OK, you are watching Speedvision. In-car camera. Indy car. The dude just pulls the lever, the engine note drops again and the Star Wars hyperspace scene continues. Geez, I think there must me something wrong with my shifting technique. NOT! All race cars have special 'dog-clutch' synchronizers on the gears. The faster you shift them the smoother they are. Motorcycles also  usually have these types of gearboxes. But they are not particularly long lived, they are quite noisy, they are expensive (good ones are anyway) and a pain in the butt to drive under normal conditions. 

If you still believe their is something wrong with your shifting technique and attempt to emulate what we see on Speedvison, you WILL break your transmission. And a Subaru, with 4 wheel drive, lets you be especially hard on clutches and gears, because while a Honda is lighting up one tire, you have just launched at almost 1 g of force on your back side. Those loads were also on the gear teeth in the transmission. That is all I have to say about "speed" shifting and drag racing type standing starts. The Subaru gearbox has a reputation for breaking. Gee, I wonder where this rumor came from? Treated properly they will run a long time up to about 280-300hp or more importantly about 250 ft-lbs torque. Just shift smoothly and wait for the gearbox. It still shifts pretty quickly.

Several owners are having trouble with the clutch and shifting. Here are comments directed at improved technique, not that the Impreza could not have mechanical improvements in this department for use as a pure sports car. For more information see the Technical Information pages.

The clutch and drive train in the road going Impreza are a compromise, a reasonable compromise. There are five drive shafts in a four-wheel drive car, so it is easy to get some "snatch" in the drive line by sudden movements of the throttle. There is noise to be dampened form the drive train, so there are soft rubber bushings common to all passenger cars. There are shock loads to be guarded against from drag racer starts and generally poor foot work by some drivers, so the pressure plate has shock springs and the hydraulic actuator is dampened to prevent shocks to the rest of the drive line.

The entire system is designed to be driven smoothly, for which the following Q&A from an early Impreza reader will make clear:

>>Brian Wrote:

Is it just my clutch or can anyone else relate? I have had my 1998 Impreza RS for about 6 months now and have close to 10,000 km on it but I still seem to have a hard time always getting a smooth shift. I have = tried everything...letting the clutch as slowly as possible...opening the throttle earlier..nothing seems to work unless I give it a lot of gas before it engages. Is there a better way? I have no troubles with the 3rd to 4th shift but 1st to 2nd isn't as smooth as I would like it to be...would revving it higher give me a smoother shift? Currently, when I drive normally, I shift at 3500RPM -4000RPM...is that too low? Any advice anyone could give would be much appreciated. I am suspicious at our transmission build because if you read the improvements on the 99 Impreza..the transmission has been beefed up significantly and a new clutch will be introduced...

>>end quote. We are still waiting on the beefier clutch, by the way. We sell them.

The Impreza has a hydraulic clutch with a damper built into it. It has a reasonable, but not high force pressure plate. The flywheel is a standard unit, designed to give smooth starts without the motor stopping. That is to say it has enough mass to make it easy to start off from stand still. These factors give the clutch is operating behavior. Also note the Subaru transmissions are tight when new and need broken in. They will not really feel good until 10000 miles or more, just like a BMW. They are built to tight tolerances so they will drive a long time. The trade off is a tight feel when new. 

As far as cold transmission shifting goes, transmission oil has better friction when cold, so the synchros tend to slip. When the oil gets hot, they bite better. The use of a quality GL-5 75w90 full synthetic motor oil such as Motul300, Valveline, Mobil or Castrol synthetics will greatly improve cold shifting. None of these are cheap, unfortunately. We do not recommend Red-Line! Best is possibly Motul M-300 75w90 which I use. This side bar is especially important for cold climate folks.

At higher rpm, road car clutches have a lot of fly wheel inertia to overcome . The driven disk attached to the transmission input shaft, while light weight, is also heavier than a racing disk which has only to run twenty to thirty hours between inspection. Road car clutch/flywheel assemblies do not want to slow down between gear changes as fast as the race car hardware.

A dog-clutch racing gear box often does not even need the clutch disengaged to up shift. It just goes 'clack!' into the next gear because of its light flywheel and button or multi disk (small diameter, low inertia!!) clutch. On the other hand, a road car needs a different attitude on the part of the driver.

Sign seen in the High Sierra on the Crest Trail: "WARNING! This is bear country. The BEARS make the rules. The rules are...." So it is with hiking that bears are important, is it also with shifting that the machine you are driving rules your moves. 

The first rule of gear change is to learn to wait on the machinery.

The second rule is to let the synchros work, push, do not force into gear, See rule #1.

The third rule is to let the clutch get all the way home before gassing the throttle. See rule #1. This does not take all that long, but there are some tricks to smooth gear changes.

Rule number four: It is just like learning the piano, first get the technique right and then go for speed. See rule #1.

Rule five is that 1-2 gear changes are a bitch, 4-5 make you look like Walter Röhl every time.

This 1-2 shift always has the greatest percentage difference in the speeds of the moving parts. Brian's observation was spot on for this reason. First gear in a US model is 45% slower than second gear while 3-4 difference is usually only 27%. What is a lousy 17% greater initial shaft speed to a gear change? It is 40% more kinetic energy to absorb. This is the rule of squares from the k=mv2 of high school physics class, in action. The second gear synchro works much harder for its dinner than does its fourth gear cousin. It also simply takes longer for everything to slow down to the new 2nd gear speed from first than it does for the 4th gear from third. It is also why down shifting to first is tricky. See rule number one.

Here is how I "road race" (i.e let the car live a long time) shift. Drag racers can stop reading here.

This whole thing takes may be two fifths to three fifths a second, depending on what gear you are going to next. The idea is to unload the drive train just before you de-clutch, then load it back up when the clutch is hooked up again. Roll out of the gas and as the nose sinks, de-clutch hard, move the lever to neutral very quickly with a soft touch. This is where you wait on the machinery. Go into gear with mild, but firm pressure. You are now going to cause the synchro clutch (yes each synchro is a mini type of clutch) to slow its gear down so the synchro ring teeth can fit over the teeth on the side of the gear. You're in the next gear, but in going to second gear the engine may not have slowed down enough yet. (Heavier than race car flywheel, remember?) Wait on the machinery again. Let the clutch out without hardly any gas at all until you know it is hooked up, then mash the gas. Think smooth, be smooth. Worry about speed when you get the motions down.

Get this right for 1-2 and use it every where - your car will like you when it has 100,000 miles on it. Your lap times will have been about the same. You should notice a smooth dip in acceleration and a smooth increase in re-acceleration, not a jerky unloading and a hard slam take up.

Mashing the gas works OK in a 2.5RS, but it is noteworthy that the early Can-Am McLaren's could snap a drive axle doing that in fourth gear. There is a 450hp WRX-RA drag racer in Australia that regularly snaps the right front drive axle inside the hub at the splines. There are some very high performance cars out there, so caution rules, some of 'em can spin, step out or generally get weird at some very high speeds when you just mash the gas. What you will find is that the 1-2 and 2-3 shifts require patience of only a fraction of a second longer than the 3-4, 4-5 stuff. The technique is the same.

This description is how to shift the car as it is. You can install a closer ratio gear box, a lighter flywheel and/or a stronger clutch to speed things up, but the technique is not going to change. These are things better considered at new clutch time. Prodrive Quick shift kits, which I sell, only make the lever move a shorter distance and make the change use more force, nothing to do with faster. However it is neat to use because your arm is not moving all over the cockpit. Combined with Group N engine and transmission mounts the car does become much more responsive in clutch and throttle action.

I hope this helps for those not wanting to actually change parts. To answer Brian's direct question, the higher you rev the more stress and the longer you need to wait. As far as opening the throttle, later and in the right amount is better than earlier. The clutch pedal, the faster the better, but with the engine not at the speed of the next gear it will jerk or slip massively. And easy on the gas until the clutch hooks up.

Here is "The Technique".

You will feel all this in your backside, not your head.

1) Car pushing you back in your seat, foot to the floor, long pull in second gear, say.

2) Roll out of the gas, feel yourself rise out of the seat ever so lightly as the actual acceleration decreases. This is the "relax the rubber band" trick. Nose of the car drops softly, when everything goes slack:

3) The tension in the driveline is relaxed, now! Off with the gas/in with the clutch! This WAS the hurry part. Now, let the gear lever do its job. Do not just slam it, slide it, because that is what is going on in side the transmission.

4) Now, get the clutch home (foot up) before you stretch the rubber band again. Only on start-up from a stoplight should the clutch be slipped at all. From your description, this may be where you are missing it. So again, the clutch should engage with no slip, then, you can mash the gas, IF attitude of the chassis is ready for full throttle. The difference between your bike experience and a 2800lb 2.5 liter car, is for its size, the bike clutch has a much, much easier job to do.