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Old 09-27-2009, 03:35 PM   #159
Darin Morgan
Reher Morrison Racing
 
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Drives: Inferno Orange SS/RS
Join Date: Jul 2009
Location: Arlington TEXAS
Posts: 249
Quote:
Originally Posted by Red SS View Post
I wonder if Ted thought about using a motor that may still be breaking itself in.
Your thoughts on the matter are spot on. You NEVER use an engine that is not broke in (stabilized) and baselined before the test is conducted. Most people dont consider this when testing components on new vehicles. Most of the time the power changes during the break in are incrementally small so evaluating power changes with one or two component changes over 5-6 hours on the same day may be statistically insignificant. If your engine is gaining 2hp per pull on the dyno and you try three different CAI on that day in 4-6 pulls that's a max variant of 8hp. If you find that the last intake is worth 12hp over the first, the results would be 12 hp-8hp= 4hp

This is the reason you dont use an engine that you know for sure is still gaining power. The results are skewed. You CAI that's worth a whopping 12hp could actually be worth only 4hp!

This is why you BASELINE! No one can argue with a three or four pull baseline that's total variance is 2-4hp.

ALL professional dyno testing is done a certain way. First have the engine baselined so the power band is not fluctuating. Then do three pulls and average those into a BASE pull. Change what ever component you wish to test. Make three more pulls with the new component and average those pulls into a single one. Then put the original component back on the engine and do three more pulls and average those. If there is a statistical variance from the first BASE to the last base the data is thrown out. If the first and last BASE are the same or within exceptable limes then then you can quantify your results for the component that was changed.
A-B-A testing.

Oh yea, the oil temps, water temps, head temps air temps can not fluctuate either. Not even a little bit. 10 degrees of oil temp can be an easy 2hp increase in power. Drop engine coolant temp by 10 degrees and that's 4hp more you just made. Now think what happens when your testing a CAI, your oil temp just shot up by 10F and you water temp dropped 10F. Your engine just jumped up by 6hp and the CAI your testing just showed a 16hp increase.

No, it made 10hp not 16hp.

Dyno testing is a very scientific proceadure whos underlying variables are often overlooked or worse yet, totaly dimised.
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Darin Morgan
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