Womer steering box setup picture request

[mikehinkle]

Looking for some close up of the Womer steering box or other over the leg steering box setups. Also would like your input on advantages and disadvantages of this design.

Thanks!

[karmaboy]

I had these handy...

[Parker]

I moved the box up by 1" but otherwise, this is the EV-3 setup.
I really liked this setup as it uncluttered the front bulkhead and allowed the pedals to move very far forward.
Can't comment about the geometry except to say that it worked well.

[mikehinkle]

Fast replies!
Thanks.

In the Womer I see the box is lowered instead of using a big offset in the pitman arm. Also the box is center in the car requiring a side offset in the arm.
Are you guys legs on either side of the box? Or is it above your legs all together? Would it be advantageous to offset the box slightly and use a bigger offset in the pitman arm but keep it straight. Any input from someone that has tried a similar setup would be great!

[problemchild]

The integrity of the pitman arm is critical in these applications. Virtually everybody I know who has run this kind of setup for an extended period ...... I have also seen running around the paddock looking for someone to weld up their pitman arm. The best ones use a stock pitman arm with bolt-on extension, or leave much of the original arm and weld extensions on with the weld spreading over a large area. I am sure proper heat treating would help too, but definitely a job for a really good professional fabricator.

[mikehinkle]

Thanks Greg. I plan to hopefully leave the pitman arm alone and only use a aluminum quick steering addition. This is a quick sketch up of the plan addition to my car although looking at Ed Womers setup he has a lot of bracing in this area but he also drops down the box.



With this setup I can use a stock box without modifications I think the Adams uses a similar setup. Does anyone have a close of of the Adams Aero setup?

[problemchild]

I will look for the Adams style setup I put on the last car I built. I was amazed, that in all these under dash designs, it was so difficult to locate the box so it cleared the driver and located the steering in a good spot. Don't underestimate that part of it. I would try and measure up an existing car.

If you have a BRD, I would certainly stick with the beam mounted location. There is plenty of room for driver and steering without the compromises involved in mounting the box elsewhere. Unless you go full-blown Citation or Adams setups, you won't beat the steering performance, IMO.

[BLS]

It might be worth asking why you wish to go to this type of steering? Not disparaging the design, just curious as to why you feel the need to change it.

[mikehinkle]

I'm trying to get lower in the car if possible maybe its more work then its worth for a couple of inches but racing is all about a couple of inches isn't it? If i move the steering rods out of the way I can move he pedals forward, lowering my body and possibly that giant roll hoop/wind sail I have.

[problemchild]

I drove the works BRD for several years. I just brought my knees up, moved my butt forward, and built a diagonal seat structure. My eyes were at the cowl level and I had 10+" to the standard roll bar. It was a "wide" chassis but I expect you could do something similar.

[problemchild]

Now that I think of it, we did modify the upper firewall and change the x-bracing so that my head could tuck down and back.
Attachment 56796
Unfortunately, this is the "before" picture.

[mikehinkle]

I think i'm about as far back as you. I had the cross member moved back as well so the firewall is a little more leaned back. My knees are currently bent but perhaps I could go more .. I didnt want to make entry/exit to tight but compared to other cars i've sat in I guess I have a ways to go.
http://www.puckstopperphotography.co...5971#h5c9d59a1

[BLS]

I'm trying to get lower in the car if possible maybe its more work then its worth for a couple of inches but racing is all about a couple of inches isn't it? If i move the steering rods out of the way I can move he pedals forward, lowering my body and possibly that giant roll hoop/wind sail I have.

Yes, a couple inches can be a lot. As part of my modifications, I changed the steering on the Citation. The picture shows another possibility. To move the pitman arm as far under the torsion tubes as I have it requires not having the traditional frame uprights, but you might have some amount to gain. I looked at doing the womer style steering, but the side frame members and my legs didn't really cooperate...

My mods remain untested. that is what "next year" is for I hope.

[mikehinkle]

I had considered moving it forward with another bar ahead of the beam because I have seen others do that as well but I have very height in the nose I would have to drop it down as well and im not sure if it would work.
I'm not a setup guru but does the extreme angle of the tie rods effect anything? Like ackerman? Would straighter rods be more desirable?
Also funny note my car has a cut in the belly pan exactly where you cut out to access the front.

[BLS]

Yes, that requires a high nose or big bump to clear the steering box. The position of the box vertically is critical in my case to have the pitman arm between the torsion tubes and be able to get the bolts in the tie rod ends. Since you would likely have yours further out it might not be a problem. I drew it all up and decided the only issue with the angle was decreased steering ratio, compensated for by the tierod outer placement closer to the spindles, with reduced ackerman. As I said, untested at the moment...

To have that setup requires removing the uprights typically used to mount the beam. And of course designing/fabbing a new mounting system. Clearing them requires the pitman arm to be back much further, and would eliminate the gain I made in car length.

It would be much easier IMO to go with the womer setup if it will work on your car and your body.

The belly pan was cut because I lengthened the frame to get more legroom. The Citation has the min wheel base of 81.5. Mine is now 83.4.

[aerobullet]

Here's one we designed for the Citation Silver Bullet body conversion. Race tested, very simple, very effective, uses the stock Citation Pittman arm, near 90 degree and level tie-rods, light feel, quick enough for the Sebring hairpin, and negligible bump-steer. Driver is 6'1", 200 lbs.

http://www.apexspeed.com/forums/atta...1&d=1446220955

http://www.apexspeed.com/forums/atta...1&d=1446220955

[Ed Womer]

I must say that everyone talking about the Womer style steering is nice to hear! I initially went this direction so I could have more leg room in the car and saw the design from a D13 S model and started using it. I originally just ground off the locating teeth and welded the arm on in the opposite direction but as Greg mentioned it was prone to the weld cracking and always at the track.

I finally looked at it carefully and in order to get the steering wheel centered in the chassis you have to mount the steering box off 1/8" of center line so the steering shaft is on center line of the chassis. I also cut off the pitman arm and made my own so that you could easily change the steering box if it became damaged at the track. With my own pitman arm it was easy to get the tie rods the same length so you don't have to carry different spares and with spacers you can adjust the bump steer under braking to have a slight toe in which I think helps in stability under braking. Unfortunately if the chassis goes up as under curb hopping or a quick rise in terrain like the hill at Lime Rock without some limiting the front will toe out. If you don't want that to happen you would need to work around it but I really didn't worry about it since it is just for a slit second and like all racecar design is a bunch of compromises that you have to accept.

The big gain from this style is about 6" of additional leg room but the steering box is over your legs and the tie rods are behind your feet. I always had a foam pad under the box to protect my legs and the one time I had a spectacular crash at Summit Point and did two endos and landed upside down I only had a slight bruise on my leg where it hit the foam protected box. You also get a lay down style of seating and can have a lot of leg room. I also moved the rear hoop back but that means you need to remove the firewall to take out the engine but again the compromise issue. When asked about the additional time to change an engine my standard reply is you need to change engine builders if you have to change engines all of the time and besides once you have it down it really isn't that much more time.

The pictures posted are of my car I sold to Kevin so it is as I raced it from the time it was built to replace chassis #1 that was slightly damage in the huge accident at the pro race at IRP on the oval plus the #1 chassis had 1 1/4" roll hoops and SCCA decided that that had to be increased to 1 3/8" (major improvement?) so I just built a new car and also redesigned the side bracing as well.

I have built 17 Womer EV3's and most of them are still raced and my friend and factory driver Dean Curtis did win the Challenge Cup series this year and Chris Elwell also did well but had to miss races due to a new job. Andy Pastore did also run one of my cars this year at Majors as well as the runoffs. If anyone is interested I still will make a car but don't have a chassis sitting around so you need to order one.

Ed

[budawe]

Several cars have run this style of box mounting. I think the first I saw of it was the Darts on the west coast. The the first Lazers had this as well. It's a simple strong approach but the first time I saw this approach I developed a sore knee just thinking about it. I chose to mount the box on a separate tube in front of the h beam like BLS photo shows. You get all the foot space you need without having tie rods, that can bend or break, behind your feet or a iron box between your legs. Plus I had a concern regarding the length of the pitman arm when transmitting forces back through the steering wheel.

Bump steering a vee can be a challenge since the outside steering pickup is not going up and down in a straight line but doing so on a curved path. Finding the radius of a curved path is not easy. It's actually a cone with the tip occurring on the center line of the h-beam. The closer you can mount the inside tie rods to the center line of the h-beam the better. The shorter the tie rods the worse the bump steer.

[mikehinkle]

Thanks for all the great info guys this is a interesting topic. I'm going out of town so I wont be able to 'mock' anything up until I get back but I am planning on setting up the steering box in a Womer type position to see how much room it would give me in the car before I start welding anything in place.
Greg, I originally had to raise my knees to fit into the car when I first got it and I tried raising them more to get me down to where I want to be but I see two problems with this. First I am concerned about getting out of the car with my legs so much higher then my butt and less space for the legs to get out. The second problem is my knees/lower thighs running into the wheel. I would have to move the wheel about 4-5 inches closer to my chest. This might be a better racing position...? I'm not sure.

For reference here is a couple of pictures of my cars setup as of now.

[gbmetcalf]

I always liked the Adams setup. Does anyone have experience with it?

http://www.apexspeed.com/forums/atta...7&d=1381185728

G.

[budawe]

It's what is called a drag link system. Large trucks, motorhomes and Sprint cars use the system. While there is no bump steer under braking, since the wheels are locked together, there is roll steer if one tire goes into compression. The car rolls to one side and forces the car to steer slightly sideways. In addition, there is no way to develop ackermann to assist turn in. The Adams used a bit of tow out to help on turn in but that can increase instability.

[mikehinkle]

Does anyone have close ups of the Adams setup? I would like to see it. I love the look of Adams cars.

[john f]

It's what is called a drag link system. Large trucks, motorhomes and Sprint cars use the system. While there is no bump steer under braking, since the wheels are locked together, there is roll steer if one tire goes into compression. The car rolls to one side and forces the car to steer slightly sideways. In addition, there is no way to develop ackermann to assist turn in. The Adams used a bit of tow out to help on turn in but that can increase instability.

Whether you are using a drag link set up , the original VW set up, or the "Womer" set up, your akerman is developed the same way. Front steer requires the steering out further than the king pin. Rear steer requires the arms in further than the king pin.

john f

[budawe]

John, how does the toe change when both sides are tied together via the common tie rod. If the inside tire is turning more quickly due to the location of the steering arm, isn't the outside tire forced to turn the same amount negating the inside tire lead?

[Parker]

Only if you have a parallelogram will both wheels change angle the same amount for a given lateral movement of the tie rod.
What is there is a trapezoid with one pair of opposite sides of equal length and the tie rod being the shorter of the remaining links. This setup has "Akerman" and the inside wheel steering rate increases while the outside decreases until the angel between the tie rod and the outside steering arm reaches 90deg. At that point the outside wheel rate will begin to increase but not catch up with the inside wheel rate.

[mikehinkle]

Look at this link

http://www.rctek.com/technical/handl...principle.html

I use to race RC and still reference it for car setup because they have every adjustment you could imagine. Many aspects of the setups go from one extreme to the other so you can really understand the changes.

[problemchild]

The Adams FV had a bunch of things going on that were not apparent without study. The steering arms on the spindles were straightened out, which changed the length of the steering arms, while almost creating a parallelogram. The pitman arm length had to be relative to the steering arm length, and tee length on the drag link. Then the beam had to be located relative to the steering box longitudinally and in height so that all the arcs of the moving pieces were co-ordinated. Then the front end was preloaded so there was hardly any travel or roll. It had less scrub in nearly all conditions than any other FV I have worked on. Of course, some people want some scrub in some of those conditions, so you have to buy into the theories it was designed to.

I would not casually try to reproduce the system. I put it on my last FV (Problemchild SM4) and I copied it directly from an Adams front clip that I had. I saw a few Adams owners who replaced the system with an inferior generic layout without appreciating how awesome it could be.

Probably not a design feature, I also discovered that you could set the drag link at a height that it bottomed out and acted like a 3rd spring in bump.

The whole car had a lot of progressive features. Although I repackaged it, I used the same unconventional rear suspension setup on my FST cars, and they handled great.

[G.B.]

http://www.apexspeed.com/forums/showthread.php?t=60232

[BLS]

Probably not a design feature, I also discovered that you could set the drag link at a height that it bottomed out and acted like a 3rd spring in bump.

Problemchild, would you elaborate? Do you mean the drag link contacted a part of the framework?

[problemchild]

Problemchild, would you elaborate? Do you mean the drag link contacted a part of the framework?

Yes. You had to spend some time shimming all the various pieces so that different pieces could all move on their various arcs with minimal binding. I discovered, by accident, that you could have the drag link interfere with the pitman shaft in the steering box. Too much interference, and it bent the link, but that became another parameter I would set. Unfortunately, I got laid off my job shortly after I started running my Adams, and sold it, but incorporated things I learned in future cars I built or raced. I expect it would have been a much better seller if it looked half as good as it handled, atleast if setup properly. I think many owners tried to set it up like they set up other Vees. You needed to spend time getting certain things right.

[mikehinkle]

Thanks Guy.
I do have those pictures in my collection but there is no close up of how the pitman arm is configured. I wouldn't attempt to copy it as it sounds a little to elaborate for me but since this discussion has come this far... and for future readers on this topic it would be nice if someone who has some pics of the setup could share them.

[BLS]

Thanks Greg!

[problemchild]

The pitman arm is a stock VW arm but only one hole is used. The short one if I recall.

I actually came across my "Adams spindle steering arm straightener" jig the other day when I was looking for something else I never found.

[budawe]

Thanks Greg, great stuff to think about.

[Mark Filip]

Mike you do remember I live 15 min from you and I have a Womer you can take all the pictures you want.

[mikehinkle]

I would love to come by! I'll send you a p/m

[Keith Lawrence]

With the steering box "upside down" what is found to be the best lubricant to use in it?
Heavy grease?

I have Jon Van De Car's old D-13S and am rebuilding it over the winter for its vintage debut in 2021.

THANKS!!!