I installed mine about 2 weeks ago and went to the bottom hole. My suspension is stock/ car is not lowered. Should I be at the middle hole?

Aaron

 

Should be in the middle one if not lowered.. It's not gonna really hurt anything but should only be in the lower holes if it's lowered.

 

I've heard bottom hole no matter what. I don't relocation brackets though.

 

I just want the best traction possible.

Aaron

 

If anything, my car sits a little higher than stock, since it has the Eibach Drag Launch springs in the back. The Spohn LCA's are mounted in the lowest hole in the Spohn LCA relocation brackets, and the car hooks like crazy. I haven't seen any negative affect from driving it this way, street or strip. Steve Spohn installed all the bits and pieces himself, and that was the way he wanted to set it up, and that's where he bolted the LCA's..... lowest hole.

Its defiinitely going to hook better on the lower hole.... but you might want to try mounting the LCA's in both locations to see if you like the street handling, cornering and braking with them in the lowest hole or the middle hole. Depends what is most important to you.

 

I don't know for a fact that it makes any difference. The relocation brackets are recommended if the car is lowered. Seems appropriate to use the middle holes if the car is not lowered. I have them, use the bottom holes, and my car is lowered, FWIW. Hope this helps!

 

Hey Fred
Do you suggest getting the adjustable LCA's if you have relocation brackets?

 

when i put my lca to anything lower than the stock location my tire sits back farther than normal. does anyone else have this problem or is it just me. and would adjustable lca's fix this?

 

The tire changing position is normal. It could be a good thing too depending on what you want from the car.

 

If the LCA relocation brackets are properly designed and properly installed, they should NOT alter the front-to-rear positioning of the wheel in the wheel opening. The holes in the brackets are arranged in an "arc" so that as the LCA drops down, shortening the horizontal distance from the body end to the axle end, the bottom bracket hole is located forward slightly to compensate, and keep the axle in the original position. The Spohn LCA relocation brackets are designed this way.

If for some reason there was movement of the axle housing, front-to-rear, you could compensate with adjustable LCA's. The only reason you would need adjustables woud be for relocating the axle, e.g. - for clearance issues with large diameter slicks - or to compensate for the axle not being perfectly perpendicular to the longitudianl axis of the car, causing thrust angle problems.

But it isn't normal for moving the LCA's in the brackets to alter the axle position.

 

The LCA relocation brackets must be installed so the new holes line up vertically with the original holes. The Spohn brackets are a bad design. The 'in-an-arc' theory is a sales gimmick.

And it is normal for the position of the LCAs to affect the placement of the axle within the wheelwells (which is why you buy LCA brackets) since they swing in an arc.

(Mock this up with your meccano set if you can't visualize this)

The idea behind the "in-an-arc" gimmick was that people could use the lowest holes for maximum anti-squat without the effect of moving the axle forward in the wheel well, so they did not have to buy expensive adjustable LCAs. The problem with this is that the 'arc' only works with the car at one set ride height. If you lower the car (lower springs, springs settle, rear passengers) your 'arc' is screwed up and now you have to get adj LCAs to fix the placement of the axle or cut off and replace the backets.

If the holes are aligned vertically, and you use the holes that keep the LCA parallel to the ground, the placement of the axle f/r will not change from stock. This is the original intent of installing the backets on these cars. The brackets work properly regardless of the ride height you choose.

If you plan to take it to the strip and use the bottom holes for maximum anti-squat, as a serious racer you should also be investing in ALCAs with rod ends, which will allow you to fix the placement of the axle, particularly for clearance for slicks.

But there is no free lunch. Remember that, with trailing arm suspension, the rear axle steers left/right as the car leans in a corner - this can't be avoided. With the LCAs parallel to the ground (or slightly higher at the rear), the effect is minimized. With the LCAs in the lowest holes the axle will steer opposite of the front wheels, resulting reduced cornering ability (at best) to dangerous oversteer. You can post testimonials all day on this but it doesn''t change how the suspension works.

Hope that clears it up for a few people.

DaveH

 

Just to provide an alternative viewpoint... the purpose of the brackets (with regard to drag racing) is to lower the axle end of the LCA so that the force applied to the body end of the LCA is "upwards", causing a reactive downforce on the axle. Failure to do this, on a lowered car, or even one that "squats" on launch will lead to massive wheel hop. For that reason, it would not even be logical (for drag racing purposes) to set the arms horizontal.

Rather than look at my "meccano set" (not sure why you feel compelled to offer condescending insults to someone with a differing point of view) I've worked things out in the past with free-body diagrams and a little bit of geometry.

The LCA is approx 19.25" center-to-center. Assuming a worst-case scenario - i.e. the LCA was perfectly horizontal before you lowerered the body - dropping the body causes the following "shortening" of the distance between the body connection point and the axle connection point:

1.0" lowering = 0.026" displacement
1.5" lowering = 0.0585" displacement
2.0" lowering = 0.1042" displacement

So... worst case scenario... the axle moved 1/10th of one inch forward. And if we take the less pessimistic view of the initial position of the LCA on a non-lowered car, these displacement numbers can easilly be cut in 1/2. So... in a 1.0" - 1.5" lowering, there is likely no discernable displacement of the axle, assuming the axle end of the LCA was already 1/2" - 3/4" (what I would guess from my original setup) below the body end. Its just the 2" drop people who have to worry about relocating the axle, and the "worry" amounts to 0.05" - 0.10".... hard to believe the average person could even visually notice this small movement, to the extent described by "RedWS6TA".

The Spohn design pushed George Baxter's 3,900# 30th SS convertible to 9.04@155mph. Before the brackets he couldn't get the car below a 1.4X 60-ft. After the brackets, and one or two other tweeks by Steve Spohn to the suspension the car routinely ran low 1.3X 60-fts.... so they can't be all the "bad". . You call it a "gimmick".... I call it taking care of details.

I can only comment on the drag racing application. I'll defer to your knowledge on road handling and braking.... I only use these things for one purpose - hooking up in a straight line.

 

i am not trying to bad mouth anyone but i know for a fact that my back wheels where pushed back towards the rear of the car. i could tell by looking. they were so far back that when i hit a bump in the that was of good size i could here the the tire and the fender rubbing. the relocation brackets that i have where on the 9inch i have when i bought it. i bought it from an individual so i am not to sure who fabbed up the 9 inch under my car. but everything is fine once i put the lca back to the highest setting? anyideas

 

I made the same mistake as the guy who installed them on your 9-inch - just didn't get them positioned right before welding. So the top hole is the same as the stock position, but the bracket is swung a bit forward, so that when you move the LCA to the bottom position it pushes the axle back.

An adjustable LCA can be used to correct this, or of course cutting off and re-welding the drop brackets.

Dave