We have 3 dynos, two from Stuska and one Superflow, capable of 2500 HP. All are equipped  with the most accurate and precision depac dyno instrumentation, including the famous auto-dynamic load (ADL) control system, which allows us to test a drag engine from 7000  to 9000 rpm in 2 seconds or test a circle track from 3000 to 7000 in 6 seconds and still get repeatable results most of the time with in a 1/2 HP. Our system also has weather probes that measure absolute humidity, absolute (dry) atmospheric pressure, and absolute air temp. If we test your engine on a humid  day in July  or a dry day in January we will get the same results.  We use the newer SAE standard for dyno testing J1349 which is dry air temp 77 deg. at a pressure of 29.23 hg which is closer to the normal operating conditions of an engine. Others use the older J607 SAE standard, which is about 5% different, and still others use a "racers" standard that is made up to make you feel good, usually 20-30 hp more than it should be.  On our system we also have a true inertia correction that is infinitely adjustable, this has to be addressed if you want accurate results. If you have a heavy flywheel or a lite weight crank your inertia factor is different.  If you have any questions please call anytime,  we are dyno smart ... we  eat, breath and sleep this stuff!