[Idea] vacuum system idea to increase MPG? [/Idea]

[ps2fixer]

I could be looking at this the wrong way, but if you could disable all (or near all) vacuum devices on your engine including brakes etc, I would think you would get better MPG. I have read a little about some disabling the vacuum boost to their brakes so my idea might be ok.

Onto my idea...

Direct electric driven vacuum pump + large container to maintain vacuum and keep the electric motor need to a min. This is of course in a tightly sealed system with no leaks. Idea behind how it would inprove MPG would be the engine has to work less to suck in the air (non-turboed in my case).

Looking at þÿ I will want to leave my vacuum sensor and EGR system minimum intact correct?

I do need to search more details about vacuum systems, but figured some feedback as to MPG increases is my desire.

Side note: When doing a few EOCs, I found the brakes are fine, but I don't notice anything in the diagram relating to the brakes. Power steering is the oppsite, pretty high geared so steering isn't very good while EOCing and probably will only EOC if no one is around and during the day time.

Side note #2: If a vacuum system is in good shape, could it be tested by hooking all of the intake lines to a "collector" and using a vacuum pump (to 5psi vacuum) and watch for it to loose vacuum?

Input always welcomed.

[kurzer]

many diesel alternators have a mechanical vacuum pump at the backside.
maybe this is woth knowing.

for a first test, just close the hose and make a testdrive.

[ps2fixer]

I think just closing the vacuum hoses wouldn't give a very accurate restult due to effecting the EGR so much, and of what I can tell, the scangauge won't work with my car (not sure why). Vehicle compatibility - ScanGauge MPG gauge - EcoModder.com

Also not on the list for UG UltraGauge OBDII Compatibility

Only thing close I could do is read vacuum with and with out the mods driving at say 55mph with the idea of higher vacuum would result in better MPG.

If I could get instant fuel usage/MPG reading, I'm willing to test ideas. I live in the country and traffic is pretty low.

Also on the subject of diesel, the engine does not use a butterfly, so the engine does not have excess vacuum to use so it needs the vacuum pump to provide the vacuum.

[pete c]

I think this is a bad idea.

It means ignoring a free vacuum source and installing an extra electric motor to take it's place. This is an extra load on the alternator and will surely reduce mileage.

BTW, you do have braking with EOC, even if it is only 3 or 4 pumps.

I could see maybe installing a small electric motor to maintain vacuum for braking, but not as a primary vacuum source.

[Josh8loop]

Were you thinking of applying this to gasoline or diesel engines? If it's gasoline, I can see no benefit. The engine is counting on some external air-in leakage and modulates the idle air control valve to accomodate. If you were to remove this vacuum system air-in leakage, the IAC would just open a bit more to compensate. Even off idle where the IAC has no control with reduced vac system air-in leakage, the throttle would just need to be opened a bit(extremely small amount) more to maintain the same overall manifold pressure.

On the diesel side of things, reducing the volume of air throughput through the vacuum pump may give a slight and perhaps unperceivable efficiency bump. FWIW


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[drmiller100]

what josh said. the engine is making vacuum no matter what - you might as well use the "Free" energy for brakes and stuff.