Stifflers Mustang Subframe Connectors Installation

Stiffler Mustang Subrame Connectors

Ford has greatly improved the design in its S197 Frames. They are about 30 stiffer than previous generations. However these mustangs still have a Unibody design and are spot welded versus seam welded, and because of that it will still flex. Many things that can make the unibody design desirable can also make it weaker. For instance the lack of complete framerails gives the lighter, less-rigid body opportunity to flex under load. This flexing can be felt big time in drag racing and road racing scenarios. This can also create longer term problems, such as metal fatigue.

In true Mustang aftermarket fashion, many companies have developed subframe connectors Stifflers is one of those companies with one of the nicer solutions on the market. Theirs allow your mustang suspension to work better, improving ride quality, handling and increased range of suspension tuning. Thus transferring more power to the ground. Also increasing driver confidence with the feel of a full frame chassis.

I picked up a set of these from Emmetthead Performance. I then had the guys over at MC Racing weld these on the car.
 Stiffler Mustang Subframe Rails As you know I am a big fan of items that are well packed Stifflers did a great job of shipping these Subframe rails.
  Here is the bag of supplied hardware. You have two sets of control arm bolts and 4 frame end caps. 
They also supplied nice end caps so water will not get inside the boxed rails and rust.
 Mustang Subframe Rails Here are the subframe connectors unpacked and ready to go.
  Stifflers went the extra mile and taped the leading edges that get welded to the frame. So just peel the tape off and your ready to move on. 
  Start off by pulling your lower rear control arm bolts and put on the rails.
Here is how they bolt on. 
   On the drivers side is a fuel line shield. We marked it up where we want to cut it where it would be in the way of the frame rail. 
   You will want to pull it off. 
  here are the markups.
  Cut out the marked areas. 
  Here it is all cut and ready to go back on. 
  Now hold your rails in place and then you need to remove the factory paint around the weld points.

Once that is done then you need to set the car down on blocks or other system so that the frame is loaded with the full weight. If you don’t then your doors might not line up once you welded them one due to body flex.

Then tack weld everything. Also be sure to unplug both terminals on your battery.

  Once you have that done then you can go back and complete the welding.  Note the car is down on blocks.
   You can see here the area we brought down to bare metal and then the weld spot on the rail.
  Then you can go over it with some rustolium type paint to cover your bare metal.
  Here is the drivers side
 Stifflers S197 Mustang Subframe Rails Here is the Passengers side. 
  Tap your End caps in.
 welded subframe connectors Here is a shot of the both subframe rails. Now get out there and enjoy a stiff ride!
 FIT-M03 Here is a link to the Stiflers Installation Instructions. Read these fully before starting so you are familiar with the factory recommended install.