Citation Rack and Pinion for a C3?

496BBC

496BBC

Well-known member
Joined
May 13, 2008
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Location
Deep in the marsh, South Louisiana
There is a reference to a Citation rack install in the Speedway catalog, they offer a conversion U-joint for this conversion. I looked the rack up and it is a end take off rack. Has anyone tried this rack in a vette? It looks like an end take off rack might be a better fit for our vettes. Not sure if the ends would be the correct length. May try and find one local to measure.

Neal
 
496BBC said:
There is a reference to a Citation rack install in the Speedway catalog, they offer a conversion U-joint for this conversion. I looked the rack up and it is a end take off rack. Has anyone tried this rack in a vette? It looks like an end take off rack might be a better fit for our vettes. Not sure if the ends would be the correct length. May try and find one local to measure.

Neal
Click to expand...

For the stock a arm geometry (long lower arms, cross shafts about 16" apart) you will need a very narrow end take off rack, the tie rod joints have to be in the right spot to get a proper bumpsteer geometry. Don't know the width of the citation rack but it's probably a lot wider than around 16". That's why I used the appleton rack, but it's front steer.
 
I agree with TT, as my junkyard and parts house shopping went crazy for some months trying to find a rack that was narrow enough, and still had power assist, and still tossed the tires ~6" in either direction....and was rear stear.....

I never found one, closest I could find was a Ford Taurus, and the tie rods would be abut 6-9" long...WAY in hell too short....

:crutches:
 
The Mustang II/Pinto PS rack is 42 inches end to end (I think a C3 is ~43 inches). I'm not sure if it's a rear steer.

I happen to see a Honda Civic rack that looks pretty compact and is a rear steer/center take off. Don't know what year it was from.
 
Well I finished the alignment today and was able to take a short drive. It definantley has a better feel, now I'm no track driver so this is just my opinion on regular everyday driving on public roads. Its more responsive to driver input and has little to no slack on center.

The one thing that bothers me a little is there is a small amount of deflection of the center bracket that bolts to the rack and connects the tie-rods together, when turning the wheel while the car is sitting still. I'm thinking of adding a guide to this center bracket that would bolt to the frame rails and allow the center bracket to slide on, this would reduce the deflection to almost nothing.

I'm curious if anyone else is seeing this deflection of the center bracket. It may just be a poorly rebuilt rack. If I grab the center bracket with my hand I can move it around some. It would be nice if I could find a diagram of a grandam rack to see what's inside. To try and see what may be moving around.

I still have to change the lower column BRG

Neal
 
496BBC said:
The one thing that bothers me a little is there is a small amount of deflection of the center bracket that bolts to the rack and connects the tie-rods together, when turning the wheel while the car is sitting still. I'm thinking of adding a guide to this center bracket that would bolt to the frame rails and allow the center bracket to slide on, this would reduce the deflection to almost nothing.
Click to expand...

I saw this Grand Am rack on a Mustang(?) that was listed on Ebay. Looks like they did what you are saying, put the center bracket on a guide rod to stabilize it. That twist on the CTO point can't be good. I'm surprised it isn't the source of binding.

449d17a2e93e52.jpg

449d17a2ddab15.jpg
 
BBShark said:
496BBC said:
The one thing that bothers me a little is there is a small amount of deflection of the center bracket that bolts to the rack and connects the tie-rods together, when turning the wheel while the car is sitting still. I'm thinking of adding a guide to this center bracket that would bolt to the frame rails and allow the center bracket to slide on, this would reduce the deflection to almost nothing.
Click to expand...

I saw this Grand Am rack on a Mustang(?) that was listed on Ebay. Looks like they did what you are saying, put the center bracket on a guide rod to stabilize it. That twist on the CTO point can't be good. I'm surprised it isn't the source of binding.

449d17a2e93e52.jpg

449d17a2ddab15.jpg
Click to expand...


That's what I'm talking about, maybe not that heavy but the same concept
 
THAT linear bearing concept is heavy as hell, and subject to extreme wear in a street environment....I also see it hanging up under heavy use..:ill:

THE one reason I never did any long legged center adaptor to my install was just that, I stuck one of the bolts in, clamped with vice grips in line, and twisted to see how much play in it, when doing the mock up...and the amount of necessary slop in there told me there was too much inherent twist to the slider, AND I was not putting any additional torque on it in any twisting mode via the tie rods....IMO, too much for the rack to handle.....

What that M/E I worked with....some comment I made about some aspect, he says 'Engineering first law, thou shalt NOT STRESS the Merchandise'.....I took that to heart in my install....
 
496BBC said:
I'm curious if anyone else is seeing this deflection of the center bracket. It may just be a poorly rebuilt rack. If I grab the center bracket with my hand I can move it around some. It would be nice if I could find a diagram of a grandam rack to see what's inside. To try and see what may be moving around.

I still have to change the lower column BRG

Neal
Click to expand...

Mine too deflects a little when I try to go lock-to-lock when the car is stationary. I dont think I can move my center bracket by hand though. There definitely needs to be some kind of stabilizer like that mustang, although I personally dont feel comfortable having anything any lower than the rack, especially another steering component.
Maybe if you moved that stabilizer bar off the rack, and had it mounted behind the crossmember, between the two A-arm cross shafts. That would seem more compact and keep things from hanging low. only problem I see is that you might have to have those slides that ride on the bar too close together to do much.
 
mrvette said:
THAT linear bearing concept is heavy as hell, and subject to extreme wear in a street environment....I also see it hanging up under heavy use..:ill:

THE one reason I never did any long legged center adaptor to my install was just that, I stuck one of the bolts in, clamped with vice grips in line, and twisted to see how much play in it, when doing the mock up...and the amount of necessary slop in there told me there was too much inherent twist to the slider, AND I was not putting any additional torque on it in any twisting mode via the tie rods....IMO, too much for the rack to handle.....

What that M/E I worked with....some comment I made about some aspect, he says 'Engineering first law, thou shalt NOT STRESS the Merchandise'.....I took that to heart in my install....
Click to expand...

Gene I agree to a point, there has to be some consideration to steering geometry (bump steer) when determining the length of the tie-rods. This is a given length so you don't have much room to play with. The added weight is not a big concern to me, I can always add more HP if needed. The added twist can be easily fixed with the above mentioned slider. If the correct parts are used it should function without binding.

Neal
 
vette427sbc said:
496BBC said:
I'm curious if anyone else is seeing this deflection of the center bracket. It may just be a poorly rebuilt rack. If I grab the center bracket with my hand I can move it around some. It would be nice if I could find a diagram of a grandam rack to see what's inside. To try and see what may be moving around.

I still have to change the lower column BRG

Neal
Click to expand...

Mine too deflects a little when I try to go lock-to-lock when the car is stationary. I dont think I can move my center bracket by hand though. There definitely needs to be some kind of stabilizer like that mustang, although I personally dont feel comfortable having anything any lower than the rack, especially another steering component.
Maybe if you moved that stabilizer bar off the rack, and had it mounted behind the crossmember, between the two A-arm cross shafts. That would seem more compact and keep things from hanging low. only problem I see is that you might have to have those slides that ride on the bar too close together to do much.
Click to expand...

I've studied the locations that I could possibly mount a system like the mustang, it looks like I will have room up high enough that it would be above the rack and the oil pan.

Neal
 
I readily admit my equal length tie rods...at 19 on driver's side, and 21 on the pass side are not ideal length which I think Norval said 17? inches anyway...i'ts certainly better than stock....so I called it quits....
 
The use of a guide rod in industrial applications is very common and basically bulletproof. The end of a end take off rack is a rod with a wiper and a sleeve bearing.

I think the Mustang setup could be packaged better than shown. I think it should have a dust boot to protect the bearings and I'll bet it could be made lighter that the giant Steeroids bracket (because you don't need a heavy bracket if you are taking the twist out).

Somebody should do this. Don't let the Mustang guys show us how it's done:crap:
 
I'm looking for a linear bushing that could work for this application right now. I've been in the shop working on a small coolant leak. Now that I have that issue fixed I'll have some time to get the guide figured out. The mustang guide is close but I think I need to support it form both ends. This would be simple to support form the frame on both ends. I need to come up with the bushings. I had some teflon stock that I was thinking of using just can't find it right now. May just make the bushing from the teflon stock and bolt it to the center section, bore a hole for the slide and see how it works. I'm thinking the same thing BBshark, it don't need to be as heavy as the mustang piece.

Neal
 
I would only attach the guide rod at one end. If it is attached at both ends you might get binding if the rod is not absolutely parallel with the rack. And, attachment at one end is just as effective as attachment at both ends.

There are some linear bearings with lip seals on both ends that I have used before. I will see if I can find a source for them.
 
Those will work. Make sure to keep them clean with boots over the rods. A little dirt will lock up the ball circuits. Those bearings are best instaled in a light press bore or slip fit and held in place with snap rings.
 
Sorry guys, I"d be paranoid as a mother effer over them thing handing up in some shituation.....I see nothing but problems,....chancy though with my rack install, but it did work out...so far....I look at it lots though.....

paranoia reigns supreme.....

:harhar::bonkers:
 
mrvette said:
Sorry guys, I"d be paranoid as a mother effer over them thing handing up in some shituation.....I see nothing but problems,....chancy though with my rack install, but it did work out...so far....I look at it lots though.....

paranoia reigns supreme.....

:harhar::bonkers:
Click to expand...

A rack and pinion works exactly like this. The rod slides in and out of the rack with bushings and seals.

With 10's of millions of rack and pinions on the road, do you hear about any "handing up" (which I assume means binding)?
 
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