Project Max Effort Cougar - The Ultimate Track Day 9-Inch Part 2

With our 4.10 gears mounted in the case, Currie checked the backlash and set it to .010 inch, per Motive Gear's spec. Not all brands are the same, so as a rule of thumb always follow the manufacturer's recommendation.

For our differential, we needed exceptional torque transfer and power handling capability, but we drew the line at a complete race differential that requires frequent maintenance in favor of Eaton/Detroit's strong and reliable TrueTrac. For those not familiar with what makes this piece superior to traditional clutch-style limited-slip diffs, check out Tech Letters in this issue.

Currie rarely has an issue with noise using gear sets from Motive Gear-which is why that's the only brand they sell-but to ensure proper alignment, the gears are spun with dark and light grease splotches so the Currie technician can see the meshing pattern of the teeth.

With everything checked out and torqued to spec, the third member is lowered into the Speedway housing via an electric winch. A Currie lightweight or aluminum gear case would have saved a good deal of weight, but we need the sheer strength and rigidity of good old heavy nodular iron.

Our gear case of choice was Currie's 9-Plus Race Case. It may look familiar, but this completely reengineered nodular-iron piece is over 100 percent stronger than a stock 9-inch, and can handle up to 850 hp, thanks to upgrades like extra ribbing and bearing supports. It's also ideal for dealing with the loads that will be transmitted by Max's torque-arm-based rear suspension.

Remember that brake breakthrough we mentioned in the last installment? May we present Baer Brakes' new internal parking brake assembly for 9-inch floater rearends. The brilliantly simple piece will relieve our fears of slipping out of gear while parked, and probably even work with the stock Cougar/Mustang parking brake handle. Watch for more on this one-of-a-kind brake option later.

Not just any axle can be used with a cambered housing; our sticks are Speedway Engineering's crowned 31-spined axles, gun drilled for weight savings. This is the only correct way to run a cambered rearend with offset hubs and make it last. Those massive wheel studs are mounted in a Baer Brakes rotor hat.

After sliding on the retaining plate and tightening its two retaining screws, a plate with three Allen screws caps the axle. Now you can see why it's so easy to swap out axles in a floater if necessary-and why they're safer in the event of breakage.

That big beautiful monoblock of billet astride a 14-inch rotor is Baer Brakes 6R series Asphalt Competition brakes-ideal for those times when you're doing 160-plus mph on the back straightaway headed into a tight right and absolutely must stop right now without fail. Based on Baer's 6S architecture, these brakes step up the features for serious competition cars. There's an internal crossover to prevent fluid circulation restriction, bridge bolts, and a quick-change clip to allow the option of quick pad changes in endurance races. That's an industry first, and exclusive to Baer Brakes.

Our rearend is complete, but before it can be installed we've still got lots of chassis and suspension work to do. We may be a bit overkill with those big bad 6Rs and 14-inch rotors on the rear, but only high-speed track testing will tell for sure. We'll let you know.