Would I still need an LT4KM if my PCM is tuned for specific timing?

 

Yes, because even if you are running a different amount of timing, that doesn't change the fact that you can be vulnerable to false knock that can be brought on by header or valvetrain noise. That is why it was factory specified on the LT4 Corvette.

 

wow I was wondering the same thing but I figured that programming could take care of the false knock....good info!

 

But doesn't false knock just cause pulled timing? Therefore, PCM tuning would fix it? Or am I wrong there?

Man another thing to spend money on, sweet! Where can I find them and how much do they normally run?

 

I just saw a guy selling a used one for $20 shipped over in the sales section....forgot his name...

 

Mine was $36 shipped right to my door. Very handy little piece of equipment!

 

VERY easy to install...

 

Where do they install at?

 

Just take out your PCM.....you'll see 2 screws in the center area of it where the knock sensor sits...unscrew and replace with the LT4 knock...

Of course do all this with the battery disconnected

 

I have found them usless and tune with a stock part.

 

Have you verified that you have a knock issue (monitored the knock sensors)? If you do have knock, you should verify it's false knock...run the car with race gas and verify that the knock remains...if the knock goes away using race gas, then it's not false knock! Pulling timing from the motor will hurt your performance unless you're running power adders that require the timing to be backed off. If it's true knock, you need to find out why it's occurring (i.e. in need of a tune-up, running the wrong heat range plugs, bad gas, bad EGR system, low fuel pressure, bad O2 sensors). What power adders do you have?

 

Sorry...forgot to look at your signature for mods! RR's and long tubes can definitely cause false knock, but I'd verify it first with the race gas.

 

I haven't verified it, just was wondering on what the chances are of me needing one, esp since my car can't pull timing very off because of the tune...

I will try to get it checked out sometime though and verify if I am indeed sensing knock or not.