Knock level limited?

[iecku.tavea racing]

Hey

 I am currently tuning a MR2 [MR2 V2-3 #TST205 latest firmware] with a 10mm bosch knock sensor.

I was trying to adjust the gain of the knock channel so that all cylinders are running around max. 4-500 under normal conditions.

But it seems that all recorded levels above 400 are cut down to 400. Typical max values are 1000!

Using a very low gain [max levels below 400] i see the typical rising curve of a knock sensor on a normal operating engine.

I haven´t had this problem on other 3sgte´s with a link g4+ before and can´t find any setting which will cause this problem.

Heiko

[Brad Burnett]

please post a copy of your cal file.

[Simon]

That sounds like the output of the sensor is too strong and is saturating the input to the ECU. 

This could be a really noisy engine or the sensor is to sensitive. Likely only option will be to use a different sensor.

[iecku.tavea racing]

Hey Simon,

thanks for the reply. I was also thinking that the sensor could be the reason as this is the only part which is different to the other engines before. I am going to try a different one! But i think it is a bit strange that it cuts straight at knock level 400 as i thought the gain is done by internal knock detection.

I attached the log and the tune with the low gain setting. I stopped the dyno session after that as there were too much other problems with the car.
 

dyno knock level issue verly low gain.pclr

dyno very low gain.llg