i'm not sure i understand how redlining affects the tranny?

if you mean dropping the clutch while redlining, then yes, it will destroy the transmission.

if you mean redlining in a particular gear, then actually, the worst stresses on the tranny occur at peak torque, which is not at redline... it's a good couple 1000 rpm lower.

the tranny really doesn't care how much POWER is being transmitted through it, it's about TORQUE. power is a function of both torque and RPM, whereas torque is simply the turning force.

hth
ken

 

Just be nice to your car in 2nd and 3rd gear, and don't launch it hard. Try to rev match, and don't clutch dump

 

The thing to remember is that after you redline a gear, you will be near the torque peak upon upshift to your next gear. Being careful to rev match is important, especially on 1st to 2nd and 2nd to 3rd shifts, as they have more mechanical leverage. If the rpm's haven't dropped enough, then you drop the clutch and hammer the throttle it is going to put a significant shockload on the gear you are engaging. I have a feeling this is how a lot of second gears are broken. Barking second gear is cool in a powerful rear wheel drive car (or at least it was when I was in high school ), but in an awd car you are less likely to bark the tires and more likely to break a gear...

This is a good read as is this .

Welcome to the world of Subaru!

 

good points. as far as chirping the tires thing, i was talking to my dad about getting mods to lower the engine's rotating mass.. ie lightweight flywheel, crank pulley, etc, to make the revs drop a little more quickly between gears. he replied, "why do that? just pop the clutch and chirp the tires." i had to tell him that it's a LOT harder when you're getting hustled along by ALL FOUR WHEELS! (he comes from the musclecar era, with four different vettes, a couple of camaros, etc, under his belt.)

i am a firm believer in slipping the clutch when necessary to smoothen things out: the clutch is a LOT cheaper and easier to replace than anything else that's gonna take the hit!

ken

 

I think most second gear breakage occurs because of inexperience, not necessarily because of abuse, as some might call it. The WRX has an absolutely ridiculous lack of power before the turbo spools up ( this is how it is with all low compression, turbocharged small displacement engines). I am sure many people have experienced this sort of Dr. Jekyl and Mr. Hyde personality that the WRX engine has. It is typical of the type.

The biggest shock load takes place when one is railroading through first gear...feeling the boost build...and then slams into second, inadvertantly dropping the RPM, and in effect pausing the turbo's spin (this is what is known as turbo lag)...at the same time, the continued increase in the car's momentum has become dependent upon a sustained increase in power. This turbo lag causes a severe "bucking" in between gears (because of that momentary power vacuum...and hence the inability of the engine to generate the power needed to increase, or at least maintain momentum)...this results in a significant drivetrain shock (magnified in an AWD car, of course). Anyone, whether experienced or not, has witnessed this phenomenon, at some point, when doing a "zero-to-sixty-test" type acceleration down the road. Truthfully, I am willing to bet that most of the gearbox failures are due, overall, to general unfamiliarity, and inexperience, with the laggy power drops that are characteristic of a heavily-turbo-dependent engine such as the one motivating the WRX.

 

rentankonko-

Then how to we stop this lagging vaccum of power between 1st and 2nd gear?

I'm a newb boys, so take it slow. I don't redline too often, but sure don't want to break anything.

 

Since y'all aren't reading the above links, I'm forced to use the dreaded "ctr-V"!

From this link...
Another exercise: When upshifting, try to use the same 'egg-shell' pressure on the shift lever to slip it into the next gear. When the clutch pedal is pushed and the shift lever moves through neutral, the intermediate shaft drops in speed and will quickly match the speed of the higher gear. This is the point that it will almost *seem* to pull itself into gear. The engine takes slightly longer to slow down because it has more inertia. This usually works out well because it is a moment after the gear is engaged that the clutch needs to be re-engaged. If the clutch is re-engaged and the power smoothly reapplied at just the right time, there won't be any 'shock' in the drivetrain.

And from this link...
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.


I get no discernable turbo lag by using the above technique...turbo lag happens only if first gear, without a slip clutch launch.