ts99

I need some feedback on the "Knockout Box".

I have a 99 GMC Sierra, that has 8* of knock retard. I have logged with 100 octane fuel and still get the same 8* of knock.

This box is one that reportedly plugs (no splicing) between the computer and the knock sensors.

I believe Oxidizer has/had one of these.

Any comments as to its performance would be greatly appreciated.

Thanks

ts99

BlownChevy

iTrader: (20)

if you have that much KR with 100 octane gas, you have a problem! I would try to figure out the problem first before you try to band aid it.

TwoFast

iTrader: (23)

Sorry for me being a dumb **** but what is a knockout box and what does it do? I have a 99' Sierra and how do you know what degree of knock you have?

BlownChevy

iTrader: (20)

Not sure "what" the knockout box is....I have heard of them but never seen one. I believe it lets you change the level of sensitivity on the knock sensors. If a truck is seeing that much KR then there is a problem that needs to be addressed. 2-3 * is acceptable.


You can check KR with diagnostic software like EFILive or AutoTap. If you plan on modding you should look into on of those programs to "see" what is going on inside of your motor.

TwoFast

iTrader: (23)

Blownchevy how much is one of those and where can you get them. So they will basically tell you if you motor is running correctly? Thanks for the great info and fast responses all the time Blownchevy!

BlownChevy

iTrader: (20)

Any Time!

http://autotap.com/

BigTex

iTrader: (16)

I have one. I loved what it did for my 99 chevy. I was seeing random degrees of KR that wouldn't go away with better gas or less timing. It would just show KR. I bought the knockout box used and it worked great. I always had my timing set in the 27 degree range with LS1 edit, but would only get 21 or so after KR. When I plugged in the box, I think it showed over 30 degrees. I backed off the timing w/ edit and it ran great afterwards.

Jlwz71 also bought one for his 99 truck and reported similar gains.

The box is a little circuit oard with resistors. You plug it in between your PCM and knock sensors. It then filters out all but the loudest knock.

BlownChevy

iTrader: (20)

Is it possible that this is something that can be caused by bad Knock Sensors?

Ryan23silverado

iTrader: (1)

The '99 trucks seem to have issues with the KR programming written into the stock PCM. I did the same test as you 'ts99' with adding 100 octane and running wide open throttle logs on AutoTap. Yep, 8* KR registered. That alone does Not mean there is a problem with your engine. If that happens during that test, it is false knock, as the engine is not really detonating.

You can turn down the sensetivity of the knock sensors using LS1edit. At WOT I still get full KR (I set max KR vs. RPM to 2 using edit) But when I set it to zero KR vs. rpm I hear no audible pinging from the engine. The '99s have some issues with KR programming...
Tony/Nineball on this forum makes the knock out boxes. PM him with your questions -he is a smart guy

gonzo 6.2

iTrader: (8)

Your engine can be running totaly within spec and still have major faulse knock.Get yourself a knockout box and then watch your timing come up along with power.