Too much of a good thing --15 minute gravity drop

[cfg83]

NachtRitter -

Originally Posted by NachtRitter

Seems like you could take advantage of DFCO, where you get the benefit of both the vacuum being generated for the brakes and zero fuel use of EOC... At least what I'm understanding is that the route is steep enough to require brake use, so taking advantage of engine braking too would (slightly) reduce the need for brake use.

I agree.

endurance -

You should be able to tell when DFCO happens. As you decelerate closer to your idle RPM, the ECU/PCM will turn the injectors on again. There should be the slightest of "bumps" when this happens, unless your RSX is silky smooth.

dennyt -

Sweet setup!

CarloSW2

[endurance]

Thanks for all the great replies. I bought a used Scangauge on e-bay last weekend, so in a few days I should be able to really test what gets me the best mileage and how much of a difference it makes between EOC vs. EFCO with the Acura. It's a pretty even descent and while there are definitely some corners that require getting on the brakes and I always have to be on the lookout for deer, I don't have to worry about overheating the brakes if I'm smart about how I use them. I really hesitate on holding my foot on the pedal for a long time because of the duration of the descent, so I'm not sure I want to try that strategy.

I did find a brake vacuum pump on e-bay designed for electric vehicles that's $179, so that seems like a decent option. It only draws 4.6amps and for 15 minutes with a long climb for the alternator to recover after the descent, I think the battery fully recharge before getting into work. I also have my eye on some well priced deep cycle batteries for a home solar project, so perhaps that would add some insurance if necessary.

My goal is actually to piss off a coworker with a Jetta TDI and get better mileage than him, so eventually, I'll be willing to go to extremes if that's what it takes. A mid-life ego is a dangerous thing to mess with. He may have youth and the better mileage car, but I have the resources to convert the car to run on unicorn farts if that's what it takes to win. Cheat to win!

[Angmaar]

Originally Posted by endurance

He may have youth and the better mileage car, but I have the resources to convert the car to run on unicorn farts if that's what it takes to win. Cheat to win!

That's the spirit!

[endurance]

After looking at another thread on the subject of coasting, it sounds like DFCO only works when the car is at operating temperature. The descent is from my driveway, first thing in the morning, so I'd guess with an operating temperature of 50F when I start and barely getting up to operating temperature 5 miles into the descent, I wouldn't reap the benefits. Does that sound correct? I'm still planning on putting the Scangauge to work testing out different techniques.

I did have one bad commute on this tank, but I'm definitely noticing that simply coasting in neutral whereever I can is really making a difference. A month ago I had a Yakima bike rack on top and was content with 29mpg. Now I'm craving 34 on this tank and dreaming of 45+ with mods and more nut behind the wheel adjustment. I think I have a new addiction. Thanks for the crack guys. ;-)

[bestclimb]

where do you get your unicorn farts?

I have been considering removing my vacuum assist all together. The thing that bugs me most about EOC and loosing vacuum assist is when braking is the sudden drop in effort and lots of extra braking when I bump start.

[euromodder]

Originally Posted by endurance

it sounds like DFCO only works when the car is at operating temperature.

On my car DFCO works right away.

[NachtRitter]

Mine too... though it's at a higher rpm that it kicks in when the engine is cold... 1200rpm instead of 900rpm or something like that.

Of course, one way around that is to use a block heater... probably would help out all 'round (warm engine gets better FE than a cold one).

[VegasDude]

An engine kill switch that cuts power to the fuel injectors does the same thing as DFCO, but can be used at any time, at any RPM. I use one on my Altima to slow the car at lights. Normally the injectors turn back on around 1500 RPMs, now I can DFCO below that. This maintains brake pressure, and adds a little juice to the battery. The latter is essential at night since my commute home is mostly downhill and the engine is off far more than it is on.

[user removed]

Get a block heater.

regards
Mech

[endurance]

An excellent suggestion and one that I plan on following through with. I've had them in the past when I lived in cooler climates and really appreaciated them. We moved into this new house just a couple months ago and we're still getting everything out of the garage. Hopefully the unpacking will be done before the snow flies so I'll have a convenient place to plug in and won't have a windshield to defrost in the morning.