Quote:
Originally Posted by oldman
The as measured HP from a dynojet is as accurate as anything know to man. It takes HP to spin up a heavy roller PERIOD. As measured on a dynojet is as accurate as you can get and it is comparable to anywhere, anytime, to another as measured on a dynojet.
Am I saying the same car with the same mods will make the same true as measured HP? Nope, the car will put out different HP depending on conditions (and location of dyno). The is an highly abused SAE correction factor for that, which should be used under very limited adjustments (read that as a few %) and never on a FI engine. So why don't we all use as measured? Which is 99.9% accurate completely repeatable?
The Mustang dyno is a programmable load dyno and can literally spit out ANY number. It is VERY useful in tuning a street car on street gas especially FI cars as these cars tend to ping / detonate underload.
You get into real trouble when you want to race a dynoject against a Mustang dyno. As a dynojet is a true fixed load no way to cheat as measured, and a Mustang dyno is NOT.
It is near laughable when we get to Unicorn HP on FI using STD, STP et al.
|
Where did I say the dynojet were not repeatable ? I perfectly understand a fixed mass to rotate will provide repeatable measurements. After all, what should I know, I only have a Master in engineering and a PhD in physics...
The issue I see with Dynojets is that the pulls are really short for most of them, you don't load properly the engine, which is obviously an issue with turbo engines. Moreover for tuning the adjustable load of a Mustang dyno is very usefull even on an NA engine to look for knock and or simulate very high loads.
It is common knowledge that most of the time Mustang Dyno, properly setup, yield lower numbers than dynojets by few % (max 5% ?) . There is no science behind the words " heart breaker" but yet they come from experience of several users.