what do you think about this?
02-12-2004, 11:14 PM
#41
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This post is a good informative one but I keep wondering why no one has posted what I'm thinking.
I'm thinking I have a generalized grasp of how the ECU functions. Our cars basically tune themselves via the ECU on a day to day basis. ECUs follow a preset map and make some adjustments for, essentially, environmental factors. The ECU learns the proper values it runs with over time, often over several miles and days of driving. These values are a starting point for the next time the car starts.
<---- Says to Self: How can any gains an aftermarket performance part generate be accurately measured when some parts take days and a few miles to come to peak performance?
Sure some bolt ons are immediate like pulleys, but when people installing parts that change air:fuel and try to do a fast swap on the dyno I ask myself..., self, how are these numbers even remotely based in reality and how are they related to what I MAY see in gains, on my car, 2 months from now?
I feel for all_bark and the crap he went thru for this dyno and props to him for remaining cool under fire LOL. However, I must admitt I was a little happy to hear that all_bark couldn't run the after dyno with the plenum installed later that afternoon. He was forced to delay for a week(?). Hopefully the ECU had enough time to adjust to the new parts and produced a more representitive HP gain. My only wish is that all_barks' car would have been stock.
I believe most "breathing" parts should be tested after the ECU has stopped making Air:Fuel changes. THIS is somewhat representitive of what would be seen on a day-to-day basis. Testing this way helps the buyer AND the vendor by seeing more reproducibility and possibly even bigger gains. I know that this is not practical and would never be instituted, but the days of glass packs and 4 barrel carbs are gone. These days Air:Fuel changes are learned by a chip, not changed with a screwdriver.
Having said that, SAE correction is the only way to level the playing field by compensating for what CAN BE compensated for, environmental conditions. SAE correction, while not perfect, attempts to normalize the gains so that fair comparisons can be made across many cars. Using SAE correction is NOT an option. This correction is the last step in a sequence of steps that prepare the raw data for analysis.
NOT using SAE correction would be like saying you just lifted 600 lbs, but forgot to mention that you did so on the moon.
What was my point? Oh yeah, thanks all_bark and Kinetix.
I'm thinking I have a generalized grasp of how the ECU functions. Our cars basically tune themselves via the ECU on a day to day basis. ECUs follow a preset map and make some adjustments for, essentially, environmental factors. The ECU learns the proper values it runs with over time, often over several miles and days of driving. These values are a starting point for the next time the car starts.
<---- Says to Self: How can any gains an aftermarket performance part generate be accurately measured when some parts take days and a few miles to come to peak performance?
Sure some bolt ons are immediate like pulleys, but when people installing parts that change air:fuel and try to do a fast swap on the dyno I ask myself..., self, how are these numbers even remotely based in reality and how are they related to what I MAY see in gains, on my car, 2 months from now?
I feel for all_bark and the crap he went thru for this dyno and props to him for remaining cool under fire LOL. However, I must admitt I was a little happy to hear that all_bark couldn't run the after dyno with the plenum installed later that afternoon. He was forced to delay for a week(?). Hopefully the ECU had enough time to adjust to the new parts and produced a more representitive HP gain. My only wish is that all_barks' car would have been stock.
I believe most "breathing" parts should be tested after the ECU has stopped making Air:Fuel changes. THIS is somewhat representitive of what would be seen on a day-to-day basis. Testing this way helps the buyer AND the vendor by seeing more reproducibility and possibly even bigger gains. I know that this is not practical and would never be instituted, but the days of glass packs and 4 barrel carbs are gone. These days Air:Fuel changes are learned by a chip, not changed with a screwdriver.
Having said that, SAE correction is the only way to level the playing field by compensating for what CAN BE compensated for, environmental conditions. SAE correction, while not perfect, attempts to normalize the gains so that fair comparisons can be made across many cars. Using SAE correction is NOT an option. This correction is the last step in a sequence of steps that prepare the raw data for analysis.
NOT using SAE correction would be like saying you just lifted 600 lbs, but forgot to mention that you did so on the moon.
What was my point? Oh yeah, thanks all_bark and Kinetix.
02-14-2004, 08:17 AM
#42
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all_bark's dynos
Sponge, I agree with you. It's good that all_bark took a week or so after some installs to do the last dynos. I have a tendency to believe that the ECU adapted a little bit more to BOTH the cats and the plenum when the dynos were done on the final day. I'm guessing that a little bit more of the final dyno might have been due to the cats vs. the plenum because of that. Heck, I may be wrong, but both mods together really look excellent anyway.
