Trim tab question

There are a good bit of threads over on the hull truth about this subject. Do a search on the boating forum.

quote:

---

but I'd like to get out of the hole a little quicker and maybe get some better performance in general

---

Have you considered a different prop, possibly a good 4 blade?
Could be all you need. Call Powertech props with all your engine, boat, and current prop specs handy and some numbers on max rpms and top end speed. Explain to them what you have and what you would like to have, I'd bet they can help.

You shouldn't have to use trim tabs for normal hole shots. You need to play with a few props to find the perfect set up for your boat. I would suggest googling your boat and motor setup to see what other people have tried

Saying that, if you do get trim tabs you want them to be adjustable. I have electric lenco tabs. The only time I use mine are for getting out the hole is in less than a foot of water. I mostly use them for rough water to keep the bow sucked down for a smother ride. I have a 22 ft skeeter fwiw

quote:

---

direct extension to a guy

---

Does the name Marcus ring a bell?

LSUMurse - Things you need before calling.
1) RPM's at WOT (max throttle) with a light load and trimmed up some. Should be above 5000 rpm's
2) brand and model of your current prop. Should be a name and numbers stamped somewhere on it. "13.25X3R15P", as an example.
3) make, year, model engine you are running. I know you said Tohatsu 115 HP, but the year built will also be needed.

Don't remember, I got the number from Baggy's Prop in Houma. I had a little flats boat and Baggy wasn't super familiar with what prop would work best with it, so he got me in touch with the guy.

I just found my max speed (played with all my trim, jackplate, etc.) until I got may best and remembered the RPM. At those settings, I also found my speed at around 4700 RPM's. Gave them that info and told him some of the problems I was having (blowing out on turns,etc) and they gave me some options. Ultimately, I had the best prop, just needed to learn how to make adjustments as I was driving (using blinker trim to lower jackplate during hard turns etc.) My boat was just designed to get skinny, not perform like a race boat.

1) smart tabs are junk, do not waste your money
2) bennett tabs are what you want, hydraulic
3) bennett has the BEST customer service in the marine idustry, contact them and they will absolutely lead you in the right direction
4) for a 19' bay boat, you likely want M80 sport tabs LINK

quote:

---

Yamaha saltwater series

---

Your whole explination is on point Seapickle. And the above is actually what I'm running now.
I directed him to Powertech as their costumer service is really good and it seems he's simply looking for something a little better than what he has now and they should certainly be able to help.

excellent prop advise can be found here

PROPGODS

ask for ken

quote:

---

Im not sure a larger pitch prop can turn the same rpms and be more efficient. I could be wrong, but I thought pitch was the theoretical distance the prop would displace water with no slip. Therefore a 20 would move you one more inch than a 19. All other variables the same, that would make more force and bog down your engine. Slip allows you to reach the same rpms. Slip isnt always a bad thing. Helps in the hole shot for example by getting rpms up. But ultimately slip takes away from the theoretical efficiency. Cupping and blade shape make some performance changes that are going to play a huge part as well. As in cleaver props have grrat top end amd cupped props have good grip. I could be wrong about some stuff, but thats the kind of discussions I had with the powertech guy. I'm a mechanical engineer so to me it was a really interesting phone call that lasted about 40 minutes.

I do know that is another option. You can have someone work your prop by boring holes at the base of the blades to get your rpms up in the hole shot. Saves some money and it does work.

---

You are exactly right. There are many gives and takes when talking props. Another aspect that you forgot was hull lift: my own example - my 19" powertec could not lift my hull to run on pad. It was simply pushing the boat through the water (which boggs down the motor also), not on top of it. It could not lift because the blade design was not adequate, so the dealer put the highest pitch possible that allowed the motor to stay below 6000rpms. The trophy's larger diameter and larger surface area of the blades (along with cupping and blade design) allowed it to lift the hull out of the water creating less drag allowing the motor to turn more rpms which yields being able to turn a larger pitch. That's what i meant by "efficiency".
My trophy is a 19" by design, i had it worked to a 20" with extra cupping. OP could have more cup added to his prop and that may help if he already has a quality prop for his set up
-also, the trophy is a vented prop. I can adjust the size of the vent holes to allow more rpms on the hole shot with the large prop. I can open them when i have a heavy load or plug them up when really light. It allows more exhaust gas vs water in to adjust slipping to get the rpms up or down. The vent holes are at the base of the barrel by the lower unit end.
-i spent lots of time trying MANY different props to get my set up running like it should. Im currently looking for a 21" tempest to be my last one to try