New cars, old cars and horsepower ratings.

[Ed Wright]

Originally Posted by KRatcliff

If you rely on the ECU to tune the car going down the track then you will be slower. The ECUs are not capable of reading, correcting, and optimizing the tune within the few seconds of the pass IMHO.

Of course, I am still learning and have a long ways to go.

Your absolutely correct. I hear that all the time. It does not work that well. I don't know many fast guys doing it that way. That is assuming it always runs quickest, in all weather, with any number of water grains, at the same air/fuel ratio. Not in the real world. The majority of the faster EFI cars use it as a reference, same as the carbureted guys do. We have different tune ups, or fuel pressure adjustments we make for different conditions, just like the carb guys changing jets. The guys telling the "It tunes it's self going down the track" simply don't know what most of us actually do. I have helped several guys pick up by putting their cars back into Open Loop so they don't try to make adjustements. It simply does not work that well in the real world.

[69Cobra]

Originally Posted by Ed Wright

Your absolutely correct. I hear that all the time. It does not work that well. I don't know many fast guys doing it that way. That is assuming it always runs quickest, in all weather, with any number of water grains, at the same air/fuel ratio. Not in the real world. The majority of the faster EFI cars use it as a reference, same as the carbureted guys do. We have different tune ups, or fuel pressure adjustments we make for different conditions, just like the carb guys changing jets. The guys telling the "It tunes it's self going down the track" simply don't know what most of us actually do. I have helped several guys pick up by putting their cars back into Open Loop so they don't try to make adjustements. It simply does not work that well in the real world.

I must have misunderstood what I was told then. I used to hang around some NMRA guys and I was under the assumption that a certain Super Street Outlaw turbo car that was pretty fast and was being tuned this way. I have no first hand knowledge just hearsay. The EFI guys can tune cylinder to cylinder better and more efficient than you can with a carb, yes???

[KRatcliff]

Originally Posted by 69Cobra

I must have misunderstood what I was told then. I used to hang around some NMRA guys and I was under the assumption that a certain Super Street Outlaw turbo car that was pretty fast and was being tuned this way. I have no first hand knowledge just hearsay. The EFI guys can tune cylinder to cylinder better and more efficient than you can with a carb, yes???

Very few can do each cylinder properly. It is slightly more exact than a carb car with staggered jetting, but that isn't all you are limited to on a carb car. You still have the ability to advance and retard timing to each cylinder and/or hotter/colder staggered plugs.

[Ed Wright]

You can, most don't. You do know how to stagger jet a carb, right? If you don 't, you need to learn how. We were doing that in the 1970s. Sharper guys before that, I'm sure. Tuned properly, that turbo car would be at least as fast in open loop. If his ECU has to make adjustments going down the track he hasn't done a real good job of tuning it.