A-body coilovers

[wally8]

I'm thinking about just going with coilovers on the front of my LeMans.

The car is pretty nose heavy though so I'm a little worried about strength. Any opinions?

Does anyone have pictures of some upper mounts for an application like this? I have some ideas but I've only actually seen it done with front down tubes and I don't think I want to go that far.

One note is that I'll be using adjustable UCA's with no cross shaft.


Wally

[Conekiller13]

Mine will be mounted to roll cage down tubes. So I take it You don't want to use the bolt in kind? I would think somthing like DSE's Camaro kit would work.

[MrQuick]

There are upper a arm brackets that have the kick out provision for coil over or shock mounts. The 71 im building next is going to run them, the owner told me the name of the supplier but I can't remember who it was now? I will try to get info if you need it...I don't see why the DSE one wouldn't work, just modify the a arm mount a bit. You basically weld it where you want it right?

[Norm Peterson]

It's not just the upper mount you have to think about. I've been hearing reports of front c/o shocks pushing out through the LCA's even if you have the shocks' cross-shafts mounted on top of the LCA's. I gather that the cross-shaft starts to bend and takes the edge of the LCA hole along with it until something finally gives. Sounds like reinforcement is necessary.

Norm

[wally8]

Thanks guys. Good point on the LCA's. I'll be fabbing up some new ones so that shouldn't be a problem.

The DSE mount was interesting. I was planning on mounting it outside of the frame however. I want a better motion ratio than the stock location. I could use a similar mount though, just move it out on the frame. It looks like I would have to cut the pocket bulge off and box it with some flat. That would make the frame a little stronger as well.

I'll keep thinking on it a bit. If anyone can find some pics that would be cool.

Thanks.



Wally

[Mean 69]

If you have a pic of the current config, post it. I had an A-Body (never should have sold it) years back, but can't recall too well what the front looked like. As far as the hump deal, I vaguely recall this, but cutting/inserting a new section isn't really going to help strength (sorry, picking nits here, really unimportant). There has to be a simple way to do a C/O on a car that already has SLA, especially if you are going to do custom a arms. Hey!!! While you're at it, why not play with the control arm pickup points frame-wise?!

Sorry, I'll shut up now.
M

[Marcus SC&C]

We`ve done a few such conversions at the shop. If you`re going all out I like them either mounted to the cage down tubes or to mounts reinforced by tubes run from the down tubes to the frame. While you`re at it,as you said you might was well improve the shock`s motion ratio by moving it outboard on the arms. Moving it outboard means you`ll need to run a slightly longer coilover to get the same travel of course (hence liking them mounted to the down bars). I generally cut the outside of the frame and weld in a section of 5"OD 3/16" wall tube. The LCAs are either heavily reinforced or we make tubular LCAs with beefy mounts. It`s a good idea IMO to have several holes for the mount to give you the ability to change the rates,ride heights and motion ratio if you want to in the future. The relatively long coilovers used in most conversions like this put the upper mount pretty high off the frame rails,that`s why I like to take advantage of cage downtubes if possible. If you mount directly to the tubes try to either mount them so that their brackets are inline with the lower mount to keep the cage tube from becoming a big torsion bar itself. If you must run them mounted to the sides of the down tubes you can weld a tube through the down tube for the coilover bolt and run a vertical tube from that tube down to the frame to keep the down tube from twisting. Is it totally necessary? No,but it`s good engineering sense and it`s easy so why not? All this is of course for a full road race style over the top car. If you didn`t want to get that carried away you could reinforce the stock LCAs by welding a nice beefy plate into the stock spring pocket with the mount on top. Then cut out the stock upper shock mount so you can put the coilover through the frame and fab a new upper mount gusseted to the frame. There are a ton of inexpensive prefab brackets for coilovers available through race catalogs that make the process much easier. Marcus SC&C

[wally8]

M69,
Yeah, it won't add much but I was planning on using a 90 degree piece and going all the way underneath to fully box it. Still not much addition but it should add at least a little section height.

I will be moving the upper LCA mounts around to optimize them but the LCA's are going to stay put. I've already put way too much thought into this and really just need to get after it and fab something up.

I'll shoot some pics tomorrow night and highlight what I'm talking about.

I have a chance at some 7" and 9" Integras for a really good price so that's what's motivating me here. They're cheap enough that it wouldn't make sense not to use them.

Marcus,

No downtubes so I'm thinking of doing something like the DSE mount but not through the stock spring hole. I think I'll move it outward. I know there's room for a shock with cutting the bulge away but I don't think a coilover will fit.

The LCA's will just be your typical stuff 1.125" o.d. tubing with a standard racing shock mount on it. I'll use a plate insert for reinforcement. The LCA's are another reason to go coilover since they'll be easier to fab than making a 5.5" spring pocket.




Now if I could just decide on spindles...... I should probably start another post on that subject.

Thanks for all the input.


Wally

[airrj1]

Mark,

Not Wally' car, but here (http://www.buffnet.net/~airrj/CBB%20Construction.html) are some photos of my A-body front suspension. Not great photos but hopefully you can get the idea.

[wally8]

Hey, thanks RJ.

Those pictures are perfect. suspension1.jpg and suspension2.jpg show the bulge that I want to cut off and box in. On suspension2.jpg, imagine trimming it straight with the rest of the frame.

Suspension3.jpg illustrates the problem I'm trying to solve; the fact that there is no room for a coilover inside the UCA.

So, cutting off the bulge, boxing straight across and using a DSE type of bracket should accomplish what I'd like to do. Like I said earlier, I'll be using pole position type arms without a cross shaft so the a-arm mount won't be an issue either.

Good? bad? don't care? :-)

Thanks.


Wally