# Tunnels, Tillers, and Steering Torque?



## Smackdaddy53 (Dec 31, 2012)

If you are running a motor that high the tab will be nothing more than just another sacrificial anode on any size motor tiller or center/side console. The only time that tab really works is when the cavitation plate on the lower unit is even or just a little higher than the bottom of the transom. I ran both my 90 and 70 with and without them and noticed no difference. They were not tillers but the 90 had no power steering. The only thing that really helped that 90 was a Tran compression plate. I went from having to hold the wheel hard left when fully jacked to being able to steer with two fingers after installing the plate. It channels a lot of water and I can only imagine how much less stress is put on your steering system.


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## Vertigo (Jun 3, 2012)

I've tried a couple of different skeg tabs as well as modifying the skeg shape, all with not much luck. As noted above, the skeg is not doing much when the prop is getting most of it's water thru the tunnel. I've modified the trim tab on my current motor with an epoxy compound to make it larger and longer. Since it always sits in the prop wash, no matter how high the motor, it does help to control torque. At lower motor positions, tilt/trim can come into play to take the load off the tiller.


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## crboggs (Mar 30, 2015)

So basically expect more steering torque when you're jacked up and your control surfaces on the lower unit aren't able to help offset?

That makes sense. Sounds like I'll need to fine tune the engine height and trim angle to see what works best for long / normal runs.


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## Smackdaddy53 (Dec 31, 2012)

crboggs said:


> So basically expect more steering torque when you're jacked up and your control surfaces on the lower unit aren't able to help offset?
> 
> That makes sense. Sounds like I'll need to fine tune the engine height and trim angle to see what works best for long / normal runs.


Yes, I noticed much more torque steer as the motors are raised probably because the tab is less effective the further you lift it and the prop is grabbing the water differently. I can’t tell as much on the 70 because it has hydraulic steering.


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## sjrobin (Jul 13, 2015)

Tiller but no tunnel, micro jack, with/without Tran plate, more torque the higher or lower the prop is above the hull. Like anything else, there is an optimum elevation depending on how the water flows off the stern. Set by design, speed, load, and water conditions.

On clockwise prop rotation outboards, the tab/anode should be rotated full right standing behind engine.


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## devrep (Feb 22, 2009)

I've got my torque tab at a pretty radical angle and it does help some but I still fight the tiller. It is worse the higher I go.


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## Sublime (Oct 9, 2015)

I ran a transport boats cavitation plate on my etec 30 tiller with little to no torque steer no matter how high it was jacked. I think the curved down edges helped


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## Smackdaddy53 (Dec 31, 2012)

Sublime said:


> I ran a transport boats cavitation plate on my etec 30 tiller with little to no torque steer no matter how high it was jacked. I think the curved down edges helped
> 
> View attachment 26120


Yessir it does for sure!


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## Sublime (Oct 9, 2015)

I completely removed the steering tab when I put the plate on.


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## crboggs (Mar 30, 2015)

Ah...so its possible I was jacked a bit too high, lifting the cav plate above where it needed to be for trim purposes?


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## Sublime (Oct 9, 2015)

crboggs said:


> Ah...so its possible I was jacked a bit too high, lifting the cav plate above where it needed to be for trim purposes?


Depends. My Spear tunnel threw enough water out the back that my plate was always "wetted". Especially if you trimmed the bow down. Whoa Nelly !


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## Smackdaddy53 (Dec 31, 2012)

crboggs said:


> Ah...so its possible I was jacked a bit too high, lifting the cav plate above where it needed to be for trim purposes?


Yes, without a compression plate the prop grabs the water and causes torque steer, with a good plate (I still think Trans are the best) you won’t have that issue even with the motor so high you start losing water pressure.


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## crboggs (Mar 30, 2015)

Good to know...sounds like I need to get in deeper water, lower the jack plate, jump on plane, and slowly raise the jack plate to see where the steering torque becomes most noticeable.

Plenty of boating experience, but the tiller / tunnel / jackplate combo is new to me. *lol*


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## Sublime (Oct 9, 2015)

Deep water really isn't the best place to test it out. You don't have to get crazy shallow, but when you get shallow enough you will feel your skiff "lift" in reaction to it. Hard to explain.


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## Smackdaddy53 (Dec 31, 2012)

Here’s how high both my boats run and the other one had just cable steering and a 90.


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## Smackdaddy53 (Dec 31, 2012)

Sublime said:


> Deep water really isn't the best place to test it out. You don't have to get crazy shallow, but when you get shallow enough you will feel your skiff "lift" in reaction to it. Hard to explain.


The hull is compressing the water between it and the bottom. That’s why airboats don’t like running in deep water, they tend to be harder to maneuver.
When running in 12” or less you can really feel the hull lift up if you are running over sand bars with deeper water in between, it’s pretty cool.


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## crboggs (Mar 30, 2015)

All the way down...


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## crboggs (Mar 30, 2015)

All the way up...


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## crboggs (Mar 30, 2015)

So I called Spear...Harry answered...remembered the boat...gave me over the phone lessons on how to trim the boat to reduce the steering torque to near neutral. Customer service goes a long way, especially on a second hand boat.


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## crboggs (Mar 30, 2015)

Update: Adjusting the steering tab pretty much eliminated the torque when the jack plate is down. And it significantly reduced the torque when the jack plate is all the way up. Love simple solutions to basic challenges.


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