Minimum IPW
Aug 18, 2010, 08:30 AM
#34
Tephra, yeah I just thought I would point it out since it might be useful for some people.
http://www.injectordynamics.com/ID10...%20(43.5%20psi)
If you look at the linearity deviation chart, you could effectively use that table to linearize the injectors at low IPWs. I would bet that is exactly what this table was meant to do, so if the information is available (people using EV14 injectors) they could use the table as intended and properly compensate for the injectors to produce a linear IPW output.
So far, I've been using the exact latency values and scaling off my IDC1000s and they have worked out great under most conditions. I have noticed some small issues at low pulse widths, maybe this table will correct for the issues.
I have emailed T1racing to see if I can get some tabulated values from that graph so i can adjust this table accordingly.
http://www.injectordynamics.com/ID10...%20(43.5%20psi)
If you look at the linearity deviation chart, you could effectively use that table to linearize the injectors at low IPWs. I would bet that is exactly what this table was meant to do, so if the information is available (people using EV14 injectors) they could use the table as intended and properly compensate for the injectors to produce a linear IPW output.
So far, I've been using the exact latency values and scaling off my IDC1000s and they have worked out great under most conditions. I have noticed some small issues at low pulse widths, maybe this table will correct for the issues.
I have emailed T1racing to see if I can get some tabulated values from that graph so i can adjust this table accordingly.
Last edited by 03whitegsr; Aug 18, 2010 at 08:33 AM.
Aug 18, 2010, 09:12 PM
#35
tidbits
- On the 8859, 8858, and 8857 ROMs, the factory IPW min is 1.024 ms (assuming a scaling of 8*32/1000 for that limiting value).
- 03white is right about the adder for the FPW.
Thinking about this a bit, injectors with high latency will be less likely to run into the IPW minimum value, so that may be one reason why the high Z injectors tend to idle better. However, the really big high Z injectors are going to have issue with the FPW floor value table.
- 03white is right about the adder for the FPW.
Thinking about this a bit, injectors with high latency will be less likely to run into the IPW minimum value, so that may be one reason why the high Z injectors tend to idle better. However, the really big high Z injectors are going to have issue with the FPW floor value table.
Last edited by mrfred; Aug 18, 2010 at 09:14 PM.
Aug 18, 2010, 09:16 PM
#36
Yes thats the bit that 0x114 or 0x104 gets compared to right?
Either way the FINAL IPW minimum was 1.28 (or 1.024 for some models as you point out)
so by reducing that limitation we are finding idle AFR for big injectors is much improved.
on the ID2000's are at a minimum of 1.128ms at the moment, anything lower and idle is unstable (as opposed to 1.28ms)
Might need to go higher on 1.128ms still thou
Either way the FINAL IPW minimum was 1.28 (or 1.024 for some models as you point out)
so by reducing that limitation we are finding idle AFR for big injectors is much improved.
on the ID2000's are at a minimum of 1.128ms at the moment, anything lower and idle is unstable (as opposed to 1.28ms)
Might need to go higher on 1.128ms still thou
Aug 18, 2010, 09:34 PM
#38
ID states at 0.495ms @ 43.5psi @14v
I have 0.75 ish.
IPW I am recording is hovering around/above minimum @ idle...
If you lower the minimum too much you get misfires and extreme lean condition.
So we are slowly increasing it (0.008ms at a time) to find where the injectors behave
I have 0.75 ish.
IPW I am recording is hovering around/above minimum @ idle...
If you lower the minimum too much you get misfires and extreme lean condition.
So we are slowly increasing it (0.008ms at a time) to find where the injectors behave
Last edited by tephra; Aug 18, 2010 at 09:36 PM.
Aug 18, 2010, 09:54 PM
#39
ok, so all you're doing is lowering the floor value as much as possible while still having a steady idle. In reality though, the injectors would like to have a lower FPW than what is dictated by the floor value that you are using. In this situation, I don't think you'll ever be able to fully dial in the idle fuel trim. I guess it will idle ok though.
If you really want to nail down the correct latency and scaling, another approach might be to jack up the idle rpm enough to the point that you're above the min FPW that the injectors can do. Key would be to make sure that the MAF Hz still falls within the idle fuel trim zone. Or alternatively, just use the T1's latency values, and set the scaling based on cruise conditions.
If you really want to nail down the correct latency and scaling, another approach might be to jack up the idle rpm enough to the point that you're above the min FPW that the injectors can do. Key would be to make sure that the MAF Hz still falls within the idle fuel trim zone. Or alternatively, just use the T1's latency values, and set the scaling based on cruise conditions.
Aug 18, 2010, 11:56 PM
#41
WHAT THE FU6K
The latency algorithm for EvoX isn't using 0x18 for the multiplier, it's using 0xF
So x*0.024 as the raw -> latency is wrong.
So for CZ4A the calculation should be x*15/1000
And if I put that into my scalings for these ID2000's they CLOSELY match the latencies from ID!
HRMMM
The latency algorithm for EvoX isn't using 0x18 for the multiplier, it's using 0xF
So x*0.024 as the raw -> latency is wrong.
So for CZ4A the calculation should be x*15/1000
And if I put that into my scalings for these ID2000's they CLOSELY match the latencies from ID!
HRMMM
Aug 19, 2010, 04:34 AM
#44
I ran into some issues utilizing the IPW minimum patch, last night...
When I couldn't get the car to start on the 2000s, I put my ID1000s back in and set the IPW minimum back to 1.280 as it was stock, and the car still would not start. I went back into the XML and deleted the scaling, and coding for the patch and the car then fired right up... any insight to this problem?
When I couldn't get the car to start on the 2000s, I put my ID1000s back in and set the IPW minimum back to 1.280 as it was stock, and the car still would not start. I went back into the XML and deleted the scaling, and coding for the patch and the car then fired right up... any insight to this problem?