Road tuners...come in. Delivered Engine Torque Confusion....

[SVT_Z06]

Road tuners,

What is the best measurement for an indication that you're making more power?

Delivered Engine Torque?
Gram per Cylinder?
Dynamic Air?

The reason I ask is because this morning, I had a rich pull, (12.0 ? 12.3 AFR), and the numbers were significantly higher than with a leaner pull (12.7-12.8). Same day, same temps. Richer AFR's seem to give higher DET's. But I feel as if the leaner pulls are faster? I know the DET numbers are based on certain calculations (MAF, VE), but I'm confused.

Shouldn't these number only be higher when you are making more power?

DynAir and ClyAir is higher too?..with richer AFR's.

When you command richer AFR's do DET's increase? This seems to be the case, because leaner, they decrease.

This is on a N/A vette.

I?m wondering if making and Acceleration Rate math will work since it won't take MAF, VE, Timing into consideration.

[MikeOD]

The numbers are only really meaningful if the VE/MAF is correct...if you add 10% to the VE/MAF table, then the air numbers will increase because the computer thinks more air is coming into the engine, but you'll also see 10% error in actual AFR vs commanded AFR.

So if you calibrate the MAF and VE accurately and see very little % error between commanded and actual AFR, then as you change things and see more airflow, it's a good indication that you're making more power unless you have the timing way off. Use the PE table to change the commanded AFR, not the injector flowrate or the VE/MAF and you'll see what I mean.

[SVT_Z06]

Thanks for the explination. Completly makes sense.

Initially, if commanded AFRs match actual AFRs, and MAF/VE are correct, then if airflow increases without messing with IFR, MAF and VE, then that's a good indication that you're making more power.

At this point, changing PE to change AFRs instead of MAF, airflow values won't change. Does that sound correct?

[SVT_Z06]

Thanks for the explination. Completly makes sense.

Initially, if commanded AFRs match actual AFRs, and MAF/VE are correct, then if airflow increases without messing with IFR, MAF and VE, then that's a good indication that you're making more power.

At this point, changing PE to change AFRs instead of MAF, airflow values won't change. Does that sound correct?

I guess airflow may rise by changing PE too...if you're making more power...

[MikeOD]

Sorry, didn't see your reply, yes as you find the right AFR and timing the engine will be stronger and pull more air through, but again if you've got what measures that airflow calibrated correctly, then when you see more, you can tell you're making more power.