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[patsmx5]

N/O = Normaly Open
N/C = Normally Closed

Hobbs switch = 2-24 PSI adjustable pressure swtich from egay.
Bleed valve = old refrigerator water supply valve cracked open.

If you put pressure on the top port of the wastegate, it pushes the valve shut, and the gate never opens. (verified by finding fuel cut/ overboost protection when I originally plumbed the wastegate incorrectly.

If you put 8.5 PSI on the side port with it sitting on a table saw, the valve cracks open. (8 PSI spring)

The hobbs switch is a normally open switch. I plan to run 12 PSI boost. So say I set the hobbs switch to swtich closed at 11 PSI. MBC is set to 12 PSI

0 boost = wastegate is shut, no pressure acting on it.
5 PSI boost = wastegate is shut, 5 PSI pushing on the top port to keep it pinned shut.
10 PSI boost = still shut, 10 PSI pushing on the port
11 PSI boost = hobbs switch closes, solenoid powers on and boost is shut off from the top port and swtiched to the side port. Freeze time........

Right as this happens, the wastegate is still pinned shut. Odds are the bitch is wide ass open, so boost is building fast, getting ready to overshoot. Boost has been removed from the top port and the valve closed, so it's bleeding off. Simultaneously, boost has just been applied to the MBC, so pressure is building on the side port, to open the WG.

And hopefully it shoots to 12 and holds flat. If it overshoots, then either

A- the top port didn't bleed fast enough and there was still some pressure holding the WG shut
B- the side port didn't get pressurized quick enough and the valve doesn't open in time.

Things that could cause A
     too much hose/area pressurizing
     too small of a bleed valve

Things that could cause B
     too long of hose
     tiny ass ports on my egay MBC suck at life

So make everything short and sweet, and if it still overshoots adjust the hobbs switch down to 10 PSI or whatever till it doesn't overshoot.

Will this work? 


On a side note, I spent like 5 hours today bench testing the WG with dual ports, dual diaghram pressure regulators, bleed valves, etc. I got this working mechanically, but it wasn't great. I think adding the electric shit will make it much better.

[patsmx5]

And I'll put another solenoid after the bleed valve, right next to the top port to act as a dump valve. So whenever the hobbs switch closes, air stops going to the top port, and at the same time, another solenoid hooked to the top valve opens to dump any pressure that's in it immediately. This should reduce latency and allow me to set the hobbs switch pressure closer to the desired boost pressure.

[patsmx5]

Looks good man. Aren't you runnin MS though? Why don't you just do the ebc mod?

Yeah, I am running MS2. But their EBC is quirky. It's open loop. You setup a % duty cycle and it does whatever the chart tells the valve to do. So if ambient temp drops from 90*F to 70*F you'll overshoot boost unless you set the table conservative enough to not do so, which defeats the purpose of EBC. Many miata guys just pull out a laptop and change their EBC table once a week, but that's not for me. I want set-it-and-forget-it.

There's also closed loop, but it doens't work either. The guys that wrote the code for it don't understand calculus or PID, and they fucked it up.

[patsmx5]

That sucks. Is the ebc for MS1 any better? Thats what i'm gonna be running and I was hopin to do use the the ebc feature.

Nope, ebc sucks on both. MS2 has closed loop, but it doesn't work either. They've "been gonna fix it" for like 2 years so far, and it hasn't happened. MS does fuel and spark good enough for what I'm doing, but it SUCKS compared to a lot of other systems out there. I dare call MS a system, it's just a good hack.

[patsmx5]

Just took it for a test drive and wow, boost is great. Running 190kPa, so like 12-13 PSI. More than before. I ran some black integra and embarassed them. I rolled on it in second for like 3 seconds and put 10 cars on us, I slowed down and they were laughing, and they laid back and I didn't see them anymore. 

[patsmx5]

I guess it all looks good, else yall'd be calling me out. 

[patsmx5]

Where do yall get a solenoid like the one I need? I'd like soemthing with some 1/4" NPT ports on it to put some barb fittings into. But I'm not finding shit. I found a 310 12VDC valve but it's 1/8" NPT and expensive.