I have gone to 3 of the local dyno houses and my numbers are way off from one another. I wont post names but here are my numbers

Dyno Shop 1- 468/433
Dyno Shop 2- 399/358
Dyno Shop 3- 425/389 (to be redynoed here next month)

This is N/A power... Have any of you done this comparison too??

 

What kind of dynos? Mustang versus Dynojet etc.

 

Sorry I've only used one shop, but if I were you I stay with the first one. :lol: Ilike those numbers.

 

I've used two different shops.

Alll of the runs except the last one were done at the first shop. At the second shop I made a revised "baseline" mod so that I could compare the numbers from the first shop to the second before I made my last change.

The second shop was down less than 5hp & tq from the first.

EBS

 

You will not have a accurate absolute hp and tq value on any dyno using rollers. Use the same shop to measure the difference between mods/tuning etc that is the most important - to measure differences :yesnod:

When comparing the roller type of dynos as an example you have 15-18% diff. between the DynoJet and Dyno Dynamics which is also quite common in the US(The Dyno Dynamics measures 15-18% lower), I do not know about the Mustang.

To have a accurate and repeatable hp/tq number you need to use the same kind of dyno as the car manufacturers use which bolts to the rear(without wheels). They are within 2% and the accuracy includes if you remove the car from the dyno and go back a week later(No errors like the ones you get strapping the car down to the rollers)



:cheers:

 

I had my car dynoed Staurday and noticed he used 1.04 correction factor. Could that be the differences in dynos?

 

A dyno is a tool, and as such a tool can become dull. The user of dyno numbers can also be fool himself by using the numbers beyond what the numbers actually represent.

A dyno in perfect operating condition should produce numbers that are within 3% of any other dyno that is also in perfect operating order--given exactly the same atmospheric conditions (temp, pressure, rel. humidity). Change the atmospheric conditions, and another couple of percent of error creps into the numbers.

An engine on one tank of gas actually does produce different amounts of TQ and HP than on a different brand/tank of gasoline! Add in engine operating temperature, air temperature, reletive humidity and the inherent inaccuracy of a rolling wheel dyno, and presto 5% differences are EXPECTED!

Dyno shop 2 and dyno shop 3 are just over 5% different; while dyno shop 1 is 10% higher. I will take this to indicate that DS2 and DS3 are representing the output capabilities of your engine/driveline, while DS1 is pulling your leg.

I would guess dyno shop 1 is a Mustang dyno, and the other two are dynojet dynos.

But more importantly, ONE NUMBER does not represent the power output of anybodies engine! The number changes from day to day, tank to tank; almost as if the engine had a soul.......