IRS swap members - show me your bracket attachment method

[Tabres]

Members with IRS swap cars - I'm starting to work on mine.

Can you show me your solution for the upper frame mount brackets and how you dealt with the bolts that should mount vertically up through the frame rails?

I've seen a few solutions, a lot of the threads are pretty old so just wanted to see what common practices are today.

Thanks!

 

[RAU03MACH]

You need to hook with white95
He has a pretty nice set up

 

[cobrajeff96]

I originally welded the front side of the cantilever brackets to the frame along with the two bolts used previously for the old quad shocks. Worked quite well.

Later unbolted them and carefully cut them off the framerails to make way for the upgraded Kenny Brown modified IRS subframe. Sent them my subframe to have it modified and it's worked quite well with all the rear tire clearance. It just uses the quad shock mounts to secure the back of the IRS subframe. Only thing I had to do was stretch out those rear flanges a bit with a hydraulic piston to get it to slide right over the frame rails.

 

[Tabres]

The Kenny Brown hardtail conversion is out of the budget at this point, but it's a nice design.

 

[cobrajeff96]

Welding the brackets after securing them with the quad shock bolts is by far the quickest/easiest/cheapest method then. Welding is ok because it wraps around the frame rail and the brackets themselves are heavy and stamped for added rigidity. I ran the IRS like this for many years and it worked quite well on the street and the autobahn.

If you're going to through-bolt through the frame, the only way in my opinion to do it is to use a thick crush sleeve in the holllow of the rail and sink the bolt in from the top side (inside the trunk space) so that you do not pinch or crush the frame by mounting in single-shear. You want double-shear especially with load-bearing subframe like that.