The mustang Dyno adds load and gets a lower reading. So what is the percentage you add for the accurate number.

So how does the Dyno jet work and which is more accurate?

 

The mustang dyno does it's calculations in a totally different way than the dynojet, it does load the vehicle in a different manner as well. There is no conversion, because of the way mustang dynos work, it allows for large error margin based on operator. A dynojet is pretty much idiot proof and will yield repeatable consistant results as long as they are at the same altitude all dynojets will read very very close to the same. Mustang dyno's acuracy is all based on operator, and can be swayed in one direction or the other easily enough that it is impossible to compare the two numbers wise, or any two mustang dynos for that matter.

 

Mustang dynos, or any other absorption-type dyno is generally more useful when doing tuning. Most Dynojet dynos have an inertia roller, so the HP is calculated from the amount of power it takes to spin the roller of whatever weight up a certain speed, etc. A roller like this is only useful as a load when it is changing speed, so it cannot be held at a constant speed for tuning a specific RPM area, etc. Absorption dynos use similar calculations, but because they can be used more as a constant load they are usually more useful for fine tuning. They also can compensate for more factors than the Dynojet setups, which is usually why Mustang numbers are different. If both dynos are used in the same way, with the right very accurate correction factors and ambient conditions, they should give readings that are similar. That slightly oversimplifies everything, but that's the general idea. It would be very rare to actually have a dyno operator put that much work in to getting everything as perfectly compensated as possible though, so that's where the big difference is. So no, you can't really compare them, but you also can't compare two Mustang dynos to each other (or two Dynojets, etc) for the same reasons.

As far as accuracy, the Mustang is theoretically the better setup based on how it presents load to an engine, but remember that there are a lot of correction factors and variables to consider. So even though the Mustang may take better actual measurements, inaccurate compensations can totally skew everything all over the place.

Mustang dynos are a sort of hybrid, they have a absorption setup and an inertial setup, so they are a little different than the pure absorption setups like Rototest, etc.

The best thing to do is to use the same dyno for all of your tuning, as that will give the closest comparison of before and after tuning, or when you make power mods, etc.

 

Fabrik8 I have a question regarding my numbers. I'm going to pm you.

But thanks for that explination it clears a lot up.

 

Post those numbers up, I'm out of the Honda loop and can't tell you if those are good numbers for an LS/VTEC. Hell, post the dyno graph up if you have one. It's usually kinda useless to post a dyno graph up, because unless it was done on the same dyno with the same operator, there will be accuracy and consistency problems. There have been a lot of people that have been tuned or dyno'd at Dyno inc though, so your readings should be somewhat consistent with a lot of other people here.

This is what I'm saying though, because of the differences in the calibration and correction factors in each dyno (basically the differences in each dyno from shop to shop) it's pretty hard to get a fair comparison from car to car when using different dynos. So if you go to one shop, and your buddy with the exact same engine setup goes to another shop, don't be surprised if the numbers are different by a fair margin. Similarly, you'll get different numbers from shop to shop too, especially if the dyno is a different brand or model.

 

Okay I put out 1xxhp and 1xxftlbs. They told me there to add 15 to 20 pecent for a more accurate calculation.
I got tuned Friday then added my Jacobs electronics ice pack ignition system saturday and got dynoed Sunday during the poker run to see gain or loss.

 

Originally Posted by Somalia: Okay when I got tuned, I got tuned at Dyno Inc. I put out 1xxhp and 1xxhp ftlbs to the wheels.Its a ls vtec in a 91 ed6 with a jdm b16 tranny. I'm building this car for street and weekend track events like hpde ect. I'm not into drag racing.
I have a modest suspension set up now. Rs*r racing springs and tockico blues. I am happy with that on the street. I know I still have a lot of body roll & still have a lot to go suspension wise. But as far as motor do you think I can be competitive? I'm looking into road racing and autocross also. I would love to get some racing licenses and move up to various events. But I want a car that's competitive.I still have a lot of power to tap out of the motor cams, intake manifold, fuel system, head work ect.

 

I'm going to post my graphs, when I find someone with a scanner anyone willing to help me with that pm me.

 

Okay, I see I have to make a thread in hondaswap.
But thanks for the dyno awnsers gentlemen.