[kriszty]

I had my car flashtuned last week ( dynostar Dyno ), coming from a JB4 i know a bit how the car was driven, althought the car is running smooth and fast, i thought ( maybe only in my head ) the JB4 was a small fit faster ( map 2 ) so i dyno the car somewhere else...

with the ecu tune they measured 434pk and 620nm with the dynostar, but when i dyno somewhere else ( no dynostar bank ) they only measure 386 pk and 577 nm , how can there be such big difference ?

[NISFAN]

Estimated flywheel power vs wheel power?

[bryan_G01]

a dyno is a way to measure the difference between A and B.

Did you run the jb4, than the flash tune on the same dyno, same day, same weather?
If not, than you wasted money basically.

Meaning you have a starting number and a end number. Each dyno can be setup differently, and lie.

This is why dyno numbers are complete bullshit. PPl today will sit and compare dyno sheets like its sacred, its al bullshit. You use a dyno to tell you what was gained by changing.

[dradernh]

Originally Posted by kriszty

how can there be such big difference ?

Dyno machine operators at both Turner Motorsports and Dinan Cars told me when I was having my cars tuned in their shops that with everything else being equal I could expect a difference of +/-5% on successive days. That is: same dyno machine, same dyno operator, same weather, but on different days. It isn't the different day that makes the difference - it's the inherent variability in the results produced by dynos. So that's a potential difference of 10% in results under conditions that are as identical as possible.

Dynos are best used for tuning a car. When it comes to the numbers they produce, I think they give only an approximate idea of a car's output.

Race engine builders will tell you that the only way to truly measure engine output is to run it on an engine dyno.

More info on this fairly complex subject here: https://www.hotrod.com/articles/1106...-engine-dynos/

One last thing to keep in mind is that if you tell the dyno operator you want the biggest numbers possible, it's likely he can make adjustments to help you with that.

[kriszty]

i went back to my original tuner with the dyno sheet, they where at first a bit angry cause i did believe the other tuner and not them, so i asked for another dyno run, it appears i was right, they flashed the wrong file, and indeed it was only 386hp , so after q quick talk they decided to flash again with the good file, and measure again... after the flash the car was completly different, now i could feel the power gain from the flash... after the dyno the car has 444hp ,,, so now i feel much better..

[mike@x-ph.com]

Originally Posted by kriszty

i went back to my original tuner with the dyno sheet, they where at first a bit angry cause i did believe the other tuner and not them, so i asked for another dyno run, it appears i was right, they flashed the wrong file, and indeed it was only 386hp , so after q quick talk they decided to flash again with the good file, and measure again... after the flash the car was completly different, now i could feel the power gain from the flash... after the dyno the car has 444hp ,,, so now i feel much better..

Glad to know its all good now