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my BOVs were leaking and the turbo was doing about 8000rpm more than it should have been based on the compressor map / VE mass flow calc and Pressure ratio from the ECU.

put in new BOVs and it was back down where it should have been.

1 hour ago, Nosure said:

I checked. It’s 14 blades. And we did some cams adjustment first. Did not help much. But still make 430awhp on 14psi.  So this 8474 still make more hp/psi even on very low boost.  I just need turn boost up until reach 125k rpm.  If it’s accurate wheel speed reading i think It will hit speed limit by under 25psi. 

What capacity engine is it mate?   2.6/2.8/3.0?  

I have 2 bov. 1 on turbo (plumb back) 1 on intercooler pipe.  The one on intercooler pipe is 100% work fine.( we already done pressure test) But I’m  not sure about the plumb back bov. If that one leak I might have high wheel speed low psi problem.   But if everything work fine i will just max the turbo and see what it can do. 

6 hours ago, Nosure said:

e85.  But if only 20psi. I think I can run 98:). 

 

Its 2.8. 

I’m going to change stock efr bov back. Now I have turbosmart plumb back bov on turbo. That make sense if bov leaking. 

Turn the one on the comp cover up as high as you can. That should do the trick. ?

8 hours ago, Nosure said:

I’m going to change stock efr bov back. Now I have turbosmart plumb back bov on turbo. That make sense if bov leaking. 

Ahh.  I would probably sooner run a blank on the EFR compressor housing than go back to the stock one if you have another BOV, I get the impression the stock ones are not great.

2 hours ago, Piggaz said:

Turn the one on the comp cover up as high as you can. That should do the trick. ?

Or this, if it's an option

for reference, I was talking about the stock twin BOVs on my setup leaking, I have a blanking plate on the turbo housing bov, I swapped out the stock ones for 2x GFB mach 2 plumb backs which bolted onto the stock bov pipe and wound them up pretty tight.

I wasn't happy with the oriface size on the comp cover bov for the high flowing turbos (83 and 91mm versions). was still getting loud choof (comp surge) with it. no such issue with the mach 2s.

  • Like 1
33 minutes ago, Nosure said:

Stock efr bov does the same.

As comments above warned, it's not unusual for the stock BOV to leak.... trying the stock BOV wasn't necessarily going to rule it out.  If anything, it could be argued that it proves that the other BOV may have been leaking as well if you didn't end up with worse turbine speed - as this is the reason people often blank off/replace the stock one.

Fingers crossed it's either not an issue, or something else.   Good luck with the rest of the tune!

 

 

Edited by Lithium

Yeah I’m getting blank plate tomorrow. And test it again. At moment 25psi drop to 22psi on high rpm already on limit of 3 ports solenoid, turbo speed is 114k. Now we need change to 4 ports boost solenoid to increase boost and get bov blank plate to test if it’s leak.  

6 hours ago, burn4005 said:

for reference, I was talking about the stock twin BOVs on my setup leaking, I have a blanking plate on the turbo housing bov, I swapped out the stock ones for 2x GFB mach 2 plumb backs which bolted onto the stock bov pipe and wound them up pretty tight.

I wasn't happy with the oriface size on the comp cover bov for the high flowing turbos (83 and 91mm versions). was still getting loud choof (comp surge) with it. no such issue with the mach 2s.

timely post, im weighing up replacing the stock efr bov with a turbosmart one, recall Geoff posting at higher boost (25-28+) stock needs a stiffer spring, hadnt heard much re: comp surge on these (i have 8374 1.05), but im now leaning towarding biting the bullet and replacing twin factory bovs with turbosmart items

On ‎11‎/‎08‎/‎2019 at 10:20 AM, Nosure said:

So far I got 610hp on 20psi with 8474 1.45a/r. And 280 272 cams.  

My 3582 gen2 0.82a/r with type b cams Made around 500hp on 20psi.  But 500 rpm sooner.

 

the 8474 already over 100k rpm. I’m not sure it was read wrong or something else. Will do some cam adjustment and boost up early next week.  

ill be running 8374 1.05 on 2.8 vcam shortly on e85, starting to think i should have upsized and/or gone black series

On 8/6/2019 at 4:37 AM, R.3.2.G.T.R said:

I assume you opted for 3 port Mac valve instead of std offering

the OEM borgwarner EFR / pierburg solenoid is more desirable than 3 port mac.  some tuners prefer twin pierburgs to a 4 port mac. Certain other turbo manufacturers even purchase these solenoids from Full Race, it definitely is a quality piece to come standard

On 8/10/2019 at 8:20 PM, Nosure said:

So far I got 610hp on 20psi .. the 8474 already over 100k rpm.

 

On 8/11/2019 at 9:33 PM, Nosure said:

Yeah. There is no leak or any mechanical problem.

EFR 8474 on RB 2.8L revving to 8000rpm @20psi at sea level is likely in the 420-440m/s tip speed range depending on VE and other factors.  You said you are seeing over 100krpm shaft speed...

450m/s tip speed on an 84mm compressor = 102k rpm. 

450m/s at 20psi sounds like a leak, but im thousands of miles away and purely guessing here.  What pressure are you boost leak testing to?  Are you at altitude?  Many variables at play, so I suggest to further inspect the TB shaft seals as well as the intake manifold sealing surface.  good possibility there is a small leak in your system

Edited by Full-Race Geoff
On 8/13/2019 at 1:45 AM, R.3.2.G.T.R said:

timely post, im weighing up replacing the stock efr bov with a turbosmart one, recall Geoff posting at higher boost (25-28+) stock needs a stiffer spring, hadnt heard much re: comp surge on these (i have 8374 1.05), but im now leaning towarding biting the bullet and replacing twin factory bovs with turbosmart items

fyi - all EFR turbos include the stiff BOV spring since mid-2018.  this was a change i rallied for, you guys should not need to change it.

the oem configuration vents from 360 degrees, so i prefer this design to the turbosmart which only vents through a slot.  if youre going to change the EFR bov, i suggest to go to a traditional external rather than a plug and play

  • Like 1

We did a test with a standard EFR BOV with a low power setup and we were seeing slight leaks even at 25 PSi region, where we got a little increase in power by blanking it.  So it's definitely something to address.  This would have been the pre mid 2018 one.

My Nitto 2.8 Vcam 264 / ex 260 setup with EFR9180 will be on the Dyno in coming weeks.  

I'm looking at then using this same setup to test a 8474 to see if the front end can produce 9180 like flow.
Then also looking at testing a 9280, to see how it compares against a 9180.  

  • Like 1
5 hours ago, Full-Race Geoff said:

fyi - all EFR turbos include the stiff BOV spring since mid-2018.  this was a change i rallied for, you guys should not need to change it.

 

That's good to know!

 

5 hours ago, RB335 said:

My Nitto 2.8 Vcam 264 / ex 260 setup with EFR9180 will be on the Dyno in coming weeks.  

I'm looking at then using this same setup to test a 8474 to see if the front end can produce 9180 like flow.
Then also looking at testing a 9280, to see how it compares against a 9180.  

That will be some very interesting testing!  Particularly the 8474 versus 9180 stuff, as the 8474 actually appears to have the edge on flow - it'll really clear up how much of a choke point the 74mm and 80mm turbines may or may not be.

Hope the setup has lots of data and all the supporting systems, needed... you could end up with a pretty serious performer from this, not to mention have the kind a data a LOT of people would love to know about :)

10 hours ago, Full-Race Geoff said:

the OEM borgwarner EFR / pierburg solenoid is more desirable than 3 port mac.  some tuners prefer twin pierburgs to a 4 port mac. Certain other turbo manufacturers even purchase these solenoids from Full Race, it definitely is a quality piece to come standard

 

EFR 8474 on RB 2.8L revving to 8000rpm @20psi at sea level is likely in the 420-440m/s tip speed range depending on VE and other factors.  You said you are seeing over 100krpm shaft speed...

450m/s tip speed on an 84mm compressor = 102k rpm. 

450m/s at 20psi sounds like a leak, but im thousands of miles away and purely guessing here.  What pressure are you boost leak testing to?  Are you at altitude?  Many variables at play, so I suggest to further inspect the TB shaft seals as well as the intake manifold sealing surface.  good possibility there is a small leak in your system

Hi we did replace 3ports to 4ports.  We tested both oem and turbosmart bov. They both does the same job. Now I’m going to use a blank plate. 

So far there are no leak we can find. And shaft speed 23psi on 8000 rpm is 114krpm made 630-640awhp.  After we change to 4 ports we will increase boost see what it can do.   Same dyno we got 660hp at 28psi with 3582gen2. 

14 minutes ago, Nosure said:

So far there are no leak we can find. And shaft speed 23psi on 8000 rpm is 114krpm made 630-640awhp.  After we change to 4 ports we will increase boost see what it can do.   Same dyno we got 660hp at 28psi with 3582gen2. 

Something really doesn't sound right, are you going to the 4port due to having issues holding boost?

If you are maintaining 23psi through the run and your wheel speed is 114,000rpm then the turbo is moving a LOT of air, like over 90lb/min.... but you are only making 70-75lb/min power levels:

image.png.2cbe3e9ee001ec510f41cfa60ed2dda7.png

What kind of ECU are you using? 

 

7 minutes ago, Lithium said:

Something really doesn't sound right, are you going to the 4port due to having issues holding boost?

If you are maintaining 23psi through the run and your wheel speed is 114,000rpm then the turbo is moving a LOT of air, like over 90lb/min.... but you are only making 70-75lb/min power levels:

image.png.2cbe3e9ee001ec510f41cfa60ed2dda7.png

What kind of ECU are you using? 

 

And if you are operating at that point on the MAP that Lith shows - its not very efficient at that point of the map - so are your intake temps getting very hot?

If they aren't this might indicate you're not actually at that turbo speed and perhaps you are reading it wrong.

If they are, then I guess that backs up that you are working the turbo hard and there is likely a leak.

22 minutes ago, R32 TT said:

And if you are operating at that point on the MAP that Lith shows - its not very efficient at that point of the map - so are your intake temps getting very hot?

If they aren't this might indicate you're not actually at that turbo speed and perhaps you are reading it wrong.

If they are, then I guess that backs up that you are working the turbo hard and there is likely a leak.

The tricky thing with hot intake temps is with some of the really good intercoolers these days I've actually seen people "off the map" and still have reasonable intake temperatures, so you can't actually be sure that is the issue.... pre-intercooler temps will tell a clearer story there.   I'm betting that exhaust manifold pressure is going up big-time, and it's part of why I asked about the boost control.  

At the moment it seems a lot like either the engine isn't converting the airflow into power well, or the airflow is being lost somewhere - like a boost leak or something (as is a recurring theme in the line of questions).     This is one of those cases when an airflow meter is handy haha, but with the wheel speeds being mentioned it seems a lot like the turbo is working hard.

I suppose there are two other options which could cause this kind of thing, if there is an intake restriction pre- or post- turbo - like if someone left a rag in the intercooler or something when things were being changed over.... that would mean you wouldn't see a leak, but it would boost the pressure ratio across the turbo HEAPS but you wouldn't see that pressure at the intake manifold.

Temperature and/or pressure at the compressor outlet may help build a better picture.  I'd be wary of pushing it much harder without getting to the bottom of what is going on, as it seems like the turbo speed is probably configured right it means a lot like something isn't performing correctly and it's costing power, probably spool, and could compromise reliability too.    

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