Lets start a load value thread

[QWKSNKE]

bringing this old topic back up.

Eric and I were discussing load values the other day and his SCT book actually mentions that higher the load the more efficient the motor is. Now I am assuming that the book is referring to power and not fuel economy. I'll start another thread about that.

[93Cobra#2771]

Yes, if you are achieving a super high load, that means you are performing at the motor's max (or close to it) efficiency.

For example, blown combos will hit high 100's low 200's, while us n/a h/c/i guys feel good in the 130's or so...

[Wicked]

130 sounds high for an NA car.

Is your Pro-M cal'd for other-than-stock injectors?

[Wicked]

Originally Posted by QWKSNKE

bringing this old topic back up.

Eric and I were discussing load values the other day and his SCT book actually mentions that higher the load the more efficient the motor is. Now I am assuming that the book is referring to power and not fuel economy. I'll start another thread about that.

Thats exactly right.

200% load means you are moving 200% of the air that should flow through it at ambient pressure. My load hits 170%(when the maf pegs at 4960) which means I am moving 70% more air than I would be if I was sucking atmospheric air.

[Doug904]

One more small thing about load at idle, don't forget that when you adjust the CID to bring the load into the correct range at idle that you also adjust the MAF transfer and the a/f ratio in doing so. SO when you do this remember to readjust the short term fuel trims first and then check your WOT a/f's as well.

High load at idle can cause poor idle conditions and even surging.

Later, Doug.

[93Cobra#2771]

My ProM is cal. for my stock 24's, but with the X3Z. Been a while since I looked at one of my load datalogs, so I may be off a little bit on my numbers.

[QWKSNKE]

Originally Posted by 93Cobra#2771

My ProM is cal. for my stock 24's, but with the X3Z. Been a while since I looked at one of my load datalogs, so I may be off a little bit on my numbers.

yeah you shouldn't see more than 100% n/a. Realistically an n/a car probably will not see much over 80%

[Doug904]

Originally Posted by 93Cobra#2771

My ProM is cal. for my stock 24's, but with the X3Z. Been a while since I looked at one of my load datalogs, so I may be off a little bit on my numbers.

Ahhh, then you need to scale your load to correct for the calibration factor by the Pro-M.

Do this, divide your stock injector size by the calibrated injector size and multiply your engine displacement by this value.


So you would do this 19/24 = .7916 x .0016655 = .001310 and this is your new engine displacement value because of the way the Pro-M is calibrated. This should correct your load value or get you very close, this is for a 302 size engine.

Then go back to your base load and fuel trims and adjust everything from there up.

Please excuse this if you've already done this or know this as I'm just trying to help.

later Doug

[Sendero]

Originally Posted by QWKSNKE

yeah you shouldn't see more than 100% n/a. Realistically an n/a car probably will not see much over 80%

Maybe Eric could chime in on this, but what is his load under WOT. I am curious to see if Ford keeps the load range between 15% and 100% on the factory boosted vehicles.

[Wicked]

Originally Posted by Doug904

Ahhh, then you need to scale your load to correct for the calibration factor by the Pro-M.

Do this, divide your stock injector size by the calibrated injector size and multiply your engine displacement by this value.


So you would do this 19/24 = .7916 x .0016655 = .001310 and this is your new engine displacement value because of the way the Pro-M is calibrated. This should correct your load value or get you very close, this is for a 302 size engine.

Then go back to your base load and fuel trims and adjust everything from there up.

Please excuse this if you've already done this or know this as I'm just trying to help.

later Doug

Its a 93 Cobra, 24's were stock.