BUILDING A RACK & PINION GEAR BOX FOR A SPEEDSTER/ SPYDER

I looked into converting our bug based Speedsters into rack &Pinion instead of the old gear box. There is a kit offered in Europe that is a bolt on rack and pinion setup I have seen them online. I wanted rack and pinion steering in my Magnum GT that had a VW bug H beam front suspension and VW bug steering gear box. I decided to buy a bolt on replacement double wishbone with adjustable coil overs and rack & Pinion suspension setup from a company called Red 9 design. Carey Hines and his crew installed the new suspension while they had my Magnum for a Subaru conversion. The suspension setup comes complete and bolts into the bulkhead holder that the old H beam axle was bolted to. Here are some pics of the suspension. Carey is just about finished with my Magnum after having the car a little more than a year. They are scheduled to drop the Magnum off at my house on March 9th. I can report on how I like the front suspension and steering.

Thanks Jimmy.   Looks like about 4" of travel each way.  Is the ratio  about 3 to 1 ?

Bruce

@aircooled, what you describe sounds a lot like the Polo rack I and others have installed. Kits are available from several sources.  It has been discussed on this site.

The Polo Rack is the one I was referring too in my post; I just couldn't remember the name.

Bruce, why are you trying to re-invent the wheel? Is there some sort of parts supply problem for the Polo system?

@Jimmy V., Bruce is working with a Spyder.  Those Mendeola/iMohr/Red9 front ends will not fit, there just isn’t enough room.

My long time friend owns the two biggest junk yards in Kansas City Mo. He says the Euro Polo manual steering box is getting harder to find because it's not a fast enough moving reuseable part. That most of them are going to the scrap metal bins.

Std. VW steering boxes are becoming a little faded in availability as well.

No Danny, I'm not trying to reinvent the wheel, just what steers it Ha Ha....... No, right now, I'm looking for some worthy projects and this one perked my interest.  So while I'm still able to communicate between my hands and my brain I continue to explore many opportunities to take on projects that there may be a need and tweak my interest.  I have come to find that on this site there are quite a few of you people like me and I trust that those of you who are,  will express your thoughts and opinions.

The biggest obstacle on this one may be liability.  Stamping the component with "Off-road use only". may be a lame way of getting around this as it has been done with other components. Some of which may well have a higher risk of liability than this one. Frames and suspensions, brake components, steering wheels, wheels, to name a few.

Please give me your opinions. For or against but respectful ?..............Bruce

The Polo was never sold here, which may be why your friend in KC doesn't have a good supply. I can't imagine any salvage yard in the US has ever had a good supply of them.

I'm not sure why anybody would want a used rack, though. I'm not sure what the parts availability for remanufactured Polo racks is, but the price cannot be more than building a rack and pinion setup from scratch. I can't imagine that the market for conversion racks for VW Beetles and their variants is big enough that you'd ever run out of parts. I can't imagine selling more than 50 of them in 10 years, even if Greg started offering them as an option.

Rather than a "from scratch" setup, I think what the world needs is a stateside supplier of the kits Alex 77 and CSP already sell. Alex is hundreds of dollars less expensive than CSP, but buying from either is a bit too clumsy for builders who just want to make a call and have a brown truck show up with the parts 3 days later.

I'd be that guy. Find a source for Polo racks (new or reman), buy 30 of them. Build kits.

Sell the kits here.

Bruce, I also would rather be in the garage doing Motortrend stuff instead of watching it on TV. I've done many things that might be considered a waste of time, but I enjoy the challenge. Working the brain and hands is never a waste of time.

Stan does have a valid point though. Maybe you could acquire one of those Polo racks and see how it can be improved.

One of the problems Danny had when he attempted installing the Polo rack in his Spyder was lack of room. The corner above the clutch pedal in the foot well needs to be cut to allow clearance for the left tie rod. The passenger foot well is already cut for the VW tie rod. Unfortunately the clutch pedal needs that space. Maybe if the tie rod was an arc instead of straight, this might work??? Who knows, but that's part of the fun.

Wow !  But I got what I asked for !  Thanks to you all.  My KC junk yard friend did check with his junk yard friend in Belgium. He's the one  this information came from about that part availability drying up. I should have mentioned that.  Junk yards are currently concerned about their future if everything goes electric. Handling modern electronic components is certainly different than mechanical. Testing them and storing them properly is already becoming a problem says my friend.

Anyway, after doing some exploratory surgery on an R&P box I discovered how simple they are. This is what triggered my interest.  What I don't have is a good handle on how many of these I could sell, say, in a year.  Stan,  you provided a pretty good shot from the hip and certainly it's worth looking closer at the market for such a thing.  Like Carlos alluded to.  I could build one just for me. I still enjoy the challenge.

Then there is this idea in the back of my mind about the entire front suspension on our cars. Especially a Spyder.  After looking at one over the years we all have concluded that a re-work of the entire front end would be required. Perhaps a mechanical (or even an electric).  worm shaft with floating nut connected to the tie rods. Currently this is used in almost every aircraft.  There are a lot of ways to do this and all are worthy of looking into.

More comments would be very helpful............Bruce

It isn't safe IMHO to have a tie-rod that is anything but straight.

And as I said before, if I was building a new car, I would figure out a way to do A-arm/coilover in the front. I'm 100% sure it can be done. Rear IRS isn't hard, that could be done in my car now.

But on an existing beam Spyder a rack is almost a drop-in. The fiberglass in the footwell needs to be slightly re-configured for the left tie-rod. Some minor fab and re-glassing for the steering tube, add a U-joint or maybe shorten the steering shaft. The only reason I didn't install the rack on mine is because the car is finished. Pulling the carpet and cutting/re-glassing was something I wasn't willing to do.

Bruce, I appreciate the challenge of building a rack. But it doesn't make any economic sense whatsoever. Get some used ones imported from Europe. Make the mounts for the beam. Make the machined piece to pick up the tierod ends. Inner tie rods can be heim joints, outers VW, then just a couple fabricated rods. Drill and tap. Easy.

Finally, TRW steering boxes are no longer available. But, now these ARE available and in stock.

$260:

https://www2.cip1.com/vwc-113-415-061-cbr/

There was a guy on TheSamba selling new boxes, disassembled and rebuilt with the proper seals, grease, etc.

I wish I had a link. I don’t.

As a mechanical engineer schooled in the strength and stiffness of materials and structures, I'll bet You could make a curved tie rod stiff enough to work properly, but you would not like how much it weighed.  Simply bending an OEM one would be foolhardy. But don't ever run it into a curb . . .

His name is Heimlich, and he deals in many NOS VW parts.

https://www.vwnos.com/113-415-061-c

@El Frazoo posted:

As a mechanical engineer schooled in the strength and stiffness of materials and structures, I'll bet You could make a curved tie rod stiff enough to work properly, but you would not like how much it weighed.  Simply bending an OEM one would be foolhardy. But don't ever run it into a curb . . .

Yes, but how would you adjust it?

Jason

Jason.......In one full turn increments ?  just kidding.............Bruce

Mr. Frazoo.........Can you do the RBM calculations for various lengths and diameter of DOM tubing ?  Like 2.5" X 12'.............Bruce

RBM? -- you got me there.  Not sure what your asking for here, but yes, I can do lots of calculations.  actually, I get my computer to do the calculations, I just tell it what I want.

@aircooled posted:

...

Then there is this idea in the back of my mind about the entire front suspension on our cars. Especially a Spyder.  After looking at one over the years we all have concluded that a re-work of the entire front end would be required. Perhaps a mechanical (or even an electric).  worm shaft with floating nut connected to the tie rods. Currently this is used in almost every aircraft.  There are a lot of ways to do this and all are worthy of looking into.

More comments would be very helpful............Bruce

I wish you all the luck Bruce but I must dissent. "We all" have not concluded that a re-work of the entire front end is required. Required for what?

I think they're fine as-is, as long as one sets the ride height and alignment correctly, maintains the gear and doesn't try to put elevendybazillion horsepower behind them or drive like Andretti in his Lotus 79. Because to do that would require both new suspension systems front and rear, and also a lot more chassis tubes than most of us are willing to sport in any street car—let alone these specific street cars.

And here's the thing I know nobody wants to hear: very few—vanishingly few—of us are equipped to drive any kind of elevendybazillion horsepower device (or any other actual road-going device) in the style of Andretti. Our reflexes, eyesight and (hopefully) common sense auger against it.

A good rack & pinion to get the steering to feel like a Toyota Corolla? Sure, fine. Why not? But much more of the "more is more" philosophy, when applied to fake Speedsters and Spyders, usually isn't.

.

Ed's point has been argued, and will continue to be argued, probably forever.

Like the famous elephant and the five blind men, these cars represent something completely different to each of us. I get trying to pull all you can out of any car, modifying to the max. I really do. And that is a noble pursuit. But while that may be someone's thing, it's just not my thing.

I like adding just enough power (and messing with the gears just enough) to stay with modern traffic. But I also like driving these antiques and seeing what I can do with them just as they were. Maybe learning something about how our mythical heroes did what they did?

Truth is, I'm driving at four tenths a lot more than eight tenths. And I would be nuts to even attempt nine and a half.

As Ed suggests, if I want to be fast, I'll get a Corolla.

.

I’d be remiss if I didn’t tell my Andretti story after seeing his name mentioned.

He and my dad were friendly and quasi neighbors. Close enough to know where the other lived but couldn’t see each others houses. There was a little diner that Mr Andretti would eat at every morning. One morning he and my dad were going to have breakfast together. Andretti told my dad to meet him at the diner at 7:07am. Not 7am, not 730 am. 7:07am.

my dad thought this to be a bit odd, so curiosity got the better of him and he showed up at 7am.

As he is waiting the waitress asked if she could get him something and he said a coffee and then mentioned that he was waiting for someone else to join. She said- are you waiting for Mr Andretti, by chance? And my dad said, why yes I am. The waitress looked down at her watch and said- oh he will be here in 7 minutes, you’re a little early.

now my dad is equally freaked out as curious as to how this waitress would know such a thing.

a few moments later my dad hears the roar of an engine, a V12 to be exact. It turns out that it takes exactly 7 mins to get from Mr Andretti’s house to this little diner. He knows this because all of the stoplights from his house to said diner are timed. He figured out when they would be green in a perfect, beautiful synchronicity, and knew exactly how long it took to get there at “a certain speed not to be mentioned of”

I was lucky enough to sit in that new 1984 Lamborghini Countach that had a certain V12 engine that made the ride in 7 mins and as a then 9 year old it’s one of my favorite memories.

Sr. Frazoo........RBM.......Resistance to Bending Moment.   I need to know what this would be in the center of a 12 ft length of 2.5", .125" wall  common DOM steel tubing.

This is for another hare-brained project I have going...........Bruce

Building an  R &P steering box just isn't that difficult to do. Even as a one-off.   Sand casting could be used.  A CNC machine could carve the box out of a block of 6061 aluminum.  The gears could be broached or milled out several ways.

Maybe  a rack and pinion isn't the way to do this.  Perhaps a fixed worm shaft with a floating ball bearing nut could be used.  This would eliminate any useless protrusion from the left side of the box.  Also make it easily adaptable for electric assist steering.

There's lots of ways and everyone of them are interesting and challenging. Each of us wants to modify, improve, make-it-better, change-to-suit, fit better, look better, cleanup for appearance, and on and on because these cars are a passion of sorts to us.  Thats what I like about this site and the people in it.............

Chuck and I have been chatting about this for a while now.  He just added a rack to his beetle, using all US based parts, and he is very happy with it.  I'll ask for more details before he heads home this afternoon.  

"using all US based parts"

That is the biggest part of the equation and the opposite to what a lot of kit car designers did.  Like using the front windshield from a 1974 Camaro (only) in a Lambo kit.  Really?  Where the hell am I supposed to find that?

Chuck's got it right.  Grab something from a recent American car that will work for the most critical part(s) and design around that.

As I said more than 10 years ago on the Spyder Club site:

If you power through a turn you will under-steer; if you get off the gas you over-steer...it has not changed !

ReV

Thanks Carey.  I'd be very interested in what you and Chuck see as a workable steering gear box.  I've even thought about using a VW   T3 box mounted in the center with two small 90 degree bevel gear boxes to transfer the steering wheel torque to the new box position. Using two of these small boxes gets the rotation back to original direction needed as well..............Bruce

I  would think most modern rack and pinion steering is also powered ,

can you use the rack and pinion of a car that has electric power steering under the dash  , since  the rack would not be powered ?

I must say that having electric power steering is interesting if you have to parallel park or have wide front tires…….

lets see what Chuck came up with

@aircooled, I can do that calc., but need to know the load.  And be advised that bending and buckling are two different things.  Bending of a beam depends on how its loaded: point loads, location thereof, or distributed.  also how the ends are held.  If we are talking tie rods, then the ball/heim-type joints at each end would be simple supports.  The Buckling load of a column in compression is another sort of estimate.  I'd assume that sort of load to be the one important to a tie rod.  Like if you run in to a curb.

Aside: I took my 2018 Honda Accord in for some maintenance and was asking about what might be indicated per factory recommendations.  I specifically asked about the service interval for the power steering unit, getting that flushed, or whatever.  The answer was: never.  I said : Huh?? and was informed that it is electric, not hydraulic  Well, son of a gun.  One less thing to worry about --until it breaks.

Electric power steering actuators are NOT necessarily part of the rack and pinion unit.  The electric steering actuator can be a device that works with the steering column between the steering wheel and the firewall.  That is how Nissan and Honda do it and in that case, the R&P unit itself is pretty simple.

My last three cars/truck and my current Subaru and Acura all have electric P/S and they have all been great.  The Acura provides the most assistance (lightest steering) but other than that and as the Service guy says, there is no maintenance.

Wait...how many gearboxes? placed in series? With their backlashes multiplied...?

And, umm. Isn't building a power steering system for a 356 replica a bit like deploying a gantry crane to hoist a beach ball?

What is going on in this thread?

I got lost when we were talking about using sand castings . . .

@Gordon Nichols posted:

Electric power steering actuators are NOT necessarily part of the rack and pinion unit.  The electric steering actuator can be a device that works with the steering column between the steering wheel and the firewall.  That is how Nissan and Honda do it and in that case, the R&P unit itself is pretty simple.

My last three cars/truck and my current Subaru and Acura all have electric P/S and they have all been great.  The Acura provides the most assistance (lightest steering) but other than that and as the Service guy says, there is no maintenance.

I have had a few Acura’s and they were nice but the steering system that impressed me the most was my 535i  BMW1987.  Speed variable self centering and at 85mph it would get very manual to being hard to turn … not so with the Acura RL or Mdx or any Honda product like the Odyssey the centering was not pleasant IMO

I guess there must be a reason they call it the ultimate driving machine …

Absolutely right Ed ! Too much backlash. Next was using a drag link and a centered bell crank.  Same thing, too much play but better and maybe even acceptable with the right components.  I have not scratched this one off my list yet. A available electric power steering assist unit could be mounted in a Speedster right now to accompany  this modification for about $700.

Electric power steering may be the answer. How much power assist can be adjustable so that eliminates the crane to lift a balloon problem.  My wife hated the steering in Rhonda because it was hard to steer while parking.  Some of you on this site have complained about this as well. To me,  achieving a decent "fail-safe" or manual backup mode in the event of a failure of the electrics comes into play here. So far I have only looked at 3 electric power steering systems. The first one being on my 2017 GMC Canyon. (which has failed once due to a big rock injury off roading) which cost  nearly a thousand in parts.  For a 4 X 4 all terrain vehicle, the placement of this under the truck couldn't have been  worse. Even the skid plate doesn't protect it ! It is too bulky to be used for what I'm trying to do.

There has to be a way to do this that will not cost an arm and a leg, be adaptable, light weight, safe, manual back up, allow equal length tie rods, simple, rugged, adaptable to Rt. & Lt. steered cars, perhaps selectable ratios...............Bruce

@Michael McKelvey, how is the steering in your speedster with the polo rack.  Do you find it hard to steer at low speeds and parking?

Bruce, are you trying to solve a nonexistent problem?

Rick, I can't do the @thing for you. What is the letter after L?  Is it an uppercase i or a lowercase L?

I haven't had an issue with low speed or parking.  It seems to be about the same as with the old steering box.

I have a Super Beetle bushing in the end of the column tube.  It is a bit tight and the steering doesn't return to center by itself.  When that loosens up the effort might be a bit less.

The diameter of the steering wheel might be more of a factor in effort needed.

@Michael McKelvey posted:

Rick, I can't do the @thing for you. What is the letter after L?  Is it an uppercase i or a lowercase L?

I haven't had an issue with low speed or parking.  It seems to be about the same as with the old steering box.

I have a Super Beetle bushing in the end of the column tube.  It is a bit tight and the steering doesn't return to center by itself.  When that loosens up the effort might be a bit less.

The diameter of the steering wheel might be more of a factor in effort needed.

@Michael McKelvey, thanks!  It's an uppercase I.  Stands for Long Island-Rick.  

@LI-Rick, the @thing is working now. I thought it might be Long Island.