Bulldog Rear Ends has been producing live-axle rearends for Sprint Car racing for years, b
If you race in a horsepower-limited class—typical for anyone racing crate motors, spec engines, or small carburetors—finding just a bit more power simply isn’t an option or it’s prohibitively expensive. But quite often many different components between the end of the crankshaft and the tread on the rear tires are still open. If you can find increases in efficiency by cutting friction anywhere along the driveline, that’s equivalent to finding more horsepower in your engine.
That’s not a new concept here at Circle Track. We’re constantly testing lighter oils, new components, and different configurations in order to help you find more success on the racetrack. This article is no different, except this time around we’re thinking big.
Instead of a single component or product, we’ve decided to put together a dream quick change rearend. The lightbulb for this project went off when we were admiring a pair of billet wide-five hubs from Joe’s Racing Products and thinking about all the applications where these components would be a benefit (while trying to keep the drool off).
We’re pairing the Bulldog rear with a pair of wide-five hubs from Joe’s Racing Products, i
The original plan was to pick individual components and put them together, beginning with the Joe’s hubs, building a rearend that is as efficient as possible in order to maximize horsepower to the rear tires while also being strong enough to handle the abuse that racers dish out. But that all changed once we found out about a brand-new stock car quick change unit from Diversified Machine’s Bulldog Rear Ends line.
Bulldog Rear Ends has been around for a while, but it has never really made much of an impact in the stock car racing arena. Instead, Bulldog has concentrated on live-axle rearends for Sprint Car racing. It’s been quite successful in the Sprint community and attracted a loyal following, so when we learned Bulldog was hard at work developing a quick change rear for stock car racing, we knew it would be a quality piece. But when a finished unit was revealed and we got a closer look at it, we realized our original plan of piecing together a rearend one part at a time was a bit pointless.
The Bulldog rear—named the CT-1—is a closed-tube quick change that packs a ton of great features into one unit, and we expect it will start showing up on winning race cars on both dirt and asphalt.
In this article we’ll take a closer look at both the billet wide-five hubs from Joe’s and the CT-1 from Bulldog Rear Ends and how they go together. Next month we’ll follow up with a second edition where we mount a set of birdcages, rotors, and brake calipers from Wilwood, and show you a few tips for mounting your completed rearend in your race car.
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We asked gear specialist Jim Cook to help us tear down and rebuild the Bulldog rear, and o
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Instead of a standard round O-ring that seals between the center section and the bell, Bul
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Here’s a look at the center section. Notice the extra large struts around the pinion gear.
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This photo shows the opposite view of the center section. Notice the three studs that atta
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Lower rotating weight makes for better acceleration, and to that end Bulldog includes an a
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The jackshaft is set up to accept standard quick change gearsets. So your collection of qu
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The rear cover has been machined to accept an O-ring which should provide much better seal
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After our visual inspection, driveline specialist Jim Cook put everything back together. T
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The axle tubes are anodized aluminum. If you don’t like the blue, you can also get them in
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Here’s another nice touch we noticed. Bulldog includes a few extra-length bolts to fasten
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Even if you’ve ordered a brand-new rearend, it’s still a good idea to check the endplay in
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The machined aluminum nuts that hold on the quick change cover plate include flanges machi
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With the rearend back together, the pinion plate can be bolted on. This rear is going into
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The Joe’s hubs are machined from billet aluminum. They don’t really save much weight versu
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Here, we’ve already bolted up the brake rotor bracket. It’s designed so that you can bolt
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Like the Bulldog rear, the Joe’s hubs also have several very thoughtful features that can
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Joe’s also sent us these bearing spacers. They use a collar, held in place with set screws
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Bulldog also included these gun-drilled 31-spline axles. They’ll be installed when we fini