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Old 02-20-2009, 05:45 PM   #78 (permalink)
Denny McLain
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Sometimes shops who do group dyno sessions will make three quick passes to get off the car as quickly as possible so the next person can get on. Or for an individual who wants a trophy dyno run for their records just to say they have a dyno run. That's OK in that case, however for serious tuning or performance verification, you always a maintain a constant run temperature with proper allotted cool down for consistency.

Each run has to be the same regardless and if your tuning........only change one parameter at a time unless your adding a known tune. Easiest way in the world to get lost is changing too many things at the same time or be sloppy with engine temps.

Not sure about the Nissan timing maps, but some factory ECU software will alter the timing according to water temp. The objective is to eliminate as many extraneous variables as possible or you're wasting time and money.

There is a lot of science and study methodology that is used if you're going to do it right. Some of them good-ol-boy NASCAR mechanics ain't so dumb after all.



Quote:
Originally Posted by Kyle@STILLEN View Post
In between each dyno run you allow the car sufficient time to cool back down to a set point, then begin the next run. You aren't just doing one run after the other which, like you pointed out, would raise the engine temp more and more over each pull. This is the most basic explanation I can offer of dyno testing.

1) Perform your first pull
2) Allow sufficient time to let car return to optimal engine temp ranges.
3) Perform next pull
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