Consistently low Dyno numbers? got an idea why.
11-04-2005, 02:29 PM
#16
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Neil, I'd say there's probably nothing wrong with your numbers since you're getting them from, what I believe is, a double roller Mustang. Compare your number with other HO's on the same dyno with the same operator and the then worry if your low. I consider 407 hp off the Mustang good for your combo. Looking at your torque vs. hp, there may be some tire slippage. 900 torque, with only 407 hp, seems high. It's hard to get good hp numbers on those 18" rollers.
The Mustang is a loading dyno, and so numbers recieved from it can be changed depending on what the operator does. There is a local diesel shop, around here, which uses the Mustang for selling their products. They are notorious for manipulating the dyno to make themslves look good. You can take your truck into them with someone else's injectors, change over to their injectors, and SURPRISE SURPRISE, you're suddenly making more power.
Not looking to get in any sort of a dyno war here, but I'd say you'd be at least 50 hp higher on a Dynojet. Dynojets are quite consistant in their readings no matter where they're located. They are acceleration dynos, using a set load, and the results from them are easily compared to other Dynojets around the country. There are a few tricks the operator can do to improve hp numbers, but for the most part they're much more consistant than Mustangs. Correction factors, from them, are really the only factor you have be concerned with, in comparing to other parts of the country. Their correction factors are more for gasoline engines and not necessilary accurate for turbocharged diesels.
The highest hp number I've ever personally seen from the double roller is close to 500. We had to put 8 guys in the back of the truck, to get the traction, to get there. If you're using the single roller Mustang, then I don't know what to tell you. (Sorry, can't remember the model numbers of the Mustang's)
The Mustang is a loading dyno, and so numbers recieved from it can be changed depending on what the operator does. There is a local diesel shop, around here, which uses the Mustang for selling their products. They are notorious for manipulating the dyno to make themslves look good. You can take your truck into them with someone else's injectors, change over to their injectors, and SURPRISE SURPRISE, you're suddenly making more power.
Not looking to get in any sort of a dyno war here, but I'd say you'd be at least 50 hp higher on a Dynojet. Dynojets are quite consistant in their readings no matter where they're located. They are acceleration dynos, using a set load, and the results from them are easily compared to other Dynojets around the country. There are a few tricks the operator can do to improve hp numbers, but for the most part they're much more consistant than Mustangs. Correction factors, from them, are really the only factor you have be concerned with, in comparing to other parts of the country. Their correction factors are more for gasoline engines and not necessilary accurate for turbocharged diesels.
The highest hp number I've ever personally seen from the double roller is close to 500. We had to put 8 guys in the back of the truck, to get the traction, to get there. If you're using the single roller Mustang, then I don't know what to tell you. (Sorry, can't remember the model numbers of the Mustang's)
11-04-2005, 03:20 PM
#17
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Hey Bart thanks for the info. This is indeed a double roller Mustang and the higher HP guys do have to put weight in their beds (pallet of old 7.3 heads) 
The printout graph of my run doesn't show any signs of slippage though. Their is a Dynojet in my area I might talk to them and dyno to get some numbers to compare with other H.O. that run on Dynojets. My torque does seem really high for the HP, it has always been like that with this truck. My previous combo got me 330/782. which was higher than others TQ. Does the dynojet allow you to build boost without the loading? Thanks for the info!
The printout graph of my run doesn't show any signs of slippage though. Their is a Dynojet in my area I might talk to them and dyno to get some numbers to compare with other H.O. that run on Dynojets. My torque does seem really high for the HP, it has always been like that with this truck. My previous combo got me 330/782. which was higher than others TQ. Does the dynojet allow you to build boost without the loading? Thanks for the info!
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