i'm interested in learning more about dyno's, why they can vary so much and which ones you all find "accurate". i have been on 3 different ones and have different results to show for it.

i have formulated my own opinions but am interested in hearing yours and why. please don't base your opinions on just highest numbers. i would enjoy some discussion on the differences when numbers are not consistent. there's entirely too much information out there for any one person to learn it all.

 

We have a Dynojet 248h, as they seem to be the most consistant dyno out. As for the best results, most people are happy with the results they produce. But they are pretty much the ruler or say yardstick that best measures the power of these diesel trucks across the country, since it has no variables to change to scew the numbers besides the elivation you are at and the humidity and temperature. But with using the Uncorrected factor it keeps things in a pretty fair ball park.

Brett

 

The dyno is a tool that helps you tune your truck. I like to use the same dyno and operator when trying something differant. The drag strip will back up what the dyno says. I can use the calulators and my times to got a close figure on what my truck is making.

 

One of my buddies did 386 with smarty TNT, mp8, silver 62, and glacier fuel system on a mustang! I think it was a little off

 

Like Billy Ram said, the dyno is a tool for tuning and diagnosing. To get any meaning from them you need multiple runs off the same dyno, preferably under the same conditions. Comparing dyno numbers you obtained on one dyno to another guy who got his numbers at some other place at some other time is comparing apples to oranges.

 

I trust dynojets. I have found them to be VERY consistent. Last year I went to two different dyno days 3 months apart on 2 different dynojets and dyno'd within 1 hp of each other everything else being equal. Other times the dyno sheets were within 10hp or so.

..

 

This is why I only dyno one to two times a year. I like to go to events with lots of trucks so I can compare my numbers with other guys see what they run, see their set up, and see if everyones #s are checking out. To go around to a few different dynos with different operators leads to too many variables, and may lead to serious depression .

 

thanks for all your responses. i have used multiple dynos and have recorded similar results on the dynojet, and different results with the dynomite. any of you done loaded runs or hlll simulations to see the difference in numbers. i'm going to try different methods because i want to see if loading the drum will make a difference in numbers.
once again, thanks for your response. consistency seems to be the name of the game.

 

just a note on dynos to think about.... make sure you trust the operator because i know that there is a way to "adjust" the computer to make readings higher or lower on the dynojet 250 motorcycle dynos. i'm sure that this can be done on the truck ones as well. while at a shoot out there really isnt much to be gained from this adjustment unless you want to make sure that a truck you tuned wins the shoot out. i have seen guys get their bikes tuned by a "reputable" shop on tuesday and by the dynojet factory truch at the races on thursday and be off by 10+ horsepower. on a 600cc bike that makes 125ish tuned thats a lot. on the bigger 1000cc bikes it can be off as much as 15 to 20 hp. depending on what the shop wants the customer to believe he just paid big bucks for.

 

good point. the dyno i use has a full active weather station and by altering any of those imputs, can dramatically change numbers. printed dyno numbers when marketing a product can be accurate or misleading. "independent testing" as they call it needs to be questioned to some extent.

 

DynoJet! These conversations sometimes get like oil and transmission wars. ( -:

 

Dynojet 248 is the only way to go.

 

Yep...I have been within +- 10 hp UNCORRECTED in several locations on several 248's.

 

The only way to get a real reading, is with a loading dyno using a calibrated strain gauge. This is the only method to accurately attain actual torque readings. Without torque, you have nothing. I have never been on a Dynojet, that could load me correctly. If you can't make actual boost, how can those be actual numbers. If you can't load it to the point of stalling down the engine, you will never reach maximum torque. After all horsepower is torque x rpm/5252. Personally I would rather see undisputable, actual numbers, based upon what Eddy current absorbers indicate.

 

Define real?

A "ruler" works as long as everyone uses the "same" ruler.