From a different thread that went off the rails. https://www.miataturbo.net/diy-turbo...m_content=post

It's been a month of coding and testing. It's a hobby right?
What's my goal? idk, kill a month of my life? Really I think it would be great if the turbo drove like a big naturally aspirated engine. Any movement of the throttle and the boost just follows. It can go from basically no boost by holding the gate wide open to keeping it fully shut. It's a really complex way to get maybe10% better control over typical closed loop boost systems. The most difficult thing to do is to hit a set point and hold a flat line. Drag racing really needs a flat boost response. This is not a drag car. Autocross almost never requires full throttle for more than second at least not at high power levels.

The graph shows how it regulates. There are two mac valves. Bottom half of the graph shows the white decrease solenoid which opens the gate and the red increase which bleeds off dome pressure to let the spring close the gate. It's operating at only 25psi.

Normally this would be called dome control. Usually you'd use a co2 tank or high pressure air system to control the dome side of an external waste gate. There would be boost pressure to open the gate and high pressure to close it. There would be a pressure sensor in the dome to help regulate the gate. This is entirely different. There are still two solenoids to increase and decrease the pressure in the actuator but in this case the actuator is an ordinary single port internal gate that opens with pressure applied. The only feed back to the system is manifold pressure and there is not connection to the boost port on the turbo. It's sketchy AF.

Simply running out of pressure in the compressor will cause the gate to stay closed. So there two safeties. I already have a valve on the manifold which allows air in for rev matching down shifts. That's a different system but multi purpose. It can let out excess pressure. Also over boost protection which kills fuel at a boost limit.

Now, I have no idea how well this system will work in practice. It might just be a flop and constantly give me issues. Keeping a compressor in the trunk really kind of sucks too. I already forgot to turn it on and it's only been a day. See previous thread for "test setup number 1." See above for what happens when it runs out of air.

Anyways, this is only the beginning.

2nd and 3rd gear pull

 

Crazy stuff man. Idk if the tank is worth it weight wise, but that's for you to decide. Now if it doubled as a spool shot I might be convinced.

Let's see the code!

 

I will pm you.
The compressor is 10 pounds. The pump is 3 pounds. I am looking at options for making some lightweight tanks. It really doesn't take much air.
Although, we all know why a miata could use an air horn...

 

 

I recommend either moving that regulator to the engine bay, or adding a secondary pressure tank up there (coke can sized should do)

 

Ya there are some really small stainless ones on amazon but I'm thinking plastic or aluminum. I might even put a soda bottle behind the glovebox.

 

So far so good. I've been to two autocross weekends without issue with the boost control. A low elevation event in Washington on a cold day and another in Las Vegas during a "warm" spring day.