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32 minutes ago, Dale FZ1 said:

Some pics on the WG placement and pipe angles would  be a big help for people to understand what's the problem.  Bench testing the gate for correct function and all intact would also be a good idea.

Pretty sure most of us are guilty of failing to review/check ALL the basics when something doesn't seem to work as it should.

LOL!  I have been trying to put my response together in fits and starts for the last hour or so, this is very much what I was thinking when I wrote mine two.   Very much agree with this, I've been here done that myself.

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It's a 6boost T4 TS Manifold with a 50mm external gate on it. I think the merge is pretty shitful to be honest, but again, not the only one running a gate in this manner.

I am using the BOV internal to the EFR itself
I attached a picture of my exhaust merge. It is a 3in from the dump, and 2in from the wastegate that merge into the 3.5 section after the cat.

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I have used this with the controller off. I had all of this setup in the past with a GTX3582 making 420+ through the auto and downsized to use a smaller turbo with the EFR. I was able to run as low as 4psi with the GTX3582 with a gate off the turbine housing, so I know the controller works/is disabled when everything is zeroed out.
 

I did get boost spikes back then too, way way WAY worse, which I had assumed happened when loading up the car through the converter in a high gear.

But now manual, now EFR, similar problem. Trying to run low (18psi) boost is some tiny amount of duty cycle, which I can only assume is a byproduct of 1.05 housing and 2.8 and a small compressor.

The 5 port I have because I've always had it. Scottynm35 provided it way back in the day. The only difference I can see is that it has 2 exhaust ports instead of 1 - It still runs off 2 wires like any other boost controller connected to a Haltech PS2000.

I suspect it's setup related, that the gate angle is just crap and a "big" motor spinning a "small" turbo on sharp opening of throttle, perhaps a little 'worse' given how responsive/transient the EFR is.

nice exhaust system :)

looks like a few people with the same idea as I had initially.. still a cat in there?

Can you post up a log from the halaltech when you come on boost say in 3rd or 2nd, etc.? I suspect could be timing related as there's a table that allows you to retard timing as you come on/off the throttle to make the transients smoother.

Yes, it's running a 5in cat in there.

I can try and post a log, but it'd be a day or so or two or three weeks before doing that because not so easy to organize such a run lol.

However there is no table for transient timing advance on the PS2000. So the timing is going to be what the base map is specifying.

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1 hour ago, Kinkstaah said:

 

 6boost T4 TS Manifold with a 50mm external gate on it. I think the merge is pretty shitful to be honest,

I attached a picture of my exhaust merge.

I did get boost spikes back then too, way way WAY worse, which I had assumed happened when loading up the car through the converter in a high gear.But now manual, now EFR, similar problem.

Trying to run low (18psi) boost is some tiny amount of duty cycle, which I can only assume is a byproduct of 1.05 housing and 2.8 and a small compressor.

I suspect it's setup related, that the gate angle is just crap and a "big" motor spinning a "small" turbo on sharp opening of throttle, perhaps a little 'worse' given how responsive/transient the EFR is.

Firstly, that plumb back merge does look good.

But, I agree with your assessment on the WG angle.  Gas has mass.  And if it's highly energised pressure pulses trying to change direction rapidly, not going to happen easily.  Workmanship on the 6boob manifold is no problem, but that WG design doesn't look right (to me) with a short hard 90 straight off the collector, not going generally with the direction of flow first. Reckon I would be doing some re-engineering there.

Does it currently have a divider right up to the WG valve? Twin scroll, needs completely separate gas flow paths.

Is there an inline restrictor for the MAC plumbing?  This is where you make the thing really sensitive to duty cycle changes.  I have used a 1.2mm MIG tip to great effect many times in plumbing MAC valves, cheap too.  A novice error I have made twice is to have the ports connected to the wrong nipples. Worth knowing.
 

From comments, there's a historical problem showing even with a different turbine/WG setup. Presuming you've used the same tuner, and approach to tuning.  Could be a basic error there, require a second set of eyes over the tune file to see if things are all good there. (Suggestion is directed towards problem identification, not blaming or flaming individuals)

 

 

Edited by Dale FZ1

Hey guys, just wanting to confirm the routing of the BOV vacuum line, are the old charcoal cansiter hard lines appropriate for this? I've seen a few others that look like they've done it that way - it also looks a lot tidier. Let me know if there's a better way to do it!

I remember SAU VIC pres Tony's red 33 having boost control issues, and for 300+kw required 2x large waste gates just to get it out. This was all under Racepace tuning/instruction. I don't know where they installed it, but apparently did the trick (though they don't use electronic boost control, but I won't delve into that...)

Alright I did some more testing as promised, and you can see what the logs look like below.

First three small runs I had the controller setup as a 4 port mac.
Last two I disconnected the top hose, so boost isn't being fed into the top chamber. As you can see there's more duty cycle there from the controller - So that may be just inducing a small boost leak into the system.

In any case you can see how the controller does drop off from 100% to ~20% duty cycle, there's clearly a delay and a spike.

This is with the controller being told to stop going 100% 6psi before hitting target boost, which is 18psi.

Note: These pulls were in 3rd gear. The first 3 were up a big hill, (obviously me backing off as boost was spiking out of control) as was the last one.

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I moved the source for controller from my charge pipe just before intake, to the compressor housing, but it doesn't seem to have made much difference in terms of responding quicker.

boost.csv

Would have been good without the ECU boost control turned on so we know if we are dealing with a mechanical boost control problem.  This makes it look a lot like a tuning issue - if I were tuning it the first thing I would be doing is getting a baseline with purely mechanical boost control to know with certainty where I should be looking.  We could go around in circles with ECU setting discussions if it's mechanical, and alternately trying to work out what is going with the mechanical side of thing with data skewed by quite a lot of ECU influence makes the data hard to draw any meaning from 

Edited by Lithium
  • Like 2

It's possible from that chart a combination from too light WG spring + too much preload+ lots of backpressure.  Purely guessing from the other side of the planet and not aware of your setup ?

Edit I see the 6boost above which turbo and housing is this

 

Edited by Full-Race Geoff

This morning I did exactly that, and run a line directly from the compressor housing and the bottom port of the 50mm gate.

Drove to work, will post logs when I do some actual testing. Response felt about the same and it made 12psi pretty solidly, at least as much as you can see "solidly" when looking at a gauge and not at the road.


Just for Geoff, it's a 7670 with a 1.05 rear on a 2.8 with VCT. The housing is really massive. The below picture is a comparison betrween the EFR (bottom obviously) and a GTX3582 with a .82 rear.

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9 minutes ago, Kinkstaah said:

Drove to work, will post logs when I do some actual testing. Response felt about the same and it made 12psi pretty solidly, at least as much as you can see "solidly" when looking at a gauge and not at the road.

 

Sweet - so yet to be confirmed, but probably not the turbo/setup itself so much as how the ECU boost control is setup then.  Here's hoping that's the case, it'll be a lot cheaper/easier to resolve :)

I see you are using a 50mm waste gate.

Is that a turbosmart progate or progate lite?

The lite version is unsuitable for 4 port boost control in my opinion. I would only consider using it if nothing else would fit. The diaphragm to valve area is only around 1.3 so is more susceptable to manifold pressure differences with a light spring.

The real progate 50 has a diaphragm to valve area of around 2 so has much better control.

Edited by burn4005

It's a full progate.

As more testing unfolds (i.e line directly to gate) it's starting to really look like the boost threshold is something I have to live with. It will spike when running directly between compressor housing and bottom port of wastegate with nothing else attached.

When it wants to spin up it really will spin up. Suppose it's just a compromise from choosing the setup I ended up choosing. Looking at the exhaust housings back to back is pretty telling, and I chose the turbo so it wouldn't be maxxed out/overheated/choked etc, so I ended having that at the expense of less power and more lag relative to the Garrett Option ;)

With 0% duty cycle it (boost) behaves the same as being connected directly to the turbo with nothing in the middle of it. This will cause boost to come on full at about 4500rpm (3rd) and peak at 15psi, I've then fed in duty cycle to continue it to climb up to about 19.

I'd change the housing at the rear, but there is no housing to change to. Being RWD perhaps there's not much sense having 20psi at 3000RPM anyhow.. car feels pretty planted and on the edge of slip all the way through the rev range so I suppose that's also good.

Still think the 7670 EWG (1.05) would be bad news on a 2.5 with that housing though. OFC if someone buys one and has wildly excellent results then I'll go hunting for fixes again :P

Having a look at a 9174 (when they were all bought) the rear of the 7670 1.05 is actually basically the same damn size. I am sure at this point an 8374 would do what the 7670 does but with just more power tbh. The delivery of the thing belies its "lag" as it really does just get on boost and keep pulling in a very linear, very stable very unrelenting fashion. There's no power skids here (almost, though!) and personally I like that. If I did have monster midrange, I would have setup boost by gear to effectively create what I currently have.

The target was always about 350kw running moderately lazy because I have melted manifolds and rear housings in the past at the track - so I suppose I have this and it fits the bill. It just feels a bit agricultural to be using open loop, but in the grand scheme of things I had to control the controller manually to get the result.


Will have a dyno result in about 3 weeks when it goes there and shall test the accuracy of my butt dyno.

2 hours ago, Kinkstaah said:

it's starting to really look like the boost threshold is something I have to live with. It will spike when running directly between compressor housing and bottom port of wastegate with nothing else attached.

it's just a compromise from choosing the setup I ended up choosing.  I chose the turbo so it wouldn't be maxxed out/overheated/choked etc, so I ended having that at the expense of less power and more lag relative to the Garrett Option 

With 0% duty cycle it (boost) behaves the same as being connected directly to the turbo with nothing in the middle of it. This will cause boost to come on full at about 4500rpm (3rd) and peak at 15psi, I've then fed in duty cycle to continue it to climb up to about 19.

Being RWD perhaps there's not much sense having 20psi at 3000RPM anyhow.. car feels pretty planted and on the edge of slip all the way through the rev range so I suppose that's also good.

Still think the 7670 EWG (1.05) would be bad news on a 2.5 with that housing though. 

 

My first response is that NO setup is going to be the "silver bullet" for performance.  It's only about achieving an acceptable compromise.  It's always been amazing to review logs for how an engine behaves on-road (or track) and see how different that is compared to a dyno.  What you've got isn't necessarily bad, but with the spiking there's room to make it less wrong.

Secondly, the big thing (for me) is how does it feel? And can the chassis setup (which includes tyres) actually use it without just turning rubber to smoke?  Edits ^^ from your post sort of indicate that you're actually in "about" the right performance area for a 2wd R chassis. Without the cheater traction advantage of a GTR, it's pointless IMO to try to emulate/expect the same sort of engine performance as a GTR because it probably won't work to best effect.

 

https://www.sau.com.au/forums/topic/358438-34geeteetee-daily-track-project/?page=111

 

Have a look at what Mat has achieved with the 8374 on a 25 Neo.  And look closely at the WG takeoff angles.  Now he has no issues with boost control, but the target in that instance is going to be North of 20psi so direct comparisons aren't possible if you are for some reason targeting 15psi (arbitrary figure chosen).

Perhaps Mat could offer experiences/opinions regarding the 8374 on an RB25, and his take on what applications that would best suit and/or what compromises would have to be accepted.  Bear in mind it's experiences from a guy who's actually achieving some pretty solid results without major dramas.

** Somewhere in amongst this, I'm seeing that we are fixating on boost pressure as the measure of turbocharger control.  There is enough tech available in Greg's setup that perhaps turbo speed is where the thoughts are best focused** :)

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