Pete Epple Technical Editor
June 28, 2010
Photos By: Vision Haus Photography & Design

Once the 4.6 Aluminator engine was resting comfortably in the engine bay, it was time to install the new gearbox. But before the trans was lifted into place, we wanted to switch clutches. Centerforce sent us one of its LMC-series (Light Metal Clutch) to run in front of our new Magnum. Centerforce LMC-series clutches are low-inertia performance units, designed to reduce rotating mass for road racing or circle track applications. These clutches are SFI-approved and machined from high-strength aircraft-grade billet aluminum before a heat-treated replaceable friction surface is attached. They also feature a ball bearing-actuated diaphragm and centrifugal weight system, offering very high levels of grip, while maintaining comfortable pedal weight for daily driving.

Centerforce included one of its aluminum flywheels to complete the lightweight package. The aluminum wheel is machined from high-strength billet aluminum with replaceable steel friction surfaces, which have been heat-treated for abrasion resistance and long life.

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We wanted to know just how much rotating weight was being removed, so the scales were pulled out. The Centerforce LMC clutch, aluminum flywheel, and aluminum driveshaft from D&D checked in 36 pounds lighter than the stock counterparts. That's some impressive weight savings!

After the new T56 was installed, we put roughly 600 easy miles on the car to break in the engine and clutch. Pedal pressure is now slightly heavier than stock, but it isn't too heavy by any means. Engagement is smooth, and the LMC-series has more than enough bite for our naturally aspirated Four-Valve.

All in all, we're very happy with both the Tremec T56 Magnum from D&D Performance and the Centerforce LMC-series clutch. Once we get back on track, we'll give you an update onour improvements at the dragstrip and through the turns.

Gear Ratios
When we ordered our transmission from D&D, we had an option when it came to gear ratios. Tremec offers two different gear sets. The lower (numerically higher) gear set offers shorter First through Third gears with taller Overdrive gears. This gives you the ability to add gear ratio for local driving with the benefits of lower rpm in highway conditions. The higher gear set is less aggressive, allowing you to stay in each gear longer. Due to the shorter overdrive gears, the rpm on the highway will be higher--or the box with the 2.97 First would be better for drag racing, the other box better for corner-carving on an open road course.

LowHigh
First2.972.66
Second2.101.78
Third1.461.30
Fourth1.001.00
Fifth0.740.80
Sixth0.500.63

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