Steady state tuning : practical Dyno use

Hi all,

I’m new here, and first of all I would like to thank you for all those very valuable courses on EFI standalone tuning and the info provided through this forum.

I’m a car enthusiast and an Evo owner for many years, and practiced « remapping » with the oem evo 8 ecu, in particular using « tephramod » upgrades.

Now I’ve built a second engine for my current car, and goes standalone with a Syvecs ÉCU.

For the moment I run this ecu on a quite stock engine with only a few bolts on, because I know quite well how this engine is « reacting » and I want to start using the Syvecs with a base I know well.

Starting and idling works very well yet, now time to go to the steady tuning part.

So here is my point / question : I’m looking for this type of dyno which with I can do steady tuning by loading more or less the engine for a specific rpm value. Could someone elaborate a little bit more, in a practical way, how the dyno is operated (course is very clear from the ecu part, but I didn’t really get how it works from the dyno).

I understand you make the resistance or braking from the dyno varying (in order to increase or decrease load), while maintening a specific rpm value using the Throttle ?

Thanks for any input, I really want to make this part technically clear in my mind

Most modern dynos with a retarder will have a "constant speed" mode where you tell the dyno what RPM or road speed you want to hold the engine at and it will automatically vary the amount of braking effect to control the engine or road speed exactly on the target you set. The set-up varies a little depending on the type of dyno and the available hardware or software - for example some dynos may use hub or roller RPM and an entered gear ratio to back calculate engine RPM, some may use a signal from an ignition or injector pulse to measure engine RPM directly, some may use OBD2 or CAN from an ECU etc.

Thank you very much Adam for your answer. Sounds clear for me !

As Adam said, you can't do this with an inertial/roller dyno' though, which most "tuners" seem to like because they're cheaper, faster, and easier to use.

I would strongly advise making sure you have a LOT of airflow, not just for the radiator and coolers, but also to feed cooling air under the vehicle to reduce transmission and exhaust heat build-up - that can be equal to as much as half, or more, of the wheel horse power!

Thanks a lot, finally find the appropriate dyno, not so far from my home !