The Glader (Supercharger)

What made this car so unique was the funky item under the hood known as the “glader”. It was a scroll type supercharger that VW used in its motorsport rallye efforts. It’s unusual design was efficient but unreliable. It was considered by most to be the Achilles heel of the car. Very few corrados were sold in the United States. They were introduced in the summer of 1989. Sales were dismal by any standards and the car was expensive when compared with other available hatchbacks. The supercharged version of the corrado was sold in the US until 1992 when it was replaced with the VR6 equipped version. Today, glader equipped cars are extremely rare. Most gladers have not survived the passage of time. Many corrado owners discarded the cars once the glader failed. Replacement costs often exceeded the value of the entire automobile. It is this odd piece of engineering and machining that I find fascinating.
The glader is a difficult concept to visualize. How does it create positive manifold pressure? The outer casing has two inlet ports and an outlet. There is a pulley on the front portion that is connected to a belt. Inside however, it is very different. One of the pulleys is connected to an eccentric, which rotates in an elliptical rotation. The outer casing when separated exposes a number of G-shaped plates that fit closely together. One side rotates compressing the air trapped in between the G-shaped plates. This motion forces air trapped between the plates in the direction towards the outlet. The supercharger was also known as the G60 because of the G shape. The plates were also 60mm in width. This is what it looks like disassembled.

I knew this piece of equipment was going to be the most coveted item for corrado owners. I was fortunate at the time that New Dimensions in Santa Clara California was the North American distributor for TEC Automobiledesign. TEC was responsible for VW Motorsports Rallye efforts in Europe and was one of the foremost experts on the glader. TEC pioneered a ported glader which they called the RS. The modified glader sported dual redundant belts and ported intake and exhaust ports. It was reported to spool up to pressure faster creating a more responsive acceleration. The RS also addressed the problems with the small 8mm belt . If the belt should fail, the internal eccentric shell would collide with the other half causing the magnesium glader to shatter. This was a catastrophic failure sending metal shrapnel into the intake manifold and engine causing further damage. The dual belts of the RS eliminated belt failure as a showstopper. I eventually converted the twin belt to a 19mm belt with the help of Bahn Brennar Motorsport. This robust 19mm belt is indestructible.
Comparing the standard Glader to a ported RS, the visual differences are subtle unless one knows what to look for.
Examining closely the first noticeable difference is the larger 19mm drive belt which is an optional conversion from BBM.

The RS also has an enlarged intake compared to a stock glader. This enlargement allows greater volumes of air to flow more smoothly and quickly into the chambers for compression.

Once pressurized, it exits the rear through the spider vanes. This outlet is also ported to allow the least amount of material to impede airflow. Amateurs have shaved these vanes too thin causing weakness in the structural integrity of the Glader. However, most important is that few realize, there are oil arteries inside one of the vanes. Some have machines through this vain exposing the oil feeds for the main spindle. This renders the glader useless.
What you see here is my freshly rebuilt Glader. I have them professionally rebuilt every 40k miles. I know that is excessive but I’ve never had one fail.

One interesting note: Whenever I showed up at automobile gatherings, my 15 year old car always drew more curiosity when parked next to modern contemporary show cars. Most are unaware of the corrado and even fewer know anything about the glader. That curiosity is always

worth the price of admission.

Since this is the defining item on the G60 corrado, my brother and I have been scouring salvage yards over the years in search for others. At present we've each got an authentic TEC 2RS installed in our cars and a fresh spare rebuilt Glader sitting on a shelf (Just in case)