Somebody in lighten me on the differnce's in dyno's.

Mine was done on a mustang and guys tell me they are "wrong #'s". Are they rated high or low.Who's to say one is, one isn't right trying for accurate #'s i changed my set-up so won't know if my old #'s are right.But would like the next time to be.

 

Mustang dynos usually read lower than Dynojets, but they are supposed to more accurately load the rear tires like they would be for real driving.

 

so if u want accurate numbers for the wheels then use the mustang dybo cuz it simulates a load like driveing and not free flowing lol

 

Something like that. Most people like the dynojet cause it generally gives better numbers for bragging rights.

 

An excellent article in the May 2004 issue of HOT ROD magazine comparing the way each dyno operates, its strengths and weaknesses, how they can be "fudged" and showing results for the same car (unfortunatley a brand new 220rwHP 'stang GT) on a Dynojet, a Mustang, a SuperFlow and a Dynapack dyno. For this car, the Dynojet SAE corrected was 221.9 rwHP/263.3 lb-ft, compared to the Mustang at 219.1 rwHP/239.3 lb-ft. SAE corrected on the SuperFlow was 216.2 rwHP/259.0 lb-ft.

 

The term "accuracy" only makes sense if you define your "gold standard" - the technique you will compare the others to. The one that gives the closest measurement to the gold standard is the most accurate. Most chassis dyno are used for tuning though. In that context, "accuracy" is really not relevant. What counts is repeatability and "resolution". By resolution, I mean the ability to measure small differences and repeatabilty means that the same conditions will consistently produce the same measurement. If the dyno used has good resolution and provides repeatable measurements the accuracy is irrelevant when it is used as tuning tool.

So, the answer to your question will depend on your purpose in making the dyno runs. If it's to get a number for "bragging rights", I guess the higher the better. In that sense, they are "wrong" because the Mustang usually gives a lower number than the Dynojet. If you were tuning, "wrong" has no real meaning as explained above, as I understand both the Dynojet and the Mustang both provide repeatable results and are precise to within a couple of HP. I have mades hundreds of runs with my car on a Dynojet and when the conditions are as close to identical as possible the results will vary my quite a bit less than 1%. In the range of 2-3hp at the 600-700rwhp level. That's why a dyno is so useful as tuning tool. Differences that small cannot really be analyzed at the track due to the large number of uncontrollable variables.

Rich Krause

 

My goals are to get the most correct reading,As stated dyno #'s are for bragging rights.The max a engine make's at it's peak rpm does nothing on the street.My old #'s where 497 back tire before i changed to a less "kill set-up".All i'm doing is changing cam's bringing the rpm range down to a streetable range.


Anyway thanks for the input.