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| More horsepower and torque means the tranny requires more clutch surface. Mike’s five-second glide has a purpose-built clutch drum and holds eight clutch discs and eight “sliders” or steels. That much surface is needed to dissipate the heat and keep the clutch pack from burning up. |
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| A deep aluminum pan, pickup and filter are a mandatory for the trans to hold enough transmission fluid. Mike recommends his specially blended trans fluid that doesn’t break down as soon under heat and stress as over the counter trans fluid. |
In the mid 1980’s, when the NHRA still allowed OEM transmissions in Alky dragsters and Funny Cars, Mike was approached by Funny Car racers Frank and Lena Williams about building one of his ‘glides for their Alky Funny Car. He agreed to do so and used a stock case (aftermarket ‘glide cases were still a few years away), some specially modified stock internal components, and some custom-made parts.
Frank and Lena ran as quick as 6.60’s at over 205 mph in 1986-87 using that Mike’s Transmission Powerglide behind their supercharged big-block Chevy. When the NHRA found out the pair were using a modified OEM GM transmission to record those speeds and ETs they got very nervous about the possibility of a stock-cased ‘glide blowing up and oiling the track, although one built by Mike never had. Nevertheless, NHRA decided to rewrite their rules outlawing OEM transmissions for use in their alcohol classes!
When the NHRA took away the Alky funny and dragster market, Mike turned to Top Dragster racing himself and he dominated the West Coast with a series of big-block Chevy and Hemi-powered dragsters. That began a 20-year quest to make the first five-second pass behind a Powerglide. He accomplished that feat in 2007 but he was not the first ever. An Australian team made the first five-second pass with a ‘glide a few years back in a blown dragster, but Mike was the first in North America to run the number.
He soon realized, as did other tranny builders, that no amount of modifications to the stock OEM components of a GM ‘glide from the case to the internals to the input or output shafts would stand up under the abuse a 2,000hp supercharged or nitrous oxide-injected engine developed, regardless of whether it was in a dragster, funny car or doorslammer.
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That’s when the Powerglide camps such as Mike’s Transmission, ATI, TCI, and some others began taking the then 40-plus-year-old original design to the next performance level by re-engineering each part. Today a purpose-built Powerglide like Mike’s Monster Glide that he used to make his five-second pass has evolved the same way the Chevy rat motor has. A state-of-the art all-aluminum Sonny Leonard rat resembles the 427 in your Chevelle but it isn’t close to stock. Same applies to a custom ‘glide. Their new cases, gears, shafts, pumps, and clutches resemble stock parts but they are all of them custom built and share only appearance and function of a stock GM Powerglide.
The first and perhaps most significant improvement, and one of the keys to the development of the five-second ‘Glide, is the aftermarket case. By the early ‘90s, good case cores were becoming scarce so several companies started casting up new, improved versions. For a transmission that will enhance a 2,000-hp engine, Mike Stewart uses Reid cases that feature roller bearings and a custom extension housing.
The next step was to build stronger, more durable, internal parts. Initially, many builders, including Mike, used a Vasco material to build bigger and better input shafts and other components that were subject to stress. Mike’s “Vasco ‘Glide” uses many modified and improved stock pieces and they are strong enough to survive in heavy (2800-3500-pound) door cars that have engines making as much as 1500hp. Many racers with those cars used ‘glides with Vasco components.