February 8th, 2014: Intake completed! (continued)
Next I did something I am particularity proud of. I developed a new vacuum system that will give me peak power both off boost (peak power at zero boost) as well as on boost
Here is the problem.The ABV is normally closed. It needs a vacuum supply to become "open".
If I switch the Supercharger off (override the clutch pulley) and go full throttle, then vacuum drops to zero and the ABV closes (remember there is no vacuum at WOT). Well, then what the hell am I doing all this work for in the first place? hahaha Just kidding, of course there is a good reason because I'll have plenty of vacuum 99.99% of the time cruising on the highway in the flat lands, and the ABV will be fully opened all the time yielding maximum fuel economy (from my observations, the vacuum never drops below 12 inches while simply cruising at highway speed).
But, my weekend commute consists of two steep grades (up both sides of Pacheco Pass) and if I can put my foot to the floor without needing the Supercharger, then that is just going to be that much less gasoline consumed week-in week-out. So I have a real need for maximum zero-boost, zero-vacuum power.
So here is what I did.I built a dual channel ABV vacuum system that operates in a parallel configuration, consisting of a normally-open electronic solenoid and a one-way check valve.
Configuration 1: Supercharger Switched Off. In this configuration, the electronic solenoid is energized (so that it is closed off), and the engine vacuum sucks through the one-way check valve opening it up and activating the ABV which is behind the check valve. Because I am using a one-way check valve, if the vacuum source is suddenly removed, ie. when I am passing someone, vacuum is trapped at the ABV and the ABV remains fully open. Now I can operate the engine at maximum economy.
Configuration 2: Supercharger Switched On. In this configuration, the electronic solenoid is de-energized (so that it opens), and the engine vacuum sucks through it to activate the ABV (and probably also sucks through the one-way check valve which is present at all times). The moment vacuum is lost, ie. when you slightly roll into the throttle for boost, the vacuum is released from the ABV closing it, and you get full boost sent to the engine (it simply by-passes the one-way check valve through the opened solenoid instead). Now the ABV and boost operate as if they were 100% stock: ABV closes under boost and opens under vacuum to allow boost recirculation, reduce heat build-up, and minimize parasitic losses from the Supercharger.
Additional design implementations include:
A. I have included the "New ABV Mod Design" (see
this link) (a new method of forcing the ABV shut under boost that takes a pressure source immediately from the outlet of the S/C rather than the traditional method of reading boost late downstream from the intake manifold, thus reducing pressure signal lag to the ABV for a more responsive and more positive ABV closure).
B. The electronic solenoid draws power from terminal 87A of the relay that is used to disable the S/C clutch! All-in-one setup. This terminal is HOT whenever the clutch is switched off, and COLD whenever the clutch is switched on.
Both were natural implementations and came together so well. Didn't have to add any bulky relays, it's all controlled from the same, single switch, and I get the benefits of the New ABV Mod without even modifying the stock S/C outlet pipe!
Time for some pictures!
1: Spent some head-scratching moments figuring it all out. I originally thought I'd have to operate two solenoids and an additional switch which would have been so annoying and also excessive.
2: Here it is installed. Check out where I am getting my vacuum from ... the original outlet port of the ABV! You can also see it in the 2nd picture from the previous post above. I just drilled and tapped a 1" pipe plug that is inverted and installed with a hose clamp into the factory ABV outlet port. When I revert the intake back to stock, this pipe plug simply comes out and all the stock parts go back in. No drilling into the stock S/C outlet manifold (like they did in the above link) and nothing to try to hide from the smog technician when he smogs my car.
3: This is the relay I installed to override the S/C clutch. This is how I've been doing it since 1999 (with my old GZE). All I've done is I've interrupted the ground circuit to the pulley so that whenever the ECU tries to turn the SC on, it fails. The +12v power supply is always present and this is the power that I have at relay terminal 87A, but is absent from 87A terminal the moment the relay turns on. So with the flip of my one original SC clutch switch that I am already so accustomed to, the relay turns on, solenoid turns off, vacuum bypasses the one-way check valve, and everything operates as Toyota intended.
Side rant: I probably installed that relay the very same week I got the car running back in 2010. I've always overridden the S/C clutch on all of my 4A-GZE engines. At highway speeds the SC is constantly cycling, for instance when you go up and over an overpass, or you just need to accelerate slightly for a lane change. My 300 mile weekend commute consists of about a 5% Supercharger duty cycle. Unless I'm really, I mean really in a hurry, I never have the SC turned on. Why build up all that heat, why loose all that gas mileage, why wear out the SC, belt, bearings, et cetera. Now if I'm up playing in the hills oh yes, that switch is flipped on and it stays on buddy
4: Here is the solenoid wired into the relay and plugged in. ABV system is now 100% done and ready to rock'n'roll!