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Old 04-14-2012, 03:44 PM   #1
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Default Do I need a FPR? or a better map?

The Setup:
99 Miata
  • Built motor
  • FM head
  • TD05-18G turbo - SR20DET hotsidestyle flange
  • RC-550 injectors
  • Ebay IC
  • 14psi

Symptom: in 2nd once I get to about 4k rpm 5psi ish my afr drops off and the engine starts to cut out, in 3rd it's the same unless I slowly roll on the throttle then it pulls like a effin monster but afr is low @ 10.2.

I have solved all boost leak issues
Plugs are set at 30

Do I need COPS?
A tune shop I called said that I need an FPR, but I thought the xede was supposed to take care of that

images of the map soon to follow
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Old 04-14-2012, 04:29 PM   #2
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Here is the map I got from begi - built motor 14PSI
Attached Thumbnails
Do I need a FPR? or a better map?-begimap.jpg  
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Old 04-14-2012, 05:37 PM   #3
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more thne likely you need to adjust your maf scale but you need a obd2 scanner to monitor grams a second \ maf voltage to be able to adjust it properly
something that can give you real time data out from the ecu
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Old 04-14-2012, 05:56 PM   #4
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Quote:
Originally Posted by romanservices View Post
...I get to about 4k rpm 5psi ish my afr drops off and the engine starts to cut out...
What do your AFR's look like when this happens? By "drops off" do you mean it goes lean?

This is discussion from the first thread I started on MT (other than my intro) asking about what sized injectors I needed for 250hp in an NB with the stock fuel pressure regulator:
Quote:
Originally Posted by EO2K View Post
As long as the pressure is maintained, as in the NB system, can this number be counted on as a constant?
Quote:
Originally Posted by codrus View Post
No. What you're missing is that the pressure in the injectors has to fight against the pressure in the manifold in order to spray fuel. NAs have a fuel pressure regulator which is relative to the manifold pressure, so as MAP goes up 1psi, the fuel pressure goes up 1psi to match. NBs don't, they have a constant pressure, so when running 15 psi of boost, the rail is effectively 15 psi lower than is when running WOT when naturally aspirated.

265 rwhp on my NB with stock pump and 550cc RCs, and the stock pump was the limit. I put the 255 walbro in, but haven't been back to the dyno since.

As for the 255 overpowering the stock FPR -- FM says that's known to be an issue when using it on an NA, but that NB regulators are usually fine.

--Ian
Does that possibly sound like something you may be running into?
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Old 04-14-2012, 06:05 PM   #5
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[QUOTE=EO2K;864395]What do your AFR's look like when this happens? By "drops off" do you mean it goes lean?

QUOTE]

Yes it goes lean
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Old 04-14-2012, 06:12 PM   #6
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how do you know it goes lean and not super rich that it is reading lean?
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Old 04-14-2012, 06:14 PM   #7
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Quote:
Originally Posted by Techsalvager View Post
how do you know it goes lean and not super rich that it is reading lean?
I guess I don't...did not know that could happen

I have an apt to bring it in to a local tuner untill then the car sits.
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