Nistune Forums

ECUs will pull out timing after certain TP/RPM conditions when the 21 - Knock DTC is present

I have wired a headphone jack onto a stock type knock sensor, bolted it to the next available hole by the stock sensor. That plugs into the laptop mic input jack and played through the headphone output jack to my nut.
It's kinda hard to for me to zone into det while driving so when playing with timing I record the run using sound recorder (default windows program) so I can listen again when parked up.
I also have a ks4 with it's own knock sensor hooked up in case I miss the det.

Here is how it sounds, as far as I'm aware there is no det in this run.
Click the link if embed doesn't work:

Edit: didn't embed, link below.

http://soundcloud.com/immy21/timing-added-short

How does that sound compared to other electronic listening set ups?
Particularly compared to PL's super expensive DIY kit

Seems noisy to me, plan was to get some runs with det recorded then dial in an equaliser program for a cleaner sound but I might just try PL's mic in a tube insted. Not really had a chance to experiment much including finding det limit due to chasing other issues and I have not tuned any other cars so don't have anything to compare the sound clip with.

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Sounds clean to me too.

I'll try to get some recordings of what comes out of my setup. Yours sounds pretty nice to me!

PL

g

immy21 wrote: Here is how it sounds, as far as I'm aware there is no det in this run.

cool, i like this, cleaner than mine, going to make one
do have a run where you are aware of det?

i use a PL based mic rig, works well, BOV's are loud tho

sssbassil wrote:

immy21 wrote: Here is how it sounds, as far as I'm aware there is no det in this run.

cool, i like this, cleaner than mine, going to make one
do have a run where you are aware of det?

i use a PL based mic rig, works well, BOV's are loud tho

It's good to hear from you guys the sound is clean as I didn't know any better.
Oh and the sensor you are listening to is bolted above the exhaust manifold, not by the stock as mentioned earlier. It's the ks4's sensor that lives by the stock one.

As for a run with det, unfortunately not. I have been chasing a couple of problems for some time which kinda halted the progress on the map. A bad stutter only when on track, turned out to be fuel pump which has just been fixed now and a noisy DLP which stops me logging. I want to sort the DLP before I can push timing
viewtopic.php?f=33&t=1892&start=15

When I get a det run recorded I will put it up.
Stock SR20DET VVT engine.

raddy wrote:Hi there. Recently I made quite extensive testing of phormula ks-3 knock sensor on ca18det and sr20det engines. I found that with correct setting and calibration of device you can clearly find situation that predict knock onset. With lot of back testing of AFR and timing influence I found that you can use whole scale of knock level, not just clearly (audible) knock situation. I can call it how "nervous" is knock activity. As soon as you learned reaction of it to different engine situations, you can dial your timing as good as on dyno, but on the road. You can distinct between clearly non-knock situation, any transition in knock activity (without any audible results) to the clear engine knock (also often hard audible).
In summary: buy good electronic knock sensing device, learn how to use it than tune ignition at the road.

p.s. very good position for aftermarket knock sensor/microphone on the sr and ca is one of 8mm bolt threads on the head that are located just above exhaust manifold....

Hey raddy im going to purchase this system also, is it possible to log this with nistune or is it something I visually have to note what rpm I am getting knock and figure out where in the map to fix it?

Its not really possible to log that information as the feedback from those devices is not something like a knock count which can be pulled in against other RPM/load data

Matt wrote:Its not really possible to log that information as the feedback from those devices is not something like a knock count which can be pulled in against other RPM/load data

That sucks, so basically you would just have to hear the sound if your driving with headphones and look to make a note of what rpm the detnation is occuring?

Here it shows them using innovate logworks and I do have a Innovate LM-2, would it be possible then to inject the log count from this device into Nistune through the use of my Innovate LM-2?

UNISA JECS wrote:

Matt wrote:Its not really possible to log that information as the feedback from those devices is not something like a knock count which can be pulled in against other RPM/load data

That sucks, so basically you would just have to hear the sound if your driving with headphones and look to make a note of what rpm the detnation is occuring?

I can give you one simple advice: when you hear or see knock immediately close throttle and after that in nistune log you can easily find that place. So basically you are making a point in log, where you saw detonation. This is the way I did and it worked quite well. Not the best way to tune car, but still better than nothing

unex wrote:

UNISA JECS wrote:

Matt wrote:Its not really possible to log that information as the feedback from those devices is not something like a knock count which can be pulled in against other RPM/load data

That sucks, so basically you would just have to hear the sound if your driving with headphones and look to make a note of what rpm the detnation is occuring?

I can give you one simple advice: when you hear or see knock immediately close throttle and after that in nistune log you can easily find that place. So basically you are making a point in log, where you saw detonation. This is the way I did and it worked quite well. Not the best way to tune car, but still better than nothing

Thats not a bad idea, better than nothing, thank for that littel tip.

Use the space bar whilst logging to flag a knock indication in Nistune. This can be visible on playback

I spoke to one of the firms in Australia making knock sensing equipment and discussed about input into Nistune. There are many issues with reliably reporting a knock count. As you can see from the images with the knock graph, the signal indicating knock shows a deep spike. However these spikes are also produced by other engine noise and can be wrongly interpreted as knock

This is where careful adjustment and inspection of the knock signals reported by these units is required. Each engine will have its own footprint so to speak with regards to how knock is reported. Also there can be many samples in a small time frame making passing a count value to external software unreliable due to external baud rates and lining up with other information (such as RPM)

Where I have pulled the raw filtered knock count (note not all would be actual knock) in the earlier Nissan ECUs it is passed with the same consult information at that time so is the most reliable form of monitoring I can do using Nissan hardware