The Diesel Garage banner

1 - 3 of 3 Posts

·
Senior Member
Joined
·
1,130 Posts
Discussion Starter #1
Everyone here should read this guy's post and some of the answers. It is pretty in depth regarding Dyno's and SAE correction factors.

Two things jumped out at me:

Turbocharged cars need not apply. The use of the standard SAE air density corrections for turbocharged applications is plain wrong. As stated in the standard, without any need for additional clarity, “For example, boosted engines with absolute pressure controls shall not be corrected for ambient barometric pressure”. It need not be any clearer. You will notice by the way that all of the PDXTuning posted data is non corrected. Further in the document, the use of intercoolers is discussed, and there are changes to the air temperature corrections based on the efficiency of these intercoolers.
AND

Using a correction factor of more then 6% total (3% air and 3% fuel) is considered non standard. This is VERY important. Consider that every line of text in this standard has undergone significant review and discussion. This section is very clear for a reason. To help understand this issue, I’ll make the case for it below.
He cites his source out of the SAE1349 Standard that describes Correction factors.

Without further rambling from me here is the link:

Proper use of dyno correction factors (a must for those professional tuners)
 

·
Senior Member
Joined
·
2,334 Posts
tgatch said:
Everyone here should read this guy's post and some of the answers. It is pretty in depth regarding Dyno's and SAE correction factors.

Two things jumped out at me:



AND



He cites his source out of the SAE1349 Standard that describes Correction factors.

Without further rambling from me here is the link:

Proper use of dyno correction factors (a must for those professional tuners)
i can easily see where the correction factors for a turbo'd engine mean nothing really. when you compress air it gets hot... its not rocket sciece... and with an intercooler it changes it a little bit me... hmm good find there tom
 

·
Senior Member
Joined
·
1,130 Posts
Discussion Starter #3
Thanks. I thought that it might clear up some things up.

Now, there may need to be SOME correction factor for a turbo charged engine, but NOT the SAE correction factor. SAE Correction is designed to be applied to N/A engines. Tadd and Robert both have run faster 1/4 mile times at lower altitudes.

Our next Dyno event here in Idaho is in August. I will be running twice, once in the morning and then later in the day. I will get both SAE AND uncorrected graphs. I know that our last event varied the CF between 9 and 11% based on the time of day. I want to see if my Uncorrected changes as the temp outside increases. I'm willing to bet that it doesn't change much if at all. But say I am putting down 391 uncorrected. This last dyno event could have had me at 426 or 434 depending on when I dynoed that day.

I also know that the Dynojet we are using can't load us up very well. There was a cummins truck that was there with twins on it that only put down like 675 at our event. This same truck put down over 800 at an event in Washington earlier this year. I assume that the place in WA is pretty respectable because Maddog was there and took top honors at that event at over 1,000HP.
 
1 - 3 of 3 Posts
Top