hydrofoil for 115 Opti

[mark poulson]

I have a TR117 with a 115 Opti.
I am looking to add a hydrofoil to help me get on plane faster.
Does anyone have one they would recommend?

[Whoopbass]

Have you tried a lower pitched prop or raising the motor one bolt higher off the transom (if possible)? These worked for me. Unless your severely under powered I would not get one.

[mark poulson]

Whoopbass,
I don't think I'm severely under powered, although my boat is rate for 150 hp.
I do have trouble getting on plane at altitude, with a full load.
I don't have the option of raising my motor, and I've played with my prop until I have gotten the maximum all around performance from my boat.
Why wouldn't you get one?

[Whoopbass]

You have to drill holes in your LU unless which sucks unless you get the kind that clips together. They have a tendency to bite or dig in when you turn which doesn't feel right.
Check out the Triton owners forum on the BBC and see how they are setting their boats up. You can also check out the props or boat topic forums on iboats and see if someone there can help you.
If your only option is to get a hydrofoil I think I have a couple of the bolt in types laying around. You can have one of them.

[Fishaholic68]

my old 1995 stratos 201pro with a Johnson venom 225hp had a hyrdfoil on it when I got it, the guy said it came that way new witch i thought was kinda funny for such a big motor. I can tell you this with three guys full gear and both livewells full of water it would still jump out the hole and get on pad faster than my buddies boats with same motor and no foil with half the load!!

Never had any trouble running or turning at low speeds ether, ran great with no issues!

[Whoopbass]

Why don't you go buy one of the no drill hydrofoils from Bass Pro. They are pricey compared to the drill type but if it works great if not return it.

[mark poulson]

Why don't you go buy one of the no drill hydrofoils from Bass Pro. They are pricey compared to the drill type but if it works great if not return it.

First of all, thanks for the generous offer, but I live in SoCal, so I'll pass.
I read the review on Bass Pro of all the clip on models, and everyone said they come loose, so those who liked them wound up bolting them on. The motor is out of warranty, anyway, so drilling four holes is no big deal.
My buddy has the same motor with an SE Sport 400 Hydrofoil from Bass Pro, and he says his boat, which is longer and heavier than mine, jumps right up on plane, and does 40+mph, which is plenty for me.
As soon as my Merc. mechanic weighs in, I'll probably go ahead and order one.
Thanks to all for the advice.

[Oldschool]

I have a TR117 with a 115 Opti.
I am looking to add a hydrofoil to help me get on plane faster.
Does anyone have one they would recommend?

What is a TR117?
If your boat is rated for 150hp, think about selling or trading the 115 and upgrading, it's your best choice.
Hole shots are about torque, the 3 cylinder 115 Opt doesn't have enough, the hydrofoil is a pain in the arsh!
Tom

[Rod Martin]

I had a TR117 2008, I thought they were rated for a 115, I had a high 5 on for hole shot and better low and midrange.

[mark poulson]

I had a TR117 2008, I thought they were rated for a 115, I had a high 5 on for hole shot and better low and midrange.

Rod,
That's what my Merc. mechanic said. I have no idea.
What is a high 5?

[mark poulson]

I have a TR117 with a 115 Opti.
I am looking to add a hydrofoil to help me get on plane faster.
Does anyone have one they would recommend?

What is a TR117?
If your boat is rated for 150hp, think about selling or trading the 115 and upgrading, it's your best choice.
Hole shots are about torque, the 3 cylinder 115 Opt doesn't have enough, the hydrofoil is a pain in the arsh!
Tom

Tom,
It's fine at Castaic, but it's slower at Pyramid.
What makes a hydrofoil a p in the a?

[Oldschool]

I have a TR-175,with 115 Opti, 17' 6" bass boat with Laser II # 48-16990, 20P SST prop, runs good at sea level and occasional 7,000' alt. you lose about 25% hp over 6,000'. Pyramid is about 4,000', don't see much drop off in performance there, about 3-4 mph top end, about 50 mph normally. Hole shot is good with the motor trimmed all the way down.
I don't use my livewell much, that makes a big difference in weight distribution; 15 gal of water is 120 lbs.
Anything you bolt on creates some galvanic corrosion with the aluminum and can loosen or break. I don't know anyone who has added hydrofoils twice!
I would take out or remove everything you don't use from the rear stowage lockers, don't fill the gas tank more than needed, don't fill the livewell until you need to, move everything you can to the front lockers and live with the slower on plan issue at Pyramid.
Tom
PS, my days going 75+mph are over! Discribe your TR117?

[mark poulson]

Tom,
Your hull is 10 mph faster than mine. My buddy has your boat, and he flies.
Other than batteries and a spare gallon of oil, all of my heavy stuff, except my fishing buddy, is up front. Hahaha
I do need to remove some soft plastics.
Since I switched to 91 octane gas with a fuel additive, it's been better. I'm just trying to make it even better. A new boat/motor aren't in my future, unless you're buying. Hahaha

[Oldschool]

Still haven't found your boat online.
AGM 31 battery weigh over 80 lbs, Lithium weight under 30 lbs, save 100 lbs in rear near the transum!
Expensive, yes.
Moving your buddy butt about 4' forward sitting on the front deck facing you while you get up on plane helps.
Why do you need a spare gallon of oil, check your reservior level before you luanch, it's only 6 lbs., that is a lot soft plastic plastic you may need. Do you really need that beer keg and ice!
Aviation gas is 140 octane.
Tom

[mark poulson]

Hahaha He's lost weight, so he's doing his part, but I'll pass on your advice!
Thanks for the advice. I'll see what I can thin out.
I don't want to fly, just get up on plane a little more quickly.

[Rod Martin]

I said TR117 but what I had was a TR177 2008 it was that throwback 40th Anniversary. Heavy square nose, the high 5 held it up better, seemed to have more bite to lift the nose.

https://www.mercurymarine.com/en/us/pro ... /highfive/



https://www.youtube.com/watch?v=CpMdVyH2WyM

This is the boat I had

[Oldschool]

I said TR117 but what I had was a TR177 2008 it was that throwback 40th Anniversary. Heavy square nose, the high 5 held it up better, seemed to have more bite to lift the nose.

https://www.mercurymarine.com/en/us/pro ... /highfive/



https://www.youtube.com/watch?v=CpMdVyH2WyM

This is the boat I had

Thank you for posting those links. The 5 blade props give a lot of bow lift and low end torque, perfect for the Bomber style hull design. Forgot about that hull. Still don't know what a TR117 is?
Tom

[mark poulson]

Tom,
It's 17'7", and is a shallower V hull. It is a very wide, stable fishing platform in front. Because the front is squared off, you get to the wider part of the deck faster.
The downside is it isn't as fast a hull as the Ranger 175 with the same motor.
But I get on plane, with fully loaded boat, just fine when I'm alone, and pretty quickly when I have a partner and a full live well, when I'm down at Castaic.
It lags a little up at Pyramid. That' why I was considering a hydrofoil.

[Oldschool]

Get a loner 5 blade as posted above by Rod and test it at Pyramid ,that should help a lot. It's like have a lower 1st gear to get started, problem solved. The Bomber hulls were narrow back in the day, this retro 177 hull looks stable, wider and confortable to fish from. 35 mph on our local lakes and I know some do that at night! Cool looking boat!
Tom

[mark poulson]

Tom,
I tried a 4 blade at Pyramid, but had to go back to a 3 blade to get the rpm's up into the horsepower range to get up on plane. It did ride great, and cornered great, but I had to shift my non-boater up onto the front deck to get up out of the hole and on plane.
My friend, Mike Iljin, spent half a day and helped me play around with different vent plugs, to try and get the 4 blade prop to work up there, but I finally went back to the 3 blade that came with the motor, and it performs better, overall.

[Rod Martin]

sounds like you need to drop a inch or 2 in pitch.
At WOT how many RPMs are you getting compared to what you motor is rated for?

Its been awhile but I think I went with the 5 blade and dropped 1 inch in pitch .

With that 115 I never tried to get max out of it. just good hole shot with all my gear onboard and smooth ride

Now my Champion202/ XB250 was another story all together lol

[mark poulson]

Rod,
I max out around 5200 rpms.
I am thinking that I'll wait to buy a hydrofoil until the end of summer, to see how the boat runs in the warmer weather. It ran great in 90 degree, 62 degree water with just me.

Man, I bet you fly!

[Rod Martin]

https://www.mercurymarine.com/en/us/eng ... 15-250-hp/



5000-5750 rpm so if you are running 5200 you're giving up almost 10% of your working rpm. The best way would be a summer and a winter prop. but if you set it for 5700 WOT winter it should be around 5450 to 5500 during the summer, still 350 above where you are now . At 2.07 to 1 350rpm ends up being about 169 turns of your prop each min. just of the top of my head I think you would be like taking off in 2nd gear in a car.

now you could add a jackplate with a little more wedge to get your prop tucked farther under for take off and with your motor farther back it would lift the front better and allow more HP to be used for speed , but with a 115 its all a trade off. plus running your prop higher increases RPM some.
On my small boat it wasn't worth it for me I just dropped pitch in the prop and took a smoother ride .

[Oldschool]

Mark, contact the folks who set your rig up and borrow a 5 blade. The prop should be able to run at max rpm under ideal conditions at top end. Your hull has a wide transum with lots of surface area to plan onto, the problem is weight to hp ratio, you are under powered. To resolve that you need a 4 or 5 blade prop. The High 5 sounds ideal.
I run a 20P, 3 blade SST you need a 19P and whatever that equals with 4 or 5 blades. Bow lift comes with rake and cup, you need a standard Merc prop and the High 5 looks perfect.
All the hydrofoil will do is push the bow down, it can't increase torque, only a 4 or 5 blade prop can do that for you.
Hot dry air decreases hp, cool high humidity air increases hp, altitude decreases hp. Your performance should decrease in the summer at Pyramid, not increase. Water density has a minor affect on hull drag, altitude is the problem.
Anyway, I am done with this, hope you figure this out.
Tom

[mark poulson]

Mark, contact the folks who set your rig up and borrow a 5 blade. The prop should be able to run at max rpm under ideal conditions at top end. Your hull has a wide transum with lots of surface area to plan onto, the problem is weight to hp ratio, you are under powered. To resolve that you need a 4 or 5 blade prop. The High 5 sounds ideal.
I run a 20P, 3 blade SST you need a 19P and whatever that equals with 4 or 5 blades. Bow lift comes with rake and cup, you need a standard Merc prop and the High 5 looks perfect.
All the hydrofoil will do is push the bow down, it can't increase torque, only a 4 or 5 blade prop can do that for you.
Hot dry air decreases hp, cool high humidity air increases hp, altitude decreases hp. Your performance should decrease in the summer at Pyramid, not increase. Water density has a minor affect on hull drag, altitude is the problem.
Anyway, I am done with this, hope you figure this out.
Tom

Thanks for taking the time.