Efficiency of Turbos. Who talks about it?

[Alkoran]

I've been here a while now (even before buying my car, 2 years ago) more as a reader than a commenter (partially because I'm french canadian so I'm more confortable reading than writing or worst, talking!) and there's two things that strike me the most about the performance threads that I read:

1. I've not seen much talk about turbo efficiency and flow charts when it comes to swapping the stock turbo to whatever options there's available (Hybrids and Big Turbo) but so many seems to stick on PSI obtained and what not.
2. Again, everybody talks about big intercoolers but nobody talks about what is the right size and pressure drop. I see massive intercooler like the Bravo and can't help to think: is it really needed? Is it efficient, for the, what, 350-400whp it'll see at most, or is a smaller one would do the same? I see plenty of highr whp builds in other tuner scenes that don't use that kind of size and simply don't need them.

Now, I start this thread to talk about the first point and if you have half an hour to spare, I suggest checking this video about turbo efficiency.

I understand that not much information is available for either the stock nor hybrids or even some big turbo when it comes to compressor maps so we could compare apples to apples. But once again, pretty much all I see is talks about maximum boost attained. I just wanted to get a conversation going about what I think is a more relevant piece of information (flow rates and efficiency) when deciding which way to go when buying a major upgrade. What do you all think about this?

 

[RubenZZZ]

Very good points.

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[New_Daily]

Very good points and cool vid.

My thoughts in why these aren’t really discussed for our cars: since it’s a stock turbo vehicle and good aftermarket turbos are already relatively expensive, we want something that can bolt right up. That means we’re relatively limited in our turbo selection. So we let the turbo manufacturers do all the compressor efficiency map analyzing for turbos for our engine and we trust them to select compressors that wil work well.

Now when you consider that there are actually a number of turbos we have to choose from, doing the homework could certainly be beneficial. But, most people probably don’t know how to effectively use a compressor map. Hell, even in the video, when he was plotting his engine data onto the compressor map, he was making assumptions, like that each 1 lb/min of airflow is about 10 hp at the crank. I think that’s probably specific to his Miata engine.

Something I will say I have been surprised by. When I was into Mustangs in the late 90’s then a Merkur after that which has the older Ford 2.3 turbo motor, very few people would actually get their car on a dyno. It seems a much higher percentage of people who want more power from our cars actually go to a dyno now a days. But also, the factory ECU‘s and ability of modern tuners is much greater than the old Ford EFI. So maybe I’m not giving enough credit to the modern car guy and gal in making choices for power increase.

 

[Dpro]

Honestly having owned other Turbo cars with intercoolers just slightly larger than our upgraded intercooler. On a 2.5 liter inline 6 I might add with a HKSGt2530 I can I could get that setup to spool instantly. It also realized 300 whp and was running in a car the same weight as ours but RWD. I might add it had upwards of 400ft lbs of torque. To say that car moved like a missile is putting it mildly. Yes indeed if your not going for over 400HP the Bravo Alpha is really not needed strictly speaking from the fact that our engines can only pump 1.6 liters of volume anyways. So anything around a CPE/Whoosh V3 etc in size is going to be plenty good enough for someone lookng to make around 300-325 wheel. People get caught up in crazy HP numbers and looking to make our cars into drag machines . Of course having been in several different turbo setups now S242, Whoosh Hybrid, Gt2860 II , with different intercooler setups I can all seemed to work. One car had a Mountune intercooler at the time S242 which was switched out to a Whoosh V2, The other had a Whoosh hybrid with a Whoosh V3, and the one with GT2860 II had a DHM. Not really sure how big the DHM is. I personally drove the Whoosh setup and it spooled instantly and pulled hard. The S242 had instantaneous pull as well. The GT2860 did not seem to lag but was definitely a bit more linear but pulled hard and went. So ya one does not need the Bravo Alpa in my opinion unless they are going high HP. I cannot attest to its possible lag or where the powerband. Really the big difference is the fact that our stock intercooler was entirely a bit on the Tiny side and never intended for more than stock HP increases. I think one people start adding tunes and turbos it definitely changes up the game . As far as volumetric efficiency goes most of the Turbos being used on our cars are pretty much in the ballpark. Even though we talk about big turbos and what not these Turbos for the most part are not really all that big. lol

I can also say that on the S280 different tuners are actually working on tuning the Turbo effiiciently on our cars and turning out insane numbers while experimenting with overspinning the turbo i.e taking it out of its efficiency range.
Modern Turbos are pretty cool as you can push them farther than you could old school ones due to impeller designs and port designs. In the old days on like say a Gt25 anything above 11 lbs of boost and you were blowing hot air . Our stock Turbos are actually that size or even possibly a bit smaller and yet you can push 23lbs of boost and get power. So maybe people do not talk as much about efficiency of Turbos because modern Turbos are a lot more efficient by design?

P.S. I have not watched the video completely as I actually am hungry and want to go eat dinner. lol I will check it out later.

 

[Ford ST]

Honestly having owned other Turbo cars with intercoolers just slightly larger than our upgraded intercooler. On a 2.5 liter inline 6 I might add with a HKSGt2530 I can I could get that setup to spool instantly. It also realized 300 whp and was running in a car the same weight as ours but RWD. I might add it had upwards of 400ft lbs of torque. To say that car moved like a missile is putting it mildly. Yes indeed if your not going for over 400HP the Bravo Alpha is really not needed strictly speaking from the fact that our engines can only pump 1.6 liters of volume anyways. So anything around a CPE/Whoosh V3 etc in size is going to be plenty good enough for someone lookng to make around 300-325 wheel. People get caught up in crazy HP numbers and looking to make our cars into drag machines . Of course having been in several different turbo setups now S242, Whoosh Hybrid, Gt2860 II , with different intercooler setups I can all seemed to work. One car had a Mountune intercooler at the time S242 which was switched out to a Whoosh V2, The other had a Whoosh hybrid with a Whoosh V3, and the one with GT2860 II had a DHM. Not really sure how big the DHM is. I personally drove the Whoosh setup and it spooled instantly and pulled hard. The S242 had instantaneous pull as well. The GT2860 did not seem to lag but was definitely a bit more linear but pulled hard and went. So ya one does not need the Bravo Alpa in my opinion unless they are going high HP. I cannot attest to its possible lag or where the powerband. Really the big difference is the fact that our stock intercooler was entirely a bit on the Tiny side and never intended for more than stock HP increases. I think one people start adding tunes and turbos it definitely changes up the game . As far as volumetric efficiency goes most of the Turbos being used on our cars are pretty much in the ballpark. Even though we talk about big turbos and what not these Turbos for the most part are not really all that big. lol

I can also say that on the S280 different tuners are actually working on tuning the Turbo effiiciently on our cars and turning out insane numbers while experimenting with overspinning the turbo i.e taking it out of its efficiency range.
Modern Turbos are pretty cool as you can push them farther than you could old school ones due to impeller designs and port designs. In the old days on like say a Gt25 anything above 11 lbs of boost and you were blowing hot air . Our stock Turbos are actually that size or even possibly a bit smaller and yet you can push 23lbs of boost and get power. So maybe people do not talk as much about efficiency of Turbos because modern Turbos are a lot more efficient by design?

P.S. I have not watched the video completely as I actually am hungry and want to go eat dinner. lol I will check it out later.

Maybe a little off topic but since we're talking about turbo efficiency and how intercoolers may play into that.
How do you like your mountune intercooler fit finish?
Also do you believe it is a perfect fit for the OEM turbo.


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[Alkoran]

I can also say that on the S280 different tuners are actually working on tuning the Turbo effiiciently on our cars and turning out insane numbers while experimenting with overspinning the turbo i.e taking it out of its efficiency range.
Modern Turbos are pretty cool as you can push them farther than you could old school ones due to impeller designs and port designs. In the old days on like say a Gt25 anything above 11 lbs of boost and you were blowing hot air . Our stock Turbos are actually that size or even possibly a bit smaller and yet you can push 23lbs of boost and get power. So maybe people do not talk as much about efficiency of Turbos because modern Turbos are a lot more efficient by design?

That's the point of the video. Talking about PSI is kind of irrelevant when comparing turbos even on the same engine because it's the mass of air that the turbo can flow that determines the power it's able to make. I'm really curious to know what's the flow range of all the options we currently have and how much more can we push them and still be in their efficiency zone/out of choke zone.

 

[M-Sport fan]

The other had a Whoosh hybrid with a Whoosh V3, and the one with GT2860 II had a DHM. Not really sure how big the DHM is.

The DHM is substantially larger than the BA (like close to Pro Alloy size! ), since it will not fit behind the factory crash bar at all, and needs either their, or one of the 'copycat' replica, tubular crash bars to fit.

 

[SerialBrain2]

I have the mountune intercooler and it is outstanding

 

[KnockOff]

From what I understand its all about lb per minute. Just like the fact the stock turbo can make 26 or 27psi but make less power than a 2860r on 20psi. Just my 2 cents.

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[Dpro]

Maybe a little off topic but since we're talking about turbo efficiency and how intercoolers may play into that.
How do you like your mountune intercooler fit finish?
Also do you believe it is a perfect fit for the OEM turbo.


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My Mountune is the later bar and plate version. It actually can support a upgraded Turbo. Its actually larger internally than there original Tube and fin model. They pare it with the MRX in a kit now.
It does the job fine I do not see high charge temps. I do not run into heatsoak in the canyons with it. I have not tracked it yet.

That's the point of the video. Talking about PSI is kind of irrelevant when comparing turbos even on the same engine because it's the mass of air that the turbo can flow that determines the power it's able to make. I'm really curious to know what's the flow range of all the options we currently have and how much more can we push them and still be in their efficiency zone/out of choke zone.

First off, my first post that you quoted was prior to watching the vid, and I stated that.
Second off we work with Tuners who look at that stuff.
Which begs the question do we ourselves need to worry about that?

You have to get a tune for your Turbo setup and the tuner actually does look at that stuff when making the tune.

The DHM is substantially larger than the BA (like close to Pro Alloy size! ), since it will not fit behind the factory crash bar at all, and needs either their, or one of the 'copycat' replica, tubular crash bars to fit.

Yes the DHM was built for high HP numbers. It could be overkill and honestly I rode in the GT2860 II car and that car is putting out numbers in the 350 plus range and is still getting completely tuned. I did not notice less donkey acceleration on the bottom but it spool quickly enough that at 3k it really started to move Also I should add the driver did not mash it hard as to avoid tire spin. lol his car can move.

From what I understand its all about lb per minute. Just like the fact the stock turbo can make 26 or 27psi but make less power than a 2860r on 20psi. Just my 2 cents.

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Ya and that is the point were the stock Turbo is completely out of its efficiency range. I would hazard a guess that the Stock Turbo’s efficiency range starts to taper at 23lbs and above. At that point one is probably starting to overspin it.

 

[New_Daily]

That's the point of the video. Talking about PSI is kind of irrelevant when comparing turbos even on the same engine because it's the mass of air that the turbo can flow that determines the power it's able to make. I'm really curious to know what's the flow range of all the options we currently have and how much more can we push them and still be in their efficiency zone/out of choke zone.

Well yes it’s the mass of air the turbo can flow but don’t forget the engine it’s going on. It you bolted up our tiny stock turbo to a big V8 it’s quite likely it wouldn’t even make boost, or much at all, because the larger V8 already moves so much more air.

The video kinda alluded to that when he was talking about putting the same turbo on a motor that makes 100hp and one that makes 200hp. The 200hp motor would only see 6psi and the turbo would be at it maximum there. So for the total air mass moving the motor has to be taken into account. But since this is a car specific forum we are obviously all talking about different turbos on the same motor.

That’s also part of what I was initially saying in that our cars are stock turbo so the companies making turbos for our cars just tailor the compressor for our motors. But the video, putting a turbo on a car like a Miata you have a lot more choice because the system is essentially all custom, even if it’s a kit that’s been made specific for that car.

 

[Dpro]

Well yes it’s the mass of air the turbo can flow but don’t forget the engine it’s going on. It you bolted up our tiny stock turbo to a big V8 it’s quite likely it wouldn’t even make boost, or much at all, because the larger V8 already moves so much more air.

The video kinda alluded to that when he was talking about putting the same turbo on a motor that makes 100hp and one that makes 200hp. The 200hp motor would only see 6psi and the turbo would be at it maximum there. So for the total air mass moving the motor has to be taken into account. But since this is a car specific forum we are obviously all talking about different turbos on the same motor.

That’s also part of what I was initially saying in that our cars are stock turbo so the companies making turbos for our cars just tailor the compressor for our motors. But the video, putting a turbo on a car like a Miata you have a lot more choice because the system is essentially all custom, even if it’s a kit that’s been made specific for that car.

Very good point and was what I was alluding too in my initial comments. Most people do not need to think hard about the math for these reasons. I should also add that having an AP lets you see a damn lot of the stuff covered in the video if one desires to configure the gauge setup in their accessport to monitor that stuff.

I was actually pleasantly surprised the first time I went through the gauge setup and possible monitoring points when I first fired mine up. I came from the world of Apexi PowerFC’s that piggybacked on the ECU. It was either that or get a Flash tune that you could not monitor. The Cobb is a pretty damn cool little piece of kit in the tuning world.

I really also am surprised no one really got aftermarket EFR to work right with our cars as stock we are Borg Warner and they really have it over Garrett in the Turbo design game at this point. I thought I heard they are now owned by the same parent company?

So TLDR cool vid,. most of the Turbo designs for are our cars are already within parameters so we do not need to worry about them,
Plus we have so many tuners making tunes for them they can do the dirty work for us as well and actually do when making the tunes.