efr9180 choking?

[Predator1]

Hi guys,

I recently had my car re tuned for a few reasons, and we decided to put some timing and boost. It made some good power for starters. It made 450kw on 14psi, and 565 on 25~ (rwkw for now).

On high boost, the tuner was concerned with the IAT's sky rocketing every pull. I saw the temps going from 40-65C on every run. This only happened on high boost. I was very shocked, as the turbo's not running alot of boost. The tuner had no idea why this was happening. He didn't have a pressure gauge that he could stick on the exhaust(I have a spare port). The IAT is is located on the intake piping just before the plenum, and is the Bosch high resolution sensor.

At this point, I'd like to think the turbo's running out of puff, or being choked, but how?! I didn't have a speed sensor installed back then. The 9180 with 1.05 housing is rated to 1000 flywheel hp, but I'm only making 820hp, or 612kw.

The car is an absolute weapon, and I've only used high boost a handful of times, but I'd like to sort this issue out as no point doing ethanol tune so far.

Looking at the compressor map, with the given boost of 24-25psi, I have a pressure ratio of 2.8.

I was working out my flow rates, so something like 1lb/min = 10hp, so in my case, I'd be consuming around 82lbs/min?

If I plot that on the compressor map it seems I'm sitting very close to the choke line? Could I really be choking the turbo with only 25psi? Perhaps if someone knows more about compressor maps could chime in and shed some light?

 

 

Here's some pics of the dyno pull

 

Here's my setup:

 

RIPS Built 3.2 - From what I can calc, its a 8.3:1 cr
New RB26 Head CNC ported
286/278 degree cams
EFR9180 with 1.05 exhaust housing
60mm Turbosmart w/g
6Boost manifold(standard thickness, not the thick ones)
4 inch dump, no cat, just 1 muffler - The whole exhaust if 4 inches in diameter
Hypertune G2 FMIC. Unsure of exact sizes but its around 115mm thick.
 

If any of you guru's could perhaps shed some light?

[GTSBoy]

Yeah, it's not so much that you're near the choke line specifically, in that, it's not that likely that you're actually choking the turbo. It is possible that you're choked, given the possible range of errors in your placement of your operating point on the map (ie, estimated crank power from wheel power, estimated relationship between air flow and power). What happens when you choke a turbo is that you reach the local sonic velocity in the compressor inlet and hit the wall in terms of how much air you can get through it. In order to get more air through the inlet, you start to pull a vacuum right in front of the compressor wheel and that "stretches" the air that you're trying to compress. That effectively lowers your starting pressure for calculating the pressure ratio. You're not starting with atmospheric air - you're staring with a lower pressure than that. And that hurts production, driving the mass flow down and the PR up.

There may actually be some more horrible effects of choke resulting from shock waves and resonances in between the compressor blades, so it is wise to stay away from choke conditions. But there's not a lot of evidence to show that it's particularly bad for the turbo and to stay away from choke just for that reason. The fact that the turbo is tapped out and not giving what you need from it is the main reason to stay away from choke.

What is actually the biggest killer, and would directly point to the IAT problem, is that being right over on the edge of the map places you a long way from the efficiency island. Instead of operating the compressor at the highest efficiency available (over 75%) you're way down at <65%. Could be as low as 60%, depending on the above mentioned errors in the location of the operating point. And that loss of efficiency turns up directly as temperature.

A useful question to answer is, where is the operating point for your lower boost result? I had a quick look, and sadly it appears to be on the same (64%) efficiency line. So that probably (possibly?) rules out the boost increase driving the OP off to the right.

That would suggest the IC is heat soaking. But it's a big Hypertune unit, so......hard to imagine. Perhaps though, you should consider sticking some fine thermocouple tips onto the core tubes at each end of the core, to see how hot the core itself is getting. You'd best benefit from (temporary) IAT measurements in the hot and cold pipes also. Or at least adding the upstream measurement, seeing as you already have IAT in the plenum. Got to see how hot the air is getting as it exits the turbo, and what it is doing to the IC core. If the air T isn't much worse out of the turbo (on the high boost, cf the low boost) but the core is getting hot, then you could conclude that the turbo efficiency isn't changing, and the IC is no good. If the turbo outlet temperature is going through the roof, then you would conclude that you are actually suffering an efficiency change.

[Lithium]

There could be other things going on as well but you are definitely at the upper end of that turbo.  The 9180's compressor efficiency is better suited to running at higher boost levels, I've generally suggested people who run them not run massive head specs if running an RB with one so they "need" more boost to make their power and run in a happier zone.

It is a bit surprising it is getting so hot still though, it shouldn't be THAT bad I wouldn't have thought so I'd be weary of possible boost leaks or something like that.  A turbo speed sensor pays off a lot in this kind of situation - but again either way a 3.2 with a big head IS going to choke at modest boost on this turbo, there is not going to be a massive amount more power on the table no matter how you look at it.

These are a very good turbo for something that came out  13 years ago - will still be not super easy to get something which makes more power without giving away response but a lot of what you're seeing here is how the engine and turbo need to suit each other very well to get the best results - some setups will make the same or more working the same turbo less.  

Borg have since released the 9280 which would sit in it's place and walk away from this power level with minimal impact.  Already know a couple of people running 3.2-3.4 engines making around 700kw at hubs with them on the 1.05 hotside but it would give a bit away in the lower rpm- but pretty much anything capable of making more than this will.

[Lithium]

Actually, just noticed that the TCF is set up for estimated flywheel power.   Hmm it does seem a bit on the low side for this turbo, I would be checking for other issues in the setup if you haven't had it boost leak tested etc 

Edit:sorry missed it's on pump gas.  Nevermind, this is big power for this turbo on pump gas.  As above, it's one which works better at high boost - I'd normally aim for 500-550kw absolute max at the hubs on pump with one of these.   

Yeah, you'll need a bigger turbo if you want bigger numbers on pump - probably bigger on both sides... I wouldn't be aiming for an EFR for 1000hp on 98.   E85, fine. Really 1000hp you should be considering a better fuel regardless of what turbo 

Edited June 1, 2022 by Lithium

[Predator1]

Thanks heaps guys for your input so far. I don't have a full spec list on my head, but got the whole Kelfords catalogue at it. I just dug my specs up, its a bit, but here's the flow numbers at max lift:

.450" - In=295, Out=214. Apparently that's meant to be quite a bit?? Feel free to advise.

Could it be that my flow rates are off now seeing as my heads flowing a lot more, per pound of air, that my flow rate calcs are off now? Instead of needing 82lbs/min, it needs less? If that's the case, then it will change the efficiency island I sit on? Hope that makes sense.

Yeah its 1.10 tcf indicating fw, but it made 560~ at the rears quite happily, noting that the tuner didn't need to put a lot of timing into her either. He was going to push around 30 but we stopped as its only a stock box for now and pump.

We checked for boost leaks as well - None at all. I was kinda expecting around 600 at the rears with this setup on pump, so a bit disappointed.

Does this mean I cannot run more boost on my setup???? I really wanted to push it to at least 2 bar. I have plenty of fuel for my current power, but I will have to get bigger injectors to reach my goals.

The turbo is bloody responsive don't get me wrong. I love this turbo. The response is fkn awesome, coupled with the low down torque of the 3.2, but top end of the curve doesn't give me a lot of confidence.

 

 

 

 

[GTSBoy]

On 6/1/2022 at 6:01 PM, Predator1 said:

that my flow rate calcs are off now? Instead of needing 82lbs/min, it needs less?

Nah. Air to power is the same pretty much independently of how well the engine flows. The only way that the air to power ratio changes is if you change the stoichiometry. Richer or leaner means that you have a different amount of air for the amount of fuel you're putting in. At any given load & speed the air flow is approx the same (for the same engine), but if it is pig rich then it won't make as much power as if you lean it out a little. So, starting from rich, if you take some fuel out you make more power, but the amount of air remains the same. So the air to power ratio changes. As you approach stoich you sort of go towards a peak of how much power you can make from that qty of air, then as you go over stoich to the lean side, you start making less power again.**

** All of that presumes that you do not melt or detonate the engine to death first, which is what will actually happen in a turbo RB. But in an engine that is a looooong way from the detonation threshold (say, NA, 6:1 compression ratio) then the above paragraph is all true.

On 6/1/2022 at 6:01 PM, Predator1 said:

Does this mean I cannot run more boost on my setup???? I really wanted to push it to at least 2 bar. I have plenty of fuel for my current power, but I will have to get bigger injectors to reach my goals.

More boost = more flow = keeping on going up that compressor map towards the top right. You will stay on the RH edge of the map regardless. The only way to push yourself back towards the centre of the map is to introduce a big restriction somewhere.

So, I tend to agree with Lith. Turbo is maxxed out. Needs a bigger turbo, or at least one that is better optimised for more flow and less PR.

[Predator1]

Cool thanks. That sucks! This turbo is just so damn responsive. My power goals 1000-1100awhp. I knew from the start that the turbo wouldn't make 1000 wheel. I was expecting around 600-650awkw.

Silly question then, will she make more power on e85 then on the same boost?

Would I be correct in assuming that my next turbo will have to flow around 100-110 lbs/min?

Looking at the 9280 map, id be on a similar island, around 62% with around 85lb/min and 2.8 PR?

 

[GTSBoy]

On 6/2/2022 at 5:20 AM, Predator1 said:

Would I be correct in assuming that my next turbo will have to flow around 100-110 lbs/min?

That sort of ballpark, yes.

 

On 6/2/2022 at 5:20 AM, Predator1 said:

Looking at the 9280 map, id be on a similar island, around 62% with around 85lb/min and 2.8 PR?

Nah. The blue map on there would do 85 pounds and 2.8PR at about 69%. That would give you the same output on your engine, but with that much cooler charge from he better efficiency.

The 62% line at 2.8 PR would do about 97 lb/min. But you're not going to be able to operate at that point, because at 2.8 PR, your engine & turbine only want to flow what they're flowing now. So that ~85 lb/min number.

What you know is that the engine and turbine would remain the same. So the boost required to make more power must increase. Same resistance. So you can't be looking at the 2.8 PR area. You have to do an in-skull dyno/flow bench to scale up from your existing performance. So, PR say 3.2 might push you up to around 95 lb/min. That would land you on about 67% efficiency. Not bad. It'll be somewhere near there. No promises though....I did that in my head, and it's got all sorts of likely error!

Note, a big difference (beyond the simple size difference) between the 91 and 92mm comp wheels is massive increase in inducer area. That pushes the choke line way over to the right, because it slows down the inlet flow.

[Lithium]

On 01/06/2022 at 10:01 PM, Predator1 said:

Could it be that my flow rates are off now seeing as my heads flowing a lot more, per pound of air, that my flow rate calcs are off now? Instead of needing 82lbs/min, it needs less? If that's the case, then it will change the efficiency island I sit on? Hope that makes sense.

it made 560~ at the rears quite happily, noting that the tuner didn't need to put a lot of timing into her either. He was going to push around 30 but we stopped as its only a stock box for now and pump.

The turbo is bloody responsive don't get me wrong. I love this turbo. The response is fkn awesome, coupled with the low down torque of the 3.2, but top end of the curve doesn't give me a lot of confidence.

Right my last posts I tried to do hastily on my cellphone and the posts ended up quite messy - so I've waited until I have a spare moment to properly read your post and try and give you a bit of a clearer picture of how some of this works.  

Firstly - you ask if because your head flows more you need less flow?   Nope, it doesn't work that way.   lb/min is basiiiically a combination of how dense the air is, and the volume that is shifted.   Increasing head flow increases the volume of air that your engine is capable of moving, the only way to increase the amount of air that goes into the engine without increasing the actual corrected lb/min on the map is by increasing the density of the air (ie, cooling it) before it goes into the turbo.    The volumetric efficiency thing is why I mentioned above that I wouldn't suggest a 9180 for a bigger engine with a big head like yours as an option to make >600kw @ wheels because that big capacity and decent ability to move air at lower boost levels puts it in an area that the turbo isn't really likely to be at it's happiest.

Secondly, in regards to something about you 82lb/min assumption which hasn't been addressed (sorry I rushed my last responses) -  you really can't assume that you're moving 82lb/min of air, there just isn't the data available to accurately estimate that.   There could be every chance that your engine is actually moving MORE than that.... and that's because of a key thing we always need to consider when choosing turbos, fuels etc and that's BSAC or Brake Specific Air Consumption.   That's basically how efficient your engine is at making power for a given amount of airflow, and the variability of this between setups is why I'm always non-committal about predicting exact power levels for a given engine setup.

BSAC relies on a number of things, but the ones potentially most relevant to this conversation are the fuel and how hard the tuner pushes the tune on that given fuel.   I highlighted your point that the tuner didn't need to put a lot of timing into her.... I'm not quite sure how to interpret that and am not going to make any assumptions (and am certainly not criticising it) - just sharing some things to consider here.   

These 10hp per lb/min type guidelines is clearly assuming the engine is operating with a certain amount of efficiency.  Here's the trick, if the tuner has been told "don't go past 560kw on the stock gearbox" and found that the car has made that power at safe boost without needing to run a lot of timing then they could be WELL justified in saying "Sweet - Tune is safe as houses and it's making the power my customer wants, ideal!" and leave it there.    Here's the clincher with that, a "soft tune" could easily pick up another 10% more power with the timing optimised while still not actually being overly aggressive.   On top of this, you could arguably pick up another 10%+ more power over a tune safely optimised on pump gas by tuning it to make the most of E85.

Just for a thought experiment, lets assume that with a full optimised (but safe enough) pump gas tune you can make 10hp per lb/min,  but your current tune is giving away 10% of that power due to being soft, and on E85 it'd be able to make 10% MORE than on pump gas.

Optimised pump gas: 820/10 = Needs 82lb/min of air to make 820hp @ engine (like what you're assuming)
"Soft" Pump gas: 82lb/min x 1.1 (for the 10% worse BSAC because of soft timing) = 90lb/min of air 

So based off those assumptions, what would happen if you are actually running super soft timing and it's moving 90lb/min of airflow?

Optimised pump gas: 90 x 10 = 900hp @ crank 
Ethanol: 900hp x 1.1 = 990hp @ crank

Caveat: I am NOT saying this is the case, but it could be an option - and again, it's no criticism of anyone... it's just the kind of thing you need to factor when looking at this kind of thing.

So, if we assume you're off the map then there are a couple of things you need to bare in mind.   Firstly, as your compressor efficiency "runs out" the intercooler has to do more work to cool the air down and the turbo needs to do more work to move the same amount of air, which means the turbine needs to do more work to drive the compressor which drives up exhaust back pressure.    If you had exhaust back pressure and turbine speed data it would not surprise me at all if back pressure was getting a bit wild, and turbine speed is creeping up near the magic 116,000rpm EFR9180 max compressor speed limit.

So, if these assumptions were correct - what would happen if you went to an EFR9280?   You go from being well off the map to suddenly being at ~64% compressor efficiency which is HAPPY.   Your exhaust back pressure will plummet, which will actually increase your engine's volumetric efficiency, you will potentially actually move MORE lb/min for the same boost level, your intake temperatures will drop and you'll pick up a significant power at the same boost on pump gas and more significantly, you have quite a bit of headroom to make more power if you turn the boost up.

You'll also lose a few hundred rpm of boost threshold of course, on the same token @GTSBoyhas been referring to velocity at the compressor inducer - that same drop in velocity can make it take a bit longer before the compressor starts operating efficiently, and result in a bit more lag.   You don't get a lot of stuff for free, unfortunately.

Feel free to question anything I've said there, but hope it helps paint a picture of the kind of things that can be going on and why I often ask lots of stupid questions when suggesting turbos and also when trying to work out what could be going on - also why turbo speed and exhaust back pressure sensors are SUPER useful when optimising big setups like this.

 

Edited June 2, 2022 by Lithium

[hypergear]

Assuming the intercooler is efficient. From the dyno reading, the compressor is unable to keep up with engine speed at holding constant boost pressure, its a usual indication that the compressor wheel is maxed out. At that point when wastegate is loaded to increase turbine speed, compressor discharge temp skyrockets.

PS. I wouldn't worry  too much about the graphs or data manufacture put out there, they will be apprximate depending on application. 

Edited June 2, 2022 by hypergear

[Lithium]

On 02/06/2022 at 1:30 PM, hypergear said:

Assuming the intercooler is efficient. From the dyno reading, the compressor is unable to keep up with engine speed at holding constant boost pressure, its a usual indication that the compressor wheel is maxed out. At that point when wastegate is loaded to increase turbine speed, compressor discharge temp skyrockets.

PS. I wouldn't worry  too much about the graphs or data manufacture put out there, they will be apprximate depending on application. 

He's got a solid sized Hypertune intercooler, would hope that's efficient.

I did just realise that boost is tapering back to 22-23psi which drops the pressure ratio a bit, and also raises questions of if the tuner had a reason for it and also would partly explain the power rolling off harder.

[Predator1]

Thanks @Lithium - After I read your reply a few times, I'm beginning to understand it. I think I was on the right track in my mind, but I probably could have articulated it better.

I was at a point where I was trying to calc flow rates by using BSAC, AF ratios etc as I didnt think the turbo was at its peak already.

And yes, the boost was dropping off, the tuner tried to add DC from memory, but it dropped boost regardless what he did. He thought it was a boost leak, which we then validated and none were found.

I wish he had a pressure sensor which we could have hookedup, but all good.

Think what I'll do is:

1) Stick the speed sensor on
2) Stick my sequential in
3) E85 tune
4) Stick a pressure sensor and maybe a temp sensor on the turbo outlet(I'm out of temp inputs, so will have to convert an analogue to temp maybe).

On 02/06/2022 at 12:11 PM, Lithium said:

So, if these assumptions were correct - what would happen if you went to an EFR9280?   You go from being well off the map to suddenly being at ~64% compressor efficiency which is HAPPY.   Your exhaust back pressure will plummet, which will actually increase your engine's volumetric efficiency, you will potentially actually move MORE lb/min for the same boost level, your intake temperatures will drop and you'll pick up a significant power at the same boost on pump gas and more significantly, you have quite a bit of headroom to make more power if you turn the boost up.

You'll also lose a few hundred rpm of boost threshold of course, on the same token @GTSBoyhas been referring to velocity at the compressor inducer - that same drop in velocity can make it take a bit longer before the compressor starts operating efficiently, and result in a bit more lag.   You don't get a lot of stuff for free, unfortunately.

 

 

I'd be keen to see if anyone's running a 9280 on a 3.2 or similar motor. Even with that turbo, I dont think i'd hit 1000awhp, am I right?

[GTSBoy]

On 6/2/2022 at 10:04 AM, Predator1 said:

I'd be keen to see if anyone's running a 9280 on a 3.2 or similar motor. Even with that turbo, I dont think i'd hit 1000awhp, am I right?

What you should do is go set up your existing turbo on matchbot and tweak the engine parameters until it pretty much matches what you get at the two datapoints in your OP. Then you can throw other turbos at it and see what happens.

[Lithium]

On 02/06/2022 at 2:04 PM, Predator1 said:

Thanks @Lithium - After I read your reply a few times, I'm beginning to understand it. I think I was on the right track in my mind, but I probably could have articulated it better.

I was at a point where I was trying to calc flow rates by using BSAC, AF ratios etc as I didnt think the turbo was at its peak already.

And yes, the boost was dropping off, the tuner tried to add DC from memory, but it dropped boost regardless what he did. He thought it was a boost leak, which we then validated and none were found.

I wish he had a pressure sensor which we could have hookedup, but all good.

Think what I'll do is:

1) Stick the speed sensor on
2) Stick my sequential in
3) E85 tune
4) Stick a pressure sensor and maybe a temp sensor on the turbo outlet(I'm out of temp inputs, so will have to convert an analogue to temp maybe).

I'd be keen to see if anyone's running a 9280 on a 3.2 or similar motor. Even with that turbo, I dont think i'd hit 1000awhp, am I right?

The WGDC not having an effect on boost definitely suggests she's getting pretty tapped out.   Bare in mind again that doesn't mean there's not more power if the engine is able to "do more" with the air its already moving, whether the tune is soft or whether you could get more on a better fuel.

Your plans sound solid anyway, though I'd be pretty cautious about things with the turbo seemingly tapped - if it's being pushed that hard there IS the potential for significant overspeeding to be going on which isn't ideal at the best of times, the EFR turbine isn't the most tolerant.

Re: The 9280, I don't know anyone running one "hard" as such.  Jesse Greenslade is at around 890hp @ hubs on E85 at 26psi last I heard.   I don't know if that's tapped out, I suspect it's not: 

 

I know of someone else with a RB34 running an EFR9280 as well, they hit 925hp @ hubs on E85 and it definitely had more in it.  They were "only" after 650kw (870hp) max anyway, the swap to the bigger turbo was more about making the power easier while not losing response over the old turbo - as opposed to actually making max power.   Based off what I know with that one all signs suggest it's got plenty up it's sleeve but I don't know how much.

I suspect the 1.05a/r hotside will start struggling if you go for 1000hp @ hubs, and the 1.45 adds QUITE a bit of lag - anyone I know who has run it has swapped to the 1.05 on the 9280 so far.  Imho if you have your heart set on making 1000+hp @ hubs without being ruthless I'd consider looking at the likes of a Garrett G40-1150.

[Lithium]

Another thought here.   So I've spoken to people with "similar" engine specs to you who had or do have 9180s on them and you really shouldn't be running into that much of a tapped out situation still really.  Like its going to be pushing the compressor a bit, but it sounds like you're potentially dangerously tapped out right now.   They've been able to push boost levels beyond what you're seeing so even ignoring the power levels, anecdotally speaking they're probably getting at least as much air into their engines as you are - I'd definitely try and rule out this kind of thing before you spend serious money.

One of the guys who I know who runs an EFR8474 had a sudden drop off in performance and pressure tested it all and it came up fine, however it turned out that the Turbosmart "internal BOV" got a bit of grit in it and was jammed open.  The trick is it didn't show up in the boost leak test as it leaks straight back into the compressor cover.... so it won't really show up as a leak in a smoke test as it's not leaking to atmosphere, but it WILL actually be effectively a boost leak in use if something like that  happens.

The stock EFR recirculation valve is also known to just leak even when it's "working" at higher boost levels, so that could also be a possibility.  If you haven't already, I'd try and make sure this kind of thing isn't a possibility.

 

[GTSBoy]

>1000HP 9280 result

 

[Lithium]

On 03/06/2022 at 1:34 AM, GTSBoy said:

>1000HP 9280 result

I should have been more thorough with my response on the "EFR9280 doing 1000hp"

I actually know someone who has cracked 1000hp @ hubs with an EFR9280 on an RB32.   It was running a 1.45a/r hotside at the time and EMAP was STILL unacceptably high.... and that's a big step up in housing over the 1.05a/r - so imagine how bad that would be?   

I understand the next logical comment could be "Well why not run the 1.45a/r then?".   The 1.45a/r on a EFR9280 adds significant amount of lag.   Like 400rpm on top of maybe the extra 300ish you'd lose in spool going from a 9180 to a 9280.   The 1.45a/r EFR9280 acts like a BIG turbo, does crack 1000hp but does it basically completely tapped out and big EMAP when run on an RB32 and you're likely to be looking at full boost getting up near 5000rpm... the combination just starts not really making sense imho.

I realise the Rigoli 4G63 makes 1000hp @ hubs in time attack form but you gotta remember that it's on a 2.2litre engine that will run like 45psi to make that power, the 3litre is going to be running in the area of 15psi less boost to try and move the same amount of air on a compressor map that is happier at higher boost levels - basically the 3litre is likely to have similar or higher EMAP with significantly lower IMAP, which doesn't do great things for encouraging air to flow cleanly through an engine.

I am a fan of the EFR range but the EFR9280 is one of my less favourite of them just because it isn't "quite" right - at least on RBs IMHO, though if you're "only" looking for 900hp range then going that with the 1.05a/r hotside should give a nice jump in power potential over the 9180 without pushing it too hard and losing too much response.   If you're looking for 1000hp+ then it really is probably time to start looking at things which have turbines which are more enthusiastic at that kind of power level.

[GTSBoy]

On 6/3/2022 at 6:24 AM, Lithium said:

you gotta remember that it's on a 2.2litre engine that will run like 45psi to make that power, the 3litre is going to be running in the area of 15psi less boost to try and move the same amount of air on a compressor map that is happier at higher boost levels

Yeah. I think that was the salient point to take from the video. 4G63 finds itself on a completely different part of the comp map.

I just like the thumbnail.

[Predator1]

On 02/06/2022 at 4:09 PM, Lithium said:

One of the guys who I know who runs an EFR8474 had a sudden drop off in performance and pressure tested it all and it came up fine, however it turned out that the Turbosmart "internal BOV" got a bit of grit in it and was jammed open.  The trick is it didn't show up in the boost leak test as it leaks straight back into the compressor cover.... so it won't really show up as a leak in a smoke test as it's not leaking to atmosphere, but it WILL actually be effectively a boost leak in use if something like that  happens.

The stock EFR recirculation valve is also known to just leak even when it's "working" at higher boost levels, so that could also be a possibility.  If you haven't already, I'd try and make sure this kind of thing isn't a possibility.

 

Yes, I was also advised about the stock bov, so I upgraded to the TurboSmart one. I have no idea whether its leaking though??? How heck would I test?

 

On 03/06/2022 at 10:24 AM, Lithium said:

I am a fan of the EFR range but the EFR9280 is one of my less favourite of them just because it isn't "quite" right - at least on RBs IMHO, though if you're "only" looking for 900hp range then going that with the 1.05a/r hotside should give a nice jump in power potential over the 9180 without pushing it too hard and losing too much response.   If you're looking for 1000hp+ then it really is probably time to start looking at things which have turbines which are more enthusiastic at that kind of power level.

I'm a big fan of them as well. I'm hoping that its not the turbo maxing out. I had a bit of a play with matchbot(first time i tried it), and here is what I see:

https://www.borgwarner.com/go/6BEDRE

The estimated power is very close, but theres some stuff I dont know, eg AF ratios, EGT, FMIC Pressure drop etc. The plots on the map seem accurate enough. I switched it to the 9280 and it seemed to be around 70%(given the input values are somewhat correct).

I dont know what to do with the Turbine Expansion Ratio(apart from lining them up on the chart) - Could you gents perhaps have a go?

 

[Lithium]

On 03/06/2022 at 3:07 PM, Predator1 said:

https://www.borgwarner.com/go/6BEDRE

The estimated power is very close, but theres some stuff I dont know, eg AF ratios, EGT, FMIC Pressure drop etc. The plots on the map seem accurate enough. I switched it to the 9280 and it seemed to be around 70%(given the input values are somewhat correct).

I dont know what to do with the Turbine Expansion Ratio(apart from lining them up on the chart) - Could you gents perhaps have a go?

 

That's what you're meant to do, line them up on the chart - you also need to fill the compressor efficiency cells out with the efficiency values that line up with the dots on the compressor map.

What should essentially happen is you get a general thumbsuck of exhaust back pressure etc.  Not super accurate but you can build a loose picture of things.

Worth mentioning that you probably have bigger cams/better VE than the default numbers in matchbot, and it seems that you're revving it to at least 7500rpm so probably should update the rpm scale to suit the max rpm at least.  I had a super fast rough fiddle with the settings, take with a grain of salt but I'd guess slightly closer to reality for your car currently:

https://www.borgwarner.com/go/JMZZ59