Sway bars

Fitted the new Hotchkis sway bars. The front is a 1.25" hollow bar

and the rear is an adjustable type with 3 settings. Nice bits of gear!

Diff build

My shiny new freshly built diff! Follow along and I'll go through how I built it up.

You need a few specific tools to build a diff properly, some you can make yourself, some you have to buy. Here is one of the tools I made, a spanner for holding the pinion flange while installing and removing it (which you have to do a lot!). I made two different ends, for the two common Mopar universal joint sizes.

One of the most vital tools you need and want is an impact wrench. Beats the hell out of doing things with a socket! You'd be at it forever...   Here I'm installing the pinion gear in the housing, along with the pinion flange. I used a kit that allows you to shim the pinion gear to adjust the bearing preload, instead of the usual collapsible spacer (or crush sleeve as its known).

You use the appropriate shims to get the correct bearing preload, which is 20 inch pounds for new bearings. This little inch pound beam-type torque wrench is used to check the turning torque (it bends as you turn it around, allowing you to check the resistance on the little scale).

I pressed the carrier bearings onto the Auburn Sure-Grip limited slip differential and bolted on the new 3.55:1 ring gear.

Once your pinion bearing preload is set and you've estimated your pinion depth shim (by checking the shim that was on the old pinion gear in the case) and placed the appropriate shim under the bearing (I used a dummy bearing to set this up, where by I bought another identical bearing and ground out the inside diameter so that it slips on the pinion gear as opposed to having to be pressed on and off, which greatly speeds things up and prevents damage to the bearing and the shims), you can install the carrier and ring gear into the housing. The spanner shown is another tool I made. It's for adjusting the gear backlash and carrier bearing preload.

Gear backlash has to be between 0.006" and 0.010" and is checked with a dial indicator.

Once the backlash and carrier bearing preload is set you can check the pinion depth by testing the wear pattern on the ring gear with special non-drying ferric oxide paint. This photo shows my final pattern with 0.030" pinion depth shim and 0.008" back lash. Perfect!

And that's it! Here is the finished diff and some of the tools and bits and pieces that I used. I'm looking forward to seeing how the limited slip and 3.55:1 gears change the feel of the car, no more peg legged 2.76:1 geared diff! Huge thanks to Cass aka Dr Diff for his help and advice (and the new parts)!

Drums redux

As part of the second shakedown test-run I'm building up a new diff with 3.55:1 gears and rebuilding the rear drums. Here are the parts after a thorough wire wheeling. Years of abuse and road grime leave these parts caked with greasy dirty mess.

Freshly sand blasted, solvent washed, prepped, and painted and good as new! I drove the old pinion bearing races out of the diff center and new ones back in after the paint job.

Here are the parts of the drums before a soak in white vinegar or a sand blast, depending on the part.

And those same bits after being cleaned up and painted or restored.

The freshly rebuilt drums with new Firm Feel race shoes. The drums will only be temporary until I decide if I'm sticking with the 15" wheels or going to 18"s. But it was a good exercise to rebuild them, and don't they look great!

Shakedown II work

While the cuda is in a running state, and before I pull it apart and finish the body and paint, I decided it would be a good time to mockup and test the modified steering, braking, and suspension setups that weren't on the car for the initial shakedown. So I've been working lately on getting those things ready for another little shakedown run. This image isn't really showing any of that, instead it just shows a rough cardboard rear spoiler mockup, but it makes for a nice first image! The final spoiler will be made out of alloy with the little braces and bits riveted together. I really like the little led brake light and empty tail lights, looks rad!

This is the new hydroboost unit and its accompanying master cylinder. This unit uses power steering pressure to boost the brakes, as opposed to engine vacuum. These things are a hit on the pro touring scene and give you good power and better reliability apparently, and also let you run a big cam without worrying about lack of brake boosting at idle or low rpm. I am thinking of replacing the hydraulic lifter cam in the motor with a big solid cam...

As I'm running hydroboost and a steering quickener I thought it would be a good idea to have a power steering fluid cooler in the mix to make everything happier when it's being thrashed. I made this alloy bracket to mount the cooler in the engine bay.

Here's the cooler in place roughly where the battery used to go. It's plumbed into the return line from the steering box, with a Y junction just after it and before the reservoir tank, with the other inlet on the Y taking the return line from the hydroboost unit. The cooler will have fresh air ducted to it from a NACA duct in the hood.

This shot shows the whole setup, with the KRC pump, hydroboost unit, cooler, and braided stainless high pressure lines. I love the no-nonsense industrial/racecar look!

I've also added a Moroso air-oil separator into the PCV vacuum line to catch excess oily mess before it goes into the intake manifold.

And I've added this nice little alloy radiator overflow tank.

 All together I think the engine bay is looking fantastic. I love it!

The new Mcleod Racing clutch I've got has a different pressure plate finger ratio from stock, so I needed a pedal stop to limit the travel of the clutch pedal. The factory ratio is 6:1 and the new plate is 4.8:1 I believe, so it's a wicked short pedal throw.

The stop bolted in place. Feels nice and solid and you can really stomp on the pedal, without fear of bending the pressure plate fingers or damaging the Z bar clutch linkage. The 10mm nut I had previously welded onto the firewall for just such a purpose came in very handy for mounting the stop!

Here's one of the new 11.75" 'cop' rotors with 3" long Moroso wheel studs. I have Firm Feel race pads for the factory calipers and the rear drums and that along with the hydroboost, adjustable proportioning valve, line locker, and cooling ducting, are the extent of the brake modifications I'm doing at this stage on the car. I'm unsure as to whether I'm sticking with 15" wheels and tires or going to 18" so I don't want to go all out and stuff the baddest brakes I can into the 15" wheels only to have to replace it all if I go to 18"s. I want to keep the 15"s as they match the tough old school look I'm going for on the car, but they are heavy and won't handle as well as modern 18" setups, so if they end up being too much of a limiting factor then I'll go to 18". And then of course fit the biggest brakes I can inside them. So the setup above is just the bare minimum for now, and should give good performance on the street, while lacking a bit on the track.

I'm running the rear brakes for this second shakedown run, and have temporarily plumbed the line and the line locker inside the back seat area. There's an illuminated rocker switch controlling the line locker, which is just there for testing purposes and not for doing wicked mean skids honest!

I've also installed the modified column with the 1.5:1 Coleman Racing steering quickener grafted in. I can't wait to see how this feels! The Hotchkis E-Max has a similar setup and apparently has "magical steering", so it should feel pretty good! The factory steering is slow and way too over assisted with no road feel at all, and rack and pinion conversions have too many drawbacks, so a setup like the above gives heavier faster steering with more road feel. Just the ticket!

While I love the factory pistol grip Hurst shifter and will be running one with custom carved wooden grips in the finished car, I also have a soft spot for the classic Hurst white ball. So I bought one and made a quick custom handle for it, just for this shakedown run. Looks rad in the stripped black and gray interior!

Future build ideas

I've been thinking a lot lately about what to build next after the cuda is done, and have a lot of varied ideas from full blown scratch built race cars to more sane mild street builds. It's a lot of fun to play with ideas in photoshop, and a hell of a lot quicker and cheaper! Less black snot and weld burns too. Here's the latest one, a crazy S13 Silvia drift machine. That twin blower system on the (probably) LS v8 is something I've never seen before, there's a second roots blower mounted backwards and upside down and driven off the same belt. Makes for a pretty badass monster head looking thing! I love it. The air intake on the roof is for the rear mounted radiator.

I've got a ton of these crazy photoshop experiments, and will start posting them here from time to time.

Power Steering Pump Bracket

Here's the fancy little KRC racing pro-series power steering pump that I have for the 'cuda. It's a really nice piece of gear! I went to an aftermarket pump as I felt that with the steering quickener and hydroboost stressing the power steering system I had better upgrade to a pump that can handle it. However KRC don't make a bracket for mounting their pumps to a big block mopar, so I had to come up with my own. I mocked up the pump where I wanted it on the motor, and took some measurements.

Next I designed a bracket using 3d software. The orange is the water pump boss where the bracket attaches and the blue is the body of the pump. The brackets are threaded negating the need for any nuts to bolt it together, and there's counter sunk holes for the cap screws.

Then I broke out the big guns! Meet Jordan, one of the resident genius's at Weta Workshop (he's the guy not the big robot). Jordan builds machines that build machines that build jet engines. It's as rad as it sounds! He put one of his many self built cnc milling machines to work machining the brackets.

Here's the tool paths calculated in cadcam software.

And here's the machine that was used to mill the brackets. All this was a little dream come true for me, I've always loved cnc machines, and this was my first taste of the real deal. Yes Jordan made this machine, you should see some of his others! Super rad stuff.

A scrap piece of 7075 alloy was fixed to the table and the robot went to work.

Beautiful!

Here's the nearly finished piece. I have to dress some surfaces and clean up the alloy spacers a bit.

With the pump bolted on. Man I love this stuff!

Boom! Fits perfectly and looks great! I'm stoked!

I had to modify the radiator core support of the car body, as the serpentine pulley clashed with the fans (that's what you get with a serpentine setup, a thick custom radiator, and some beefy electric fans!). I cut the old radiator mounting flange off the core support and gained an extra 10mm of space. It's tight but it all fits.

Shakedown work

Late last year I was feeling pretty bummed that the car wasn't gonna be going for summer, so I decided I'd put it together as the bare minimum and give it a shakedown run. On a closed road and controlled conditions of course, any evidence to the contrary is more amazing special effects from those crazy guys at Weta™.
To begin putting together the drivetrain I first bolted the clutch on.

Next came the bell housing and clutch fork, release bearing, etc. Then the fresh new A833 four speed from Brewers.

I drilled and tapped the intake for a vacuum fitting for the PCV valve. The Holley ultra HP carb I'm running doesn't have any vacuum ports, and the other one on the intake was needed for the brake booster (just for the shakedown. I'm currently fitting the new Hydroboost kit now). I'll be fitting an air-oil separator on the PCV vaccum line.

The great thing (well one of them anyway, this thing is awesome) about the drivetrain dolly is that the whole front cross member, suspension, and steering gear can be fitted, and easily slid underneath the chassis to fit it all to the car. Plus it looks rad to see the whole drivetrain and suspension together like this.

Ready to go in the car.

Just like this. Piece of cake. There's about 5mm clearance either side at the tightest fit though, so a lot of care has to be taken when dropping the body down.

Then the K member can be bolted in, along with the gearbox cross member, and the lot is fixed in. The upper control arms get bolted in and the brakes etc fitted next.

I wrapped the temporary fuel line as it passed fairly close to the header. This shakedown run was a lot of fun as it gave me a chance to test out various routing, fitting, and fixing options for various parts like this. Lots of little mini projects, each thing a little challenge to see how best to do it. I did go pretty overkill on a lot of things, but I think this is just the result of wanting to do a good job and test things out.

Lots of things worked out so well. For example the temporary bracket I made to mount the battery happened to perfectly fit the nuts I had welded to the body in the rear seat area for fixing a pelican case to.

Here's the mighty fuel tank. No it doesn't last very long. This bracket also happened to perfectly fit the two holes I had drilled for mounting the battery box to! I fitted a vent tube to the cap and fuel filter to the fuel line. Everything was well fixed and tied down, and the tank was very secure.

The exhaust consisted of the old 2.25" mufflers the car had when I bought it. These were bolted to a pair of adapters I made from a few step down tubes, and bolted to the headers. It's quieter than open headers, but still pretty damn loud!

The electrics and gauges consisted of the control panel I built for the run stand attachment for the drivetrain dolly. It's all you need! And it's always fun to have a push button start. The only other bit of wiring that the car needed was for a brake light.

Safety first!

It was a lot of fun to put it together like this for the shakedown, and I'm stoked with how the car felt to drive. Initially it was a bit anti climatic, as the motor was fresh and I took it pretty easy, keeping rpms below 3 and very occasionally 4 thousand rpm, and no full throttle. Plus its got the old 2.76:1 open diff in it, and first gear in the cuda is nearly the same as third in my Ford Laser daily! So that with the heavy temporarily unassisted factory steering and pretty average brakes, made the car feel a bit dull and heavy.

The no full throttle and low rev limit didn't last long though...   The motor pulls hard and sounds awesome. And I can now say with confidence that this car will be a lot of fun when the handling, steering, brakes, and diff are up to their final specs. Which is what I'm working on right now!