1.5T Power Metrics & Limitations for 1.5L Turbo (Non Si models)

Myx

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I love this thread and the discussion in it. I'm glad to see it still going. I have nothing to add at the moment. Just wanted to say thanks to all.
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Hollywoo0220

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Yes this was for the non si turbo, but the si turbo flows 300cfm @ aprox 65% efficiency. The non si turbo flows less then that ...
Also Hollywoo0220 according to the compressor map of MHI itself the SI turbo only flows 300CFM Max .So 400cfm was way off. (0.14m³/s = 296cfm. )
Ok, let me iron this out.
You stated that I was way off as to the Si turbo; which I did not mention in my Metrics.
The Non Si and Si turbos have the same compressor. The blades on the exducer are the only difference. This is the root reason behind the Si having the capability to make power past 5500rpm (expelling more exhaust gas).
Without a ‘compressor map’ to help determine the precise VE, the VE is closer to 75% (at a given PR) to NET 300cfm from a MAX of approx 400cfm.
 

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You're right i mixed up the compressor and turbine wheels.The turbine wheels are different the compressor wheels not.
Here's the compressor map from MHI's upgrade turbo and the stock si turbo.At a max psi of 23psi the PR is 2.56 .At that line close to the choke line you'll never be in a 75-70% efficiency island more like a 60% island.
The efficiency islands that are plotted on the compressor map are those of the upgrade MHI turbo.
0C0E0F26-C2E1-4B19-AFB9-021EA81C8701.png
 
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Hollywoo0220

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You're right i mixed up the compressor and turbine wheels.The turbine wheels are different the compressor wheels not.
Here's the compressor map from MHI's upgrade turbo and the stock si turbo.At a max psi of 23psi the PR is 2.56 .At that line close to the choke line you'll never be in a 75-70% efficiency island more like a 60% island.
The efficiency islands that are plotted on the compressor map are those of the upgrade MHI turbo.
0C0E0F26-C2E1-4B19-AFB9-021EA81C8701.png
Yep. The detail that is left (that is undisclosed) is that, at a lower VE than 74-75% will not produce 300cfm. We might be able to achieve it in a short span of the Compressor Map (in the RPM range), but not the whole boost target range (especially on the stock unit). With higher octane and timing you can make up some of the difference; but, that becomes “higher risk” and too aggressive for the majority of daily drivers.
Would be better to lower the PR just a tad and get more VE for a longer duration. Is that what you see as well?
 
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Yes the lower the efficiency island gets the turbo puts out more heat .Ideal would be to end in a 75% island and have some room to spare.
I can't seem to get why people push out 284whp on a stock Si turbo with fbo and flex fuel offcourse .The VE of these engines must be very high 110-120% ?
 
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Yes the lower the efficiency island gets the turbo puts out more heat .Ideal would be to end in a 75% island and have some room to spare.
I can't seem to get why people push out 284whp on a stock Si turbo with fbo and flex fuel offcourse .The VE of these engines must be very high 110-120% ?
After looking at the benchmarking, it is right there between 110-113%. They will go for a long time as long as someone doesn’t over do it.
 

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Any thoughts on how much extra peak horsepower the new turbo vs the Si turbo vs stock? Outside of what the manufacture guesstimates.

Loving this thread even more now.
 
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Any thoughts on how much extra peak horsepower the new turbo vs the Si turbo vs stock? Outside of what the manufacture guesstimates.

Loving this thread even more now.
That’s whole different thread @Myx bud...
There are all those variables to consider, that you have run into before (i.e. fueling, octane, timing, Pressure Ratio, etc).
With a slightly larger compressor and the ability to expell more exhaust you would be in a higher efficiency island for longer, hold it for a tad bit longer and a tad bit higher.
Just understand that the Si is better at scavenging in the higher RPM than the Non-Si, so I would not press it on even you bud .
 
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Are you ever going to get whp numbers on your website for your stage 2 tune CVT
 
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power metric tune
If you are referencing the KTuner Stage 2, I must add that not every dyno registers the same. But, if you are running the required octane and have an upgraded IC, then power output (@peak would be approx 207whp / 245-50lb ft). With certain aftermarket DP & Mid-Pipe set-ups you could achieve another 7-9whp in the low to mid range.
Sorry that may seem somewhat vanilla, but it is an approximate number being a CAN tune brother.

** Mind you, this would be on a Non-Si model.
** WHP is -12% of Crank HP
 
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So, reviving this post with some information that may prove useful to others.
I've had the opportunity to have 2 dyno sessions this year and I tried to understand the way that the base 1.5 delivers power.
My FC1 produced 178whp bone stock and 211whp quickly falling to 190whp on a KTuner starter21 with optimized AF in 2018. After I had my own KTuner v1.2 and digging through road logging information for more than a year my understanding around tuning for the stock turbo has been that :
- An aftermarket Intake (I have the Mishimoto) is beneficial to air flow. I have been able to register the same air flow (in g/s) at lower boost pressures past 5500rpm and that has been beneficial to power delivery as it has allowed me to play with ignition as a function of operating the turbo at higher efficiency.
- An aftermarket intercooler that does NOT introduce big pressure drop (I have the Wagner Tuning, similar results are shown by the 27Won) will assist a lot with flat power delivery, again allowing to add more timing when it is required (let alone being an investment in long-term health for the engine)
- Always tune for air-flow and not for boost targets. Why press the turbo to 21psi when you are only 2-3g/s short at 18psi? MAF calibration is key to this tuning process. AFR will be adjusted by STFT/LTFT (not outside of the US though) but you need to craft a nice air flow curve if you want to extend your power band.
- Ignition (with proper quality fuel) is key to power delivery. The starter maps will even run negative advance (aka retard), even at high rpm. This is a disaster as the exhaust gases will be super heated building even more back-pressure and crippling power delivery past 5600rpm. I have found that keeping ignition at or a little after TDC from 4000-5000rpm is beneficial to keeping consistent boost levels and torque but proper ramping to 4-6 degrees BTDC is essential to keep a nice powerband. Ignition has two functions in the 5500-6500 rpm range. First it will increase cylinder pressure (aka more power) but it will also lower the exhaust gas temperature, allowing for less back-pressure in combination with trimming boost levels as the rpms rise.

A few numbers from the dyno (not sure it is the proper place to post plots but I will if you'd like to discuss them), all of them after I have bolted the CAI & IC and using premium RON100 fuel (sort of equivalent to US93). I'm not about max numbers and I am not a professional tuner (I work with one in my home country), I like to tune for a wide torque range and a long lasting power band (I view it as a key to reliability), but my main drive is that I also enjoy exploring the efficiency limits to almost anything around me (being an engineer - even in computing)
- The stock tune with a CAI & IC delivers a 5-7whp increase over a wide rev range. So much for their advertised BIG GAINS :p
- Stock Boost Map with optimized Fuel and Ignition has delivered 210whp @ 5600rpm!!! That is more than 25whp increase @ 16.5psi . Of course this is where the CAI & IC shine (they unlock tuning possibilities)
- A 19psi map has produced 225lbft of torque @ 4800rpm (95% available from 2800-5400rpm) and 220whp (95% available from 4800-6600rpm)
- A 24psi map has produced 245lbft of torque @ 4600rpm (95% available from 2800-5100rpm) and 230whp (95% available from 4700-6500rpm)

That said, even the "entry" 1.5 is a hell of a capable power plant and I have had an incredible amount of fun messing around with it so far, so I wanted to share with this loooooong post :)

Hope you enjoyed!
 

Myx

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So, reviving this post with some information that may prove useful to others.
I've had the opportunity to have 2 dyno sessions this year and I tried to understand the way that the base 1.5 delivers power.
My FC1 produced 178whp bone stock and 211whp quickly falling to 190whp on a KTuner starter21 with optimized AF in 2018. After I had my own KTuner v1.2 and digging through road logging information for more than a year my understanding around tuning for the stock turbo has been that :
- An aftermarket Intake (I have the Mishimoto) is beneficial to air flow. I have been able to register the same air flow (in g/s) at lower boost pressures past 5500rpm and that has been beneficial to power delivery as it has allowed me to play with ignition as a function of operating the turbo at higher efficiency.
- An aftermarket intercooler that does NOT introduce big pressure drop (I have the Wagner Tuning, similar results are shown by the 27Won) will assist a lot with flat power delivery, again allowing to add more timing when it is required (let alone being an investment in long-term health for the engine)
- Always tune for air-flow and not for boost targets. Why press the turbo to 21psi when you are only 2-3g/s short at 18psi? MAF calibration is key to this tuning process. AFR will be adjusted by STFT/LTFT (not outside of the US though) but you need to craft a nice air flow curve if you want to extend your power band.
- Ignition (with proper quality fuel) is key to power delivery. The starter maps will even run negative advance (aka retard), even at high rpm. This is a disaster as the exhaust gases will be super heated building even more back-pressure and crippling power delivery past 5600rpm. I have found that keeping ignition at or a little after TDC from 4000-5000rpm is beneficial to keeping consistent boost levels and torque but proper ramping to 4-6 degrees BTDC is essential to keep a nice powerband. Ignition has two functions in the 5500-6500 rpm range. First it will increase cylinder pressure (aka more power) but it will also lower the exhaust gas temperature, allowing for less back-pressure in combination with trimming boost levels as the rpms rise.

A few numbers from the dyno (not sure it is the proper place to post plots but I will if you'd like to discuss them), all of them after I have bolted the CAI & IC and using premium RON100 fuel (sort of equivalent to US93). I'm not about max numbers and I am not a professional tuner (I work with one in my home country), I like to tune for a wide torque range and a long lasting power band (I view it as a key to reliability), but my main drive is that I also enjoy exploring the efficiency limits to almost anything around me (being an engineer - even in computing)
- The stock tune with a CAI & IC delivers a 5-7whp increase over a wide rev range. So much for their advertised BIG GAINS :p
- Stock Boost Map with optimized Fuel and Ignition has delivered 210whp @ 5600rpm!!! That is more than 25whp increase @ 16.5psi . Of course this is where the CAI & IC shine (they unlock tuning possibilities)
- A 19psi map has produced 225lbft of torque @ 4800rpm (95% available from 2800-5400rpm) and 220whp (95% available from 4800-6600rpm)
- A 24psi map has produced 245lbft of torque @ 4600rpm (95% available from 2800-5100rpm) and 230whp (95% available from 4700-6500rpm)

That said, even the "entry" 1.5 is a hell of a capable power plant and I have had an incredible amount of fun messing around with it so far, so I wanted to share with this loooooong post :)

Hope you enjoyed!

LOVE this post! Thanks for sharing and absolutely feel free to post your dyno plots as well. Very, VERY informative read here. We all can learn a lot from this and further discussion will only net more learning.

BTW: I highlighted a point you made above. You stated, "Why press the turbo to 21psi when you are only 2-3g/s short at 18psi?" What did you mean by this? 2-3g/s short of what? And how do you know if you are short of 'it'? Sorry for my ignorance.
 
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varge

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LOVE this post! Thanks for sharing and absolutely feel free to post your dyno plots as well. Very, VERY informative read here. We all can learn a lot from this and further discussion will only net more learning.

BTW: I highlighted a point you made above. You stated, "Why press the turbo to 21psi when you are only 2-3g/s short at 18psi?" What did you mean by this? 2-3g/s short of what? And how do you know if you are short of 'it'? Sorry for my ignorance.
Check your MAF in your logs (registered in g/s). So for a given inlet temperature, more boost will equal more air flow, so more g/s. Up to a point (high efficiency operation) the air flow will be somewhat proportional to boost. There will be a point where you increase your boost by a good amount and your airflow increase will be marginal (if any).
As an example, there is a certain rpm range and inlet temperature where 18psi will produce say 155g/s , which is only 3g/s short of 158 that 21psi will produce.
Do note that unless your MAF scale is well adjusted, your MAF reading will be mostly irrelevant and your g/s reading a lie :p
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