Knock Sensor...
Moderator: Matt
Knock Sensor...
Hi all i have searched but found nothing I'm running Type 3 Board on a 91 240SX KA24DE Turbocharged.... i would like to know if there is any possible way to detect knock.... i have searched but found nothing... can anyone shine some light on this matter please...
Re: Knock Sensor...
not yet. that one is a work in progress. the ECU will respond to knocking but still trying to work out how to pull knock count from it
Re: Knock Sensor...
Hi Matt what about the SR family of ecu, any word on when knock count will be available for them?
Re: Knock Sensor...
same as the KA family. once the first 16 bit ECU is working the rest should be a breeze
Re: Knock Sensor...
Knock count was something we hoped to implement relatively quickly but it has proven very difficult. Both from a coding and bench test perspective. And every different ECU family seems to have it implemented differently - making it very difficult for Matt to sort through the code. Now this has been coupled with ever increasing evidence of the Nissan knock sensing system being unreliable anyway!
So you can see why it's priority has been lowered. I know this is frustrating for the users - trust me, I'd like it as much as anybody. But I've now reached a stage where I have very little faith in the system anyway. If I have any problems with the knock sensing system false triggering (very common) I have no qualms whatsoever in turning it off. It seems some cars are much more sensitive than others. My favourite example is my mate's S15. It was pulling timing when it was COMPLETELY standard! Once we disabled knock sensing everything was fine. Yet other S15's are fine. I've seen older SR's with lots of k's on them function quite well. But not all of them. Just when I start to gain some faith in the system again I'll get another engine that's pulling timing for no reason. I'm over it...
I think people also place too much faith in the Nissan knock sensing system. Many think it'll save them if their engine knocks at all. It just ain't true. Have a look at the IGN maps in almost any Nissan engine - turn on the flags and check just how much of the IGN map is covered by knock sensing. Answer = bugger all. Most SR's are ignoring the knock sensor above 3500 rpm. So if you get any knock once you're on full boost you're on your own!
This raises the question of why it's like this. I can only assume that there's too much mechanical noise above 3500 and the knock signal gets swamped. It'd be good to do some real world testing and enable the knock sensing in the important area - 3500 to 6500 at full load and see if it can be made to work for us. But without the ability to adjust the sensitivity I wouldn't expect to get far...
My 2c...
PL
So you can see why it's priority has been lowered. I know this is frustrating for the users - trust me, I'd like it as much as anybody. But I've now reached a stage where I have very little faith in the system anyway. If I have any problems with the knock sensing system false triggering (very common) I have no qualms whatsoever in turning it off. It seems some cars are much more sensitive than others. My favourite example is my mate's S15. It was pulling timing when it was COMPLETELY standard! Once we disabled knock sensing everything was fine. Yet other S15's are fine. I've seen older SR's with lots of k's on them function quite well. But not all of them. Just when I start to gain some faith in the system again I'll get another engine that's pulling timing for no reason. I'm over it...
I think people also place too much faith in the Nissan knock sensing system. Many think it'll save them if their engine knocks at all. It just ain't true. Have a look at the IGN maps in almost any Nissan engine - turn on the flags and check just how much of the IGN map is covered by knock sensing. Answer = bugger all. Most SR's are ignoring the knock sensor above 3500 rpm. So if you get any knock once you're on full boost you're on your own!
This raises the question of why it's like this. I can only assume that there's too much mechanical noise above 3500 and the knock signal gets swamped. It'd be good to do some real world testing and enable the knock sensing in the important area - 3500 to 6500 at full load and see if it can be made to work for us. But without the ability to adjust the sensitivity I wouldn't expect to get far...
My 2c...
PL
Re: Knock Sensor...
im willing to do real life testing if u want email me silva2786@aol.com and w/e i need to implement this into my board thanks
Re: Knock Sensor...
Instead of making a new thread I figured I'd post in here.
PL, I was going to rig up a bosch sensor on my block (RB30 w/ nistune RB20 ECU) with a laptop headphone jack to listen for knock. But i was reading the sticky that we have knock count (HCR32). Is that reliable/useful for knock detection from a tuning standpoint? Or should i still rig that mic up...
PL, I was going to rig up a bosch sensor on my block (RB30 w/ nistune RB20 ECU) with a laptop headphone jack to listen for knock. But i was reading the sticky that we have knock count (HCR32). Is that reliable/useful for knock detection from a tuning standpoint? Or should i still rig that mic up...
Re: Knock Sensor...
Matt reckons knock detection on those ECU's is a goer but I've not tried it yet. Certainly be worth a go.
You'll need to do some experimenting though. Sensitivity seems to vary and it'll obviously depend on how much mechanical noise is going on too.
PL
You'll need to do some experimenting though. Sensitivity seems to vary and it'll obviously depend on how much mechanical noise is going on too.
PL
Re: Knock Sensor...
Need knock warning panel open, and monitor knock count
It gets counter per cell in the fuel map.
Knock count display in the wideband input table is broken - I need to fix that ASAP for my next dyno test since it wasnt much use last time
It gets counter per cell in the fuel map.
Knock count display in the wideband input table is broken - I need to fix that ASAP for my next dyno test since it wasnt much use last time