Gernby

The local S2000 club is getting together tomorrow for a Dyno Day, so I am looking for all the ways that we can get the most comparable numbers from the test. Some ideas for reducing the "scientific error" are listed below. If any of you can help me think of any other variables that can realistically be controlled, please let me know.

1. Inflate the rear tires to the same pressure (40 or 50 PSI).

2. Fill the engine oil to the upper end of spec.

3. Start the first run with a fully heat soaked engine.

4. Reset all ECUs before the first run.

cdelena

Why number 4? Once you have the fuel trim right, why start over with default values?

Gernby

Well, I'll give you a hypothetical case where you have two identical S2000s. If one was used primarily for long highway cruises, and the other spent most of its time in stop-n-go traffic, the chances seem high that the "learned" behaviors would perform differently on the dyno. I may be wrong, but it seems like an ECU reset will give a more objective result.

Gernby

On second thought, maybe it would be best to do an ECU reset before the last run, so that we can see a "baseline" run with defaults to compare against each other, and the difference generated by all this "learning".

cdelena

I don't understand what you are trying to accomplish.. seems to me the car that shows up is what you want to measure. I won't be there but if I was I would not be interested in testing something I don't and won't use.. a newly reset ECU.

Gernby

Well, I haven't ever participated in a "Dyno Day", but I assume the purpose is to compare performance mods. It seems to me that if the ECU is not reset, then the results will be significantly effected by circumstance.

turbo_pwr

I have to agree with the others, a ECU reset does not make any sense. It just makes the car run less then optimal, since the ECU will need to relearn everything. It's also the consensus that it takes at least a days worth of driving for the car to learn everything. So basically you'd be measuring cars that are running like crap.

Gernby

I am getting the impression that you guys view this learned data as a thing of value. I reset my ECU on a regular basis.

ultimate lurker

Don't reset the ECU. Every car is different, especially if someone has mods.

As for the heatsoak, that's a little tougher.

Ideally, you should throw out the first run. Also, you should monitor coolant temps on each car. When I dyno test, I make sure coolant temp for each run after the first is between 185-190F. As coolant temp goes above 190F, power begins to drop.

UL

SECRET AP1

[QUOTE]Originally posted by gernby
[B]I am getting the impression that you guys view this learned data as a thing of value.