Injector sizing in SManager

[2x0]

I have a set of FIC 1000cc injectors, so in my base map I put 1000cc in the new injector size.

I then decided to get my injectors cleaned and flow tested before tuning, and the report shows they actually only flow 920cc.

My basic question is, before I move on to tuning dead times and maps, should I enter the 920cc as the new injector size instead of 1000cc?


Also, does this value effect the estimated duty cycle that SManager shows in the datalogs? I plan to start tuning at lower boost, then turn up the pressure until it shows duty cycle is at or above 90%, but I do not want to rely on this if the values will actually be off due to my injector flow rate.

Thanks!

[Spunkster]

You need to enter the size base on the data you are provided, but make sure that it was tested at the pressure you are running at. Also make sure you enter the correct dead times.

[2x0]

Alright, I will go with 920cc in SManager then. They were tested at 3bar fuel pressure which is correct for my setup, and I was given dead times at 13.5v but not any other voltages.

13.5 volts

2005 - 1.256 ms
2066 - 1.232 ms
2046 - 1.221 ms
2044 - 1.212 ms

Average - 1.230

So far it has been running fine on my basemap where I just guessed at dead times and adjusted them based on idle AFR, so this should be a step in the right direction for me to begin tuning.

Thanks,

[Spunkster]

You should contact the manufacturer and get the complete dead times as this is very important.

[2x0]

I understand this, and I have tried as the same company did the clean and flow test (FIC) and they are telling me they only have the numbers for 13.5 volts.

[Hondata]

Then the best you can do is to scale the dead times so the interpolated value at 13.5v is correct. eg.
0.00 8.09 10.11 12.13 14.16 16.08 24.55
2.18 2.18 1.66 1.38 1.19 1.05 1.05

[2x0]

Yeah that was my plan, though I know it is not ideal, I did not think that having a dead time off by a few hundredths of a ms would be that catastrophic.

Thanks!

[2x0]

I have now learned the importance of proper dead times through first hand experience.

I am still tuning my fuel tables in open loop, and thought I had it dialed in for low load, idle and cruising conditions. The other day after getting back into the city on a warm evening and a decent cruise on the highway, I had my headlights and my cooling fan switched on because heat soak. When I came to a stop, the car was running so lean it could barely stay idling.

What I've found is that, with no added electrical load I am usually between 14-14.5 volts, which is where I tuned my low load fuel table. Unfortunately, my dead time for this voltage must be too high.

I only have measured dead times for 13.5 volts, which is where I am at with my fan and headlights on (anywhere from 12.5-13.5v).

Since I know my numbers for 13.5v is correct, what I plan to do is retune my idle fuel with my fan and headlights on, or keeping it as close to that voltage as possible. Once I have the AFR set there, I will turn the electrical loads off and adjust dead time at 14+ volts until there is no change in AFR.

Does this methodology seem correct?

Also is it okay to change the voltages referenced in Hondata when setting these? For example I'd like to set a value for 13.5v since I know that value, and another for 14.5v since this is where I am running at most of the time. It would make it a lot easier to dial in instead of having to try and interpolate multiple values.

Thanks

[Spunkster]

You can try doing that and see how well it works.

[2x0]

It seems to have worked perfectly, thank you!