what would happen if you overrev your engine? what kind of sound would it make and what would be the symtoms? smoke? grinding noises? would it be possible to overrev your engine and not notice/hear any damage assuming something happens in the engine that's not supposed to happen due to overreving?

 

Don't do it man, it'll explode into a bazillion pieces. OUCH.
C.

 

are you serious are are you joking...?

 

The fuel is cut off before you can do damage. I happen to hit red line last week by mistake and the fueling was cut and RPMs dropped. I shifted and went on my way

 

that's if you have a rev limiter. my rev limiter has been removed by Technosquare.

 

I'm not sure but if you do will you post what happens.
Bazillion pieces. HaaaHaaaa

 

You will blow your motor (throw a rod, lean out the fuel too much, etc..) if you do it excessively.. You can probably get away with 7400rpm or so, but if you peg your tach you're not doing good things to the motor. You're almost better off having a rev limiter because you are well on the downward side of the HP/torque map by the time you hit 7000rpm. Consider a shift light if you're really serious about this stuff.. they're cheap and easily setup. Set your light to optimize the torque/hp.. not to go as high up the tach as possible.

As for what you will hear.. there was a SC Cobra vs. Vette video where the guy throws a rod.. probably from leaning out the engine too much.. used to be at http://www.corvettekillstories.com/v...bra_vs_Z06.wmv.. might come back some day? Basically, the engine just starts making really loud knocking noises and substantially loses power.

 

Why would anyone ever remove a rev limiter? I could see increasing it, but removing it totally?

 

I didn't remove it on purpose. I think technosquare messed something up.

 

It's impossible to overrev an automatic unless you've got a 7000+ rev limiter or no rev limiter. With a 6 speed, it's quite easy to overrev the motor by misshifting into too low of a gear at high speed (ie going into 2nd thinking it was 4th at 95mph). No type rev limiter will save you if you make a mistake like that.

A handful of things can happen if you overrev a VQ motor:

1) Bend a valve. You'll hear a loud ticking if it happens.
2) Throw a rod. The VQ35 has very weak rods and they don't like high rpm speeds (7000rpms+). The engine will die and you'll see lots of smoke and oil and maybe coolant pour out the bottom of the car.
3) The clutch may blow up. This had happened to a couple VQ30 Maximas on misshifts.
4) Blow a headgasket. I know of two VQ30 Maximas with 7500-8000rpm limiters and both have had headgasket failures. If this happens the engine will run crappy, it may smoke (white), and oil and/or coolant will look frothy. I imagine the cause was that the water pump cannot move the coolant adequately at rpm high speeds.
5) Spin a crank bearing.