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RX7 FD With Bosch donut knock sensor configuration and monitoring

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Hello there, I didnt found any specific information for this.

I have a bosch donut type knock sensor on my rx7 fd, I tried to configure it, but im not sur of the informations I enterred.

The second question is how to monitor it ?

I logged a session with the car driving around the neighbourhood but to be honnest, I don't understand much, being used to an Apexi Power FC display type with a gauge of knock percentage.

I join two screenshots here

http://harodarwin.free.fr/HPA/Capture.PNG

http://harodarwin.free.fr/HPA/Settings.PNG

https://www.hpacademy.com/previous-webinars/049-setting-up-knock-control-link-g4-vipec/

Typically the 4KHz narrowband channel works best for a rotary. Gain would normally be set much lower than you have - usually more like 1 or 2.

Good to know, i'll look this Webinar.

I have to set it on 4KHz even if I use a Bosch Donut Knock Sensor ? ( I replaced the Oem by this one )

http://harodarwin.free.fr/HPA/Knock.jpg

Thanks a lot !

The Bosch donut sensors are wideband, so they will operate on any combustion chamber volume and knock frequency.

The key point is that the knock frequency is dependant on the size of the combustion chamber, and not the sensor you are using.

Ok, I totally understand now, many thanks to you two :)

So, I watched the Webinar 049 concerning the Knock, great video.

I have few questions, my car is still on basemap, so I have not the possibility to street test the car to listen and definite a "normal engine noise".

I don't know if it's possible, but I ask to you Adam if you can give me some number to enter on the Knock Target Table it will be verry helpfull...

The second question, my Knock Target Table looks like a 3D table with TP% on Y axis and Engine Speed on the X, if I want a similar table like on the video, I just have to set the Y Axis on "None" ?

Thanks :)

I don't know if it's possible, but I ask to you Adam if you can give me some number to enter on the Knock Target Table it will be verry helpfull...

Unfortunately no, every engine is different and you will need to build your own target table. There are too many factors that effect the noise signature of an engine, chassis, engine mount stiffness, exhaust system and many other factors will affect how much "noise" the knock sensor sees.

The second question, my Knock Target Table looks like a 3D table with TP% on Y axis and Engine Speed on the X, if I want a similar table like on the video, I just have to set the Y Axis on "None" ?

Yes, you can turn off one axis to make it easier to tune a basic noise target.

Ok, thanks for your replys :)

Sorry I'm late to this party but I just wanted to add that in my opinion knock control on a rotary engine is a questionable technology. The reason I say this is that with stock seals you can very quickly destroy the engine if almost any level of knock is encountered. This means that first and foremost validating the knock control system is fraught with risk because in order to set the knock control up you need to induce some level of knock. Even if you could get the system setup without damaging the engine, the chances of the knock system being able to retard the timing in response to knock and save the engine are incredibly small since it's it's only going to take a very small amount of knock at high load/high boost to do damage.

No problem Andre, after learning, I understand that the best thing to do is to listen the engine with headphones.

As my Tuner friend sayed like you, I can't rest on any knock failsafe system on rotary engine, when you have any knockm it's generaly allready too late.

The fuel map is done since a few week now on the link, by the past the car was running great with an apexi power fc.

I'll purchase later something like a Phormula Knock Analyser when my Tuner friend and me will touch the Timing Map.

PS : By the way I understand I can't use this function, but I would have liked only set it properly to monitor the global engine sound, something like the knock detection on the apexi power FC, a gauge with a percentage of noise.

I just don't know what gain to set on the software to have something like that, I don't know if it's possible.

Thanks for your response. :)

It's not a bad idea to have the system monitoring engine noise for historic data purposes, or to highlight exactly when something went pear shaped. For these purposes I'd suggest just adjusting the gain until you're getting somewhere in the range of 400-600 at maximum rpm. That will give you sufficient resolution to be useful.

Ok, I'll proceed like that, thanks again !