Strengthening Front Anti Sway Bar Mounts

[260DET]

Pics of that would be good in due course Jon, I'm still not sure how that setup works, call me thick, call me dick

 

I'll do a pic of mine when its done.

[260DET]

Here is a pic from my gallery, this method is no cure for those with stripped stock bolts of course.

[JMortensen]

Since I finished my TC rod project, I've been thinking about this again. My thought was to get some .5" OD tube that is .37 ID like this: http://www.onlinemetals.com/merchant.cfm?pid=7758&step=4&showunits=inches, drill it out to .386" and tap for 7/16"-20. Drill a hole in the frame rail .5, slide the tube through the rail and weld tube to frame rail top and bottom. That connects the top and bottom rails together. The question is should I put a plate on the bottom and top of the frame as well? I looked again at my front rail, and where the spot welds broke it seems pretty weakened by the stress from the bar over the years.

 

In the rear I'm not sure how to get the heims attached to the uprights (using a rear mounted ST bar). Thinking I could do the same procedure of tapping a piece of the tube and weld it to the upright, but I'm wondering if the upright is strong enough to take the force of the sway bar on only a .5" area, or if again a plate behind or in front or both would spread that load so that it wasn't an issue. The ST uprights are 3/16" thick so they're already a bit thicker than stock, so that might help a little.

 

Anyone have any brilliant ideas?

[JMortensen]

OK I had one for the back. Piece of angle iron running up and down with a 7/16 - 20 nut welded to the back. That would spread the load. I guess I'll tentatively plan to do my plates top and bottom in front and angle in the back unless I hear something better from you guys.

[260DET]

Like the tapped tube idea, if you are concerned about strength let it stick through the rail a bit at the top and weld a flat washer or similar to the tube and rail.

 

Alternatively, which would probably be overkill, run through bolts right through the tubes. Like how the front Xmember on a 280ZX is mounted to the rails.

[tube80z]

Anyone have any brilliant ideas?

 

Not really. For the front your idea sounds good. I'd weld in a doubler plate (could be a large washer to the tube). If you wanted to make it stronger you could wrap the frame rail so the vertical edge was caught.

 

In the back I'd just drill a hole in the upright and bolt a male heim on both sides. You can weld a washer as a doubler spread the load out.

 

My local bolt store sells uncoated steel washers that are good for this.

 

Cary

[JMortensen]

I guess the next obstacle is going to be how to attach the mounting ears to the sway bar. I remember you describing how to make a clamp by cutting a pipe, welding tabs on it then using a bolt to squeeze the two halves together. Wondering if I should do that, or weld the ears directly to the sway bar instead. I guess I'm a little wary of welding stuff to the side of a torsion bar, since that seems like a good way to break welds.

[tube80z]

If you're running hollow 4130 bars you can probably weld tabs and re-heat treat. I tried this on a solid bar and had it crack a few times, which lead to a simple bolt-on bracket.

 

I wasn't really sure what alloy the solid bar was. Maybe a different filler would have worked, maybe not. I'm sure JohnC has a lot of good advice on what can and can't be welded as far as sway bars go.

 

Cary

[Dan Baldwin]

I did what katman sez above, simple 1/8" plate on top of the frame rail, long bolts up through, tightened with nylocks. Been there since ~1996. Many many track days. No problemo! No welding required, even a moron like myself was able to do it:)

[heavy85]

Nope' date=' you make a bracket with ears that hooks to any bar that you have. Think of a split clamp with ears.

 

Here's a pic

 

[img']http://album.hybridz.org/uploads/9074/rollbar1.jpg[/img]

 

In this case the heim hooks to the swaybar. Just think of this in reverse.

 

Cary

 

 

Seems to me if you mounted each end like this then the bar can't twist can it? Normally the bar twists about it's centerline but with the heim joint sticking out away from the centerline they are severly impairing the bar being able to twist - no?

 

Cameron

[JMortensen]

Why would that impair it? The big issue with swaybars is getting them to pivot freely without hitting the frame or suspension. Seems to me that this setup allows it to pivot a lot better. The twist can still happen, and when it does the clamps will rotate around the rod ends. At least that's what I think would happen. If you wanted to prevent the bar from twisting you'd need a bolt all the way through the swaybar and into the chassis. Then the bolt would take all the twisting load. That's what I'm thinking anyway. Regardless, I don't think you'd see it on a high dollar TransAm car if it didn't work. I know that's not the best way to determine if something is a good idea or not, but it's backup for my own idea of how this would work.

[tube80z]

The bar will still twist just fine. It just has more for aft movement than before. This is a much lower friction mounting method than the typical poly/pillow block mounting. It lets the bar bend in the middle, which poly/pillow mounts fight.

 

This pic is from the rocket sports trans-am car. This is also mentioned as a good upgrade in Rowley's race car engineering book. Once you've got all the basics covered it's tricks like this that separate first from fifth place.

 

Cary

[JMortensen]

I'm looking to buy my rod ends for my swaybar project, and also for the rear control arm project (kind of a 1/2 thread jack). Just looking for some simple advice. I was thinking of getting the cheapo $4 rod ends for the 3/8" end links on the sway bar and the 7/16" to attach the bar to the chassis.

 

Then I was considering the teflon lined super bitchin ones for the control arms. The 3/4" size are going to run probably $25 each, and the 5/8" are around $20 each. That's pretty expensive. The question is are they worth it. I don't think the expensive ones are necessary on the swaybars, but I'd be curious to get some feedback on the control arm parts.

[tube80z]

I'd use the lined ends for mounting the bar. This will see a lot of stress and lined ends have lower friction. I'd also opt for them on the sway bar end links but I don't know if you'd see a measureable difference or not. Lined ends will last longer.

 

For the control arms you definitely wanted lined ends. I'd look at Aurora or the QA-1 ends that have built in wipers. I tried using some of the non-linered ends on my car and found that they wore very quickly (less than a season of autox abuse).

 

Cary

[JMortensen]

Thanks Cary. So many bearings to get that the difference in cost really adds up fast, but I guess I'd rather put it together later and only do it once.

[tube80z]

Jon, you can find economy lined bearings. But for the control arms you want the high strength ones. The other option is to do this using something like Ford tie-rod ends. But then you don't have as easy a time changing angles unless you make the mount a bolt on.

 

For sway bar end links I'm using the cheapie QA-1 lined ends from racer wholesale. I'll be damned if I can find them on their site but they were around $7 a piece for end link sizes. Mine are three years old and have no noticeable play.

 

Cary

[JMortensen]

Like the CMR6T and CML6T on this page?

http://www.khmetals.com/185.pdf

 

EDIT-still looking but I found something I didn't expect to find... a carbon fiber race with PTFE liner for about $5 for the 3/8". It's at http://www.mcmaster.com and here's the part number: 2458K141. Must be that the carbon fiber can't handle the punishment, because the rod end is like 1/3 the cost of the steel raced rod ends for the same size. Static radial load capacity looks pretty similar to the metal ones though... anyone heard of this before?

[tube80z]

Actually, I think that's what I'm using. They were cheap and so far have been fine for sway bars.

 

Cary

[JMortensen]

Thanks. They are pretty cheap, so I think I'll spring for em. So many different types, it's kind of confusing as to which to buy.

[JMortensen]

Got the rod ends a couple days ago, between yesterday searching around the garage and today I came up with the mount to go on the swaybar. This is a piece of 3/4" ID black pipe that I cut in half. I used my .103" plate and made the tabs that connect to the rod end and that the 6mm bolts go through to hold the clamp together. I also drilled and tapped the upright for the rod end. I don't have any 7/16-20 nuts, so I figured at least this would let me continue messing with the mounts and all that.

 

So here's what I figured out. The rod end mounting puts the bar about 1.5" away from the upright, leaving space for the jam nut that I do not yet have. One would assume that it will do the same in the front, and it would be 1.5" down below the frame rail. I'm thinking about not using a nut on the backside of the upright, and instead using the jam nut on the backside, like a double nut on the upright itself. Looks like it should work. I also need to grind the corners off of my mount. I didn't want to get too happy with it until I was sure it would work. It looks like it's going to work, so those corners have got to go. The tabs where the bolts go thru look like they're barely tacked on, but they're actually welded the full length on the back side, so I'm sure they'll be OK.

 

The rod ends felt really tight, but with the weight of the bar on there that sucker pivots amazingly freely. Quite a big difference from the poly mounts!

 

Pics:

 

I've been giving some thought to the control arms and how I'm going to attach the rod ends to them. I've been thinking that since my end links are going to be short due to space constraints, the end link would be laying way over if I had the bar adjustable with the typical 3 holes at the end 1" spaced apart.

 

My solution, borrowed from a friend of mine, is to weld a piece of angle iron to the control arm 3" long. That way I can line the rod end up more or less straight vertically at ride height which would give it the maximum movement as the suspension goes through the travel, and I'd just have to move it at both the top and bottom locations. Anyone with a yea or nay on that idea?