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Whaaaa 5 port.... Does that mean you are using two spools? One open one close? Can't really see that making much difference mechanically, sure makes me think about how the control system will work tho...

I am using a Blitz DSBC to control the MAC valve. It is a two position switch, just like the 3 port valves, but the pressure in the two hoses self bleeds when switched off, meaning I can control the upper and lower ports directly without the hose or gate holding pressure.

It seems it would hold massive boost as it presses down on the wastegate, (helping the spring) until it switches to the lower port, bleeding off the pressure from the top chamber and pressurising the bottom to open the gate. It just seems smarter to me than the way Turbosmart recommend using 3 or 4 port valves.

http://www.turbosmart.com.au/wp-content/uploads/2012/06/TS-0506-1001_Hypergate45_MAY_12_rev-2.pdf

I actually ditched this setup for a while as I decided to run 26psi of spring in the gate for safety. (I had a wastegate line pop off, the car ran over 3 bar for a week, causing the head to lift) The 3 springs softened over a few months though, and boost dropped to 1.3 bar so out with the 5 port again. I am now back to 2.1 bar after a tune.

Boost holds rock solid, but it still over boosts when I hit the soft limiter (when the auto decides it doesn't want to shift.) Much better response with the MAC setup too.

Have you looked at exh back pressure pre turbine? That sounds like such a weird issue to get at low rpm. With a relatively small exh vs largish intake housing your more likely to see a linear increase in exh bp vs rpm. I've never come across the issue your experiencing in any turbo car. Slight over boosts are more likely due to poor electronic control, like PI integral windup... At the end of the day the difference between an internal waste gate vs external wastgeate when you are applying pressure either side of the valve is minimal if any....

I haven't tested the exh back pressure, I need to have some sensor bungs fitted to find the problem, this is something I will be doing at some stage, but having had the car off the road for a couple of years, I just want to drive it at this stage.

I'm pretty sure there won't be much of a restriction pre exh housing, I have a ported head, 100mm Greddy intercooler, Greddy Plenum, Greddy hard pipes, and a very well hand built Sinco Manifold that are used by just about every turbo race car in NZ. I also run a custom made, mandral bent 3.5" stainless exhaust with only the one back muffler, and it's a Varex so it's straight through 3.5" when it's open.

I know there is a lot left in this turbo (prob with the bigger housing) in fairness most of the EFR8374's with the .92a/r housings getting around on cars are under 2.5ltr engines. I just think the 3ltr is prob a bit big for it.

My tuner is a very tallented guy, and I don't doubt if there was something simple that would fix it, he would do it, having said that, any ideas that people have are always welcome, I'm happy to discuss it.

Chris.

Here's a screenshot of a quick run I logged last night playing with my boost control settings. Intake air temp is amazing with the W2A intercooler. You can see that it reaches full boost (14psi) at 3300RPM.

post-35732-0-56391700-1365806486_thumb.png

Edited by bradsm87

I'll prob aim to bring the Nismo 740's to around 86-89% duty cycle with 25% ethanol in the fuel so prob around 275rwkw on as low boost as possible. I'm confident with the ethanol and more timing that I can get 14psi at 3100rpm.

I am using a Blitz DSBC to control the MAC valve. It is a two position switch, just like the 3 port valves, but the pressure in the two hoses self bleeds when switched off, meaning I can control the upper and lower ports directly without the hose or gate holding pressure.

It seems it would hold massive boost as it presses down on the wastegate, (helping the spring) until it switches to the lower port, bleeding off the pressure from the top chamber and pressurising the bottom to open the gate. It just seems smarter to me than the way Turbosmart recommend using 3 or 4 port valves.

http://www.turbosmart.com.au/wp-content/uploads/2012/06/TS-0506-1001_Hypergate45_MAY_12_rev-2.pdf

I actually ditched this setup for a while as I decided to run 26psi of spring in the gate for safety. (I had a wastegate line pop off, the car ran over 3 bar for a week, causing the head to lift) The 3 springs softened over a few months though, and boost dropped to 1.3 bar so out with the 5 port again. I am now back to 2.1 bar after a tune.

Boost holds rock solid, but it still over boosts when I hit the soft limiter (when the auto decides it doesn't want to shift.) Much better response with the MAC setup too.

Not sure I really understand what the advantage is over a 3port - you may have to draw me a schematic.. If you connect port 3 of the Mac valve to the bottom side of the actuator and port 1 to the top of the actuator, when the solenoid is un energized port 1 is deadheaded, when energized port 3 is deadheaded, there's no path for the system to bleed off other than back to manifold through port 2.

I've always toyed with the idea of having a small pressure vessel that picks up on boost pressure with a check valve to stop it bleeding back to the manifold and use that as my "pilot" supply to the Mac valve, this way you will have whatever boost pressure you run onto of the waste gate even when spooling....

If you connect port 3 of the Mac valve to the bottom side of the actuator and port 1 to the top of the actuator, when the solenoid is un energized port 1 is deadheaded, when energized port 3 is deadheaded, there's no path for the system to bleed off other than back to manifold through port 2.

Exactly how I set it up.

The other 2 ports on the 5 port MAC valve bleed the wastegate ports off when you de-energise them. They have little muffler/filters. Works perfectly on my setup, and allows a flat 33 psi on a 14psi spring. Using the original DSBC solenoid on the bottom port it would always drop boost.

  • 3 weeks later...

Yes, I'm from Croatia

One 9180 is for calibra c20let (currently bw s400sx with billet wheel=930hp)

TS 9180 is for civic B20

and one is for r33

all for drag race

and one efr 6258

Edited by riki333
  • 2 weeks later...

And in Phil Fassion the air temp sensor is cable tied up to the dyno boom so its not over inflated with air temp correction either.

Well done mate.

Where it should be... Not in a cup of boiling water or resting on the exhaust manifold :P

I think this qualifies me for the 500kw club....

attachicon.gifIMG_9215.jpg

EFR's have delivered!

That's nice. With the T618Z I get 1 bar of boost at 3500 to 4000rpm but this is on a big 3L and big (laggier) cams on the street. I dont know what it is on the dyno. We have yet to run the car at such large boost though.

  • 1 month later...

the larger the wastegate size, the lower the boost level you will be able to run. If you do not plan to run low boost, (2) x 38mm is sufficient. If you want to run low boost without creeping, thats where (2) x 44mm would be suggested

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