sub frame connectors question

[cudachuck]

i got a set from us tools and i'm going to install them my self should i do it with the tires on the ground or on jack stands and make sure the car is level from front to back and side to side? thanks

[Autophile]

  I'd like to hear popular opinion as well.

[Chryco Psycho]

I raise the car on it`s suspension so drive on hoist or jack stands under the diff & control arms , try to keep the car reasonably level to keep the frame in normal loaded mode

[rallyechall]

Make sure your doors open and close correctly before starting.

[loco440]

You should have instructions in the box they came in,it is very informative as to the fitting of them,if you havent I suggest that you get them BEFORE you start

[HP2]

There are several schools of thought on this one. One is absolutly correct, one is sort of correct, one is just easy and provides better support than nothing but is not ideal.

The absolute correct way to do it is have the car on a surface plate with no suspension. It is impertive that the the car to be absolutly level with any out of square, wedge, or twist removed. Then install the connectors.

The best reasonable compromise to this on a completed car is to support it by 8-10 jack stands, again making sure it is square and level. Suspension position with this much support is not a concern as any chassis loading that the suspension make would be found by the leveling process. If you are just using 4 points for support, then putting the suspension in a close to ride height position would be the next best approach.   

The least correct but most popular method seems to be just weld them in while the car is on the ground. The idea being that it provides better support than not having any connectors in but still maintains the panel alignment that you have already. While this is a true statement, doing this will also lock in any wedge or out of square condition your car has.

The whole point of being square and wedge free is that then any chassis changes and subsequent reactions can be evaluated and reviewed for consistency from corner to corner without having to resort to irregular adjutments to reach equal points. However, with that being said, a lot of us cannot differentiate such subtle changes and most of us will never drive these cars to a level that requires such precision.

[ntstlgl1970]

  with CP, when I installed subframe connectors on my last car from Global West, this is exactly how they said to do it. I wish that I had access to a surface plate or 8-10 good jackstands like HP2 mentions but I don't.

[cudachuck]

what is a surface plate??

[HP2]

A surface plate is the assembly platform that fabricated chassis are built on. It is typically a very heavy framework of steel plates and/or I beams that holds the chassis in a rigid position while it is assembled. Some are on casters so they can be moved, some are bolted to the ground.

I've seen entry level race chassis that have curled up like a potato chip because of inexperienced welders going to town with the welding gun and all the roll cage tubes in them. Subframe connectors have not typically been as big an issue because they are only wleded in a few areas, but the new versions that weld to the entire floor could cause some issues. It is probably worth keeping the heat levels spread out to avoid any shrinking. Weld a few inches in one area, then move to another to give the welded spot a chacne to cool before laying down more bead.  It is a pain but keeps things more even.

[RusTy/SE]

In April I spoke with Marcus at USCT who highly recommended that the carpeting not be in the car (if possible) when attaching to the bottom of the floorpan due to the heat generated. I later spoke with John, the shop owner. When i mentioned my Challenger being a 70 440 car and having factory torque boxes, John explained how the connectors should be notched to fit the boxes rather than notching the torque boxes to accept the connectors which makes sense They were both very friendly as well as professional. I ordered a set and they're already on hand

Russ

[go-fish]

I will need to do complete floor pans on my car, so is there a way I could tack them together while the floor is loose. I heard the SFC's don't fit the contour perfectly with the repro foor pans.

[ambitions2]

It may be a stupid quesiton after reading this topic, but that means you couldn't do it on a roterisse because the car really isn't level right?

[cudachuck]

i guess you can't do them on a rotissarrissri(spelling)

[HP2]

Well, I wouldn't, but again, for most people most of the time, you are not going to notice if things are a little out of square. Additionally, once all the panels are put on and realigned, it isn't going to be noticeable if things aren't square.

[Skeleton73]

Here's what they look like with torque boxes.

In my case, since it was so rusty, they welded the car to the floor & supports, then put in the multi-pc aftermarket floors, then the connectors, and then the PG torque boxes. It didn't go on the rotissere until basic welding that was all done. I think they did some touch up on it after.

If you look closely, you can see where the US tool connectors don't match the floors, and that the shop moved them around a little for the best fit with the floors (check the frame hole on the bottom of the picture)