LT4 LT4 Knock Sensors

[Hib Halverson]

Hello CAC members-
There is an urban legend I hear quite often about the knock sensors used on the 1996 LT4 engines. Supposedly, they have different (perhaps less or more narrow banded) sensitivity than other KSes used in Gen 2 engines.

Has anyone here replaced the KSes on an engine other than an LT4 with LT4 KSes in an attempt to reduce the amount of "false" knock retard incidents do to valve train noise?

Was your attempt sucessful?

How did you validate that sucess?

 

[aboatguy]

Hello CAC members-
There is an urban legend I hear quite often about the knock sensors used on the 1996 LT4 engines. Supposedly, they have different (perhaps less or more narrow banded) sensitivity than other KSes used in Gen 2 engines.

Has anyone here replaced the KSes on an engine other than an LT4 with LT4 KSes in an attempt to reduce the amount of "false" knock retard incidents do to valve train noise?

Was your attempt sucessful?

How did you validate that sucess?

It's not the LT4 knock sensor but the LT4 knock module that is programed/designed to be less sensitive. On some engines the LT1 knock module is too sensitive and it will signal to retard your ignition, after the installation of roller rockers. The LT4 module was designed to be less sensitive to roller rocker noise.

Some modified LT1s don't have the problem with spark retard after roller rocker installation.


It is easy to verify whether you need to change your module by data logging your engine and watching the knock count and track the timing settings(you can watch and see when the system is retard the timing!
So to validate success you datalog after the installation and see if the knock count dropped and that your timing is not getting retarded.

Mike

 

[Louis Bartay]

You also might try moving the MAF sensor from the bellows in front of the throttle body to the air filter box. Mid America has the kit with a new sensor and your computer will read cooler air temp and this may help some too.It was cheap ($25.00) and here in Texas it gets really hot in stop and go traffic. I also got the under the throttle body water kit so no hot water passes thru the throttle body. Hope this was a help.

 

[Tom B Hargrove]

After I put 1.6 full roller rockers on my 95, I changed the knock module to the Lt4 one. No difference. I changed back to the original one to check, and still could detect no difference between the two. Quarter mile times did not change.

 

[Louis Bartay]

After I put 1.6 full roller rockers on my 95, I changed the knock module to the Lt4 one. No difference. I changed back to the original one to check, and still could detect no difference between the two. Quarter mile times did not change.

Did you reprogram the computer? The LT4 has a different program than the LT1. Kenny Brown or one of the other tuners can do this while your car is on their dyno.The best way unless you have the software and a lap top PC and make changes on the fly.Still guessing as no air/fuel ratio meter.But I have read that some Vette owners that had a 95 and swapped the complete top end from a 96 LT4 and they finally got the bugs out. Or try to find a used LT4 computer.OBDII computers are touchie when changes are made.