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seattlejester

Wastegate upsizing

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@rossman do you happen to have your numbers? PSI and hp?

 

@softopz I had an EBC, but it turned out it was sticking or something as it would only work sometimes.

 

Following chickenman's recommendation and help I bought a manual boost controller. That is plumbed just into the bottom of the diaphragm. Top one is left open. 

 

My thought was that the gate was too small, even with subpar priority and wastegate dumping, I didn't think it would make a big enough difference remedide, but then again I kind of want my dynamic range to be from 10lbs-20lbs so holding the lower number might be asking a lot of the little 38mm flange.

 

The setup isn't problemental as in facing compressor surge or something of that nature, I'm sure the engine would take quite a bit of boost. Too much boost in the sense of it being above what I think is comfortable within safety margins of the injectors currently, possibly the axles as well.  I am sure I could stuff more boost into the motor, but I'm still on stock internals and my ECU only reads up to 2.5bar and that is absolute bar so up to 23psi or so. I'd also like to keep the power a bit manageable, 

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Posted (edited)

Hussein. Been through this with SJ already. Precision Turbo instructions only list setup for a Bleed style MBC. SJ is using a Ball and Spring MBC which operates entirely different. B&S style has to be plumbed to lower housing with top vent to Atmo. Not the same deal as an EBC or Bleed Style manual Boost controller.

 

He was getting no Boost control at all following Precision instructions. After proper setup, he has Boost control. He just has a creep problem. That's due to bad W/gate inlet and exhaust design, IMHO. 

Edited by Chickenman

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4 hours ago, Chickenman said:

Hussein. Been through this with SJ already. Precision Turbo instructions only list setup for a Bleed style MBC. SJ is using a Ball and Spring MBC which operates entirely different. B&S style has to be plumbed to lower housing with top vent to Atmo. Not the same deal as an EBC or Bleed Style manual Boost controller.

 

He was getting no Boost control at all following Precision instructions. After proper setup, he has Boost control. He just has a creep problem. That's due to bad W/gate inlet and exhaust design, IMHO. 

I dont see your pm history and he never mentioned what type.of boost controller he had. Agreed the gate inlet /outlet is most likely the cause. I could of hooked it up with HDI EBC ! I have no issues with creep 

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Sorry, I should have mentioned my boost control setup, but in my mind it was a flow problem, and still most likely is a flow problem. I think the control mechanism is likely solid now thanks to Chickenman.

 

I think I'm with Chickenman in the MBC camp unless I get into boost by gear type setup, but that would need a digital speedo input and such so not for me right now, if I really wanted EBC again, all I need to do is buy another compatible solenoid since it is all done through megasquirt.

 

Planning on swapping springs tomorrow.

 

 

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14 hours ago, seattlejester said:

rossman do you happen to have your numbers? PSI and hp?

 

I'm running a 5lbs spring in the MV-S.  I typically run 10 psi but have run 8 psi and 15 psi at times.  It seems to be stable but I haven't logged it.  No HP numbers yet.

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Posted (edited)

Comparing boost numbers between an old L6 and a 2JZ is a bit like comparing apples and oranges.  I'm sure your engine is flowing considerably more air than mine at 10 psi, requiring your wastegate to handle a higher volume of air to keep it there.

Edited by rossman

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Of course, but it gives me a bit of a ball park to look at. Like if you cannot control boost with a similar turbo with a smaller engine, lower compression,  lower effiiciency, and all that then I have no chance trying to expect control with my setup

 

I installed the 6.9lb springs (uses a 5.6 and a 1.3 spring combined to make 6.9). I did check and I had a 9.4 lb spring installed previously. I ran some data logs so I can find the exact results at a later date, but looking at the little boost gauge I'm definitely creeping in lower gears if I shoot for under 10lbs. It was reading a little bit above 10lbs in 1st and 2nd, in 3rd I definitely hit boost cut if I rolled into it quickly. I can even make trouble for myself in second if I am going up a big grade.

 

Good news is there is really good routing to try and fix it. The 90* rotation adapter for the wastegate mount, then clocking the exit flange should let me do a merge that isn't anywhere as sharp.

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On 3/15/2018 at 6:48 PM, Chickenman said:

That's a good grinder. It will pay for itself the first time you use it. Tools are always a good investment. 

 

 

I'll second that - I have a Dewalt electric die grinder, and it's quite probably my favorite tool (and I have a lot of tools).  Just get it - you won't be sorry!

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Ugh.....I don't really want to do this, but in the essence of closure I think it is right to do.

 

I bought everything to fix this, 90* rotate flange, the flex pipe for the longer tube another u-pipe etc. Bothered my friend for some time and space since my welder was at his place.

 

Got everything off, started shaving down the bolts for the clocking flange to get a perfect fit, went to go put on my wastegate when I noticed.....

 

There were two ports on the bottom, and one was unplugged. Air was feeding one side of the bottom of the diaphragm, but the other side was left open so it was likely never building pressure. Thinking back, I did pull the fittings when I was manipulating it as you couldn't get to some of the bolts in certain orientation. My best guess is that I wanted to leave both open and decide later what port to use, the other one being in the back near the valve cover probably slipped my mind. That is if I even saw it, it is far back enough that I'm not sure any more.

 

Definitely a case of user error.

 

My wastegate holds boost down to 7 lbs well even with the poor flow routing in 3rd and even in 4th gear. I used the Grimmspeed MBC, really neat unit, they said It goes up 1/4 lb per click, so I clicked it up 28 times for 7 additional lbs of boost and I'm hitting just under the 15 lb mark on my gauge.

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At least you figured it out!  All of us that were trying to help assumed that the control setup was good.  Take it as a lesson learned; start with the simple stuff first and verify before you move on to the next, more complex possible cause.

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Yea, my friend gave me a hearty earful of laughter after we found out.

 

Super interesting getting some of the upper levels in the map to finally register, never been able to rev past 4k with boost before.

 

Hopefully you'll be getting a message real soon! Still definitely want to sort some things out first though. Don't want to be tuning around a physical problem.

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