Dynos.. Mustang, DynoJet and Dynapack
 

People see dyno numbers from different tuners out there after installing their products and doesnt realize different dynos provide different results which will make their product not making enough hp and some read too high and this will hopefully iron out that issue. So if you seem a bit confused about the different types of dyno's and what numbers to expect out of them. So let's clear them up.

There are 3 types of chassis dyno's you'll run into in the USA. Dynojet, Dynapack, & Mustang. They all spit out slightly different HP/TQ numbers when you compare one brand to another (i.e. Dynojet vs Dynapack), but they are all 100% consistent if you stay on the same dyno every time. So if you are tracking your mods as you add them, go to the same shop every time.

95% of the shops in the USA are running one of these three dyno's:

1. Dynojet - most popular in the USA. Considered the "standard" here in the states since most shops utilize them. For our theoretical "car", the Dynojet will read 100 rwhp, & 100 ft/lbs of torque.

With this dyno you drive up to the rollers (single roller per wheel ; car sits on top of the roller), they strap the car down, and do a full throttle pass in 3rd or 4th gear. The dyno will calculate the power based on how fast the car will spin the rollers. This is called an inertia based dyno.

For WOT power passes that you can compare to each other on the internet, Dynojet's are perfect. They're everywhere! But most do not have any sort of load simulating capability. Since 2005 more and more Dynojet's sold have their eddy current loading device. So you can ID them, Dynojets are typically red or black.

http://www.dynojet.com/automotive_dy...vidual_lrg.jpg

2. Mustang Dyno's - not as nearly as popular as the Dynojet's, but all performance shops that have Mustang dyno's DO have the capability to simulate load on the car to map ECU's. These are also great dyno's, are very accurate, simulate load very well, and are repeatable every time. They are also inertia based dyno's where you'll drive the car up on the rollers (two rollers per wheel and it sits in between both rollers), strap the car down, and make a 3rd or 4th gear pass.

The Mustang Dynamometer is capable of accurately loading 2WD or 4WD/AWD vehicles for the highest level of repeatability in the industry. We utilize a load-bearing dyno that uses an eddy-current load absorption unit with low inertia rollers for precise and instant torque measurement and power production feedback while the vehicle is running.

These dyno's will always read ~12% LOWER than a Dynojet, which is our standard here in the states (unless the shop has messed with the gearing settings in the computer). Because of this, lots of the internet folk don't like to use them. They come on the internet, share their results and everyone says "why didn't you make more power with mod XX". So our theoretical car will show 88rwhp on the Mustang dyno.

These dyno's will always be blue.
http://www.predator-performance.com/pics/smalldyno.jpg

3. Dynapack - These are the red headed step children here in the states. Not as common as the Dynojet or Mustang, but these are the standard in Japan. These are fundamentally COMPLETELY different that the inertia type dyno's.

The Dynapack™ eliminates tire to roller interface variable by using a hub adapter that provides a direct coupling to our Power Absorption Units. There can be no tire slip, no rolling resistance, and no chance of the vehicle coming off of the dyno at high speeds. Notice that we call this a variable. Sometimes it may be a problem area, other times it may not. Tire temperature, pressure, traction, etc, are all variables that can change - not only from run to run, but during the run as well.

With the Dynapack (my favorite), you remove the rear wheels, attach the hubs of the car to the "pods", and make your pass.

The load is simulated on the car via a hydraulic pump. Because these are effectively inertia-less, they will read HIGHER than the standard Dynojet numbers by 8-10%. That number will vary depending on how "fast" your dyno run lasts (sweep time), but as a rule of thumb, they'll read ~8-10% higher. So with this dyno our car will now read ~109rwhp on average.

The pods are always red/black, but these are easiest to ID. If they are taking off your wheels, it's a Dynapack!

http://www.tunehouse.com.au/wp-conte...03/GTR-AWD.jpg

And understand one thing when it comes to dyno graphs and product claims! Every dyno graph can be cheated by dishonest individuals/companies. All of them. So always take every dyno claim with a grain of salt. If they are cheating their tests, the truth eventually comes out (usually). Be a smart consumer!

Discuss!

*got info from different forums and discussion*

DynoJets also contain a load cell so it is not just measuring time to accelerate, I was schooled recently on the complexities of such things.

http://www.facebook.com/photo.php?v=166662296807912

Main reason why i like Dynapack better, ive seen this happen many times..

excellent sticky phenom86. great info on dynos. they are all a tuning tool. you need to add dyno dynamics. pretty rare dyno, but nonetheless they are around!

You should and Dyno Dynamics which is pretty much the standard here in Aust.

The front wasn't strapped.. i mean, you can't blame human error for a dyno.

I love em! I'll be picking up one of those soon enough! :)

Not that it matters to our cars but there are HP and TQ limitations to the DynaPacks, plus they read at the hubs, not at the wheels...

Ref : http://www.modified.com/tech/modp-09...n/viewall.html

Take it for what it's worth but it should be noted that the MUSTANG dyno baseline run that was used was pre-loaded for whatever reason while the rest of them were inertia based.

I've done my own comparative studies between the Mustangs and Dynojet, both with Cobb Sugeline's new AWD dyno as well as an 18 year old Mustang and found a difference of 2-3% personally, a far cry from some of the myths that are out there...

As always, my 2 cents...


Bob @ Drift-Office, LLC

Also day temperature is a factor during any dyno runs. On cold mornings/cooler evenings cars will get higher hp reading vs hot afternoons specially using fans to force air into your airbox.

also, make sure you disable traction control before dyno'ing.

True, but that's generally what correction factors are for... to some extent. :)

Seen cars on those type of dynos where the dances side to side even strapped on and ones with the straps breaking

https://www.youtube.com/watch?featur...&v=pyK4HTk_Efg

Yes rare but pretty much the same as the mustang dyno

The Mustang dynos have a lot of settings which can change things. You should also put a section in there on correction factors, those can make a bigger difference than the type of dyno.

I like the Dynapacks although I did have someone drop the front right of my WRX on its rotor when a jack failed. It also takes longer to get cars on and off the pods.

I feel more at ease when its on a Dynapack than any other dyno, ive seen my Evo dance on the dyno more than once and its not a fun feeling