LS7 crate engine crazy injector flow table

[HRD]

This is a tune file that came with a GM LS7 crate engine. The injector flow vs pressure table looks very strange to me. The flow drops way off at 58.0 psi. Any idea what is going on here? Are there any other apparent anomalies?

Thanks.

[HoP]

E67 ECU. To me it looks like it is supposed to have variable fuel pump pressure like the ZR1 does.

[HRD]

E67 ECU. To me it looks like it is supposed to have variable fuel pump pressure like the ZR1 does.

HoP, Thanks for your response. That sounds logical, but under Fuel Sys/Fuel Pressure/Pump Type, it is set to "fixed". Doesn't that mean that it is set for constant pressure pump? Also I noticed FPCM fitted is set to "No", Thanks again for any input or observations. BTW, the engine ran rich on the dyno with this tune. We changed the flow table to something more like the stock Z06 table and it ran much better.

[DSteck]

For some reason, all the crate engines I've run across have mildly hacked up calibrations. Use a factory Z06 as a starting point.

[HRD]

For some reason, all the crate engines I've run across have mildly hacked up calibrations. Use a factory Z06 as a starting point.

Thanks DSteck, We've basically been copying from the Z06 cal. You always have sound advice.

One other thing I noticed is the Dynamic Airflow high rpm disable is set to 200 RPM and the re-enable is set at 100 RPM. I guess this is to make it run in MAF only mode at all time except while cranking?

[DSteck]

Pretty much.

[Shrek]

This is a tune file that came with a GM LS7 crate engine. The injector flow vs pressure table looks very strange to me. The flow drops way off at 58.0 psi. Any idea what is going on here? Are there any other apparent anomalies?

I prefer to work in metric units for injectors & MAF. In a naturally aspirated engine the pressure (Delta kPa) will be between 400 kPa (0 in a Gen III tune) and 480 kPa (80 in a Gen III tune).

Some of the GMPP injector flow tables will have a "Z" shape. The only part that really matters begins at 400 kPa - will slope from lower left to upper right (when viewed in 2D Chart mode).

In the LS7 calibration you posted the injector flow ranges from 4.2034 g/s (400 kPa) to 4.6301 g/s (480 kPa) - extremely similar to 2007 Corvette LS2 injector flow data.

[Mike Norris]

They still have not fixed the idle speed tables. Check out the requested idle speed at 44*C (111*F) at 100 RPM. I have been fixing that one for a few years now

Mike Norris

[HRD]

They still have not fixed the idle speed tables. Check out the requested idle speed at 44*C (111*F) at 100 RPM. I have been fixing that one for a few years now

Mike Norris

Thanks for pointing that out Mike. Any other observations/suggestions?