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Old 04-14-2014, 11:25 PM   #851
JMlegacy
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i wanna see before and after

Weekend I try this again.
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Old 05-07-2014, 07:39 PM   #852
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So I setup my hybrid boost control to use the Hallman as-is, meaning I left the bleed hole on the WG side untouched. I never quite understood why you guys were plugging it with the hybrid topology. With the VF37, I peak at 19.5 PSI and taper to about 15 PSI. Seems like I should be able to hold a little more top end boost out of that turbo but I don't know for sure.

Any chance the bleed hole has any significance here? Can someone explain why I'd plug or not plug the hole?
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Old 05-07-2014, 08:14 PM   #853
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Quote:
Originally Posted by SubNub View Post
So I setup my hybrid boost control to use the Hallman as-is, meaning I left the bleed hole on the WG side untouched. I never quite understood why you guys were plugging it with the hybrid topology. With the VF37, I peak at 19.5 PSI and taper to about 15 PSI. Seems like I should be able to hold a little more top end boost out of that turbo but I don't know for sure.

Any chance the bleed hole has any significance here? Can someone explain why I'd plug or not plug the hole?
What rpm does it start to taper? Does it hold 15psi to redline?
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Old 05-07-2014, 08:24 PM   #854
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Just to update everyone on my latest results; my turbo is damaged and needs to be repaired. It is pushing oil into the intake and coming out where the PCV tubing is attached. I'm not sure what happened, but it very well could have been a result of doing WOT pulls trying to slowly increase the boost on the MBC with the intake port on the EBCS capped. I went through about a 1/2 tank of gas until the MBC was maxed out and the boost hadn't increased at all once I got to around 12psi. I'm thinking I should have waited until I installed the map tuned for use with a hybrid system.

I'm going to send my turbo to 6 Star Speed in VA to have them completely refurbish it for $450.00.
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Old 05-08-2014, 06:44 AM   #855
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Quote:
Originally Posted by SubNub View Post
So I setup my hybrid boost control to use the Hallman as-is, meaning I left the bleed hole on the WG side untouched. I never quite understood why you guys were plugging it with the hybrid topology. With the VF37, I peak at 19.5 PSI and taper to about 15 PSI. Seems like I should be able to hold a little more top end boost out of that turbo but I don't know for sure.

Any chance the bleed hole has any significance here? Can someone explain why I'd plug or not plug the hole?
adding a post restriction (ie after the mbc or after the solenoid) bleed will cause less pressure signal to reach the wga.

that means you'll need less wgdc (or less mbc spring tension) to reach the same boost.

it will also dampen the response of the system.

whether or not you need to adjust the bleed rate (or eliminate it completely) will depend on your particular setup.

also, what is the wastegate tension on that turbo? it very well could be so low that the EGBP is blowing open the wg up top.
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Old 05-08-2014, 06:47 AM   #856
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Quote:
Originally Posted by sti2relaxxxin View Post
it very well could have been a result of doing WOT pulls trying to slowly increase the boost on the MBC with the intake port on the EBCS capped.
i can tell you it wasn't that.

the only way to prematurely kill a turbo is either poor lubrication, excessive oil pressure, overheating, overspinning, or FOD.

even then, sometimes they just wear out.
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Old 05-08-2014, 10:25 AM   #857
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Quote:
Originally Posted by ride5000 View Post

Quote:
Originally Posted by sti2relaxxxin
it very well could have been a result of doing WOT pulls trying to slowly increase the boost on the MBC with the intake port on the EBCS capped.
i can tell you it wasn't that.

the only way to prematurely kill a turbo is either poor lubrication, excessive oil pressure, overheating, overspinning, or FOD.

even then, sometimes they just wear out.
You originally had a tune that was knocking pretty bad regularly. Was it after-firing/popping at all?

Agreed with ride5000, what you did won't cause a turbo to go bad. When it gets replaced, have them give you the old turbo. How much oil are we talking about? The PCV systems on these cars do pretty good at pushing oil through the intake tract.

If this would have been 4 months ago, I would have had an excellent, LOW mileage VF39 to sell you.
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Old 05-08-2014, 11:48 AM   #858
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Quote:
Originally Posted by ride5000 View Post
adding a post restriction (ie after the mbc or after the solenoid) bleed will cause less pressure signal to reach the wga.

that means you'll need less wgdc (or less mbc spring tension) to reach the same boost.

it will also dampen the response of the system.

whether or not you need to adjust the bleed rate (or eliminate it completely) will depend on your particular setup.

also, what is the wastegate tension on that turbo? it very well could be so low that the EGBP is blowing open the wg up top.
To answer the earlier question, it looks like I taper to 15PSI at around 6250 RPM and it seems to hold steady after that. The boost begins tapering somewhere in the 5k-5500k as I'm at about 17PSI at 5500 RPM. I haven't taken many logs winding it out to 8k so perhaps I can report back when I have but that's what I dug out of the logs I do have.

I assume that the MBC bleed port affects both the MBC and the EBC since air is able to reach that bleed hole if it's flowing through the EBC since the hose is run in parallel.

Wastegate spring pressure is surprisingly low at ~8.5 PSI. Apparently the VF37, being twin scroll has a rather large WG surface area. I'm not catching on to the "EGBP"...what is that? Exhaust Gas Back Pressure?

I assume I could replace the WGA with an adjustable aftermarket one that I could swap springs on for something like 12-15 PSI which might help hold boost longer. I still think the post compensation max WGDC table is biting me though but I don't know how much air the EBC is actually leaking at 90% duty cycle...
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Old 05-08-2014, 12:27 PM   #859
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Quote:
Originally Posted by yamahaSHO View Post
You originally had a tune that was knocking pretty bad regularly. Was it after-firing/popping at all?
Not that I know of. I wasn't able to hear any odd noises from the turbo and still don't; just the loud additional noise during idle.

Agreed with ride5000, what you did won't cause a turbo to go bad. When it gets replaced, have them give you the old turbo. How much oil are we talking about?
There is liquid oil around the area where the PCV attaches to the intake duct, and lots of oil residue around the surrounding area. The Subaru Tech said the softness of the intake piping leading into the turbo was also an indication of the turbo pumping oil into the intake. See pics below to get a vague idea of where the oil is.

If this would have been 4 months ago, I would have had an excellent, LOW mileage VF39 to sell you.
I am having my VF43 refurbished by 6 Star Speed in VA. Here's their link:
http://6starspeed.com/suvfsetupere.html



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Old 05-08-2014, 12:29 PM   #860
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yeah, for oil to be leaking from the inlet pipe, it has to come through the PCV recirc system.
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Old 05-08-2014, 12:41 PM   #861
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Quote:
Originally Posted by ride5000 View Post
yeah, for oil to be leaking from the inlet pipe, it has to come through the PCV recirc system.
The tech was telling me the oil was coming from the turbo (blow by), into the intake, and up out of where the PCV connects. Is that what you mean? I don't mean to get this thread OT so you can PM if you'd like.

I'm glad I posted this issue here though as its good to know that hooking up my hybrid system didn't cause the issue.
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Old 09-11-2014, 01:47 PM   #862
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I've got a science experiment if any of you guys are interested in trying it out, as a new option in the capped/uncapped debate... Uncap the NC port (#1 for the Grimmspeed EBCS), plug in a section of vac hose, then a boost-rated easy-cracking check valve (like the brake booster hose inline unit) with the flow direction from the intake to the solenoid port. On the other side of the check valve run a vac line to the normal intake port. For bonus points, tape over the bleed port on the MBC although this shouldn't be necessary, just an optimization. The non-MBC portions of the WGDC TD tables tuning should be pretty much the same as a normal 3-port table setup.

Any takers?
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Old 09-17-2014, 07:00 PM   #863
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Originally Posted by SubNub View Post
To answer the earlier question, it looks like I taper to 15PSI at around 6250 RPM and it seems to hold steady after that. The boost begins tapering somewhere in the 5k-5500k as I'm at about 17PSI at 5500 RPM. I haven't taken many logs winding it out to 8k so perhaps I can report back when I have but that's what I dug out of the logs I do have.

I assume that the MBC bleed port affects both the MBC and the EBC since air is able to reach that bleed hole if it's flowing through the EBC since the hose is run in parallel.

Wastegate spring pressure is surprisingly low at ~8.5 PSI. Apparently the VF37, being twin scroll has a rather large WG surface area. I'm not catching on to the "EGBP"...what is that? Exhaust Gas Back Pressure?

I assume I could replace the WGA with an adjustable aftermarket one that I could swap springs on for something like 12-15 PSI which might help hold boost longer. I still think the post compensation max WGDC table is biting me though but I don't know how much air the EBC is actually leaking at 90% duty cycle...
What gear did you do this test in?

I've heard mixed responses that my vf34 2.0 should be able to hold 17psi at redline in 2nd gear upwards. I'm on a 12lb WG spring. Best I got was 15 but i'm yet to go 100WGDC in the hybrid setup
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Old 09-17-2014, 08:35 PM   #864
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UPDATE:
(3 port + mbc)

Well, it seems I'm able to hit the 17psi in 2nd gear at redline. pulling in 241 g of air as opposed to 220.

Problem is, my wgdc moved from 50% to 90... and i'm up to 20psi in the midrange from the usual 18.

I guess what I'm trying to say is the turbo is capable and i am still hunting for that balance.

Last edited by JMlegacy; 09-17-2014 at 11:45 PM.
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Old 09-18-2014, 12:01 AM   #865
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jm, for reference, with a 12lb spring, i was able to hit pressures exceeding the oem MAP sensor range. so around 26psi, at torque peak, and dropping to around 20 at 7200.

after upgrading the map sensor and adding an ewg. i'm running 27-30psi peak at 3600, dropping to the same at redline. natural turbo taper, giving her all she's got. the internal gate is still functional and stays shut enough to generate that much peak. i definitely hear the ewg quiet down as the rpms pass through 5k.

turbo is vf23 (which has the p20 housing) with a lot of metal taken off the inlet. it's the cold side that's way out of efficiency. but sub 4k spool is really nice around town.
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Old 09-20-2014, 02:16 AM   #866
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That sounds really impressive!



Am I doing this right?
What I did was look back on some old logs in the higher gear and see what WGDC it took to maintain the correct boost after that RPM. And then i use that as the initial WGDC in the 6k+ region. 53 was the number. Now, I allow the max to be 15 units higher (68) and let the 1st and second gear take advantage of that throught TD integral.
(5EAT tranny)


You said you ported the intake of your turbo? or was it the outlet?

Last edited by JMlegacy; 09-20-2014 at 02:22 AM.
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