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Hello all, Im in process of modifications on 84v citation for steering to allow more foot room for pedals, ive seen that there was a modification for using silver bullet bodywork, any measurements or instructions on the mod? Also I noticed on a few that the cross tube to mount box was angled, any info on pros and cons of this compared to just straight across, thanks in advance, Dave
Dave, The reason for angling the mounting bar is to keep the steering box IN THE CENTER of the 'box gears' even if the box pitman arm is NOT in the center of the car. IMHO, that isn't really very important - actually, generally the SLOPPIEST point of the box is in the center.. so it might even be a detriment.Quote:
Originally Posted by fv58
Anyway.. just answering your question...
Steve, FV80
I cannot in good conscience leave this be. This statement is the complete opposite of the truth. The boxes are supposed to be adjusted to give the LEAST amount of play in the center. The further from the center they get, then the slop is there.Quote:
Originally Posted by Steve Davis
I know my steering box is very tight(no slop), but not binding, nice and smooth. Mine is even a TRW brand, not OE VW.
The Womer steering is done the same way as what the OP is looking to do. The pitman arm is offset so even when the box mount is angled, the tie rods are centered.
A bit harsh don’t ya think?Quote:
Originally Posted by DannyPip
That's OK, Joe :D. Technically Danny is "correct".. however the difference is quite minimal and I don't really think it matters in the long run. I built my last vee with the arm 'square' to the frame and saw/felt no difference in the way it worked. I was still able to design the pitman arm to use 'same length' tie rods and was able to even win a few races with it. Danny probably has better steering boxes than I. When I tighten mine close to ZERO PLAY at the center position, it takes significantly more steering pressure as soon as I get off 'straight ahead'. I find that ease of initial turn in makes it easier to hit that 'turn in spot' as closely as I like it to be... so that leaves 'more slop' in the straight ahead position than I have after turn in. I hate that slop in the center, but I'd certainly rather have it THERE, than later after turn in. We makes our choices. Ideally there would be NO SLOP anywhere... I just haven't been able to achieve that in my cars - despite MANY different steering boxes.Quote:
Originally Posted by housejoe
Steve
Since my car design is mentioned here I thought I would give a little reasoning for choosing the direction I did. I realized that mounting the box on the beam immediately took up 6" of leg room in a chassis with an overall length restriction. Fortunately living in the northeast I could see a lot of different types of cars at the track and noticed the D13S models had the box over the drivers legs. This which allows the pedal travel to extend to the back of the beam thus giving max room for driver length.
Unfortunately this creates other issues that I never tried to fix and just dealt with it. First when going over a quick rise or bouncing off a curb that raises the chassis up, with for a quick moment cause toe out until the car settles back to rid height. I never found that to be an issue but others might.
The other thing is if you want the steering wheel centered in the car and perpendicular to the center line, then you need to offset the box to solve that. If I remember it needs to move 1/8" to make it work. My cars have that and when making up the pitman arm extension I move the connection point to the center of the chassis so I can have interchangeable steering arms.
Over the years and recently I have started to think about was to mount the box to essentially make the actuation of the steering arms close to that of a steering rack. It is possible to get it to work but since I don't have a vee anymore it is just a thought. Plus if I did they would then allow steering racks, kinda the rules creep that still happens today. I have acquired by chance one of the only two built Tinman chassis and it had the box mounted a few inches in front of the beam on and auxiliary mount built in front of the chassis. It could just as easily be bolted to the front of the beam's attachment to the frame bolts. But like I mentioned I just don't feel like figuring out the design and produce it. My interests are starting to go else where with some of the dumb rules which drive up the cost because someone wants to force on the masses, my opinion.
Ed
Steering boxes and racks will ALWAYS wear the most where they are used the most - in the straight-ahead position.
A NEW TRW steering box is machined (designed) to have less clearance between the worm and sector gears when in the centered position. The clearance grows as you move away from the centered position. The OEM want the smallest amount of play when driving straight ahead.Quote:
Originally Posted by Steve Davis
I would recommend the tightest clearance setting you can tolerate at the steering wheel. Do not worry about wear. You are not going to see any wear during the steering box's very short time on a FV.
Brian
It would not work, create very bad bump steer, etc.Quote:
Originally Posted by Ed Womer
To eliminate front end bump steer, etc., the steering control arms must be mounted in a fore and aft position and have the same (fore and aft) length as the suspension control arms. In other words the steering arms arc must travel in the same longitudinal plane as the suspension control arms.
I can and has been done. PM Email if you want more details.
Brian
I started this two hours ago and got distracted. BTW - Happy New Year.
“actually, generally the SLOPPIEST point of the box is in the center.. so it might even be a detriment.”
As Dan mentioned, this is not true in theory, but it might be in practice. The VW as well as most worm and sector steering boxes are designed to have minimum play, indeed some preload while in the straight ahead position. As the steering moves to the right and left, the play will increase. This is why no matter where you angle the pitman arm to get the correct geometry for your car, when adjusting the box, you should disconnect the pitman arms from the tie rods, turn the steering wheel all the way to one side and then the other, counting the number of turns, and then turn the steering wheel to the center. I would make a video but this existing one is pretty good. https://www.youtube.com/watch?v=n-1h47ILhxg
If the BOX is not centered when you do the adjustment, as you go through the “center” it will be too tight. This will result in the preload stressing the bushing and thus forcing the pitman shaft through the bushing. This creates more play and the result is you end up chasing the adjusting screw right through the cover. With worn boxes, the center develops more play (wear) and so an old used street box may feel better when properly adjusted, and I wonder if the German boxes were machined to closer tolerances. I would love to get my hands on a NOS German box - if one still exists.
The tightness in the center might give a FV a “wandering” feeling. Like falling off a fence - one side or another. This might be exaggerated if you run toe out rather than toe in. So some people do not like preload in the center so they run a little looser - this will result in play at each end, but the FV only uses about ½ the total travel of the box.
ChrisZ
Thanks guys for the advice, I will put it to good use. Still hoping somebody might have the measurements for the crossbrace to front hoop for box mounting. Thanks Dave
Hi Dave,
I just realized after reading your post yesterday that I could give you a few measurements from my drawings so you could have an idea where to locate your inverted steering box if you chose to relocate it. I don't have my car since I sold it in 2011 but I could give you an idea based on distance from the front beam which is a better way to locate things and also the distance from the floor.
Ed
The 84 Citation FV had the steering box mounted on the bottom beam and the pitman arm going forward. I did experiment with a setup that mounted the steering box on a bracket forward of the axle beam. That left the steering column as the only thing in the foot box area to inter fear with the pedals/feet. That bracket also had the steering shaft going over the top beam. The next step was to replace the steering arm on the steering box with a rack and pinion setup that would operate the idler arms that in turn operated the steering arms on the spindles. I never built this monstrosity. It was a lot of work for very little space gained.Quote:
Originally Posted by fv58
My last FV project was a car tht I did in 1994 and that car is still waiting to go to its first race.
Attachment 109815Attachment 109816These are a couple of pics I have found for conversion, just trying to get a more accurate measurement for placement
That is not anything the Ed Zink , nor I , came up with. Given the experiences of some of my drivers, I would not recommend that approach to a steering system, for safety reasons.Quote:
Originally Posted by fv58
Just curious, what are your thoughts on this setup being unsafe? We also have a lazer that has a similar setup and I believe all the layers were setup like this design
In a hard frontal impact, your knees will move upward and the steering links will impact your shins.Quote:
Originally Posted by fv58
On the original 94 Citation the anti front sway bar was in a similar location but higher. One of my drivers had a serious brake of his shin bone in a crash at WG.
Dave,
Basically, to answer your 'measurements' question - IT DEPENDS :D
Several issues come into play..
Are you planning to use the same 'intermediate pivot' that Citations normally come with? If so, that limits what you can do because the tie rods are pretty short - consider the 'swing' of the tie rod end of the pitman with the swing going 'rearward' from center instead of forward.
Desired length of pitman arm.
If you just want to match the 'standard' the the standard pitman arm and the box attached to the front beam, then get a piece of beam size tubing (HEAVY WALL.. a piece of a real beam would be safest - likely, the distance from frame rail to frame rail will be longer than the distance between the standard beam mounts). Anyway... The location of the box would be ~ 2 times the length of the pitman arm to keep the tie rods in the same orientation. i.e. the tie rod end of the pitman would end up in about the same place.
In most of the installations I've seen, the pitman arm is LONGER. That speeds up the turning, but increases the steering effort. If you build your own pitman arm, it's also difficult to make one that interfaces well to that steering box tooth'd shaft. I've seen lots that were just welded.. but the weld ALWAYS breaks eventually - often leading to SADNESS at the track, so that's not a good plan. Those teeth are needed to carry the load. When you drop a tire, or hit a curb, the load goes exponential. In my case I cut off a standard pitman and welded it 'backwards' into a steel rectangular tube - with a hole cut to access the pitman tightening bolt. It held up pretty well. (if you weld one.. or have one welded.. make sure that the weld is NOT such that it prohibits the pitman bolt to be usefully tightened)!!
You also need to consider what sort of angles the tie rods will swing as it passes through the bodywork. Consider up/down as well as left/right swings. You want the smallest hole you can manage - then probably double that size. If you don't do it right, you'll end up needing a hole WAY larger than you want.
Also depends on what the steering arm is at the wheel. Standard VW or some shorter arm - all that will change the swing you end up with.
Trying to give you exact measurements depends on ALL these things.
Here's a couple links to other threads that discuss (extensively) a LOT of those issues.
These are old posts and most of the pictures are no longer available.. but the TALK is still there :D:D
https://www.apexspeed.com/forums/showthread.php?70846-Womer-steering-box-setup-picture-request
https://www.apexspeed.com/forums/showthread.php?74715-Silverbullet-body-for-citation
Steve, FV80
Below are 2 pictures of the Citation Steering system that I designed. This is an evolution of what first appeared on the Zink Z12. The car is the last FV that I designed and built. The roll bar forward is a repeat of the 84 Citation. The roll bar and the rear is an adaption of the 94 Citation F1600/F2000 roll bar structure but with a FV engine setup.
https://www.apexspeed.com/forums/images/attach/jpg.gifhttps://www.apexspeed.com/forums/images/attach/jpg.gif
And exactly what did the Lazer manufacture do to test the frontal impact safety of its design, nothing or they would not have used their steering system design.Quote:
Originally Posted by fv58
Most safety features are 'written in blood', based on actual accident analysis. There is no archive of FV accident analysis. A designer's personal knowledge is about the best you can expect and that is going to be limited to the accidents he has evaluated. Lathrop's illustration is a perfect example. He designed what he considered a safe anti-roll bar location but was proven wrong. Chances are good that he has change the location in new designs.
You really have to expect a lot of body movement during a big frontal impact. The pedal assembly can move rearward and/or the driver can move forward. The anti-sub belts are not as helpful as you might think. What is needed is a seat design with a tall (3-4") front lip to stop your butt from moving forward.
Brian
Brian
Updated:
"I did experiment with a setup that mounted the steering box on a bracket forward of the axle beam. That left the steering column as the only thing in the foot box area to inter fear with the pedals/feet. That bracket also had the steering shaft going over the top beam. " - Steve L.
I found this picture from somewhere - it shows what Steve might have been referring to.
https://www.apexspeed.com/forums/att...d=109897&stc=1
This has the advantage of possibly allowing left foot braking and if the quick steer extension was not used, to also allow the pedals to be moved somewhat forward.
Here is another "forward box", on this Crusader.
https://www.apexspeed.com/forums/att...d=107969&stc=1
The VDF was similar - but mounted the box very low in the nose off the frame.
ChrisZ
The location of the steering box is not much of an issue in the Zink/Citation system. What is important is the steering geometry as the suspension moves up and down. The Citation system allows for a zero bump toe change with suspension movement. That means as the wheel moves up or down, the toe does not change. That happens because the link from the idler arm to the steering arm is the same length as the suspension arms that control the wheel movement. And as an added advantage, we were able to get full Akerman steering geometry with that setup. Zink originally designed this system to not have any toe change with suspension movement but with tuning, we were able to get full Akerman and it proved to be better. It gave a more precise and responsive steering.Quote:
Originally Posted by FVRacer21
Steve,Quote:
Originally Posted by S Lathrop
I know this is getting off topic... but do you have more pics of the rear frame structure?
It's always neat to see something different from the standard thinking in FV.
Mat,
Here is a rendering of that frame.
https://www.apexspeed.com/forums/images/attach/pdf.gif
Thanks everyone for the great responses and thoughts on the steering setups.
Okay I finally remembered to get my drawing book for the EV3 and bring up to the house. Keep in mind that all measurements are from the front of the frame which is also the back of the beam. And the other is from the bottom of the frame without a belly pan. I have a 1/2" steel plate that is 2' wide and 8' long that I made into a a welding table and it is bolted to the concrete floor to help with keeping it straight.
The location of the front hole for the steering box is 18 1/8" from front of frame and the mount is 12" up from the bottom of the frame. The flat surface the box bolts to is made from a 1"x2" .120 wall tube that is pre-drilled and the top has holes cut wit a hole saw to allow access to the bolts that hold the box to the bottom of the bracket. the bracket is supported but 1 1/4" tubes fit to the forward brace from back side of front bulkhead to the back of front roll hoop. Like I mentioned earlier that you need to offset the holes I think 1/8" to the right so everything is centered on the center of the chassis, which means steering shaft, but I do not have that mentioned on my drawings but the bracket/brace to hold it in place I think is where I have the offset.
This allows the use of a 10" steering wheel that will keep the top of the steering wheel level with the top of the front hoop which used to be a rule. Don't know if that is still used.
Like Steve said you cut off the stock pitman arm and I then weld 1/2"x1" solid steel to the two pinch areas that go to a 1/2" x2" flat plate that I have offset to get the two holes for the tie rods to be in the center of the chassis. I have a jig for making that part.
Warning here, I have had a few cars develop cracks in the 1"x2" tube that makes the bracket for the box to bolt to and I would switch that out to a piece of 1"x2" flat stock in the future.
I don't know if I have any easily accessible pictures of my chassis to show.
Ed
thanks, Steve.Quote:
Originally Posted by S Lathrop
is that the car that I saw you mention somewhere was never raced?
does it have the standard Citation body? the chassis looks different than my limited knowledge of Citations, like maybe it would have a high nose.
The car has been tested a couple times. This year might be the year it gets to the track in earnest.
In addition to this car, I have been working on a restoration of the car that George Fizel won back to back championships in. It was a real challenge to add the roll cage to a car that pre-existed the 1984 roll cage rules.