Dyno guys, inside please.
Thread Starter
Burning Brakes
Joined: Feb 2004
Posts: 1,069
Likes: 8
From: Sanford NC
Dyno guys, inside please.
I dyno'ed a car today on the dyno I normally use that reads about 10rw lower than other dyno's in the area. The car put down 425/407rw but it is the weather data that has me confused.
The data it read, Temp 93.7 F*, Baro 30.01 inHg, Humidity 29%. The humidity I knew was wrong. So I looked up the weather data from about a mile away.
Actual data, Temp 85 F*, Baro 30.08, Humidity 57%. I can see it being hotter inside than the outside temp due to the running cars and no air circulation but the humidity has to be the same as out side.
The question. If the weather data or humidity data was correct would the car have made more or less power on the dyno?
The data it read, Temp 93.7 F*, Baro 30.01 inHg, Humidity 29%. The humidity I knew was wrong. So I looked up the weather data from about a mile away.
Actual data, Temp 85 F*, Baro 30.08, Humidity 57%. I can see it being hotter inside than the outside temp due to the running cars and no air circulation but the humidity has to be the same as out side.
The question. If the weather data or humidity data was correct would the car have made more or less power on the dyno?
Drifting
Joined: May 2005
Posts: 1,370
Likes: 1
From: Raleigh NC
The dyno was not correcting for the actual humidity level, so if it had read the humidity correctly and corrected for it, your power numbers would have been a little higher. Probably not much of a difference though.
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
I assume you were on a dynojet. They're notorious for the humidity being off. Every one I've ever tuned on (and that would be ALOT!) the humidity was off. The difference is insignificant.
They seem to work good right after sending the stack in for service or repair, and then they degrade rapidly. Seems the issue is the airflow through the module. I've had pretty good success blowing a fan on the stack, just enough to keep good airflow across it. But again, the difference is nil.
They seem to work good right after sending the stack in for service or repair, and then they degrade rapidly. Seems the issue is the airflow through the module. I've had pretty good success blowing a fan on the stack, just enough to keep good airflow across it. But again, the difference is nil.
Thread Starter
Burning Brakes
Joined: Feb 2004
Posts: 1,069
Likes: 8
From: Sanford NC
Thanks guys. Would that explain why this particular dynojet may read a little lower than the rest around here? It sounds like it is a common problem though. I am assuming there is no way to manually enter the actual weather data of the day. Then you wouldn't have to rely on the stack. This stack is burried under a double stack bench and doesn't get much air flow.
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
Thanks guys. Would that explain why this particular dynojet may read a little lower than the rest around here? It sounds like it is a common problem though. I am assuming there is no way to manually enter the actual weather data of the day. Then you wouldn't have to rely on the stack. This stack is burried under a double stack bench and doesn't get much air flow.
