SAE correction is important to standardize the horsepower and torque readings, so that the effects of the ambient temperature and pressure are removed from the readings. The SAE standard corrects power to reference conditions of 29.23InHg(99KPA) of dry air, at sea level, and 77 deg. Farenheit (25 C). Without this correction, on a 400 hp motor, you can be up or down 20-30 hp just from a 10 degree difference in ambient temps. Just like Phil's charts above, uncorrected at 65 degrees F, his car puts out 363 HP at the wheels, but SAE corrected, is 341 HP.

Dyno operators, on a cold day sometimes show and give the owner a printout of uncorrected values because it makes the owner feel great that he has a much more powerful car than it really is.

Dynojets are one of the few dynos that have a weather station to perform the correction. Others such as Dynapack, Mustangs and such don't usually have them unless the owner added one as an accessory.

 

i have all the weather data on the page, so Ill post it when I get home.

 

One other thing I forgot to mention is that Motronic uses an air temp sensor within the Bosch HFM5 MAF sensor to measure ambient intake air temperature, which it uses to apply a trim value against the preprogrammed ignition tables. As the ambient air temps rise, the Motronic system trims back the overall ignition timing to provide a margin against knock. Therefore even if you apply SAE correction, if you dyno your car on a cold day, the Motronic system will allow you more ignition timing and thus your car will output more power than on a 100 degree day.

 

ok, I left my sheets elsewhere, but yesterday it was right around 70 degrees and pretty low humidity...just fwiw.

 

- thought "my" data may be useful for you
- posted this info 12 months ago on another board
- my car was running 94 canadian octane with 10% eth
- my car seems to run much leaner than yours (more like the cupcar at 13.3 in stock form) - with fvd software they run it a little richer at times and a little leaner at times

http://forums.rennlist.com/rennforum...7gt3north+dyno

 

Dynojet's result is slighltly higher than others. You should dyno your car on dyno dynamcis and mustang dyno also. This will give you a better vision and a median HP.

 

^^I dont think I care enough to get down to the nitty gritty...thats just where it was at that day and thats fine by me...haha. FWIW, a new viper (07) put down 440 rwhp or so the same day...just for a little comparative data./