run 17.5 x 34 4 blade mercs 118 mph but thats with 1.50 #6's not NXT's......5 blades gave me WAY to much transom lift and after 112 to 115 it would ghost steer
jima97
12-03-2008, 04:27 PM
What power do you have? What year is yours? Did you sacrifice anything going with the 4 blade? What about acceleration and planning time?
NORTECHJ
12-03-2008, 06:21 PM
1050 hp per side... 2005...... sacrifice? no because it did nothing better with the 5 blades.. it jumps up on plane no problem with or without the 1" spacers.. i don't even use the 380 k planes to get on plane
jima97
12-03-2008, 07:20 PM
What RPM are you turning at WOT?
NORTECHJ
12-03-2008, 07:32 PM
6700 to 6800
Jassman
12-07-2008, 10:33 AM
I run 17.5 x 34 4 blade mercs 118 mph but thats with 1.50 #6's not NXT's......5 blades gave me WAY to much transom lift and after 112 to 115 it would ghost steer


great numbers, impressive for a 40' boat:sifone:
ThrottleUp Props
12-09-2008, 10:16 AM
Seems all 3900s with the 700 / NXT1 package come with 18x35 CNC Merc props and are running 101 - 102. Has anyone put a 17x36 on one? What were the results?

What is your WOT RPM?

Are the props standard labs or are they CNC's, Merc or Hering?

Julie
jima97
12-09-2008, 02:59 PM
5300 CNC Merc
ThrottleUp Props
12-09-2008, 05:32 PM
Your slip is 14% so it is possible that smaller diameter props may indeed perform. Are they 16 degrees of rake or 18 degrees of rake?

Julie
Coolerman
01-06-2009, 04:01 AM
I run 17.5 x 34 4 blade mercs 118 mph but thats with 1.50 #6's not NXT's......5 blades gave me WAY to much transom lift and after 112 to 115 it would ghost steer

Don't you have the old crescent shaped lowers (not swept back) though, which may cause some steering problems?

I know our BT is as solid as a rock over 110 now with the swept back lowers and 5 blades. Before with the old cresent shaped lowers, our boat wouldn't feel totally hooked up above 110, and ran better with 4 blades.

The new swept back skegs are also longer which could attribute to allowing more transom lift with the 5 blades while still having steering, giving you that "hooked up" feeling above 110mph.

Sorry, not trying to hijack a thread or anything....