Anyone ever raise the front control arm mounts

[bondo510]

I had a 89 suburban with air bags and air ride controll arms a while ago. The front lower control arm mounts hit everything. It ended up getting all messed up in a short time. I just got a 68 suburban and am going to do a basic air bag set up on it with 16 to 18 inch wheels. I have seen the raised cross members and I know you can buy some really nice raised ones now. I am thinking I can just raise the mounts up into the subframe on the cross member. Has anyone done this?

[SCOTI]

Originally Posted by bondo510

I had a 89 suburban with air bags and air ride controll arms a while ago. The front lower control arm mounts hit everything. It ended up getting all messed up in a short time. I just got a 68 suburban and am going to do a basic air bag set up on it with 16 to 18 inch wheels. I have seen the raised cross members and I know you can buy some really nice raised ones now. I am thinking I can just raise the mounts up into the subframe on the cross member. Has anyone done this?

Search using the terms 'notched', 'pancaked', or 'sectioned' crossmember for ideas & info. I have a sectioned 1 3/8" crossmember in my dually.

[bondo510]

Yep that is what I did and read everything. What I asking is different. I want to know if anyone raised just the lower control arm mounting points.

[SCOTI]

Originally Posted by bondo510

Yep that is what I did and read everything. What I asking is different. I want to know if anyone raised just the lower control arm mounting points.

Gotcha. Good luck.

[snacks]

you can raise the ball joint with a lot of work but the whole arm ? not sure

[jimmydean]

I would think if you raised just the lower it would throw your geometry off in a very bad way. There is a reason people go with a sectioned or raised crossmember rather than just moving the lower up.

But maybe you are exploring something nobody has thought about.

[kpeztruck]

Raising just the lower control arm mounts will definately throw off the geometry in the front suspension. It will mess up the camber swing through out the wheel travel up and down, and could possibly change bump steer depending on how all the geometry worked out. All of this will cause dangerous driving conditions, unless properly engineered. Now if you could raise upper and lower control arm mounts, and some how insure they all stayed in the same realtionship one to another, and was strong, it could work. Depends on how much work, engineering, and possibly liability you are willing to accept. Paul

[jimmydean]

Originally Posted by kpeztruck

Now if you could raise upper and lower control arm mounts, and some how insure they all stayed in the same realtionship one to another, and was strong, it could work. Depends on how much work, engineering, and possibly liability you are willing to accept. Paul

That's what sectioning (aka pancaked) accomplishes. buy moving the crossmember mount position down, you are moving the arm mounts up without changing the geometry (if done correctly).

[SCOTI]

Originally Posted by kpeztruck

Raising just the lower control arm mounts will definately throw off the geometry in the front suspension. It will mess up the camber swing through out the wheel travel up and down, and could possibly change bump steer depending on how all the geometry worked out. All of this will cause dangerous driving conditions, unless properly engineered. Now if you could raise upper and lower control arm mounts, and some how insure they all stayed in the same realtionship one to another, and was strong, it could work. Depends on how much work, engineering, and possibly liability you are willing to accept. Paul

There's also the possibility that slight change between the upper & lower mounting points could improve the camber curve (meaning the GM truck set-ups were not engineered for handling/camber gain). In order to say it's good or bad would require plotting it all out for evaluation.

If a guy doesn't know how to evaluate the changes, it's best to keep things consistent (IE move both upper & lower together) to help minimize potential screw-ups.

[gringoloco]

Originally Posted by SCOTI

There's also the possibility that slight change between the upper & lower mounting points could improve the camber curve (meaning the GM truck set-ups were not engineered for handling/camber gain). In order to say it's good or bad would require plotting it all out for evaluation.

If a guy doesn't know how to evaluate the changes, it's best to keep things consistent (IE move both upper & lower together) to help minimize potential screw-ups.

NoLimitRob is working on exactly this- I'm curious to see the results...

[kpeztruck]

Originally Posted by SCOTI

There's also the possibility that slight change between the upper & lower mounting points could improve the camber curve (meaning the GM truck set-ups were not engineered for handling/camber gain). In order to say it's good or bad would require plotting it all out for evaluation.

If a guy doesn't know how to evaluate the changes, it's best to keep things consistent (IE move both upper & lower together) to help minimize potential screw-ups.

Very true, I was speaking in terms of the average home mechanic with limited fabricating skills. This is outside of my abilities, hence the reason I have my chassis fabricator take care of stuff that is above my pay-grade. The suspension in my truck was designed specifically for drag racing, as it has almost zero camber movement, and less than 1/8" of bump steer. Again, I did not design this, too much math/geometry that I have no idea how to use to gain the needed information to complete this type of fabrication. Paul

[bondo510]

fastbagged68 that was a good link thanks! I think raising them on something really dropped will help. I can not see any negative effects from this. It may even help bump steer. From what I can see I think the upper ball joint may need to be angled down .

[fastbagged68]

This might be what your looking for.....http://67-72chevytrucks.com/vboard/s...ad.php?t=60649
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[dv8customs]

I did it on mine, reworked the stock cross member so that the arms were moved up 3" and inward 1-1/8". Did the same for the uppers. I am not using that cross member now but there should be pics somewhere in my build thread showing it.