Trying to understand dynoing

Trying to understand dynoing

Joined: December 13th, 2005, 6:39 am

May 27th, 2012, 10:19 pm #1

So here we go. My stepdad just dynoed his 439BBC. It put 606hp@6600 rpm-dont remember the TQ on that run. So after they backed it up with 610hp they started talking about the accurcy of the dyno. The dyno operator said he sets the perameters to the lowest tolerance at .003 percent. He said companies like Reher Morrison and Keith Black etc... actually set there perameters looser like around .015 percent. He knows this because the dyno manufactor actually gave Reher Morrison and Keith Blacks dyno spects to him cause he was having customer complaints about his dyno giving low numbers. So he set his dyno to Reher Morrison's perameters and pulled 2 more runs. Well the 439 pulled 682hp@6600 and 567TQ@5900 and was backed up with 687@6600 and 568TQ@5900. No changes except the dyno perameters.

The dyno operator said there is a reason he sets it at the lowest setting and that is because he is here to build and tune the engines to there max hp/tq. Companies like I stated before are here to sell engines and the products on the engine "heads, intakes" etc.... so they want the customers to see the BIG NUMBERS.

So what does everyone think about this? Im not an expert on dynos at all but I was there and saw this in person. Im not bashing anyones dynoing or engine work, just wondering if anyone ever experiance the same?
Last edited by nova467spanker on May 27th, 2012, 10:29 pm, edited 1 time in total.
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Joined: May 20th, 2005, 4:48 pm

May 27th, 2012, 11:49 pm #2

...because horsepower numbers sell engines.

Would you rather have 682hp or 600hp? LOL The 682 number looks a whole lot better on a sheet that you can show to your buddies.

The dyno I use is conservative. I like it that way. I also like that I have a third party dyno operator, because I think the public thinks differently of shops that own their own dynos.

I'll tell you this....I'd rather have the 400hp engine that pulls away from everyone else than have the 500hp engine that gets left behind.......and it happens....



Brent Lykins
B2 Motorsports, LLC






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Joined: October 1st, 2004, 8:05 pm

May 29th, 2012, 5:20 am #3

Trust the stop watch ... there's no "factoring" a stop watch.



-G
____________________________________________________________

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If you use a 351C 4V powered vehicle for a grocery getter ... the eggs aren't going to make it home!
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Joined: November 17th, 2008, 12:44 pm

May 29th, 2012, 6:36 am #4

what are the parameters that make a difference? the load/ramp rate?
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Joined: May 20th, 2005, 4:48 pm

May 29th, 2012, 8:45 am #5



Brent Lykins
B2 Motorsports, LLC






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Joined: November 18th, 2002, 1:16 pm

May 29th, 2012, 2:00 pm #6

So here we go. My stepdad just dynoed his 439BBC. It put 606hp@6600 rpm-dont remember the TQ on that run. So after they backed it up with 610hp they started talking about the accurcy of the dyno. The dyno operator said he sets the perameters to the lowest tolerance at .003 percent. He said companies like Reher Morrison and Keith Black etc... actually set there perameters looser like around .015 percent. He knows this because the dyno manufactor actually gave Reher Morrison and Keith Blacks dyno spects to him cause he was having customer complaints about his dyno giving low numbers. So he set his dyno to Reher Morrison's perameters and pulled 2 more runs. Well the 439 pulled 682hp@6600 and 567TQ@5900 and was backed up with 687@6600 and 568TQ@5900. No changes except the dyno perameters.

The dyno operator said there is a reason he sets it at the lowest setting and that is because he is here to build and tune the engines to there max hp/tq. Companies like I stated before are here to sell engines and the products on the engine "heads, intakes" etc.... so they want the customers to see the BIG NUMBERS.

So what does everyone think about this? Im not an expert on dynos at all but I was there and saw this in person. Im not bashing anyones dynoing or engine work, just wondering if anyone ever experiance the same?
There is also a reason not everyone is willing to bring engines to competitions like Engine Masters where they no control over dyno numbers. At EMC engines are run by the officials not the competitors. If your dyno has unreal numbers you will be disappointed.......QUICKLY.

Last year my third place entry needed less than one hp and one foot/lb average to go to the top spot......................just think what 76 peak hp alone would have done by changing what was done on your example.



Mark McKeown
McKeown Motorsport Engineering, Inc.
http://mmeracing.com
http://racecrateengines.com
Mark McKeown
McKeown Motorsport Engineering Inc
http://www.mmeracing.com
301-246-9225
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