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where to get a LT4 knock sensor

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  • where to get a LT4 knock sensor

    I remember reading that a LT4 knock sensor will help you keep some horsepower on Lt1's(by reducing false knock readings?). Well any way, can you only get them at a dealership. If so, how much does it cost. Thanks, Ryan.
    2006 Saturn Ion Redline
    2003 Mits. Eclipse Spyder

  • #2
    Forget about it. It won't help you. That was a popular mod 5 years ago, but it has since been disproven as a knock desensitizer. One thing that has been found to help, assuming EVERYTHING else is OK with your car, is 10W-40 oil for those who are currently using 10W-30.

    But, they were about $30-$34 at the dealership and some guys bought them a little cheaper.

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    • #3
      Originally posted by Kevin - Blown 95 TA
      Forget about it. It won't help you. That was a popular mod 5 years ago, but it has since been disproven as a knock desensitizer. One thing that has been found to help, assuming EVERYTHING else is OK with your car, is 10W-40 oil for those who are currently using 10W-30.

      But, they were about $30-$34 at the dealership and some guys bought them a little cheaper.
      Wow..... that's news to me. I tested mine extensively when I installed it in 1998 and it reduced knock retard. I guess I'm really out of touch with the LT1 these days. And I guess GM was completely off base when they determined it was necessary to prevent false knock retard from the Crane Gold roller rockers they put in the LT4 engine.

      Its a filter and it works on certain mechanical noises that are know not to be knock. I would agree that the LT4KM has an endeserved reputation as a pancea for loud exhausts and other imagined problems, but as far as I know, it is effective in filtering the noise signature of the Crane RR's and simialr products.

      Easy way to determine if it might help you is to put a scanner on the PCM and see if you are getting any knock retard at all, and if you are, determining if its real knock or false knock.

      If your still interested, they are about $65 at your local dealer, maybe $45 at some LT1 parts specialists (still a GM part) and around $30 from one of these sources:

      http://shbox.com/1/4th_gen_tech2.html#Dal_and_Jason

      And one clarification.... its the LT4 knock module, not the LT4 knock sensor. The LT4 was OBD-II and used the same high resistance (100kohms) knock sensor as the OBD-II Corvette and F-Body LT1 engines.
      Fred

      381ci all-forged stroker - 10.8:1 - CNC LT4 heads/intake - CC solid roller - MoTeC engine management - 8 LS1 coils - 58mm TB - 78# injectors - 300-shot dry nitrous - TH400 - Gear Vendor O/D - Strange 12-bolt - 4.11's - AS&M headers - duals - Corbeau seat - AutoMeter gauges - roll bar - Spohn suspension - QA1 shocks - a few other odds 'n ends. 800HP/800lb-ft at the flywheel, on a 300-shot. 11.5 @ 117MPH straight motor

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      • #4
        Originally posted by Injuneer
        And one clarification.... its the LT4 knock module, not the LT4 knock sensor. The LT4 was OBD-II and used the same high resistance (100kohms) knock sensor as the OBD-II Corvette and F-Body LT1 engines.
        Will the knock module work on an OBD-1 vehicle?
        2006 Saturn Ion Redline
        2003 Mits. Eclipse Spyder

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        • #5
          Originally posted by ryan34
          Will the knock module work on an OBD-1 vehicle?
          Yes. I have a scanner and I monitored the knock counts on mine when I changed my sensor. The LT4 knock module seemed to reduce the knock counts on mine.
          2002 Electron Blue Vette, 1SC, FE3/Z51, G92 3.15 gears, 308.9 RWHP 321.7 RWTQ (before any mods), SLP headers, Z06 exhaust, MSD Ignition Wires, AC Delco Iridium Spark Plugs, 160 t-stat, lots of ECM tuning

          1995 Z28, many mods, SOLD

          A proud member of the "F-Body Dirty Dozen"

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          • #6
            Well, the reason I posted what I did was because several of us on the LT1 Edit list had run these for a couple years like everybody else and ended up putting the LT1 module back in. Five years ago, it was the mod to do, and it made a lot of sense at the time, no one really questioned it being an OBD2 part. We have been programming & tuning the OBD1 PCM for the last 6 years and spent a lot of that time trying to troubleshoot phantom knock retard and burst knock, and no one ever really solved the problem. We think there's code in there that the software authors never found. Everything under the sun was tried. A lot of the guys tries the knock desensitization circuit and others just tuned it out altogether. Some guys ended up leaving a few degrees of retard programmed in just to use as an indicator. Some even had worse knock retard with the LT4 module, for me it just didn't make a difference. I swapped it back and forth last year when I was tuning the engine and It didn't make a difference one way or another. If it helps ya, great, but there's probably another reason for your knock, and there's going to be some knock retard you may never be able to get rid of. There's a crapload written about it by more knowledgable people than me in the 84 megabytes of LT1 Edit archives out there on the internet. It's nice to see they've doubled in price - Maybe I'll wait til they get up to $100 and unload mine

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            • #7
              wasgonna say Jason Cromer but someone posted it already. Cheapest nicest guy to deal with for GM parts
              http://www.stealthperf.com
              http://www.projectgangreen.com

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              • #8
                Originally posted by ryan34
                Will the knock module work on an OBD-1 vehicle?
                Yes, it will work with OBD-I or II.
                Rob B 95Z A4 Tech Page (Part numbers / locations, how to's, schematics, DTC's...) Home Page - shbox.com

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