My Abnormal 944 Build - An American Blitzkrieg

Nice packaging effort! Must be nice to hang a muffler from above.

Your free help seems really nice. I appreciate that sort of companionship in the shop.

Thanks Mezz!

I spent the weekend increasing the polar moment of inertia of a cross beam in the 944. I had a piece of rectangular tubing that was originally part of a shipping frame for one of our CNC mills at work. I needed an angle section and rather than bend up some flat stock I decided to rip a length of the tubing down the edges to create two pieces of angle.

Then I trimmed up the sections I needed and slapped them onto the top of the existing 944 cross brace. (Sorry for the poor picture - but the new metal is the dark section.)

I did this on both sides of the tunnel. This section of the 944 is about to become important to transferring loads from the 3rd link of the rear suspension, so I'm trying to overkill the area. First with these angles which will increase the fore/aft direction stiffness. Next will be another cross bar just above the existing one. And eventually some triangulation gussets or bars over on the passenger side where the 3rd link BRACKET will be located.

Over the weekend I designed and then fabbed the cross bar, which looks like this now that it's finished:

To get to that point I first made up a quick measuring/mockup jig that allowed me to create paper templates for each end of each of the two bars.

Which then allowed me to transfer the shape of the cuts onto the actual tubes.

The paper template thing was cool because I only had to fit them once, then just unwrap and flip inside out for the other side.

I also put the stock Mustang coil springs on the rear end and checked for any problems. They have a slight interference with some brackets on the Aerostar axle. I'll have some pictures of that later. 

Here's a shot of my 1st pass at Mustang stock coils onto aftermarket Mustang LCA's mated up to an Aerostar 8.8 axle. The coils hit a BRACKET which pushes (rotates) the axle rearward and if it wasn't hitting there then it would hit lower down at the base of the coil cup.

And while I'm in this area of the car I'm wondering if anyone has thoughts on WTF Ford was thinking with the bottom coil cup and the upper coil cup being mis-aligned by a good 25-30* angle? (The stock Ford LCA's have this same situation.) I'm probably going to cut up my perfectly nice aftermarket LCA's and rotate that lower coil cup back toward where it should be, not where Ford put it.

And a shot of my brain starting to design my 3rd link.

More shaving of Aerostar axle brackets.

However this still wasn't enough to clear the OEM coils - I should have just walked over to the 7.5 axle and looked at its brackets to learn how much I needed to take off the 8.8. But hey, its always nice to practice remove and replace of the rear axle. (7.5 axle shown below.)

Sunday I finally scored on the correct u-joint flange for the 8.8. $9 at the wrecking yard and I didn't even have to crawl under the truck it came off.

Cardboard and support equipment ready for CAD work.

And a CAD part file.

And the start of what will become a somewhat complex set of BRACKETS:

Lefty will eventually have dual sub-BRACKETS, one for a shock mount and the other for the panhard bar. Righty is currently a mirror image of Lefty but will get shaved/modded later on.

Coming up soon is the design and fab of the upper shock mount BRACKETS and support frame. This meant that I could no longer dangle my muffler from above. So I spent a large portion of the weekend tacking it onto some weird mockup BRACKETS that hold it rigidly in 3D space. Then it was time for more Porsche vs. sawzall.

There - an empty area awaits blitzkreiging.

Yesterday it was time for CAD simulation software! I mocked up the 3-link geometry in 1/2 scale and played with the upper arm length and pivot location. Tried to double check this stuff against internet wisdom and just ended up getting overwhelmed by conflicting info and too many 4x4 forums. All other lengths/locations made the pinion angle vary too much in either upward or downward travel. This combo in the picture kept the pinion angle steady within 1/2 a degree for about 1.5" of travel in both directions.

If anybody has any thoughts about what you see in this 1st pic (with both lower and upper arms pointing toward the sky) let me know.

Then I did a quick mockup in cardboard and started thinking about BRACKET designs for the forward attachment point.

Lightweight laminated cardboard suspension parts are the future!

I've fabbed/machined these two things. They will serve two purposes: welding jigs for the shock mounting BRACKETS as well as mock shocks until I save up enough scratch to buy actual shocks/coilovers.

Then I mounted the shock BRACKETS (something bought not built for once).

And then did the mocking part of mockup! Looks like I will be able to lower the cross brace tube enough to have the cargo floor back where it comes from the factory. I also have cardboard disks to mimic the size of coil springs to make sure I provision for them in the future.

The cross brace is trimmed down to fit between the 944 frame rails. Welding flanges were added and then the upper shock/coilover mounts were positioned and burned into it. Eventually this will be welded into the 944 but for now it's got some positioning bolts so i can take it in and out of the car for better welding positions.

Now on to the axle side of the shocks. It was time to mock up the panhard bar. The stock 2010+ Mustang bar is almost the perfect length. On the end that mounts to the axle I plan to use a common (long) bolt to attach both the PH bar and the shock to the axle.

The rear axle BRACKETS are starting to take shape. I will be finish welding and adding more beef/gussets later when I can get the axle out from under the car.

I also started my mods to the PH Bar. Final length will be determined after I make another BRACKET.

Farewell to my wounded Ryobi whiz wheel spin machine. It had served me well through several sets of brushes and a broken brush retainer cap (note tie wraps). But the trigger switch finally started to fail so I have replaced it with a low-end Dewalt unit.

Over the weekend I made great progress. The panhard bar is now mounted at both ends and shortened to a functional length. And it can be adjusted.

To get to this point took a surprising amount of CAD work:

And clampage:

The goal for next weekend is to get this cross brace permanently welded into the 944 so that I can get the car back on the ground and able to roll around.

I only have one more BRACKET to add into the center of the cross brace. This will be where a diagonal strut ties in between the brace and the frame side of the PH bar mount.

I did one other cool thing. This is my personal best for the coveted "Most simple DIY tool that worked the best on the first try" award.

One well aimed cut with the portable bandsaw and a couple of tack welds:

And bam-o, I was able to successfully roll up some .025" shim stock and make a sleeve. The sleeve allowed me to convert the ID of the panhard bar bushings from... whatever they are, down to 1/2" diameter so I could standardize on 1/2 mounting hardware for the entire rear suspension system.

I am thinking that the frame side of the panhard mount needs a diagonal brace?

Nice work

Thanks! Yes, the diagonal brace is the last item left to design, mockup and fab before I weld everything up for good.

In reply to Sparkydog :

I have a switch for that Ryobi if you want it. 

And probably a brush cap.

Crackers said:

In reply to Sparkydog :

I have a switch for that Ryobi if you want it. 

And probably a brush cap.

Thanks for the offer Crackers but the Ryobi went bye-bye in last week's trash pickup.

Every so often I can pull off a decent weld. I think clean metal and being able to see what I'm doing has something to do with it.

I needed to be able to remove the diagonal brace for my PH bar in order to be able to remove my fuel tank. So this is what I ended up with for a diagonal brace:

And the cross brace/upper shock bar is welded into the 944 frame.

And the ex Aerostar 8.8 axle now has Blitzkrieg BRACKETS fully welded.

Here's my axle welding station!

With everything back together I was able to put the car on all fours again after several months up in the air. We celebrated by giving the car a sponge bath and a nice window clean. 

I love how totally oddball this thing is, and the re-use of whatever parts can be found at the junkyard.

If you get tired of those GM V6 things, you can always throw a Duratec in there :D

Thanks Slobird!

Next up was a few hours spent to tackle the routing of the exhaust pipe further aft - over the axle and through the woods.

I had 3 areas of clearance challenges: the top of the axle for suspension travel, the panhard bar end and allowing room for potential coilover springs.

I feel like I've succeeded on at least 2 of the 3. The coil spring clearance is too tight - in the end I may need to BFH the side of the pipe a bit. Or I can rotate the coilover upper mount point to the next hole, which would then probably cause clearance issues with the side of the 944 frame rail. But for now I'm happy with the routing.

Before I continue the rest of the pipe out the back of the car I will need to add a flange joint and some hanger BRACKETS.

And no sooner had I finished welding in a nice big bracing tube and started designing how the 3rd link would attach to the frame then my subconscious came up with a better, cleaner idea. The dark square tube on the left is the start of the new idea and I've already cut out my perfectly good previous brace there on the right.

I then proceeded to complete the fabrication of the 3rd link attachment bracket and how it mounts on the brace, then welded the brace into the car.

On a Binky scale my BRACKETS are about a 3 out of 11 but I'm certainly getting more efficient on making them.

Almost finished with the fabrication of the 3rd link!

In reply to Sparkydog :

thanks for putting that big red arrow in there, otherwise i wouldn't have known where to look!

In reply to AngryCorvair :