Help needed on Flexible Steering Shaft

[musclemotor]

I need help finding a product. I am building a LandSpeed racer for the Bonneville Salt Flats. I'm putting a SBF NASCAR engine in a '86 Merkur XR4TI. The headers take up all the room in the engine compartment and I have no room for the steering shaft. Someone came in our store and said there was a company that makes a flexible steering shaft (this would solve my problem). Does anyone know where I can find such an animal? Thanks,
Bob Gribble

 

[patprimmer]

Would the cable systems used to steer outboard motors on boats be adaptable to your application.

I don't think they are precise enough for a street car, but if you only need a very poor turning circle, you might set the leverage in the linkage to give good precision

Regards
pat

 

[GregLocock]

Good idea Pat. We often see weird and wonderful steering linkages on solar cars, using push pull cables, and getting the compromise between low friction and low backlash is very difficult, since both are important. I wonder if the original poster has thought about using a steer by wire system?

I get the impression he was hoping for a torsionally stiff, flexible cable, like a speedo drive. I doubt that such a cable capable of providing steering loads would be low friction, and if it was the backlash would be too much.





Cheers

Greg Locock

 

[patdaly]

Muscle, if you find such an animal, please post it! That being said, in 20 plus years, I have never seen one I would trust at 50 MPH, much less at Bonneville.
Indeed, most sanctioning bodies forbid any flexible "cable" type of shaft. I would look to multiple short shafts, and Borgeson (SP?) joints, then modify the headers as necessary. Hey, we stuffed a 460 BBF in a Ranger, you should have seen that mess!

 

[patprimmer]

Another system I have seen used to offset steering shafts is a chain drive. It is used here for left to right hand drive conversions, but I must say, I don't trust them, and they simply ofset a solid shaft, so they might not solve your problem.

I am presumeing that a Bonneville racer has a lot of room, and mainly needs to be kept going straight at high speed. I would expect the car to have a bunch of castor, like at least 6 degrees and possible as much as 15 degrees. This would keep it pretty straight with no steering wheel at all.

The boat steering I am thinking of is called a ride guide. It has a steering wheel with a curved rack and a pinion gear. This pushes or pulls a very hefty Bowden type cable. On faster boats they use twin Ride Guides, so one is always pulling. This also allows adjustment of each cable with some preload to pull the slack out of the other cable, thereby considerably improving accuracy. These can also be had with power assist, which are then typically used on large sterndrive units for offshore racers. In raceing applications, stern drives are mounted high on the transome to allow the propellor to surface, there is a considerable torque on the steering from the paddlewheel effect of the surfacing propellor, thus makeing power assist necessary.

I would be takeing a close look at what someone like Mercury Marine has to offer on their Mercrusier range.

Regards
pat

 

[Psydwaze]

The company I work for had used a flexible steering shaft in the past with unfavorable results. It was some type of laminated flexible cable that did not work well when subjected to the high heat and heavy loads. The few failures occurred while manuvering in parking lots at very slow speeds or when stopped. DO NOT use type of a steering shaft on your land speed vehicle.

 

[DickAnderson]

The Ford PINTO used a flexible shaft in their steering. It is very easy to work with and reasonable strong. I have one installed on my 32 Ford Street Rod (for about 20 years!) with no problems. I would certainly heed some of the other warnings. It would not be a good idea to bend it thru much angle - it is best used for small "offsets" or angles - and turning the wheel while stopped is certainly the hardest on it BUT that goes for ANY steering! Is your car Rick Byrnes old car? Very nice.