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Borg Warner R2S regulated 2 stage turbo in an NB Miata

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Borg Warner R2S regulated 2 stage turbo in an NB Miata

 
Old 10-30-2018, 12:12 AM
  #101  
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What are PM3, 4, and 5 assigned to in the IO pin list(s)?
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Old 10-30-2018, 12:13 AM
  #102  
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So for solenoids, you might actually want open drain, which would be injector outputs.

edit. To tes those you will want a pull up if you want to use the volt meter
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Old 11-01-2018, 01:48 PM
  #103  
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Well, ****.

I was told, in no uncertain terms, that I would not be able to get any additional programmable outputs from my MS today.
Wish I had known this since January.

Off to explore new possibilities with Hakan, the electronics guru here in Turkey, who builds and sells MaxiGauges.
I talked to him today, and he says we can expand the gauge interface unit in my car to allow programmable outputs to drive solenoids and whatnot.

Not. an. easy. project.
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Old 11-01-2018, 02:11 PM
  #104  
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Check out the stuff from JBperf if you have CANBUS.
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Old 11-05-2018, 07:56 PM
  #105  
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Thanks to Reverant, I now have all the programmable outputs I need, and they all work!

My MS has 2 programmable outputs, and I needed a third one.

I used the PM5 (warmup LED) output per Rev's suggestion, and used an N channel mosfet plus a flyback diode, again, as instructed by him.
Since I am paranoid about overloading anything, I also used an optocoupler relay module, packed it all in a box, and tucked it away.
The idea is removing any load and stray anything from the MS output.
Tested several times, all is good.



Red is switched 12V
Black, ground
Yellow is PM5 output from MS
Grey is the lowside trigger for the vacuum solenoid.

I am sure electronics gurus will laugh at me, but it works.
So there.
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Old 11-11-2018, 11:22 AM
  #106  
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Quick question:
I finally started the engine and did the break in run with very gentle throttle inputs and 3rd gear decels for about 10 miles, and noticed it was pretty rich all over.
My current tune was perfect with the supercharger, and I will tune it for the turbo setup.
I was expecting some change in behavior, but never thought the difference would be so drastic.
I have to take away fuel everywhere...
Gentle tip-in yields 10.5 AFR, cruise at anything over 3000 rpm is at 12.5 or below.
Idle settles down to 14.7 after ASE..
Is this normal between a SC and turbo setup?

Edit:

Another point worth noting is EGT..
Even though my observation is limited to a relatively short drive so far, EGT seems to be much lower than "before".
The sensor is in the same location, and while it is in no way an absolute value, the before and after readings can be compared.
Could be a product of the rich AFR numbers, that remains to be seen, but I am talking about 200 degrees difference (in C).

Last edited by Godless Commie; 11-11-2018 at 11:34 AM.
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Old 11-11-2018, 12:05 PM
  #107  
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Considering you just put a couple of turbines in the exhaust flow......yeah I'd expect part throttle efficiency to drop off considerably. I saw a pretty big change going from NA to turbo in my part throttle maps.
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Old 11-11-2018, 12:09 PM
  #108  
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Originally Posted by Bronson M View Post
Considering you just put a couple of turbines in the exhaust flow......yeah I'd expect part throttle efficiency to drop off considerably. I saw a pretty big change going from NA to turbo in my part throttle maps.
Please help me understand this:
You are saying efficiency has dropped, and yet I have to take away fuel (by re-tuning my VE table).
Would that not mean an increase in efficiency?
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Old 11-11-2018, 12:18 PM
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For a given map and rpm value you move less air and therefore need less fuel. Map and load are close cousins so yes, less pumping efficiency. Now what you do with that power output factors into BSFC or overall efficiency of the engine. Since you're no longer wasting power to turn a blower over you may be at a lower map / load cell for a given amount of power.

To simplify you may be able to pull the same hill at 30kpa that took 40kpa before.
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Old 11-11-2018, 12:26 PM
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Originally Posted by Bronson M View Post
yeah I'd expect part throttle efficiency to drop off considerably.
Originally Posted by Bronson M View Post
To simplify you may be able to pull the same hill at 30kpa that took 40kpa before.
I do not mean to contradict you, just trying to wrap my brain around this properly...
If I can do the same hill at a lower kpa (load) than before, does this not mean the efficiency has in fact increased?
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Old 11-11-2018, 12:39 PM
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Originally Posted by Godless Commie View Post
I do not mean to contradict you, just trying to wrap my brain around this properly...
If I can do the same hill at a lower kpa (load) than before, does this not mean the efficiency has in fact increased?
Yes
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Old 11-11-2018, 12:57 PM
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Yes sorry shouldn't have said "less efficient" in my first explanation, just less pumping efficiency. Pumping efficiency and BSFC are not one and the same, but certainly related.

You're over complicating things again, give the motor what it wants, in this case less fuel for a given map/rpm point.
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Old 11-11-2018, 06:19 PM
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Originally Posted by Bronson M View Post
give the motor what it wants...
I like that. Simple.
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Old 11-11-2018, 06:27 PM
  #114  
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Now you can clearly see how much power (and fuel) you were wasting spinning that supercharger
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Old 12-18-2018, 07:09 PM
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I thought it would be best to reserve this thread for technical discussion, so I started a separate build thread:

https://www.miataturbo.net/diy-turbo...n-turbo-98818/
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