Dyno Tune Misconceptions..

[Hal]

Originally posted by brads
. As for why his tuning was so far off on Vishnus dyno, which is an eddy current dyno from what I understand, I couldnt guess without knowing more about the test.

It's Vishnus dyno?

Was he playing with the "knobs" again?

I wouldn't bother asking him for explanation, you'll just get (IMO) a bullshit answer or he'll come off as "how dare you question my methods or results".

I'd write off the money spent as a learning experience, and then take the car to someone who really knows what they are doing.

Hal

 

[GrocMax]

Glad to see I have some positive influence in the world

The GrocLessons have stuck.

Originally posted by NosLaser


You're kidding? You mean LOAD actually makes a difference on an engine? You mean when I sit in my driveway, and free-rev my motor, it doesn't make the same horsepower as it does when I am doing a 3rd gear pull uphill? You mean my aluminum flywheel doesn't increase spoolup because it's lighter and provides less load? The horror!!!

Regards,

 

[NosLaser]

My God you have no idea how many times I beat my head against the wall trying to explain the concept of engine load to people. Try as I may, it falls on deaf ears. I try to explain the importance of using a MAP sensor/target air/fuel ratio table/wideband O2-equipped engine management system on turbocharged cars to sense those subtle changes in load. Oh well. I guess that's the reason why a 'certain' group of people will always be faster than the others.

Regards,

 

[brads]

I'm aware of the engine load concept, I see it often with bikes etc on the dynojet inertia dynos that seem so popular. If we had a speed density system, I'd expect that to be a real problem when it comes to tuning. But I guess I am not fully understanding the problem when it comes to the mass air systems, and the AF ratio changing. If the load changes, then the actual amount of air the engine sucks in will change as well, correct? That would explain an AF ratio change with speed density. But on a mass air system, if the load changes, and the airflow changes as a result, that should make the fuel flow change in correlation, and keep the stock AF ratio, correct?

Brad