camaro subframe install -- need help

[56chevy1300]

Hello

I'm new to this forum and am building a 56 chevy stepside and need some help!

I just laid the first welds on my camaro subframe graft and did a subsequent measure. Everything is level (frame/subframe) however, the anti-dive angle on the passenger side is 7.0 degrees and on the driver's side is 6.0 degrees; an indication that my subframe may be bent.

My understanding is that I should be between 6-8 degrees, but is this difference going to create problems with my steering or suspension? Will my truck pull to one side or the other?

I do not want to go out and buy a new subframe; they are hard to find. And I'm not sure if I can straighten out the one I have.

Thanks in advance.

Sorry I don't have specific photos, but you can see other pics of my build at:

http://www.cardomain.com/ride/2430784

Ross

[jds319]

I'm not sure i even know what the anti-dive angle is. If it's level, i would tend to think you'd be good to go.

[56chevy1300]

Thats a good question...

The top of the coil spring hats have a bracket that the upper control arm attaches to; it is supposed to be at an angle of between 6 and 8 degrees for proper anti-dive.

Anti-dive is defined as "a tuned-in front suspension characteristic that converts braking-induced forces in the suspension links into a vertical force that tends to lift the body, thereby reducing dive under braking."

Here are some pics.

Thanks

[68c10owner]

I`m no expert but I would`nt think that 1 degree would make that much of a difference. Looks like a great start though.

[1-ton of fun]

mine is dead even, side to side.

maybe yours warped from cutting and welding on it. still, 1 degree may not matter. i would just worry about having to redo it all if it pulls to one side under hard braking.

[bretcopsey]

If the rails are paralell, level and square, you could just redrill the upper a frame mounting holes to correct the issue. I personally would probably not worry about it and see how it handles once it is on the road.

Actually, you should probably be measuring from the imaginary line that runs though the center of those holes anyway vs measuring off the top of the bracket.

[fireout]

I would tighten down some bolts in the holes and measure the angle using a straight edage across the bolts to make sure its not just the top of the control arm bracket that is off. I really don't think 1 degree is going to be an issue though.

[MARTINSR]

This is how I did it, I put the upper control arms EXACTLY the same as they were on the Camaro, thats what. Now, the truck can be aligned just as it would be if it were a Camaro. The one degree isn't going to make a hill of difference in the "anti dive". What that one degree will do is make reaching the desired caster harder (possibly). You could end up with a big stack of shims on one studd getting the thing to the caster you want.

Brian

[56chevy1300]

Thanks for all the input!

I have been doing some research on camber, caster and toe.

Here is a quote from a website I found on caster setting:

"Most cars are not particularly sensitive to caster settings. Nevertheless, it is important to ensure that the caster is the same on both sides of the car to avoid the tendency to pull to one side. While greater caster angles serve to improve straight-line stability, they also cause an increase in steering effort. Three to five degrees of positive caster is the typical range of settings, with lower angles being used on heavier vehicles to keep the steering effort reasonable."

So Brian, you're saying that caster is adjusted using shims at the upper control arm shafts. And my understanding is that toe is adjusted using the outer tie rod ends. So how do you adjust camber?

I also like bretcopsey's recommendation to re-drill the upper control arm mounting holes, that makes sense too.

Thanks for the input!

Ross

[bretcopsey]

Originally Posted by 56chevy1300

Thanks for all the input!

So Brian, you're saying that caster is adjusted using shims at the upper control arm shafts. And my understanding is that toe is adjusted using the outer tie rod ends. So how do you adjust camber?

Ross

Both camber and caster are effected by the shim stacks. You may want to peruse www.pro-touring.com and look up info specific to the second gen Camaro to apply to your truck project. This is probably a little more "hard core" than what you are trying to acheive, but the basic information is still relevant.

Also, just as an FYI, the fisrt gen Camaro subframe suffered from some not so great suspension geometry. Enthusiasts correct this by performing what is known as the guldstrand modification which consists of lowering and moving rearward the upper control arm mounting points.

The GM engineers fixed this in the second gen cars, so the modification is not really necessary. However, if you cannot obtain the alignment settings you desire on your truck, you could certainly do the "G mod" to your second gen frame to get everything where you want.

You could also drop some cash for some adjustable upper control arms, but it is going to make a difference from what your starting point is. And since this is really no longer a "stock" application, the only way to know for sure is to start taking some measurements.

Here is but one thread to get you started
http://www.pro-touring.com/forum/sho...ignment+gen%2A

and the adjustable arms
http://www.scandc.com/spcarms.htm

[56chevy1300]

Hi Brian

Thanks for the info!

Do you think that the alignment shop is going to be able to get my caster and camber correct by using shims?

I would guess that this 1.0-1.5 degree amounts to about 1/16"-1/8" difference in height at the front of the upper control arm bracket (side-to-side).

I am comforted by the fact that I can purchase adjustable upper control arms to correct a foreseeable problem -- looks like they have tons of adjustability.

Ross

[bretcopsey]

Originally Posted by 56chevy1300

Hi Brian

Thanks for the info!

Ross

Bret here, sorry to jump in when you were asking "Brian"

I personally would invest in one of these

http://www.longacreracing.com/catalo...id=131&catid=5

combined with a couple tape measures and have a go at it! If you consider what one alignment will cost, and the liklihood that the shop doing the work will not necessarily be that accomodating when it comes to "custom" work. Plus, if you have the ability to do a subframe swap, an alignment should be a breeze! And yes, I think that "likely" you should be able to make up for the side to side difference without major hassles.

Here, check out this "how to" for some basic info.

http://www.carcraft.com/howto/24880/index.html

[56chevy1300]

Hi Bret,

Thanks for the info...jump in anytime!

I love the Car Craft article...just what I've been looking for. The drawing of the control arms is exactly what I wanted to know.

Thanks!

Ross

[MARTINSR]

You have it all there Ross. My original point was that if you set it up with the upper control arm shafts at the same angle as it was on the Camaro, you just can't go wrong.

Most cars are a little off one side to the other, don't worry about that, that's what shims are for.

Brian

[Coronas56]

Does that no limit video Help any? Any one Have pics of their Job? elevatormanjc@msn.com thanks from Minnesota.............

[56chevy1300]

No, the video simply goes through the installation of the subframe; I guess it assumes that both sides would be the same.