Can anyone explain technically why it is bad to do this rather than it is bad and a

 

Yeah, why is it bad? On that Japanese S2000 video thats been around this board lately, they rev it up to 9 grand several times, and thats on an engine thats under 600 miles!

 

I've known since I was 12 that it was a bad thing to do,

and as others have asked, I don't really know why either

 

It does not damage anything, that is associated with older vehicles. When you rev with the clutch in to downshift that is "not under load" let me guess that damages the engine too? All my vehicles i have revved in neutral and have had 0 problems with any of them mechanically. That is nothing but an old timer myth.

 

I think if you rev in neutral, lubrication wouldn't be as good as when the car is moving and under load due to lack of splashing, just a guess. I think it is worse for the Cat than the engine for reving in neutral.

 

what about drifting? isnt' that under very little load as well?

 

Could it be that you don't have sufficient airflow coming in for the combustion process (ie inadequate air/fuel ratio)??

 

Well, I'll be the "old timer" to give you a reason. Take it as a myth if you want. Ask any seasoned mechanic and he'll tell you something similar.
I've explained this in depth once already, so I'm going give the abbrev. version, if you can call it that (and I can't search out that thread, either).
It has to do with what the parts of the engine has to go through AFTER the power stroke. With load, all the little gaps in all those "clearances" are closed and stay that way. With no load, all those little gaps slam back into each other at terrific speeds on every stroke thereafter. Noone will tell you that this will kill your engine BUT it certainly will not do it any good in the long run if it is repeated over and over again. And remember, we're not talking about a little wussy revving here. We're talking about near redline revs where the piston speeds are staggering.
Lemme give you "another" analogy:
You're pedalling an excercise bike with some tension (load) on it. For example your knees are meant to push against that tension, to counter gravity, if you will. You're pedalling nearly as fast as you can, then suddenly, some dork releases all the tension and you start "free wheeling" (and your feet are tied to the pedals). With no load, at the bottom of your "power" stroke, the gaps in your knee joint gets pulled apart. This is NOT what they were designed to do. Sure, if you do it once or twice, no biggie. But if you were to have that same dork "surprise" you with the same stunt every time you excercise, it won't be long before you have some serious knee problems. Well, your engine's little spaces in the "big end" bearings, the piston wrist pins, the crank bearings will "feel" what your knee feels. It'll still run just as you will still walk, but in time, how well?
So then you say, "Well that happens when you engine brake!" Yes, it does BUT it did it once when you load the power train the other way. It does not do it on every stroke of every piston. But hey, what do I care, it's your car.

ps. And "supwithyou", you're all of what, 19 years old? I guess most things will be "myths" to you as you haven't lived long enough to prove any of them right (since everyday nothing happens, you've proved them wrong). Just because you haven't blown up an engine in those few short years you've been doing stuff like this to cars does not mean you're doing no harm. It only means that for you, nothing has happened. May your "luck" continue till you are an "old timer".

 

in neutral =

 

I have done it million times......


I feel bad......