Installed Smart tabs and now i still need a proper prop

[fourwinnsnate]

So i put on my smart tabs and let me tell you...they are awesome
The boat is waayy more stable at high speeds
It gets on plane really quick
I can plain with my SS 23 at about 17mph compared to 24 mph
But my top speed stayed the same and my top RPM with the 23P actually went down. What used to Be 48mph at 4200-4300 at WOT has now become 48Mph 4000-4100 at WOT
The motor seems to run fine but i did notice with the 23 only it bogs a little when you go for more speed and it doesnt do this with my 21 or my 19
The engine may need a tune up but frankly judging by how smooth it runs, how it fires up first crank every time i believe this is just too much prop for the boat....
There is an advantage to this prop though...i can do 32mph at 3000rpm which makes fuel consumpion very good when doing a lot of cruising

 

[wca_tim]

Re: Installed Smart tabs and now i still need a proper prop

So i put on my smart tabs and let me tell you...they are awesome
The boat is waayy more stable at high speeds
It gets on plane really quick
I can plain with my SS 23 at about 17mph compared to 24 mph
But my top speed stayed the same and my top RPM with the 23P actually went down. What used to Be 48mph at 4200-4300 at WOT has now become 48Mph 4000-4100 at WOT
The motor seems to run fine but i did notice with the 23 only it bogs a little when you go for more speed and it doesnt do this with my 21 or my 19
The engine may need a tune up but frankly judging by how smooth it runs, how it fires up first crank every time i believe this is just too much prop for the boat....
There is an advantage to this prop though...i can do 32mph at 3000rpm which makes fuel consumpion very good when doing a lot of cruising

running that engine with a prop that maxes out at 4000 rpms is not a good thing and will eventually (maybe later, maybe sooner) trash the engine. do it a favor and run the 21 to keep your rpms up more. the engine really shouldn't use much if any more fuel running little higher rpm easy than a hard lower rpm...

 

[bruceb58]

Re: Installed Smart tabs and now i still need a proper prop

Your prop is probably fine...what happen when you trim your outdrive out a bit?

 

[fourwinnsnate]

Re: Installed Smart tabs and now i still need a proper prop

Yah these speeds are trimmed out...if im trimmed down its only about 42mph
How will running this prop blow up my engine??
And should my boat not do 55mph?? i mean a 6 cyl on the same boat will do 48mph so what is going on cuz with the 19 21 or 23 i cant seem to get more than 48 outa the boat..What do i do??

 

[bruceb58]

Re: Installed Smart tabs and now i still need a proper prop

What do i do??

Dump the smart tabs!

 

[ramster]

Re: Installed Smart tabs and now i still need a proper prop

Smart Tabs will not decrease your speed, I've done testing with and without, differance on GPS was 1 tenth of a mph. As long as they are not set to stiff they only help. I agree you should see at least 55 mph with a 5.7, I just did some jetting changes on my 5.0 and I get 55.1 @5100 with my Apollo 14X20 SS four blade, and 55.8@4600 with a Stilletto 14.25X21 three blade.These speeds were with just me in the boat, with the family on board, speed drops to 53@4900 with the four blade. When your motor can't reach max rpm, (4600-4800 for V-8's) it puts more strain on the bearings and rods. You may be cruising at a lower rpm, but you are likely at more throttle opening, like a truck trying to pull a hill in high gear vs. downshifting to get the revs up. Your motor will be happier propped to spin max RPM at WOT. If you have four barrel carb, has it been cleaned? And are the secondaries opening?

 

[hwsiii]

Re: Installed Smart tabs and now i still need a proper prop

Nate, after running some more analysis and using the new gear ratio of 1.79:1 I find that with the 23" SS prop your prop slip is about 8%, whih is very good. In my opinion you need to buy either a 21" Vensura SS 4 blade or a 21" Solas Amita 4 blade aluminum prop, and both of these should get very lose to maximum RPM and will cruise at midrange speeds better than the SS you are using now as well as blowing it away as far as hole shot and acceleration throughout the whole RPM range. I do not believe you will lose more than 1 or 2 MPH on top end speed as well. They will work great for skiing and wake boarding and you will like how they feel when you are running. They are two totally different props but will both do a great job for your toys. I believe you are getting the maximum speed you can with your present setup.
Remember, you only have 250 HP and if everything is perfet it is still 11years old and at 2,000 feet it will lose about 15 HP on a good day, on a bad day it an easily lose 25 HP. The consequences of high humidity and temperature at altitude can be HARD on horsepower. IF you have any more questions please feel free to ask.
And Ramster is right about the smart tabs not losing RPM or speed if they are setup right, I have had them on my boat for about 3 years now.

H

 

[fourwinnsnate]

Re: Installed Smart tabs and now i still need a proper prop

Alright that makes sense
yah i keep forgetting that i am 2000ft above sea level and my boat isnt going to perform like it should that does make sense to lose about 7mph because the guy that had the boat before me was at sea level. and i've been doing some research the new 4.3 GXi puts out 225hp so at sea level a new 4.3 will put out as much power as mine does here. Thanks for all the help i will order the aluminum 4 blade i dont really have $800 to spend on an SS right now.
And Ramster if you have a new 5.0 your boat will have more horsepower than mine so it makes sense it would be faster and if not than u might be closer to sea level.
But this winter im gunna get a mechanic to go over the engine with a fine tooth comb just so i can be sure everything is fine
Nate

 

[hwsiii]

Re: Installed Smart tabs and now i still need a proper prop

Nate, if you run at that altitude all the time have him hange the high speed jets out and it will run better. Iboats has that prop I told you about for about $ 115. Your jets are too big to be running at that altitude, it will help it is not a mirale but it will help.


H

 

[fourwinnsnate]

Re: Installed Smart tabs and now i still need a proper prop

The boat is fuel injected...im pretty sure it doesnt have jets

 

[hwsiii]

Re: Installed Smart tabs and now i still need a proper prop

Then he ould hange the injetors, but I don't really know if that will be eonomially feasible.


H

 

[fourwinnsnate]

Re: Installed Smart tabs and now i still need a proper prop

Alright ill talk to him about it...the local mechanic here is pretty good.
Hey its kinda weird but the on plane speed between my 21aluminum and my 23SS is pretty much the same but the SS23 gives a way nicer wake and holds on plane whereas the 21 will fall off if the wakeboarder carves too hard etc.
Shouldnt it kinda be the other way around?

 

[hwsiii]

Re: Installed Smart tabs and now i still need a proper prop

Nate, the SS prop usually has a lot more cup and it may have more blade surface area.


H

 

[fourwinnsnate]

Re: Installed Smart tabs and now i still need a proper prop

Ok
i will order the other prop either today or tomorrow i just have to check out my local shop here cuz if they can get it in i can probably trade off my SS 23 for it but their price might be outrageous so ill probably just order it off iboats
one thing i have to say is thanks Hwsiii i can't believe the time you take with people like me to help us find the correct prop so we dont just throw money away and we get optimum performance this site really is incredible i have never met the amount of people on here that are willing to help out guys like me...i just hope once i get more experienced with all the technicalities of boating i can only return the favour to newbs. once again thanks hwsiii and iboats in general for providing such a helpful and easy to use website
Nate

 

[hwsiii]

Re: Installed Smart tabs and now i still need a proper prop

You are very welome Nate, and please ome bak and give me the WOT RPM and speed.


H