DYNO JET vs MUSTANG dynos and others::

[madpowerstroke]

I know there has to be members out there that are very knowlegable about dynos. I'm sure it has been talked about alot but I would like the info in one place. Here's some of the questions I have:

I have heard that a dynojet is a true measurement, that tire size doesn't matter. You basically put truck on it and spin the drum as fast as the truck will do it in a certain amount of time with a certain amount of resistance to calulate, so is that true?

I alway heard that the dynojet dyno measures on low side?

Does the dynojet work well with diesels since the load isn't inceased for turbo to spool hard?

Is the Mustang dyno better for diesels because it can be loaded?

Does gear selection matter with the dyno jet?, I know the mustang should be at 1:1.

Any help would be greatlly appreciated, I have a dyno event coming and they are running a dynojet so I wanted a little info ahead of time. I'll be running at track to get numbers to compair either way. I also know dynos are a tuning tool, not a accurate measurment of horepower that's why I will be hitting track. Don't want a debate on track and dyno just what to except from certain types of dynos, for my and others information. Thanks

 

[Chris]

In my opinion Dynojets are more accurate from one to another and to real world results. Now there are tons of variables that can make numbers differ, but they seem to be more repeatable from one dynojet to another, as opposed from mustang to mustang.

I dont have much info on mustangs, as we have a dynojet. There are 2 popular models of dynojets, 248s and 224s. the 248 was an inertia only dyno with a 48 inch drum. the drum had a good mass to it and calculated hp pretty much exactly how you described, measuring how fast you could spin the drum at different speeds. the 224 replaced the 248 and has a 24 inch drum. it can be used as a intertia dyno, or can have a eddy current load cell. We have a 224xlc, which is an extra width and load celled 224. we can vary the load for trucks that have large turbos that dont want tos pool or wont spool all the way. the dyno corrects its readings for the load placed on it and in my opinion the numbers are quite accurate. the dynojet doesnt care about gear selection. when you have the tach pickup on the front to pick up rpm it will actually calculate gear ratios even if you have a downshift or upshift and run through 2 gears and ask what one you want to chart. now it doesnt know enough to get rid of the actual spike a gear change could have made but the graph still comes out right and its up to the operator to decipher around the shift spike, if there is one. im not sure about a mustang dyno needing to be 1:1.

So that being said, and i may be biased, but i prefer the dynojet with a load cell. I know brian at BTS has the same dyno and loves his as well. it is a very useful tuning tool, and diagnostic tool.

 

[01PSD]

Enter Charles in 3.. 2.. 1..

 

[madpowerstroke]

Thank you Chris that explains alot and answers alot of my questions. I hope a Mustang dyno owner can chime in.

 

[Dzchey21]

I really only have experience with dynojets as i help hallers repair with thier mobile dyno from time to time. I know with a dyno jet the only thing that can be changed is the correction factor, nothing else, no calibrations nothing.

Mustangs can be calibrated, there is also a load on them which can vary, as well as run lenght ect. They do load turbos well, but they are hard on trucks (Aarons input shaft at DPC 2012) and seam to vary from one dyno to the other.

Some other feels that Superflow is the only way to go, but i feel opperator plays a big part of that. I had a single turbo on my 6.4 years ago, and i went to a superflow and layed down a massive 250 hp... went to a 248c dyno jet, and put down 580


here is the dyno jet run 580 hp

http://www.youtube.com/watch?v=bM-SMzGvD1Q&feature=share&list=UUfrWrzky1_GrHCpGNbYvuTw


here is the superflow run 255 hp... i think within two weeks of each other

http://www.youtube.com/watch?v=OK-tmw6-Rvo&feature=share&list=UUfrWrzky1_GrHCpGNbYvuTw


then i ran on hallers 224 c dynojet , which means it has a 24 inch drum instead of the 48 inch drum, single turbo it did 614, with a little more fuel than seen on the dyno jet video



http://youtu.be/GPtpKz_edoc
k and then here is my black truck again on hallers dyno 62/86, with 150s 850 hp, transplanted now into my reg cab, track times say 850 at this altitude and 930 at sea level...

 

[Jeff@Spartan]

I think most are going to acknowledge that the Dynojet is going to be the best option.

 

[JoeDaddy]

Load factors used in conjunction with an engine that sees artificial increase as its loaded isn't a good example of "real world", at least when we're discussing DD unloaded. On the strip for example, when you take your foot off the brake the load reduces to the amount of weight moved per time and resistance of gravity and wind.

A DJ only gives you weight per time. The resistance based dynos artificially introduce resistance and output can be manipulated based on load. For example if you want to see how much power you put to the hiway pulling a 25k GN 60mph.

 

[madpowerstroke]

Thanks for the info, so the dyno jet is still an est. and needs backup run on track to show the horsepower numbers better. I will be putting my truck on the rollers on nov. 3, on a dynojet, so I'll see what it does and then I'll get track speed to back up the horsepower.

 

[Dzchey21]

All dyno are is a tuning tool. Dyno before and after and see your gains. That goes with ask brands. Dyno jets are considered standard because there are no adjustments or calibrations