sub frame connector welding question

[rav440]

when you weld in the sub frame connectors does the car have to be perfectly level ? a few years ago when i was looking for sub frame connectors i read the install directions on a set from summit and it said the car had to be level

kinda makes sence and kinda doesnt . IE: i have my car up on jack stands with the read about 12"s lower than the front and side to side there may be as much as 1" tilt 


thanks RANDY

[HPP]

two schools of thought; 1-b leveling the car you remove any distortion in the uni-body which ensures that all the suspension and sub-frame components will in their optimal location. 2-by installing them with the car on the ground you ensure that you don't distort any of the body panel alignment you currently have and you are simply solidifying the stance your car already has.

I suscribe to theory 1. There is a reason all competition cars are built on a surface plate and that is to make sure everything is level, plumb, and square.  If you building your car and it is apart, it only makes sense to do it this way. However, if you car is finished and has an expensive paint job, realigning any body panels that might slightly change is probably not high on the agenda of fun things to do over a weekend

[rav440]

where do i put the level on the car ? COWL ? ROCKERS ? REAR TORSION BOX - TORSION BOX ? what points do i use ?  as of now there is no front sub frame / K member

[HPP]

Any major flat surface. Under the rockers for front to back. For across the car, under the radiator support, t-bar anchors or the structure where the rear bumpers mount in.

It helps if you have 3-4 foot  level. Then you can span across any of the sub-frame structure anywhere on the car.

When I've built race cars, I typically will support the car in 8 different locations. I use RV style screw jacks to make small adjustments. If you have the ratchet or pin style jack stands, then you may have to slide shims in each point to level everything. I have also run in to situations where I have had to add weight to a location to bend the car in to position. I move around the car when welding to as not to concentrate too much heat in one location. Granted, this is when installing lots of tubing for cages and major structural support, so you may not need to to go this far.

[Big Sugar]

Any major flat surface. Under the rockers for front to back. For across the car, under the radiator support, t-bar anchors or the structure where the rear bumpers mount in.

It helps if you have 3-4 foot  level. Then you can span across any of the sub-frame structure anywhere on the car.

When I've built race cars, I typically will support the car in 8 different locations. I use RV style screw jacks to make small adjustments. If you have the ratchet or pin style jack stands, then you may have to slide shims in each point to level everything. I have also run in to situations where I have had to add weight to a location to bend the car in to position. I move around the car when welding to as not to concentrate too much heat in one location. Granted, this is when installing lots of tubing for cages and major structural support, so you may not need to to go this far.

The Car needs to be level across the width of the car (from left to right) .You want to make sure there is no significant excisting twist in the unibody, So level it out across the front and rear crossmembers from left to right and measure from the exact location on each side. Don't be concerened if the body is somewhat lower in the front or rear.
 Body panels and door gaps are kind of irrelivant, if the body  has a twist it would be better to get the twist out before you start any structural welding. and deal with reseting your doors/fenders later , Chances are a twist in the body's structure may stop you cold in your tracks, at that point you should seek outside help.
If you find a nice 5' long piece of steel angle or channel (dead straight) you can lay it on the ground level it out use that as your level start point and measure up from there.
If the motor is in the car, consider putting a slight support under the K member (you dont want to lift the car ) and then check to see if the front End's of the frame rails (@ radiator Crossmember) are level as well , This is important especially if your welding in inner fender braces and the lower rad cradle brace from XV. as far as leveling the frame rails behind the rear wheels this is going to be tricky as in order to get a twist out back there ,your into quarter panel tweaking....yikes..! but once your car is level you should consider looking to see if the front leaf spring mount is level and then check to see if the rear shackle mount is level, you could get some adjustment at the spring mount locations to ensure the rear suspension is on a flat plane. (From left too right NOT front to back).

Putting the car on 4 ramps or blocks and leveling from there can be kind of tricky as there  very well may be a uneven leaf spring or torsion bar setting the car out of level.  Putting the car's wheels on blocks may help give you more access to the underside of the car and make welding a little easier. But you'll still need to slightly lift the car at each frame  point to insure it's level across the width while the wheels are sill making contact with the blocks or ramps.


The flatter you can get your chassis before welding anything structurally the better your chassis is going to respond to performance upgrades.
If your under the car anyway dont be afraid to beef up all the excisting factory lap joints in the chassis with a bit of stitch welding here and there and if your adding square tubing subframe connectors don't  forget to tie them into your seat frame supports under your car just to limit the amount of flex the connecter might be getting.

Firm feel has a good writeup on beefing up your K member as well, not a bad Idea if you've already got the welder out.

Here's a quick tip, if you've got a spinning self leveling laser or even a Self leveling standard laser on a mini tripod. leveling the chassis is a whole lot easier.

If you have a twist in the chassis unlatch your doors, check again, if your chassis is still loose in one of the leveled support locations you may need to pull the chassis down with a turnbuckle or ratchet strap attached to the floor at the off location as well as the diagonally oposite corner. If your a little unsure or if the twist is significantly large Call a reputable chassis or body shop to give you some assistance, Or contact the guys at Auto Rust Tech, Im sure they could steer  you in the right direction.

Just a note, I am not a chassis specialist nor am I a car builder !! I'm a well read enthusiast. Do your homework !! Make call's too professional people, and plan your stragedy, don't go in blind and hope you can make it work .  
For gods sake don't monkey around with scraps of wood or stuff that looks like it might be OK to support a 4000 pound car. Keep at least two  REAL  fire extinguishers around and be extra cautious around Gas lines and fuel tanks.
The Money your saving doing it yourself isn't worth putting you and your family at risk


Ron

[flyinlow]

I welded my connectors on with the car on a frame contact hoist. Did I screw up?

Car seams more solid with them . Less rattles. Some rattles came back when  I installed poly k frame isolators.

[Big Sugar]

I welded my connectors on with the car on a frame contact hoist. Did I screw up?

Car seams more solid with them . Less rattles. Some rattles came back when  I installed poly k frame isolators.

Hard to say, you'd need a good chassis alignment to find out, But welding anything that adds structural integrity while on a out of square or  twisted lift arms isn't really a recommended way of doing it.