Dyno graph autopsy - stage 2 vx220 turbo
Discussion
I don't understand the first chart - the AFR doesn't start until 4k which is when the problem started, and looks all screwy anyway. Did you speak to the operator to find out what happened and why he didn't rev it out?
The boost looks odd too - I don't think it should peak low and then drop off like that.
The boost looks odd too - I don't think it should peak low and then drop off like that.
davepoth said:
I don't understand the first chart - the AFR doesn't start until 4k which is when the problem started, and looks all screwy anyway. Did you speak to the operator to find out what happened and why he didn't rev it out?
The boost looks odd too - I don't think it should peak low and then drop off like that.
It actually starts at the left hand end of the graph, goes all the way across to the right hand end of the graph & then for some reason the graph reverses & ends where yiou think it is starting if you look a bit more closely.The boost looks odd too - I don't think it should peak low and then drop off like that.
Is that too rich, 4000rpm, full load on a lightly turbocharged engine?
Do you have any previous dyno runs since the remap?
It being 7:30 I thought at first we were trying to figure out why the torque suddenly drops to 0
Unless it was knocking I'd have revved it out, not got much to go on otherwise. No record of VVT angle or spark timing?
Do you have any previous dyno runs since the remap?
It being 7:30 I thought at first we were trying to figure out why the torque suddenly drops to 0
Unless it was knocking I'd have revved it out, not got much to go on otherwise. No record of VVT angle or spark timing?
Edited by scarble on Wednesday 18th March 07:44
Yes, with the benefit of it's not morning any more, that is hella rich.
Probably it's running open loop because power curve? So without lambda sensor feedback, meaning the fuel quantity injected will be based on MAF/MAP/modelling and a target AFR so either what the ECU thinks is the right amount of fuel to get the the right AFR is nonsense due to what the ECU thinks the amount of air going in being nonsense OR the ECU is getting the amount of fuel right but more is getting put in due to something like a stuck injector or the wrong injectors or.. high fuel pressure? Never really heard of anything like that happening.. and the third possibility, the target AFR is nonsense due to something like a dodgy remap (most likely).
But I might be way off, to be honest thinking is a bit difficult right now, I'm about ready for bed
Probably it's running open loop because power curve? So without lambda sensor feedback, meaning the fuel quantity injected will be based on MAF/MAP/modelling and a target AFR so either what the ECU thinks is the right amount of fuel to get the the right AFR is nonsense due to what the ECU thinks the amount of air going in being nonsense OR the ECU is getting the amount of fuel right but more is getting put in due to something like a stuck injector or the wrong injectors or.. high fuel pressure? Never really heard of anything like that happening.. and the third possibility, the target AFR is nonsense due to something like a dodgy remap (most likely).
But I might be way off, to be honest thinking is a bit difficult right now, I'm about ready for bed
Edited by scarble on Wednesday 18th March 21:14
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