Not sure what breaks doing what, however here's a quote from my Subaru 4EAT technician manual:
(Damn, this is long, oh well, I love ya' guys! :lol: )
Do not continue the stall test for MORE THAN FIVE SECONDS at a time (from closed throttle, fully open throttle, to stall speed reading). Failure to follow this instruction causes the engine oil and ATF to deteriorate and the clutch and brake band to be adversely affected.
Be sure to cool down the engine for at least one minute after each stall test with the select level set in the P or N range and with the idle speed lower than 1,200 RPM.
Exact quote. The stall test, BTW, they refer to requires a tach (50 RPM accurate), vacuum gauge, and oil pressure gauge, ATF temperature gauge, and known stall speed to compare against. After reading the test (which basically is flooring it, so I was wrong) I would not do that to my car - it's harsh!
Oh, and here are those stats:
Stall speed (sea level) 2,750-3,150 - normal (non turbo) and 2,450-2,850 (turbo)
Higher or lower means problems, I have a list of about 20 things! :lol: