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Old 01-30-2011, 10:22 PM   #4 (permalink)
Unclemeaty
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Thats some great info. From what I've been looking at thus far, my timing seems to be approx 3-5 degrees less advanced than yours. Of course a CAI would help that out a bit by lowering intake temps enough to where the ECU can advance timing and hit the same temperature ATDC.

My MAF is matching your stock one thus far. I see ~4.15 at a peak from 6500-7300 rpms. That is indicated on the UpRev as 268.8 GM/S.

Check this out. Rough estimating now...

Divide gm/s by 7.5598 then multiply by 14.47 to get Airflow in CFM

268.8 gm/second = ~ 510 CFM

Using 510 CFM, I can then calculate the engine has approximately 340hp at the crank. Or I could have looked at the sticker at the dealership. LOL

To make it pretty simple, multiply CFM by .666 to get approximate HP.

To make it even simpler, multiple GM/S by 1.25 to get approximate HP at the flywheel.

For wheel horsepower, multiply GM/S by about 1.10 for 15% drivetrain loss to get approximate wheel horsepower.

From here, you can actually take the UpRev datalog CSV file and put it in Excel. From there, you take HP over RPM and place the converted GM/S data int a chart showing approximate horsepower over engine RPM (Kinda like a dyno sheet). I compared this chart with a base/stock dyno pull I did about a month ago and it is within +-5 HP for most of the range.

Now this is all asuming things about MAF and engine efficiency, but if you can raise the MAF value during your datalogs then you'll likely make a little more horsepower. About every .666 GM/S gives you ~1 BHP.

Last edited by Unclemeaty; 01-30-2011 at 11:17 PM.
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