Quote:
Originally Posted by abogart
I will be making the 180 mile trip across the state again today, and I should have some results of how the E30 performs.
|
The results are in: 33.5 MPG on E30 up from 33.2 MPG on E20
. Note that I did increase tire pressure 40 to 45 PSI during this time and the weather has been warmer. I did have to adjust the SG fuel% up a few more points again, thinking this might affect trip MPG readings.
Knock retard kicks in at about 26" MAP. at 2500 RPM and 24" at 1500 RPM TC locked. Fuel trim ran +4 at cruise and up to +6 city. Mid-range horsepower is diminished under normal load, but still manageable for reasonably good acceleration without tripping the knock sensor, however low-end torque is even better than on E20. I actually found it difficult to cruise above the 12.4" MAP where the TC unlocks, cruise control just pulses between locked and unlocked. Cruise throttle is only 8% relative TPS, so some VERY fine footwork is required to maintain steady-state cruise.
I just put an E40 blend in the tank last night. I could immediately tell that mid-range power is reduced even more during acceleration between 2000 and 2600 RPM. Low-end torque seems even better than before. I was able to run up to 29" MAP (100% load) without tripping the knock sensor
. Still not sure if BSFC is better in this range though. Fuel trim ran +7 city, I haven't seen it go higher than that yet, hopefully this is just because the AFR is right and not because it can't adjust any higher.
One thing that I have noticed is that I can cruise at idle for quite a ways with the trans. in D now. I'm wondering if this has anything to do with the fact that I just cleaned out the EGR passage in the intake. Another theory that I have been tossing around is that the extra vapors from the ethanol in the tank are being collected in the EVAP canister and released during deceleration. This might explain why fuel trim drops to -4 or even less during deceleration in-gear, most likely signifying EVAP purge operation.
I have also noticed that the car starts and runs a lot smoother on higher ethanol blends than on regular gasoline. I will post when I get the results from the E40 tank. Not sure if straight E85 is going to work in this car, but these blends have some seriously promising results.
