Subaru WRX Transmission - Gear Attack

Gear set solutions

From the February, 2009 issue of Turbo & High-Tech Performance

By Scott Wills

The Subaru WRX has established its superiority with an affordable price tag and unforgettable all-around performance.

The WRX in stock trim can be a competitor almost anywhere it goes, whether it is rally or road racing; out of the box, this car disappoints many adversaries.

The five-speed transmission, however, is the topic of conversation for many enthusiasts on the street and many competitors at the track. The majority of the complaint list goes as follows:

Gear Set Symptoms
1) Hard launches break first gear
2) The car will not go back into first gear unless you come to a complete stop
3) Fifth gear is absolutely useless at the track
4) Constantly stuck between the top of first and the power in second
5) Transmission makes noise during decceleration

These aren't reflective of the opinions of the average WRX owner, but instead from those who push their WRXs to the very edge. Of course, as always, preventative maintenance is the name of the game for the WRX and its not-so-loved transmission.

Most of our testing was done with a few rally-prepped WRXs. Rallying is the ultimate test bed for any product because of its extreme conditions. A rule of thumb is, if it can stand up to rallying, it will stand up pretty much anywhere.

1) Hard launches break first gear

Most complaints come from those who have admitted to revving pretty high before dumping the clutch. The AWD cars are great for getting power to the ground, offering astounding amounts of traction.

When you modify the 2.0 turbo engine, it's easy to find a lot of torque and horsepower quickly, but remember the rest of the car needs to be addressed to handle the power gains.

The number one suggestion is to be aware of potential weaknesses and don't side step the clutch. It is very possible to launch hard with a little clutch finesse; however, be prepared to regularly maintain the clutch linings.

The other option is going with an after market gear set. Most of the aftermarket gear sets are way stronger than stock, but hard launches can destroy way more than just first gear...trust us.

2) The car will not go back into first gear unless you come to a complete stop

It always starts with a little synchro scratching going back to first gear. A new car is usually able to find first gear from 20 to 0 mph. Eventually, that speed lessens until all you get is an excruciating grinding noise unless you are at almost a complete stop.

This noise is very frustrating at the track, especially when the track has a lot of hairpins or very tight corners where first gear would be effective. First gear becomes useless as soon as you shift out of it until you come to a complete stop. The first thing to try is upgrading the transmission oil. The factory Subaru oil is not bad, but there are some very advanced lubricants on the market that can help with this problem.

We stumbled into the ultimate Subaru tranny oil info. We all know the basis for R&D on the WRX is rallying, so what does the World Rally Championship Subaru team run in their cars? Neo Synthetic lubricants, which are manufactured and distributed here in the United States.

We tried some Neo gear oil and eliminated a lot of the issues with the synchros going into first and fourth. The car was once again able to find first gear at around 20 mph. If you have been experiencing grinding issues, there's a chance that nothing short of replacing parts can remedy the problems.

3) Fifth gear is absolutely useless at the track

A WRX with stock tires will do a little more than 120 mph in fourth gear. As best as we can tell, fifth gear is just for highway cruising and fuel economy. There aren't many venues for club racing that warrant or have the track for speeds of more than 120 mph.

Best option here is an aftermarket gear set that has ratios more inclined to keep the WRX in its powerband throughout every gear. A close ratio system is ideal.

4) Constantly stuck between the top of first and the power in second

The thing on every WRX owner's mind is the six-speed STi transmission. Yes, this is definitely the best option for some in-between ratios; however, the expense of the transplant is not cost-effective for some of the grassroots racers, nor will it be legal under some series' rules, which require a standard transmission setup.

Changing the gear ratio in the factory box is a very effective way to go about it. There are gear sets available that help to make first gear usable by making it just a little taller, and second gear a little shorter.

5) Transmission makes noise during deceleration

This is a common problem, but technically not a problem at all. It's just a matter of inconsistent factory backlash in the ring-and-pinion gear. Some models do it more than others.

The Subaru dealership can fix the problem, but not with performance in mind. The dealership will replace the 27 -pound flywheel with a heavier model to keep the gearbox loaded, thus eliminating a decelerating noise.

Going the opposite direction with the flywheel weight will not get rid of the noise, nor will it increase it. The lighter flywheel will be noticeable in how quickly the car finds its powerband. Suggestion: Get over the noise. It's not a big deal, and certainly not worth compromising power.

In our research we have come up with a gear set that can take care of most of the rally and road racers complaints. Gimmie Gears & Accessories offers a "Sport" ratio that is most effective across the board.

The taller first gear of the sport ratio tends to fill the first to second void, and when you shift through the rest of the gears, you have a slightly shorter than stock rpm drop (approximately 750 rpm per gear), keeping the WRX in its desired powerband. The gear set has fewer, yet bigger and stronger teeth, offering the necessary strength for even heavily modified WRXs.

We contacted GT Motorsports, in Rancho Cucamonga, Calif., about handling the gear install for us. Follow along as we see exactly what it takes to do a performance upgrade inside the 2002 WRX five-speed gearbox.

FROM GT MOTORSPORTS
Based on a well-known video game (Gran Turismo), we visualized a new service concept. This concept provides the customer with the ability to install a wide range of performance parts all at once. These performance parts can be selected and installed in one full sweep, or in stages.

The performance parts are available within today's automotive aftermarket and with the dream of bringing the game to life, Certified Automotive Group, INC(CAG,I) started the wheels rolling.

With the game's theories in mind, CAG,I created GT Motorsports, one of four automotive shops that fall under the CAG,I. The four automotive facilities consist of: Certified Auto Care, a full service repair shop, an 11 bay facility with ASE certified technicians. Certified Care Transmission is a full service transmission facility with four bays and three lifts. Under-car Specialists is a full service suspension, alignment, muffler, and tire facility with six lifts. GT Motorsports is a full-service performance shop with an in-house machine shop.

With each shop providing an automotive service specialty, the full gambit of automotive needs are covered. And GT Motorsports' access to the latest in computerized automotive equipment ensures no service or feature is left out.

For example, our wheel balancing equipment will not only balance all four wheels, but can also calculate the correct placement of each wheel for the optimum balance of your vehicle. With the all- wheel dyno, we can provide crucial horsepower data needed in today's competitive environment.

The repair facilities allow you to prep for your upgrades. This is a combination of service and technology.