LT1-LT4 Modifications 1993-97 Gen II Small Block V8

LT4 knock module questions

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Old May 18, 2012 | 12:08 AM
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Default LT4 knock module questions

1 - Is the false knock something that can be fixed with tuning, or would a LT4 KM then be necessary?

2 - Do I need one? FULL (I mean full) bolt on 97 z28 with LT headers, 3" Y, SLP LM1 catback. No rr's yet, but they will be done soon.

3 - If I do need one, where is the cheapest place to buy one? I'm seeing an average of around 75-80$ online everywhere I look, I remember they used to only be like 30 bucks lol...
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Old May 18, 2012 | 01:53 AM
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False knock CAN be tuned out however you may sacrifice potential performance by changing the timing to eliminate the knock. The LT4 Knock Module is less sensitive and allows for more timing with less of a chance for false knock therefore you may be able to squeeze out a little bit more power or performance.

We can not tell if you "NEED" an LT4 KM b your mods. Some people will say yes, others no. In MY opinion, you only NEED an LT4 KM if you are getting false knock while tuning the car. If your tuner gets it right here he wants it and there is no knock, then there is no real need for the LT4 KM.

My SS had Heads/Cam/Intake/Exhaust and was dishing out 411 RWHP with 390 RWTQ. I had a stock LT1 KM on the car and NEVER saw a SINGLE BIT of knock at ANY point during the street and dyno tunes or during track datalogs. There is nothing wrong with getting one to be safe, but the NEED for one is determined when you start tuning.

They are not so cheap anymore because they are hard to find and getting harder. 75-80 is the going rate right now unless you find someone ditching one cheap. Good luck.

I hope this answers all of your questions.
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Old May 18, 2012 | 03:22 AM
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Thanks for a great answer I appreciate it!

That's exactly what I needed to know - if the tuner can see knock/false knock happening so I'll know if I need it or not. I don't think I will (I hope) but with the LT headers and loud *** LM1 I didn't know if guys have experienced that before.
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Old May 18, 2012 | 07:28 AM
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Originally Posted by Z28Camaro30Ann
False knock CAN be tuned out however you may sacrifice potential performance by changing the timing to eliminate the knock. The LT4 Knock Module is less sensitive and allows for more timing with less of a chance for false knock therefore you may be able to squeeze out a little bit more power or performance.

We can not tell if you "NEED" an LT4 KM b your mods. Some people will say yes, others no. In MY opinion, you only NEED an LT4 KM if you are getting false knock while tuning the car. If your tuner gets it right here he wants it and there is no knock, then there is no real need for the LT4 KM.

My SS had Heads/Cam/Intake/Exhaust and was dishing out 411 RWHP with 390 RWTQ. I had a stock LT1 KM on the car and NEVER saw a SINGLE BIT of knock at ANY point during the street and dyno tunes or during track datalogs. There is nothing wrong with getting one to be safe, but the NEED for one is determined when you start tuning.

They are not so cheap anymore because they are hard to find and getting harder. 75-80 is the going rate right now unless you find someone ditching one cheap. Good luck.

I hope this answers all of your questions.
it really doesn't have to do with tuning though. It has to do with roller rockers. Its not designed to be less sensitive its designed to filer out other tones like those of roller rockers since the lt4 came with them from the factory.
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Old May 18, 2012 | 07:54 AM
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Agreed Adam, but it is also less sensitive to the added noise you get from adding say long tube headers. The STOCK reason was for the roller rockers, but the reason LT1 guys switch to the LT4 is mainly for tuning and to prevent false readings due to interference from RR's, Headers, etc. We can squeeze a little bit more out of the motor with the LT4 module vs the LT1 module because false knock is less likely so the PCM doesnt automatically retard or advance timing on us. If there is no knock at WOT during the tuning process, no LT4 Module is necessary.
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Old May 18, 2012 | 08:22 AM
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I put in a LT4 Knock module when I did my first cam swap (with Roller rockers of course) My reasoning is GM designed it for roller rocker equipped LT4's for a reason (to be less sensitive to "noisy" RR's)....they have a lot more engineering resources and research capability than any aftermarket company and or tuner so I trust their choice to desensitize it. If the LT1 knock module was "ok" and not causing false knock why wouldn't GM "tune" the PCM from the factory and use the same old LT1 km on the LT4
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Old May 18, 2012 | 01:07 PM
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I look at it this way, it's so cheap why even ask the question... Just install it.
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Old May 20, 2012 | 05:22 PM
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Originally Posted by Jazz-LT1
I look at it this way, it's so cheap why even ask the question... Just install it.
Because I've spent probably 2 grand on this car in the last week So if I need it, sure I'll pick it up it's cheap, but if I don't, that's 80 bucks well spent on something else. Hell I got my gears installed for 100 lol.

Guess I'll find out when I get my tune done, that was my main question. Thanks for the good answers guys.
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