re: Maruti S-Cross 1.6 Stage 3 Build: 202 HP / 438 Nm, tuned by Wolf Moto Man, your thread is a very tempting advert for a used S-Cross! Quote:
Originally Posted by d3mon These Harmonixx guys use 1.15x SAE correction factor even for turbo engines, which is not valid. SAE correction factor is only really valid for NA engines. After all, the 1-1.5PSI drop in NA engines is significant (14.7PSI to 13.xx PSI), but for a turbo engine like yours with ~30PSI of boost (for an intake manifold pressure of 40+PSI), the 1 PSI drop in atmospheric pressure is almost noise. All of their turbo dynos are vastly overrated due to this factor, even in stock form. Your true output is roughly 175-180HP / 380NM without the correction, which is still a great result. |
SAE J1349 is a pretty standard equation that is used across many countries. I don't see why there should be any confusion on the %, or rather ratio. From my experience, SAE themselves discourage a CF of over 7% for any atmospheric conditions. Of course, there are boundary conditions to 1349 - I don't think it works over 45 C for instance, since it was made for the US. There are bunch of other standard CFs from automaking countries - JIS, DIN, ISO - but since the Americans have the vast share of the popular internet, and aftermarket automotive industries, SAE specs are the most commonly used.
15%, however, is the SAE's old and gold standard for crank power vs wheel power. Are you sure that isn't the number being applied here? Personally, I think using a 30 year old measure for newer, more efficient engines is a bit much, but that's America for you.
To understand what a dyno is reading, I would compare the BSFC to the dynod hp, while metering fuel consumption as well as lambda values. This would give a more realistic indicator of the actual goings on. This, by the way, is how OEMs dyno engines. Quote:
Originally Posted by Dr.Naren IAT wouldn't affect NA cars much but it will affect the turbo charged ones. |
Where did you get this nugget from? Quote:
Originally Posted by Dr.Naren Dynapack Dyno at Arka Motorsports is the other best dyno in South India and they also use SAE correction. |
I don't understand this 'best' claim. Is there some sort of dyno comparison going around? Dynos are meant to be benchmarking tools, and I have rarely seen a 'best' or even 'better' claim going around. Also, the Germans use a DIN standard, and Japanese - from Nismo to HKS - use JIS corrected dynos, not SAE. There is no 'better', merely the right tool for the job. Quote:
Originally Posted by Dr.Naren Anyways our major objective was to compare the gains and the dynojet dyno at Harmonixx was giving consistent results in every run. |
Nice! This is the true use of a dyno - baseline / benchmarks followed by testing for gains. Anything else is futile, and for this, the dyno has to be consistent. |