olddodgetruck

does anyone know how to convert corected hp to uncorected? id like to know the truck in my sig put down 461 corected hp on a dynojet 248. it seems low to me.

fiveology

You would need to know the correction factor used on the dyno that day, it may say what factor was used right on your printout, or you may have to call the dyno operator and ask.

Your numbers do seem a bit low, but I have to warn you, you very rarely lose HP because of a correction factor. Unless it was an absolutely perfect day, or they were using an incorrect correction factor, your corrected numbers will almost always be higher than your uncorrected numbers.

Another thing with almost 200,000 on that VP she is most certainly getting a bit tired, that may be part of your low numbers.

HOHN

SAE correction is based on air density relative to a reference standard. I don't know what the SAE considers as standard (some correct to 59º, some to 70º, etc) with 29.92in hg barometric pressure and usually 50% humidity.

I prefer the "std atmosphere" because of my aviation education.

I good general reference short of Cf is density altitude. Many weather sites will furnish this, or at least the three info items (temp, pressure, humidity) you need to calculate it (which you can do on other sites).

SAE correction is not as precise as people want to think, even for the naturally aspirated gas engines originally targeted by SAE correction (SAE has other correction factor schedules for other applications, IIRC).

Applying these to a turbodiesel is somewhat misleading-- thus most "corrected" dyno runs for diesels tend to be inflated over reality. The more the correction (high altitude, hot air, etc)-- the more the runs tend to be off.

jh

olddodgetruck

i was actualy thinking about it and my edge box claims 120hp my injectors are 150hp so i should only have enough fuel for 485 hp. so im not that far off. it was a nice day to the sheet says.

78.94 degrees 30.27 in-hg humidity 7% sae .96

CamperAndy

Looks like you had a downward correction and most of that would be due to the higher baro pressure you had during the test.

fiveology

SAE .96 was the correction factor used that day, according to the numbers you posted above.

So... take your 461 corrected hp and divide by .96 and you come up with.....

480.2083333 HP

So... your truck made just about dead on 480 HP uncorrected.

olddodgetruck

wow so the edge comp and injectors are right on hp wise.