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-   -   Fully Electronic Wastegate Control? (https://www.miataturbo.net/megasquirt-18/fully-electronic-wastegate-control-81605/)

elior77 10-30-2014 03:34 PM

My fabricator gave me a good idea today :idea:.

Fix the wastegate @ the max boost you want, and install an external WG on the intake pipes, with a proper EBC you can control how much of the max boost your internal WG is making you actually want to gave the intake manifold...

I think you will go that route, I want 0-16psi.

Leafy 10-30-2014 03:37 PM

That sounds like a great way to over speed the turbo while throwing efficiency out the window.

With a max desired boost of 16psi you dont even need to do anything fancy to get pretty much linear torque with throttle position. A 6-7psi waste gate can and a normal 3 port boost controller is all you need. Now for the people who want to run 25+psi and have that sweet throttle to torque relationship the 4 port setup is where its at.

elior77 10-30-2014 03:38 PM

If you fix the wg at a specific max boost, how would that over speed the turbo ? because it does not start the spool with closed wg ?

I would like to get 0-16psi, all the range, 0 psi while the wg is open and with no boost for cruising and fuel economy. (I use a small turbo)

PiazzaT 10-31-2014 08:42 AM


Originally Posted by elior77 (Post 1179820)
My fabricator gave me a good idea today :idea:.

Fix the wastegate @ the max boost you want, and install an external WG on the intake pipes, with a proper EBC you can control how much of the max boost your internal WG is making you actually want to gave the intake manifold...

I think you will go that route, I want 0-16psi.

What you have donere is rediscover the dumpvalve regulated boostpressure. A system noticeable use sine the 70's due to its horrible inefficiency.

elior77 11-04-2014 04:26 AM

Let me correct my self please.

- Install on the actuator the spring that would give you max boost you want.
- Install blow off valve on the intake plumping.
- Connect boost control to the blow off valve.

BLV closed = max boost
BLV open = 0psi boost
BLV regulated = regulated boost up to spring.

You can now achieve 0 to spring boost levels.

Better ?

Leafy 11-04-2014 07:22 AM

No. It still doesnt work. Because you'll end up commanding lower than spring pressure boost at some point which will push the turbo past its redline and spin the bearing. Your method generates more heat for the same boost pressures as just doing it normally and typically puts the turbo in a lower efficiency range because it make it operate more to the right on the compressor map.

elior77 11-04-2014 07:52 AM

Ok then, I can understand what you're saying.

What would be a good way to get 0-16psi range ?

Thanks

Leafy 11-04-2014 08:33 AM

Run a 6-7ish psi actuator and a 3 or 4 port boost controller and use boost vs tps. 7psi would end up being the minimum full throttle boost you could get but zero psi would be around 30% throttle depending on rpm and turbo choice.

But if you actually want to get a setup that can do 0-16 psi at full throttle then you're going to need a large external wastegate and a co2 system.

elior77 11-04-2014 08:35 AM

I got AMS500 with co2, I need external WG ? How would I set it up ?

Leafy 11-04-2014 08:38 AM


Originally Posted by elior77 (Post 1180639)
I got AMS500 with co2, I need external WG ? How would I set it up ?

Depending on your turbo size even fully open an IWG can still create boost. IE on my car I cant generate less than 10psi at peak torque with the efr6758 even with the gate open as far as the actuator goes.

elior77 11-04-2014 08:43 AM

I got a small TD04-13C, when the actuator is removed I get little to no boost (0-3psi)

stoves 11-04-2014 09:39 AM

1 Attachment(s)

Originally Posted by Leafy (Post 1178231)
no no, thats just the solenoid you want with the 2 port waste gate. You want like a 7psi spring in the waste gate. The normal waste gate just pushes against the spring to open the gate, but exhaust gases eventually push the gate open against the spring even if you leave the wastegate open to the air if the spring is that soft. But with the 2nd port on the wastegate and the 4 port soleniod you can use the boost air to push on the same side as the spring holding the wastegate closed.

https://www.miataturbo.net/attachmen...ine=1415111941
This helped my understanding greatly.

Stot 12-29-2014 01:08 PM

There are electronic actuators on many modern turbos. I believe they are PWM controlled.



I'm sure they could be made to work with an MS.

There were/are many 2 stroke bikes that use a power valve system or an EXUP valve servo. They use a push pull cable system and could also likely be used.

Cheers
Stot

AbeFM 06-26-2016 04:28 PM

Er, you've guys seen these, right?

Official Turbo Wastegates | WG, 40mm, 50 turbo wastegate

They make them right in town. Their BOV's are ridiculously fast. I'm sure I can find out more if anyone cares. But it's an easy way to get a few levels of boost mechanically.

-Abe.

Joe Perez 06-26-2016 05:10 PM

Welcome back, Abe.

Is the cat dead yet?


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