Non-feed back system needed for GN boat

[capnzee]

I just drove GN-24 in the Parker 300 Enduro.For those who are not familiar with inboard racing, the GN class is a big block, blown engine in a 20ft, V bottom boat capable of speeds in the 100 mph range. The boat I drove was equipped with a cable type steering and required nearly full strength to hold in a straight line up to 90 mph. Had one slip of the hand occured, the boat would have made a hard right faster than any one could have stopped. Now, my question is, does any one make a non-feedback system (hydraulic or otherwise) that will hold these kind of pressures. (I have a Merc 200 on a Sleek that has the same problem but that can be corrected with hydraulic steering and a torque plate.) The owner of the GN boat is afraid the hydraulic system will not be able to withstand the pressures placed on the steering system by the large inboard, rudder combination. I am looking for a system that can hold all those horses allowing the driver to control the boat in corners and through traffic with out the fear of steering system failure. The system must be positive and responsive. :) Capnzee

[captcarb]

I think I would approach this differently by reducing/eliminating the torque steer. The inboard guys have been through this and should be able to help. Re-shaping the leading and trailing edge of the rudder and increasing the area in front of the rudder post would all help. I have seen inboard rudders offset also.

A dual cylinder two circuit hydraulic system is probably available also.

jim

[capnzee]

We always increase the lead in front of the post and offset the rudder on inboard hydroplanes but I haven't seen it so much on the inboard v-bottoms. I don't think the offset is feasible on a GN boat but increasing the lead on the front of the rudder is certainly a possibility. Still looking for that non feed back system however. capnzee

[us1]

On the Mod-U boats, when I was racing the Parker Enduro, we used to use 4 layers of bungee cord to pull in the opposite direction of the torque. We used them on the right steering arm. When off plane or going slow it would pull hard at the wheel. When you get it up to speed it was the perfect balance. Ed Lanes idea, it worked great.

[Jeff_G]

John, on a Mod U you shouldn't have THAT much torque :D

Hydraulic systems have been used for many a year. All the offshore boats use it. Benny Robertson used it with his F1 V-8. We have rigged some F1 UIM boats with it as well.

I would contact some of the GN guys in So. Calif. and see what they are using. But I don't see why a good hydraulic wouldn't work for you.

[us1]

John, on a Mod U you shouldn't have THAT much torque :D

Hydraulic systems have been used for many a year. All the offshore boats use it. Benny Robertson used it with his F1 V-8. We have rigged some F1 UIM boats with it as well.

I would contact some of the GN guys in So. Calif. and see what they are using. But I don't see why a good hydraulic wouldn't work for you.

I have to stop using those trolling motors for power.:D

[capnzee]

I believe the GN guys in Southern California are all using the ancient system of cable and muscle--some may have a rudder with more lead and thus less muscle required but I still believe the non-feedback hydraulic system is the most up to date and modern system in existance----if one is manufactured that will hold the torque of a big block, supercharged engine through speeds of zero (le mans start) to 100 mph (straight a way) Sometimes the outboard racers and inboard hydro-plane racers are quicker to "catch on" to the latest innovations. Certainly, I don't mean to criticize any racing community, just looking for help and the name of a good hydraulic steering system. :rolleyes: Rod

[capnzee]

I "hit" the unsubscribe button by mistake, please keep me on this thread--I expect an answer to my question will come shortly

[captcarb]

In that case, I think I would call teleflex. They make an inboard "power" steering system under the seastar name. It is hydraulic/electric. I don't know if it would handle the load, but they would.

jim

[capnzee]

The best Teleflex has to offer is for outboards up to 150 hp. I know there are better kits out there, just don't know where to look to find them. :(

[captcarb]

http://ww2.seastarsteering.com/INBOARD/inboard.htm

[capnzee]

Thanks Captcarb, I have just sent an E-mail and am about to make a follow-up call--will post the results.

[captcarb]

If it were my project I would be tempted to have a special rudder constructed with area ahead of the rudder post and built in trim tabs front and rear sort of like the modern outboard lowers. (in addition to the hydraulic steering). I like John's bungee idea also. With all that pressure, if the steering system comes apart it will hook with a vengence.

jim

[riverrunner114]

The best Teleflex has to offer is for outboards up to 150 hp. I know there are better kits out there, just don't know where to look to find them. :(

teleflex pro systems for outboards are rated for 300 hp single engine and 450 for twins.. and if you want to stay with your cable system they make a no feed back rotary that works real well.. john

[capnzee]

If it were my project I would be tempted to have a special rudder constructed with area ahead of the rudder post and built in trim tabs front and rear sort of like the modern outboard lowers. (in addition to the hydraulic steering). I like John's bungee idea also. With all that pressure, if the steering system comes apart it will hook with a vengence.

jim
I know how lead works on control surfaces of aircraft, but I believe that most of the ill effects on my particular rudder system is coming from the rotation of the water coming off the fully submerged propeller. As the speed of the boat increases and the efficiency of the propeller increases, the rotating pattern of water coming off the propeller lengthens out and the rudder pressures become less. More lead may be the answer, bungees would help and finally, a good hydraulic system could be the cure all. I am waiting for a call from the hydraulic engineers of Teleflex. Thanks for all of the input Capnzee