defjux23 Posted August 19, 2021 Report Share Posted August 19, 2021 Hello all! I have a Garrett GTX3582R Gen II turbo with a 10 blade compressor wheel. According to Garrett, their turbospeed sensor outputs at 1/8th input frequency. Using the Link provided equation, I set my calibration to 7500 and now turbospeed reads extra high on our AIM Dash, for example 93 rpmx1000 at idle. I've checked my CAN multipliers and everything is set to 1. Seems like everything should be right, what am I doing wrong here? Dan Evo Before Dyno.pclr LINK_Pro Awe Thunder_@20190316_075205_007515.xc1 PDM32 Pro Awe V1.7.zconfig Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 19, 2021 Report Share Posted August 19, 2021 I assume it reads correctly in the ECU? The ECU set up looks ok. The Turbo RPM is sent out at 10X real as it has a resolution of 0.1, so maybe you dont have a divide by 10 set up in the dash/pdm? Quote Link to comment Share on other sites More sharing options...
defjux23 Posted August 19, 2021 Author Report Share Posted August 19, 2021 Thanks! Quote Link to comment Share on other sites More sharing options...
dx4picco Posted August 19, 2021 Report Share Posted August 19, 2021 Question on that one too, if the max turbo speed ist 165k and like its shown has a built in divider, I will need another external divider, is that correct? because at full turbo speed frequency would be 2750Hz? Quote Link to comment Share on other sites More sharing options...
Adamw Posted August 19, 2021 Report Share Posted August 19, 2021 Yes Turbo RPM will usually exceed the frequency limitation on the general G4+ DI's, however the OP has a Thunder so he can always move the pin to one of the High speed DI's. dx4picco 1 Quote Link to comment Share on other sites More sharing options...
defjux23 Posted September 15, 2022 Author Report Share Posted September 15, 2022 Adam, Bringing this back from the dead. We are wanting to move the turbospeed to DI 15. Do we run the input to the + and ignore the - or do we ground the -? Thanks! Dan Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 15, 2022 Report Share Posted September 15, 2022 Leave the -ve unconnected. defjux23 1 Quote Link to comment Share on other sites More sharing options...
defjux23 Posted September 15, 2022 Author Report Share Posted September 15, 2022 Many thanks! Quote Link to comment Share on other sites More sharing options...
defjux23 Posted September 16, 2022 Author Report Share Posted September 16, 2022 Adam, We've switched and not getting any reading from either DI 15+ or DI 16+. We switched back to DI 3 and it worked as expected. We've ensured we turned on the new DI to Turbospeed and disabled DI 3. Any thoughts? Dan Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 17, 2022 Report Share Posted September 17, 2022 Is it on 5.6.8 firmware? You could try connecting the DI-ve to gnd but it shouldnt be needed. defjux23 1 Quote Link to comment Share on other sites More sharing options...
defjux23 Posted September 17, 2022 Author Report Share Posted September 17, 2022 6 hours ago, Adamw said: Is it on 5.6.8 firmware? You could try connecting the DI-ve to gnd but it shouldnt be needed. Sure enough, we were out of date. We will update. Thanks! Dan Quote Link to comment Share on other sites More sharing options...
defjux23 Posted September 17, 2022 Author Report Share Posted September 17, 2022 We updated the firmware and the turbo speed would read for a few seconds and then go to zero. We grounded the DI- and no luck, same issue. By happenstance, our mechanic held the DI- wire in his hand and all of a sudden the turbo speed started to read properly. After talking with an electrical engineer friend, we decided to try the smallest capacitor we had, 104 picofarad, from DI- to ground and now the turbo speed reads properly. Thoughts? Dan Quote Link to comment Share on other sites More sharing options...
QE1984 Posted September 22, 2022 Report Share Posted September 22, 2022 @Adamw, I'm the mechanic that was working on the car with defjux. The turbo speed works fine on DI15 with DI- grounded through the capacitor. I have no problem leaving it this way if it's working, I just want to make sure it isn't an indication of something wrong with the wiring in general, whether that be poor grounds, power supply issue etc (all have been checked to the best of my ability). To reiterate, the same wire going into DI15+ was working fine on one of the lower speed DIs, but would overrun the frequency limit around 57k turbo speed. The rpm reading at idle is the same on the high speed input as it was with the low, so for now it seems to be functioning. Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 23, 2022 Report Share Posted September 23, 2022 I dont see any harm in leaving the cap there. I dont know enough about how the differential DI circuit works to offer an explanation of the cause. Just I have seen turbo speed connected to those DI's in the past with nothing special required. But if it works and continues to work under normal operating conditions that I would be happy. Quote Link to comment Share on other sites More sharing options...
QE1984 Posted September 23, 2022 Report Share Posted September 23, 2022 Ok, copy that. Thanks. Quote Link to comment Share on other sites More sharing options...
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