Unmetered Air leak = Better MPG??? - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

Tygen1 · 09-19-2009, 05:56 PM

I'd like to think I got a pretty good grasp on automotive stuff. My hunch is I'm just fooling myself.
There is tuning software available for the Escort, but it cost more than what I'd be williing to spend. Besides Autospeed has published some pretty simple do it yourself lean burn articles. I'd avoid the EEFI, your ECM will just learn it's way around that mod. AutoSpeed just put a relay on the O2 sensor to disconect it so the ECM would put the car into open loop so it would determine mixture off the MAF. Then they just put a Pot on the MAF and nice wideband to get the right ratio. Basically a relay box to turn off the O2 and add resistance to the MAF. Simple but efffective. I've seen ZX2 guys run as lean as 17.3-1. So I know there is some room for improvement.
I'd like to try this next year, just gotta save up for a wideband. Maybe this is evidence that can help me justify a wideband.

Christ · 09-19-2009, 08:45 PM

Quote:

Originally Posted by Tygen1

I'd like to think I got a pretty good grasp on automotive stuff. My hunch is I'm just fooling myself.
There is tuning software available for the Escort, but it cost more than what I'd be williing to spend. Besides Autospeed has published some pretty simple do it yourself lean burn articles. I'd avoid the EEFI, your ECM will just learn it's way around that mod. AutoSpeed just put a relay on the O2 sensor to disconect it so the ECM would put the car into open loop so it would determine mixture off the MAF. Then they just put a Pot on the MAF and nice wideband to get the right ratio. Basically a relay box to turn off the O2 and add resistance to the MAF. Simple but efffective. I've seen ZX2 guys run as lean as 17.3-1. So I know there is some room for improvement.
I'd like to try this next year, just gotta save up for a wideband. Maybe this is evidence that can help me justify a wideband.

What's COZX2 running? I mean, he's got something going on to get 100+, right?

What's his average, by the way (real world numbers)?

Tygen1 · 09-19-2009, 11:09 PM

COZX2 never really told what he did, I presume he was running some tunning software because he said he was tweaking the fuel trims, he just never said how.... His last few posts before he disappeared were about having his ZX2 torn apart for better trans gearing, custom cams and more compression. I'm sure he was running it lean for flat ground, but it seems like he was the king of EOC and that's what really got him to 100+

His average was actually around the mid 50's. His mpg rose so quickly he never had time to accumulate those extraordinary trips to bring his average up. I remember a post about his flat groud cruise mpg being in the 60-80 territory, which places him there with the lean burn boys. Living at 10,000 feet and mastering the EOC on the hills he lived in got him past that. He even repaved his driveway in a loop to prevent losses from having to back out in the morning. He had one battery for going to work and one to return so he wouldn't have to use his Alt. He coasted so much he not only had a full grill block, but a full radiator block to try and preseve heat, in fact he stuffed his engine bay with R-30 bats to keep the heat in. Of course this was because he was shooting for 100+ mpg in the Colorado winter

Christ · 09-19-2009, 11:21 PM

This is something that I've considered with hybrids, actually... why do they really need a radiator? I mean, if the engine gets in to over-heat territory, it could just shut down, allowing the electric motor to drive the car... I'm not sure how exactly that would work, but thermo-electrics could help with the overheating issue - if you convert heat energy to electrical energy, it helps to cool the engine.

Hm.. I'm not an engineer... someone tell me why this seems too easy, without discussing price?

Tygen - As I"m sure you know, being "Master of your Domain" is one of the best ways to get better mileage from anything... once you've learned how your car and your route interact with each other, you can get some pretty remarkable numbers going on. Upset either of those things, by using a diff car, or taking a slightly diff route, you can quickly go downhill. That's one of the big problems about using a car that wasn't designed (or redesigned) for FE, that it's limited to what the driver can do, and when the driver can do it. If any one variable changes, the FE goes to hell.

moorecomp · 09-21-2009, 10:56 PM

Well, here is another 432 miles with the air line disconnected, and the mpg's are not that bad. Actually a little above the last tank. 42.77 this tank and 42.67 on the previous one. Not enough of a difference to call an improvement, but it is amazing how this leak does not affect the mpg's. My MPGuino calibration is coming along, as I was within 1% of the pump reading (.4 mpg's) this time. I think I will call it good. The miles are dead on. I am hooking the line up for this tank and we will see how long it takes the ECM to relearn the fuel trims. I hope the hit is not too bad.

Tygen1 · 10-06-2009, 08:53 PM

Ok, I'm resurecting this because I've been messing around with it. I'll post up some pic's soon. So, I pluged the line back in and reset the ECM to get a good baseline. So after a week and half of commuting, I'm satisfied that the ECM is all adjusted and working well. If you check out my fuel log, you'll see a recent drop in mpg, I suppose the winter gas is here. Anyhow, I found that the line going to the intake is a vacuum line. So why would there be a vacuum line running to the intake tube between the MAF and TB??? This line is hooked to some sort of manifold thing, I say thing because it looks like it's check valves, but I need to confirm that to be sure. So I'm gonna run it unhooked, but with a filter so I don't suck in junk, for another week and half and see if the "ghost" mpg gain is real and stays around.

Christ · 10-06-2009, 08:56 PM

You sure that's not part of evap?

Tygen1 · 10-06-2009, 09:38 PM

Yep, not part of evap and yes, it is just a check valve manifold for the PBB. The other end of the line goes to below the TB.
Check out the pics. Filter added and the red capplug on the intake tube. The other picture shows the line disconected. Also not the recent Coil On Plug conversion, sadly no mpg gain from that, but I'll never have to buy wires again

Christ · 10-06-2009, 09:51 PM

I saw the COP conversion. It's got it's own benefits, if you can justify the cost for some cars.

Tygen1 · 10-06-2009, 10:53 PM

Cost me $40 in junkyard parts. Would have cost about 15 less if I had taken the harness conectors off, instead of taking the harness.....coils were $5 each

Tomarrow morning will be the first commute with this set up, so we'll see what's up.