Quote:
Originally Posted by steve shadows
because cars will read out whatever they damn well want to read out but Ihave seen several cars I have tuned that put out 235 whp womp all over cars tuned on another brake eddy dyno that were putting out 350 whp.
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Well thats also manipulation on the engine builders part as well as the dyno tuners. I know from my experience that usually when I'm on the dyno I will do what it takes to exceed real world HP figures. Such as adding toulene and xylene fuel mixtures, or sunoco 110,or manipulating timing as if I was on a race track only.
In any real world situation hypothetically most people are bound to 91 octane unless you can find your local street blaze station with 100 or 101 octane.
I know that the dyno room at BRG racing in pacheco purposely sets up a small fireproof room just big enough to fit the car and dyno, and then a blower fan chills the room between 68*~70*F, with an inlet and exhaust out system.
Now I know that in any real world application most spring and summer days are a good 85*~90*F just the raise in temprature by 3*F for a naturally aspirated engine can drop HP, 10 to 15HP at the wheels and with forced induction depending on timing and boost from 10 to 70HP at the wheels. I actually read that in the book four stroke performance tuning by Graham Bell.
Now we are also talking about ecu tuning which is the key factor here. You can get a car that shows more HP on the dyno than another car that may have less HP using a higher octane blend, as you have pointed out in your example of a 235HP car VS. 350hp car. What they run on the dyno is manipulated as I said before from octane fuel used, timing, boost, etc, and of course the dyno tuners load settings. Infact the car that maybe making less HP may actually be utilizing pump gas more effeciently than the hyped up car tuned for higher octane for HP. Once you take an ecu, and an engine and tune it for higher octanes, it usually isn't as effecient in using lower streetable octane blends, as the cars that are tuned for those lower octane blends. this has alot to do with cam selections and bas etiming more than anything else. Its actually a way of being more deceptive on the dyno than in an instance of real world driving habits and competitive racing.
Last but not least what everyone fails to look at in the dyno is the torque band, most people become to prone to just looking at the peak HP without looking at the entire dyno graph.Torque plays a huge factor in this as well, while most people look at the HP band there are alot of engines out there with less HP, but have a much more superior beefy torque band. This would be more like the debate of the RB25det NEO VS. the RB26det which in most cases some say the RB25det neo is much more superior with its fully counterweighted crank and torque band , VS the RB26dett with its half weighted crank and higher off the wall peak hp rev range.
Just so many X factors that a car with less HP on the dyno can whomp a car with more HP on the dyno.