What does it mean when you say corrected or uncorrected after a dyno?

 

A lot of things can change the dyno readings - temp, humidity, and especially altitude. The computer uses a formula to correct for each variable. That way a dyno don in Denver in Jan can be compared with a dyno done in St. Louis in July.

 

how do you know if its corrected or not?

 

Usually lists both numbers. Or it will say "CF" or "Smoothing number" (usually on top right) for correction factor and only print out corrected.
Some Dynojets list HP & Torque as SAE HP and SAE TQ. These are corrected #'s only.... I believe.

Corrected numbers are adjusted to Sea Level and to STP (Standard Temp & Pressure).

RJ

 

is there a % you can do if yours is not corrected? I WISH they had a corrected number for the 1/4 mile track. It SUCKS up here. Almost a full second behind you guys.

 

No easy way...like a percentage.
What I think you need is the formula for "Density Altitude". It's actually designed to give you apparent altitude, kind of like wind chill factor for temps.
Check HERE. You will need to know exact temperature when you dynoed...and the altitude.
This may allow you to interpolate, but I never tried it!
I can tell you STP or Standard Temp & Pressure is 60*F at Sea Level (14.72psi atmospheric pressure).

 

Remember correction factors are designed for NA engines..... On our TCD engines CF really are not accurate.

Doug

 

Always wondered about that. But I dynoed at 5100' and 85* last month. They listed both corrected and uncorrected on print out.
They were considerably different (121 hp/212 ft-lbs). Corrected was spot on, IMHO?
Made 563.3/1086, corrected. (Having downgraded to Mach 4's for summer streetability)
RJ

 

I have dynoed at SL and almost the mile high and using our CTD and the uncorrected numbers were very close. ATS has had this problem in the Denver area, they dyno there and publish the numbers and then go to an event at a much lower altitude and the numbers don't come close to matching......

A turbo charged engine makes its own enviroment. Thus the reason planes use turbos, it gives them rated HP to a given altitude. Now if you are operating your turbos on the very edge of their efficiency at SL then you will see a HP loss and higher elevations due to the inability to compress the air any more.

Doug