Let's get technical: Tuning the ECU for mpg

[ashiga]

Originally Posted by pgfpro

I hate closed loop.

Have you tried running only open loop and build your own fuel/ign. maps. You can dial your tune in way better then stock when running in closed loop as long as you have a wideband for reference. Major gains can be made over stock by running in open loop with a good map.

I sold my wideband some time ago, but the point in raising the tps threshold is that it would switch into open loop only when I wanted performance (as I do want performance sometimes). Also as stock ecu does not accept 2 maps running at the same time (one map for performance and the other for economy) which is what I'd really want.
Apparently I had no significant improvement in raising the TPS, but I don't know whether it did or it didn't work. I've got stuck into HUGE traffic jams these days (12 miles in 1,5 hour).

[pgfpro]

Originally Posted by ashiga

I sold my wideband some time ago, but the point in raising the tps threshold is that it would switch into open loop only when I wanted performance (as I do want performance sometimes). Also as stock ecu does not accept 2 maps running at the same time (one map for performance and the other for economy) which is what I'd really want.
Apparently I had no significant improvement in raising the TPS, but I don't know whether it did or it didn't work. I've got stuck into HUGE traffic jams these days (12 miles in 1,5 hour).

You can have your performance and economy too. All you have to do is run the engine lean in light load and normal in mid to heavy load. All of this is of course based on your MAP sensor.

[dieselbenz]

Wide band tune for both FE and power. I used closed loop up to 80kpa.

[pgfpro]

Heres my low-cam fuel map.

These are raw numbers that I set by using a wide-band and real time tuning. All in tuned in open loop.

[ashiga]

That's great guys! Now I regret that I sold my wideband

[ashiga]

but I got 32 mpg cruising at 65mph on a trip last weekend. It got a bit better and brazilian pump gas is 25% ethanol.

[pgfpro]

What part of Brazil are you from?

Eventually I think the United States will be around 25% ethanol also.

[ashiga]

I'm sorry, I said it was 32mpg, but it was 36mpg (15km/l which is my native measure lol, google calculator just corrected me)
I'm from Sao Paulo, but that % applies throughout the country.
Some days ago I ran on 70% ethanol with no problem, just increased the fuel pressure. I kept some of the mods I had when it was turbocharged with E100 setup so I can do that safely now.

[pgfpro]

Originally Posted by ashiga

I'm sorry, I said it was 32mpg, but it was 36mpg (15km/l which is my native measure lol, google calculator just corrected me)
I'm from Sao Paulo, but that % applies throughout the country.
Some days ago I ran on 70% ethanol with no problem, just increased the fuel pressure. I kept some of the mods I had when it was turbocharged with E100 setup so I can do that safely now.

That's pretty good fuel mileage considering your speed and ethanol amount.

Also sounds like you have major traffic in Sao Paulo. I heard that the traffic is so bad that you have helicopter taxi's.

So most of your ethanol comes from sugar cane feed stock is that correct? Whats your price on ethanol there?

Sometimes I run E85 in my Talon for performance reasons. Its a very nice fuel for making great power at a low cost. One of my future builds will be a 800+ WHP Honda that will get 50mpg and E98 will be the fuel of choice for the performance side of things.

[ashiga]

That's pretty good fuel mileage considering your speed and ethanol amount.

Also sounds like you have major traffic in Sao Paulo. I heard that the traffic is so bad that you have helicopter taxi's.

So most of your ethanol comes from sugar cane feed stock is that correct? Whats your price on ethanol there?

Sometimes I run E85 in my Talon for performance reasons. Its a very nice fuel for making great power at a low cost. One of my future builds will be a 800+ WHP Honda that will get 50mpg and E98 will be the fuel of choice for the performance side of things.

Right now, ethanol is expensive, $3.5/gal (pump gas is $5.2/gal) it's not worth the warm-up time. In some months, $2.2/gal is the cheapest you can get. Pump gas has little to no change in price because the govt fixes its price to support the consumer price index. The break-even point we use when chosing the fuel is 0,7*GAS<=>1*ETH, so there's little saving in using ethanol right now. Also, 99% of the new cars are flex-fuel.
All of the ethanol here comes from sugarcane, the harvest excess is sold as sugar and vice-versa depending on international sugar price and demand.
It's the first choice of all tuners I know because it has bigger margin for errors regarding detonation and easily produces a few more HP.
It will be great to see your honda project . Hondas are the best when you want FE and performance.
Many people add ethanol to the gas tank for passing the smog check.
A chopper trip is not that expensive when you think about the time you'd spend stucked. When it rains it's common to average <10mph. 15-20mph on any other day.