Dave M

IMCO's brochure says that the add-on systems are not recommended for over 70 MPH. It does not say why.

I upgraded my add-on system to a full system over the winter. I haven't tried it out yet but I will report my findings in a few weeks.

formula31

I have standard cable steering with a tie bar and my drives dont move at all. If you have that much slop youve got other problems.

Whiteknuckle

I'm thinking that Scarab28 response may be starting to get close to the heart of the matter.

I'm wondering how many people have seen the cable in cable steering break. If one checks the condition of the cable at least once a year and replace it when it becomes suspect, I would think it would be very reliable. Breaking cables are rare, and the cable does not know how fast the boat is going. Does this make any sense?

HP350SC

I converted my '97 HP500 steering to WPM dual ram and had very little assist at idle. I was able to remove the p/s pump adjusting bolts and belt, and swing the pump down to modify it. You remove the pressure line (with a coffee can to catch the fluid). Next, unscrew the fitting that is on the pump. There is a spring behind it , and note the orientation of the valve when removing. Simply drill the orifice to the inside diameter of the hose fitting, around 3/16". Clean shavings, reassemble and top off fluid. MUCH better at idle.
This is the same principal modern cars use, they restrict the orifice at highway speeds. At idle, you need more assist.

Falcon

There isn't a "shuttle" valve, well not exactly. Anyways, I really don't like to say one system is "safer". The full hydraulic just has more ultimate load capacity. Remember that the cable system always has "feedback" to the wheel. It only "assists" the cable movement, it doesn't matter whether it's the standard internal cylinder or externals. The externals can have less feedback because of total cylinder capacity, but it's still there. Feedback is "load" on the cable.
You might want to try the cable add-on system and see if it satisfies your expectations. You can upgrade the add-on system by installing a helm and lines later if you think you need it.

Big_D

Not really. If you lose the power assist on the add-on system you lockup tight and can't steer because the cable cannot overpower the external cylinders without assist. So if this happens during a high speed manuver and can't correct.....you can guess the rest. Just as bad as losing a steering hose in either case. JMHO

US1 Fountain

I would rather the steering get locked vs have a drive that can turn without warning and toss the driver. At least with with it locked up, you are still going in the same direction and can pull the throttle back.

Whiteknuckle

Thank you HP350SC on that tip with the PS Pump. Also Falcon on some great information. Lets talk about what would happen with the cable helm system if the cable or any other mechanical part fails. I'm not talking about a gimbal failure but a steering failure. Also, is the cable assist system more suitable to a lighter boat than a heavier boat?

Scott

"I also understand there may be some inherent slop in the cable helm, resulting in some wheel play before the actual input is realized by the hydraulics."

I had a cable helm with external hydraulics. The play in the wheel was 7" and made the boat horrible to control at slow speeds and unpredictable when launching out of the water. I ordered a new helm and was able to take some slop out for a couple of months. Then the slop would return.

The last straw was on a fast run I launched and the girl behind me screamed (having fun scream but sounded like she just saw Freddy) it made me turn around real quick to make sure they were O.K. when I did this I turned the wheel as I turned around. When I hit the next wave coming down the boat hooked enough to scare the crap out of me. remember the slop part of the wheel had no resistance.

I installed the full Hydraulics to the helm and have enjoyed a nice solid wheel ever since I was surprised how much I really had been compensating for the slop.

The job was not too bad and I was able to do it on my own in the off season. Once again I was surprised how much of a change in the wheel it made. Worth every dime I spent and if I bought another boat without the hydraulic helm I would figure it into my costs.

Sorry I have no exact technical science just real experience and what worked for me

Cmoney

Something else had to be wrong to have 7 inches of play. There are a lot of boats that come form the factory with cable assisted hydraulic steering. I can not believe they are all that bad.
I will find out this season. I installed cable assisted steering in my boat this fall after calling at least 10 different companies. They all said cable assist should be fine for my application, since my boat tops out in the 70's, but full would be better. Full should be better, it costs another 1200-1800 dollars.