Anyone have any thoughts on relocating the Knock Sensor as described in this NissanPerformanceMag article?

 

waste of time... how hard do you drive your car? Their last comment ... This is probably one of the cheapest ways to free up some horsepower is a crock. It'll 'free up some hp' ONLY if the knock sensor was detecting knock when there was none and retarding timing when it shouldn't.

do it if you have time but don't expect noticable/measurable gains. Or even better, dyno then do it and "give the ECU a couple days to adjust" and dyno again and see if they're right.

 

That is exactly the premise they stated at the beginning of the article.

Question is, does the Maxima KS detect valve train noise (or other noise and vibration) and interpret that as knock. Sometimes I wonder if it does due to the somewhat erratic, surging nature of my Maxima's acceleration.

 

I think it does. IMO, aftermarket Y-pipes are probably the biggest contributor to false knock because of their shorter than stock flex sections, more vibration is sent back thru the motor and possibly detected as knock. All aftermarket y-pipes introduce slightly more vibration thru the pedals and cabin (minimal), which ends up goes back to the motor.

In our LT1 F-Bodies, we use to swap in LT4 (Corvette GS) knock sensors (LT4 had a less sensitive sensor) because our headers, y-pipes, and catbacks introduced more vibration thru the motor.

Would I recommend relocating your knock sensor? No way. It's just too dangerous for the 3-5 fwhp you might see. I suggest loosening the 12mm knock sensor bolt and then retorquing it just so that it's tight. The FSM calls for about 20-25 ft/lbs of torque. Try 10-12 ft/lbs and see how it runs. The idea to reduce some of the sensitivity.


Dave

 

I read the whole article and stand by what I said: "but don't expect noticable/measurable gains", backed by Dave B: "Would I recommend relocating your knock sensor? No way. It's just too dangerous for the 3-5 fwhp you might see."

 

i agree.. yeah its a cheap mod, but whats cheaper.. wires to relocate or a new engine?

but for three hp... might as well go for plain ol boost.

 

It's good you stand by what you said, because you basically repeated what the article stated from the beginning.

As for it being dangerous, I just don't see it. The purpose of the KS is not to prevent detonation under any and all circumstances, it just allows us to use lower octane gas in an engine optimized for 91 octane. If you're boosted or juiced, you're a fool if you're relying on the KS to keep detonation under control.

 

Dave KS are piezoelectric sensors. They detect high frequency noise, not vibrations. Unless the valvetrain makes very high frequency noises, I doubt it would be picked up by the KS.