[Evansa22]

Originally Posted by cjperformance

Was watching som goatrope garage, and came across the method to calculate engine hp in hp tuners using engine torque value, and rpm. Wont go into details on everything talked about in that video, but I'm seeing some interesting correlations between my time I ran at the track, reverse engineering horsepower values from that time using online calculators... and using HPTuners to calculate horsepower.

I do NOT believe these numbers to be completely accurate and/or a substitution for a dyno, but what I am starting to believe is that this can be used as a measurement tool in lieu of having a dyno. What I mean is this can be useful for comparing one run to the next for improvements/changes, but I do NOT believe that the numbers represent ABSOLUTE values. So when I say I have 725 engine hp below... i dont necessarily believe I have an actual 725 hp, but it shows an improvement over prior runs.

So the interesting bit is how much the calculated value in hp tuners, before I started the tuning, correlated with the reverse engineered hp based on 1/4 mi MPH.

Calculating engine hp from my 1/4 mi MPH yielded 540 horsepower estimated at the engine. I assume this is average horsepower over the run, not peak hp.

Calculating horsepower from Engine Torque and RPM at the start of my tuning yielded a calculated approx 580 peak engine hp at the highest. Probably averaging around 540 or so over the course of the rpm range I would have been traversing. Pretty cool correlation, whether true or not.

After some of my tuning with MAF, PE, and timing, HP Tuners is now calculating 725 HP peak. This correlates with the higher MAF freq values I've been seeing as well. Ingest more air, add more fuel, burn it properly, get more hp. This is verified by seat of the pants feel.

Do I think I have an actual 725 HP now at the engine???... meh... no way to know without a track run or dyno, but what I think it shows is a clear indication of improvement in the tune.

When estimating horsepower, were you talking about maf flow also? Or just using rpm and engine torque? Rough estimate is taking your maf in lbs/min and move the decimal over one or multiple by 10, same thing. So it was showing 724 on last log you posted. Right at the 725 you stated if everything is reading correct.