Trick Tranny Tips

Words and photos by Steve Oldani
3/7/03

Iowa transmission builder Steve Oldani specializes in modifying powerglide transmissions for bracket racers who want their trans to "hit" the tires harder in the hope that they will get those .005 to .007 reaction times necessary in the ultra-competitive environment of professional bracket racing. Some of the racers that Oldani does transmission work for include Super Comp multi National event winner Paul Pittman and Super Gas National event winner Carl Root.

Oldani recently modified a powerglide and detailed what he did to try and improve its performance. He graciously shared a few of the tricks he does to his trans, along with some photos. We thought our readers might find this information useful.

The first change to the transmission was to replace the 1.76 billet gear set with a 1.80 straight-cut BTE gear set to effectively put a lower gear in a car without buying a new rear gear ratio.	Another major area to improve is the valve body. The transmission came with a single-passage transbrake and I modified the case by adding a second reverse feed hole and a modified TCI Pro Tree transbrake.
The TCI brake was improved by internal and external milling, to allow a faster release time for Pro Tree racing.	In addition to the dual-feed case modifications, I also added two bleeds for the reverse circuit, which will allow a more consistent setting of the brake, because they allow trapped air to quickly be exhausted from behind the reverse piston.
One bleed hole is added from the "crescent" area under the rear cap of the transmission.	Another is drilled through the reverse piston itself, and it is then installed with the bleed hole indexed at the 12-o'clock position in the case. These both have proven to be major benefits to reaction time and consistency.
	A dual-ring low gear servo was added as well. The servo allows a better seal against the higher pressures needed to apply the brake.

As preventative maintenance all of the seals, gaskets, and friction materials inside the transmission were replaced. The transmission is now ready for the next race.

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