92lt1vet

I see there is alot of people that have done the lt1 to lt4 knock module swap whats the gain and reason for this and is it really worth it?

clf93lt1

i dont think you can do it on a 92 or 93

BAM92

For the later models that modify to roller rocker and such, there is a chance the computer will "hear" the extra noise from the rockers and think it is a knock and prematurely retard the ignition therefore losing hp. I am sure others can describe this better than me.

92lt1vet

ok sounds good guys looks like i dnt have a choice but to not do the mod since i cant thanks for the help guys

69427

Your description is essentially correct. (I was the ESC calibration engineer for the LT1 engines.) The ESC electronics are calibrated to deal with a particular noise signature (knock frequency, background noise frequencies, amplitudes and durations) of each engine combination. There's a lot of work involved dialing in the electronics to respond well to the knock frequency (low level detection is always the goal), but not be fooled by noise sources that emit a broad, or even narrow, spectrum of frequencies that overlap the knock frequency. When the background noise contains a lot of frequency content equal to the knock frequency, then quite often (and only as a last resort) the only choice is to set the detection threshold higher so that the non-knock component at the knock frequency won't be recognized. The down side is that low level knock will not be identified and acted upon.
Changing the module on a modified LT1 might reduce the instances of false triggered timing retard, but won't be of any real benefit in an engine that is not experiencing falsely triggered retard.
(Full disclosure: I was not the calibration engineer on the LT4. Despite the opportunity to put additional hundreds of WOT miles on Corvettes I didn't have to pay for, I got tired of living out of a suitcase, and eventually transferred back to my original design group.)

steven mack

I have a 85 vette with forged pistons they knock a little when cold and also roller rockers do you think I can use the lt4 module?Is the module the one that goes in the block ?Thanks

Red Sleeper

I've got a big cam with lots of unwanted noise. I had to turn off the knock retard. It's been off for 4 or 5 years now. With DIACOM connected i can still see the knock happen but it doesn't return the timing.

STL94LT1

No and no.

The LT4 knock module plugs into the lower side of the 94-96 PCM's.

BrianCunningham

My LT1 module was pulling out 5deg of timing due to my exhaust confusing it. The LT4 module stopped doing it.

black85

There is a different one for the '85. I put it on when I got longtube headers. Gm part #16126761 $61.84 (what I pd. at Chevy dealer). List is $88.32. Whatever that means.

Dave

larryfs

I brought one and never used it.
I will sell it at the GMpartsdirect price, and I'll cover shipping.