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milo9 · 07-02-2012, 01:45 PM

I have an older Toyota SUV that has a 6 cyl with EFI which is my main vehicle and for the occasional expedition use. After a year of following this forum and many mods, especially aero, I still have the problem of getting up the numerous hills and long steep grades, elevation runs from 3000 to 6000 feet in normal use. This model of engine has been successfully upgraded to Turbo with great results but way out of my price range. My biggest gas eater is getting up the hills at low vacuum and slow speed, coasting down the other side doesn't seem to make up for the waste.

I have added a DIY water misting system controlled by a relay off the EGR circuit, just to up the ability to run low octane gas with some more timing advance. The idea being that a water methanol mix is better than exhaust gas for the engine.

Idea 1: Install a battery operated leaf blower with approx a 130mph wind rating ducted into the side of the airbox. When the vacuum drops (I drive by a vacuum gauge) to 5"hg I flip a switch to turn on the blower. If this works a control circuit could be designed to control it.

Idea 2: The engine has a Smog Pump which according to Toyota only is used to prevent backfiring. I have added an LED indicator to the control circuit and it has only come on briefly on a long downhill run. I could reroute the hoses so that the low pressure high volume output goes into the air system where the intake was taken from, between the airbox and throttle body, switch the valve on as needed or leave it on all the time. Another case where this could be done by a control circuit. I don't know if I switch to a California CAT converter it will need more air pumped to it than the 49 State version?

Idea 3: The control circuit could be programmed to add air to either 1 or 2 by the vacuum dropping to a certain level, when engine goes into open-loop via monitoring an AF ratio meter, or when the TPS hits a set value. For now an on/off switch seems good enough when going up a hill.

Besides wanting feedback on if any of these ideas are worth trying does anyone think using boost just to get up a steep grade would produce better MPG than just creeping up it trying to keep the vacuum as low as possible without downshifting?

07-02-2012, 01:45 PM	#1 (permalink)
milo9 EcoModding Lurker Join Date: Nov 2009 Location: Out West Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts	RFC: DIY mini-Turbo ideas (long) I have an older Toyota SUV that has a 6 cyl with EFI which is my main vehicle and for the occasional expedition use. After a year of following this forum and many mods, especially aero, I still have the problem of getting up the numerous hills and long steep grades, elevation runs from 3000 to 6000 feet in normal use. This model of engine has been successfully upgraded to Turbo with great results but way out of my price range. My biggest gas eater is getting up the hills at low vacuum and slow speed, coasting down the other side doesn't seem to make up for the waste. I have added a DIY water misting system controlled by a relay off the EGR circuit, just to up the ability to run low octane gas with some more timing advance. The idea being that a water methanol mix is better than exhaust gas for the engine. Idea 1: Install a battery operated leaf blower with approx a 130mph wind rating ducted into the side of the airbox. When the vacuum drops (I drive by a vacuum gauge) to 5"hg I flip a switch to turn on the blower. If this works a control circuit could be designed to control it. Idea 2: The engine has a Smog Pump which according to Toyota only is used to prevent backfiring. I have added an LED indicator to the control circuit and it has only come on briefly on a long downhill run. I could reroute the hoses so that the low pressure high volume output goes into the air system where the intake was taken from, between the airbox and throttle body, switch the valve on as needed or leave it on all the time. Another case where this could be done by a control circuit. I don't know if I switch to a California CAT converter it will need more air pumped to it than the 49 State version? Idea 3: The control circuit could be programmed to add air to either 1 or 2 by the vacuum dropping to a certain level, when engine goes into open-loop via monitoring an AF ratio meter, or when the TPS hits a set value. For now an on/off switch seems good enough when going up a hill. Besides wanting feedback on if any of these ideas are worth trying does anyone think using boost just to get up a steep grade would produce better MPG than just creeping up it trying to keep the vacuum as low as possible without downshifting?