Whoa! I said that they made gearsets for 750hp Porsches, not subeys. Our cases are smaller than Porsche cases. I only mentioned this so you would understand that they are not new to this field and know what they are doing. They are full syncro sets. Here is the data I was given by the maker:
To maximize an engine’s power, the engine must operate consistently in its key power band, being the optimum interaction of torque and horsepower. Correct gearing produces precisely this. Correct gearing also produces greater leverage, in effect FORCING greater acceleration. There is no mystery to gearing for those understanding the principles. It is simply physics.
Our WRX gears are manufactured by PowerHaus II, a leader in Porsche close ratio gearing. Powerhaus II gears have taken Porsches to class wins at the 12 Hours of Sebring, 24 Hours of Daytona, and many other pro level races. Their gears have taken Mario and Michael Andretti and the Courage Porsches through the brutal conditions of the 24 Hours of LeMans, with three of the four Courage cars enjoying top finishes. PowerHaus II gears have taken many, many drivers to wins in Porsche Owners Club races, Porsche Club of America races and numerous Vintage and Historic race events.
These same, famous, cross-drilled, lightweight gears, the ultimate gears on the market, are now available for the Subaru WRX / RS.
The advantages to cross-drilling, a technique which Porsche once utilized before budgetary restrictions and minimum weight requirements took their toll, are two-fold. First, the gear itself is lighter, allowing for quicker rotation, easier shifts and longer synchro life in synchronized gearboxes, such as the WRX has. Secondly, the cross-drilling allows the transmission oil to flow THROUGH the gear itself, reducing heat buildup and thus giving markedly better longevity to not only the gears themselves, but the entire gearbox.
There are many factors, which determine the quality and effectiveness of gears. First, let’s examine why there is such great value and benefit to WRX owners to make these upgrades to their gearboxes.
It has already been established that the stock gears in the WRX are not appropriate for serious performance and racing use for two fundamental reasons. One, the ratios themselves are designed for typical street use. This generally necessitates a first gear that is too low (short) to be usable in performance/racing applications, and in particular fifth and/or fifth and sixth is too high (tall) to be usable in performance/racing applications. Further, the stock gearing, by virtue of it being designed for street use, is generally too wide-ratio to keep the engine in the key power band. This results in a loss of usable engine power and, ultimately, in a slower car overall. Two, breakage has been common in the WRX boxes under heavy use. This latter factor is the result of design and manufacturing techniques.
There are five areas of design and manufacturing of transmission/transaxle gears, which ultimately determine their overall strength and longevity.
1. Metallurgy The actual materials used to make the gears is a major factor. The steel alloys must be precisely right for the type of gear being made. Lesser quality alloys may be suitable for standard issue street application, but may not be suitable for higher performance/racing use. Gimmie gears are made from the finest alloys available, such as EN36A, which often costs substantially more than the lesser alloys the stock gears are composed of.
2. Hardness Gimmie gears typically have a Rockwell C Scale hardness of 60-61. Stock gears are often not this high in hardness rating. A softer gear cannot last as long as a harder gear under heavy use.
3. Tooth Pitch Gimmie gears are made with tooth pitches designed for strength and longevity, whereas many stock gears have tooth pitches designed for quietness only, which will not hold up to heavy use as will our racing gears.
4. Tooth Count Most street gearing is designed with higher tooth counts than are appropriate for high performance/racing applications. High tooth count gears can provide greater quietness, but often at the expense of strength. With helical cut gears, as are generally used in street issue gearboxes, a higher tooth count gear is favored for noise reduction. However, the higher the tooth count, the thinner the individual teeth will be, leaving them more susceptible to breakage. Gimmie gears are made with tooth counts based on strength instead of quietness only, and have teeth that are often dramatically thicker than stock gears. This results in greater durability and longevity under heavy use.
5. Final Preparation Not all street gears receive shot peening or final grinding as part of their final preparation. Gimmie gears receive both. The finished product is thus stronger and more refined as well as visually more appealing.
Whether you want your WRX gearbox to have standard gear ratios that will last much longer than what you have now, or want close ratio gears that will provide better throttle response and quicker acceleration, we’ve got the gears you need.