Borg Warner EFR Series Turbo's V 2.0

[MBS206]

1 hour ago, Borci88 said:

I spoke with Turbosmart on Friday and they said the uptake in Australia has been quite slow because it's not a known item, however they've been selling in huge numbers in the USA so we should have heard reports by now if they were no good surely. 

While it may be the gate it still begs the question, why did this happen very similarly with the Twin turbos... 

According to Josh, one of our local Americans, it seems the USA still can't get turbo systems quite right at a lot of places, so possible that they're not running great at all, but they've just not complained as NFI about getting it right...

[Dose Pipe Sutututu]

2 hours ago, Borci88 said:

Not in front of a computer until later tonight so this is probably the best I can do for now.

 

We are using both ports on the wastegate eith the 3 port Mac valve, I've just changed it to single in the photo as I was trying it out on gate pressure 

 

 

Run it in open loop for now, and drop the frequency down.

This lowers the resolution and requires more duty cycle to do anything, however good to troubleshoot.

[Borci88]

4 hours ago, Dose Pipe Sutututu said:

Run it in open loop for now, and drop the frequency down.

This lowers the resolution and requires more duty cycle to do anything, however good to troubleshoot.

Before I commit to it as I already have the wastegate off the car, would you change it to the 9psi spring instead of the 12, or whack it back on now and try your suggestion?

 

Edit: Actually I might just swap the spring and see what the logs say after another few pulls, as we know it's still spiking without the Mac valve in the picture so I need more data without the Mac valve trying to combat the issue.

[niZmO_Man]

Not that I know from experience, but in theory you'd want your gate spring to be as close to target pressure as possible, so you'd go with the higher gate spring?

[MBS206]

4 hours ago, niZmO_Man said:

Not that I know from experience, but in theory you'd want your gate spring to be as close to target pressure as possible, so you'd go with the higher gate spring?

His gate spring is already 8psi BELOW what the system will run as a minimum.

I don't expect much if any change to the boost curve.

Edited May 25 by MBS206

[Dose Pipe Sutututu]

5 hours ago, niZmO_Man said:

Not that I know from experience, but in theory you'd want your gate spring to be as close to target pressure as possible, so you'd go with the higher gate spring?

That's old school way of thinking ☺️

I run a 0.5bar spring and have boost control from 0.5bar all the way to 1.8bar

[Lithium]

Some good discussion in here, for the most part I can't really add too much to it - thought I'd add some notes to the datalog screen shot that probably aren't news to anyone but a good prop... this is assuming 25psi-ish should be the boost ceiling given the first post refers to 23psi.  

To state the obvious, this issue seems super weird.  Turbo speed seems pretty lethagic to build, like the turbo isn't getting as much drive as it needs - and it doesn't help that wgdc keeps rising AFTER boost target then completely shuts duty at a point, which in theory should have the straight gate dump heaps past the turbo and funnily enough causes the huge drop off.  It seems like pretty blunt boost control tuning but I'd not call that the primary issue, so much as possibly not helping the situation.

I'm curious, what does a pull look like with purely mechanical boost control?  Like purely wastegate?   There are things in this log and story that make it sound like there could be a significant restriction in the intercooler piping or something - but then it's also overshooting boost target which is NOT what you'd expect with a restriction.   I can see where people are coming from with the non-linear wastegate bypass (not that any valves are linear for this kind of thing), but it still doesn't make sense that it can't hold <20psi on a 12psi spring.   

Have you, or can you try measuring pressure pre-intercooler?  Be pretty interesting to see what's happening there vs in the intake manifold - sorry if I've repeated old ground, I've kinda skimmed over but I could have missed something. 

In terms of comments regarding the wg spring being closer to boost target, I haven't used a straight gate but part of the reason for having close to wg target is about fighting backpressure as well - I might be wrong, but I'd have thought that part of the point of using a butterfly valve like the straight gate does you actually don't have to resist pressure at all, on EITHER side of the gate.   It shouldn't need too much leverage to start opening, the spring being more to do with where it triggers opening as opposed to resisting boost & EMAP, though smarter people can correct me if I'm wrong there.  

Edited May 25 by Lithium

[Borci88]

7 hours ago, niZmO_Man said:

Not that I know from experience, but in theory you'd want your gate spring to be as close to target pressure as possible, so you'd go with the higher gate spring?

 

3 hours ago, MBS206 said:

His gate spring is already 8psi BELOW what the system will run as a minimum.

I don't expect much if any change to the boost curve.

The answer to this would be I followed the documentation from Turbosmart which said each spring pressure could achieve a maximum of 5x it's rated pressure so the included smallest spring being the 6psi had a range up to 30psi. I went with the 12 because I figured it'd likely hover around 15psi as a base pressure however I was obviously wrong. 

2 hours ago, Dose Pipe Sutututu said:

That's old school way of thinking ☺️

I run a 0.5bar spring and have boost control from 0.5bar all the way to 1.8bar

 

1 minute ago, Lithium said:

Some good discussion in here, for the most part I can't really add too much to it - thought I'd add some notes to the datalog screen shot that probably aren't news to anyone but a good prop... this is assuming 25psi-ish should be the boost ceiling given the first post refers to 23psi.  

To state the obvious, this issue seems super weird.  Turbo speed seems pretty lethagic to build, like the turbo isn't getting as much drive as it needs - and it doesn't help that wgdc keeps rising AFTER boost target then completely shuts duty at a point, which in theory should have the straight gate dump heaps past the turbo and funnily enough causes the huge drop off.  It seems like pretty blunt boost control tuning but I'd not call that the primary issue, so much as possibly not helping the situation.

I'm curious, what does a pull look like with purely mechanical boost control?  Like purely wastegate?   There are things in this log and story that make it sound like there could be a significant restriction in the intercooler piping or something - but then it's also overshooting boost target which is NOT what you'd expect with a restriction.   I can see where people are coming from with the non-linear wastegate bypass (not that any valves are linear for this kind of thing), but it still doesn't make sense that it can't hold <20psi on a 12psi spring.   

Have you, or can you try measuring pressure pre-intercooler?  Be pretty interesting to see what's happening there vs in the intake manifold - sorry if I've repeated old ground, I've kinda skimmed over but I could have missed something. 

I have a log here that I'll dig out that is purely wastegate and no Mac valve controlling anything.

 

If it can't hold anywhere near 12psi, does that mean the straight gate is virtually wide open during a run? Or am I thinking about this all wrong.

 

I could Tee Piece into the cooler pipe pre intercooler where the wastegate gets its feed, and send that to the ecu and see how that reads, I just don't have a spare pressure sensor currently that's all.

[GTSBoy]

7 minutes ago, Lithium said:

In terms of comments regarding the wg spring being closer to boost target, I haven't used a straight gate but part of the reason for having close to wg target is about fighting backpressure as well - I might be wrong, but I'd have thought that part of the point of using a butterfly valve like the straight gate does you actually don't have to resist pressure at all, on EITHER side of the gate.   It shouldn't need too much leverage to start opening, the spring being more to do with where it triggers opening as opposed to resisting boost & EMAP, though smarter people can correct me if I'm wrong there. 

I think you're mostly on the ball there.

With the straight gate, I suspect the weight of the spring will determine how quickly the gate can close, when not run with active pressure drive on both sides of the diaphragm. Otherwise, with drive on both sides of the diaphragm, you could almost go without a spring at all, only needing one to make sure that the thing was actually closed while completely off boost and not having pressure available to drive it closed.

Butterfly valves have mostly symmetric loading when there is flow going through them, meaning that the gas hitting the upstream part of the blade is balanced by the gas hitting the downstream part of the blade, which means you don't need actuator torque to overcome any non-symmetric flow induced loads. But the gas flow does impart a purely normal load against the shaft, which transfers into the bush/bearing at each end of the shaft and does increase the torque required to make the shaft turn. Only a little, but it is there. I have no feeling for the amount of force involved in a WG application, but it certainly could make an argument for a decent spring weight being required. But all of this is just peripheral to the actual problem here.

[GTSBoy]

5 minutes ago, Borci88 said:

If it can't hold anywhere near 12psi, does that mean the straight gate is virtually wide open during a run? Or am I thinking about this all wrong.

Either the WG is reaching full opening, or it is not. The "it is not" case could only occur if there was not enough time available to swing the valve fully open during that boost event. I would consider that to be unlikely, as this is a commercial product that is in use elsewhere, so it really should work. But in your case, because there is definitely SOMETHING wrong, it should not be assumed that things like that are working as they should.

You should put a video camera where it can see the actuator (if at all possible) during a run to see how far it is moving.

[Borci88]

36 minutes ago, GTSBoy said:

Either the WG is reaching full opening, or it is not. The "it is not" case could only occur if there was not enough time available to swing the valve fully open during that boost event. I would consider that to be unlikely, as this is a commercial product that is in use elsewhere, so it really should work. But in your case, because there is definitely SOMETHING wrong, it should not be assumed that things like that are working as they should.

You should put a video camera where it can see the actuator (if at all possible) during a run to see how far it is moving.

I will endeavour to give it a crack sooner or later.

I have the wastegate apart at the moment so I'll replace it with a smaller spring just to see what it does and if I have to go back then so be it.

 

If it spikes to 23 but can then be controlled back to 20, then the gate must not be 100% open... So if it's not 100% open then why can't it drop the boost even further than 20psi (I understand it's not linear). What a headache this whole thing is.

[Dose Pipe Sutututu]

And if it still spikes, just for now, turn off VCT completely by disabling it OR simply unplug the solenoid.

Just to rule out excessive exhaust pressure.

I recall a video from Motive DVD about a decade ago, where Hawkins original single Garrett GTX3582 or so turbo had boost control issues sub 1.4bar of boost as well.

 

Food for thought? Is there anyway you can peg the WG completely open and/or dodgily not plumb it back into your exhaust system for testing purposes?

[Borci88]

10 minutes ago, Dose Pipe Sutututu said:

And if it still spikes, just for now, turn off VCT completely by disabling it OR simply unplug the solenoid.

Just to rule out excessive exhaust pressure.

I recall a video from Motive DVD about a decade ago, where Hawkins original single Garrett GTX3582 or so turbo had boost control issues sub 1.4bar of boost as well.

 

Food for thought? Is there anyway you can peg the WG completely open and/or dodgily not plumb it back into your exhaust system for testing purposes?

I could definitely do some logs without the VCT enabled for sure. I believe we tried it on the dyno and it still spiked but wouldn't hurt to try again and have the logs 

 

I might be able to use some metal cable ties and hold the gate open entirely, I'd need to see about that one.

 

What do we think about these marks on the cap of the actuator? This is where the two parts push together where the diaphragm spring is. To me they look like air has been sleeping past?? Specifically talking about those black stains above the lower rim/lip. They can be rubbed away as if it's just an exhaust stain.

 

[GTSBoy]

Yes, well, keep in mind that the air is intake air, which equal boost + possible oil. If there is a fine deposition of oil/scunge that then gets hot and carbonises, it could look just like that. Probably shouldn't be leaking. Might just be normal for that product. Hard to know if it is relevant.

[Dose Pipe Sutututu]

Looking at the photos, you could easily just drop this pipe and dump into atmosphere 

Just 1 or 2 quick hits for data acquisition - if have a heat shield material and/or sheet metal, maybe just use wire/metal cable ties and attach it in a way to deflect heat from melting nearby wires.

 

[GTSBoy]

You'd want to cap off the re-entry back into the dump too. Just something flat that can be held on by the Vband.

[Borci88]

So a big update for those invested in here which I think might be our smoking gun in all of this and it's not something you would pick because it shouldn't have been an issue.. 

I pulled the wastegate actuator/canister off the valve and went to move the actuator arm on the butterfly valve and discovered it was extremely tight, I had to put a lot of force as shown in the video to get it to open the valve. I then loosened the three bolts on top of the valve there and suddenly the valve moved freely as you would expect as you can see in the second video.

The turbosmart does not have a 'seat' for this bracket to sit nicely into and as such I assume that when you bolt it down, it can be off by a millimetre or two and cause a bind in the shaft. I spoke to Turbosmart this afternoon and they have acknowledged that they revised this design late December '24 and have asked me to send it in for diagnosis and likely replacement.

We rigged up an air compressor and tested the valve with the bolts tightened down versus loose. With them loose the actuator started to push the valve open anywhere from the 10 to 12psi (with a 12psi spring). This seems to be perfect and as you would expect.

We then tightened down the three bolts and tried again and the valve wouldn't start opening until at least 16psi.

I can only assume that due to heat cycling and different boost pressures, this is likely our fault and causes inconsistencies between runs and how the wastegate and mac valve are fighting to control boost.

[acsplit]

Hopefully this is the issue, I don't expect this type of stuff from Turbosmart. It's normally PRP that has 17 revisions that their customer pay the privilege of doing the r&d for.

[Lithium]

Thanks for updating with the findings! It's not over till the fat lady sings, but this sounds like a pretty likely cause of the almost contradictory symptoms in terms of typical boost control.   Fingers crossed that this nicely rounds it out

[Dose Pipe Sutututu]

Yiewwwwwwwwwww that looks like the issue from this side of the keyboard!

Hopefully a quick swap out and you're back on the dyno smashing keys.