When you SC your mustang and don't do it correctly, what exactly get's f'd up? I understand the engine get's "blown," or whatever, But what specifically?

 

Mainly you blow up your engine from any type of forced induction because you get greedy and try to run too much boost/too big of a shot (nitrous oxidide)

Another one is running too much boost without an intercooler which leads to preignition.

Another common one is having a ****ty tune or no tune at all. This will lean the engine out and...yeah its bad.

 

It is very easy to correctly supercharge an engine and have many miles of trouble free boost enjoyment (many car manufactures use them for standard equipment). The problem is that lots of people like to cut corners which is where your question comes in. There are many ways you can S/C incorrectly. I assume your talking about the most common mistake of not getting a proper tune with the S/C. This problem mostly leads to melted pistons due to predetonation/lean conditions. Not preping the vehicle properly, things like not reinforcing the fuel system, will also lead to similar failures. Most forms of F/I if incorrectly done will eat pistons. If you simply over boost, blowing the engine can consist of anything from cracking a block to busting a connecting rod. If you simply do your research on the subject then supercharging your car will be a trouble free pleasureable experience.

 

well, blown is sometimes used to mean you've got a blower(supercharger) on it.
blown up on the otherhand is a mess of problems. You can have spark blow out (like a candle). You can melt pistons, You can have detonation which is when the air/fuel mixture goes off from compression instead of the spark (adding fuel will correct this). You can throw a rod or worse, crack the block or head. At the very least you could head gasket.

 

I have a question how much psi can you run on a 90 lx engine to keep it safe running on 93 octane. I am going to be buying a 90 lx, the motor is already bored .030 over, probe forged pistons, e cam. I want to put a 2.2L KB on it running bout 12psi. Also I was wondering what compression ratio I could do that with. Would the stock 9 be ok?

 

9PSI would be fine on 93 octane. Just make sure you get a good dyno tune.

 

Sorry, what I really meant is 12psi ok om 91-93 octance on the stock 9:0.1 compression ratio or would you suggest lowering it a lil bit. Also I was wondering if it was true that a 90 5.0 had a forged crang and rods from the factory?