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Turbo Technics S280 Turbo Kit Dyno, Virtual Dyno, and Datalog Thread

wetwea33

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Ahhh good call on the type of dyno I didn't know about that! Highest boost I saw on AP was just a hair over 27, and let me tell you this thing feels amazing. Third gear pulls snapping my head back into the seat is a ridiculous feeling in the Fiesta.
For 27 psi on a mustang dyno those are great numbers. I was running 35-36psi. Get an aem manifold map sensor and up the boost if you want more power. It was a huge difference going from oem map sensor boost levels to 35-36. Imo tho the power get super unusable on the street with this type of spool unless ur doing a ton of highway roll racing. Also up your ethanol content.

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Se7eN

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Imo tho the power get super unusable on the street with this type of spool unless ur doing a ton of highway roll racing. Also up your ethanol content.
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That's exactly the issue my friend from the dyno graph has. Yesterday he picked up some 180tw tires and it still spins in 2nd gear a bit. This being on stock map sensor I can't imagine him having any more torque down low. Even with ramping up the boost later on in the RPM these things produce a lot of low end torque.
 


wetwea33

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That's exactly the issue my friend from the dyno graph has. Yesterday he picked up some 180tw tires and it still spins in 2nd gear a bit. This being on stock map sensor I can't imagine him having any more torque down low. Even with ramping up the boost later on in the RPM these things produce a lot of low end torque.
Second gear was unusable even with r888r

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1st look at data logs from my S280 install. Not necessarily new info, but very happy with spool. Will be interesting to see how comparison changes as the 280 3k boost target is increased going forward. Considering RPM to achieve (low) 12 lb/min Airflow, the 280 is only ~300 RPM lagging stock. Feels great already.
 


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It will be interesting to see what happens when you increase the boost! The fact that your boost pressures at 5200-5300 rpm are the same and your airflow is roughly the same at that same point is interesting.


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"The fact that your boost pressures at 5200-5300 rpm are the same and your airflow is roughly the same at that same point is interesting."

Good observation.

Same flow circuit from turbo discharge to manifold (turbo is a pressure source) Flowrate is simply going with source pressure. They are the same since it's the same circuit at the same source pressure..


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"The fact that your boost pressures at 5200-5300 rpm are the same and your airflow is roughly the same at that same point is interesting."

Good observation.

Same flow circuit from turbo discharge to manifold (turbo is a pressure source) Flowrate is simply going with source pressure. They are the same since it's the same circuit at the same source pressure..


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[/QUOTE]

As efficiency of the compressor goes up, and/or back pressure on the turbine side presumably drops, (as in pressure in the exhaust manifold decreases) one might expect to see mass flow rate increase for a given pressure?


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wetwea33

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It will be interesting to see what happens when you increase the boost! The fact that your boost pressures at 5200-5300 rpm are the same and your airflow is roughly the same at that same point is interesting.


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The accessport airflow pid is not accurate and gets further inaccurate with aux fuel.

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The accessport airflow pid is not accurate and gets further inaccurate with aux fuel.

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What are you saying isn't accurate? The PID or the Airflow and other measurements used in the PID? I'm not sure how the PID is relevant here? I'd expect the airflow to be accurate being a hot wire, especially at the same baro and Tamb. The same comparisons could be used just looking at MAF voltage given baro and Tamb were the same.

Probably not intended discussion per the intent of the thread. If I'm missing something I appreciate the feedback, PM if so.

As far as the coveted spool, my opinion is airflow is a more direct measure of benefit. Boost is ok, but it doesn't account for the different flow characteristics of the compressor, so I showed both, but would choose airflow if I had to pick 1.
 


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As far as the coveted spool, my opinion is airflow is a more direct measure of benefit. Boost is ok, but it doesn't account for the different flow characteristics of the compressor, so I showed both, but would choose airflow if I had to pick 1.
I would feel same...airflow if accurately read would seem to be a more direct proxy for power than boost. One way to find out!
 


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Thanks Ron & @wetwe33. I'll have to dig in to understand why and implications. Appreciate the feedback.
Copy/pasted from a previous explanation so you won’t have all the context but this may get you started...


Here is a basic calculation of the airflow mass:

Datapoint of peak mass airflow to closest 500 rpm

Basically, if I didn’t take any air/fuel out of the equation at 6500rpm and 26.25 psi of boost = 40.94 psia = 83.35 inhg.

Equation for airflow mass per event is y=mx+b where y is MAP in inhg, and M = mass in lbm/event. Y is slope (taken from tune before aux was turned on) B = zero offset

83.35 = M* 30626 +2

M = 0.002656.

6500rpm = 3250 events per minute (events are intake strokes basically) = 8.6328lb/min per cylinder * 4 (number of cylinders) = 34.5 lb min. @100 degrees F. Multiplied by the same density factor below of 60 vs 100 degrees is 37.1 lb/min. I believe that is a little high as the exhaust backpressure at that boost will start to bring that number down.

Just to check my work, I used the same numbers but current- 29.017 times 0.865 (13% STFT removal) = 25.15 (this assumes 100 degree F temp). Multiplied by (0.0763/0.0709) (density at 60 vs 100 degrees F) = 27.06lb/min. The actual value calc’ed by the ECU was 27.15lb/min. You can see its pretty close using the same calculations.


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Thanks Ron & @wetwe33. I'll have to dig in to understand why and implications. Appreciate the feedback.
I may start a thread to continue this discussion for those interested, but a bit more digging explains my confusion. It seems we have a MAF sensor, and it could be used to get a good read on airflow (as I assumed), but it is not available in the AP3 sensors. It also seems only the IAT signal is used from the MAF sensor. I would have been happy with MAF voltage, but not available. The airflow is calculated in a "speed density" algorithm using several other sensors. So, I'll leave it at that here, but this explains the comments on airflow accuracy as reported by the AP3. When making comparisons using airflow, being aware of this helps understanding of whether the comparison is meaningful.

Thanks again guys for pointing this out.
 


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