another know it all.
12-04-2006, 02:50 PM
#1
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another know it all.
read post #3. I've read so many posts where this dude goes on a wild tangent that stock fuel pumps cannot provide enough flow at 60psi. Am I wrong or should the returnless still work in the exact same manner as I posted?
http://forum.miata.net/vb/showthread.php?t=210531
http://forum.miata.net/vb/showthread.php?t=210531
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12-04-2006, 04:20 PM
#6
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oh I have no doubt about that. When I swapped out the 255hp pump for the 190 my car started to actually run a lot better. Its not so damn rich anymore out of boost but still has more than enough fuel under boost.
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12-04-2006, 04:32 PM
#7
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yeah, see i dont see why he thinks the stock pump cant fuel for 200hp at 60psi. it's dependent on what the injectors can flow at 60psi.
Previous posts from him state that his fuel pressure rapidly decreases after 5k, even with the 255, but not as much so.
I still think it's all the same except we can run a fmu and he can't.
Previous posts from him state that his fuel pressure rapidly decreases after 5k, even with the 255, but not as much so.
I still think it's all the same except we can run a fmu and he can't.
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12-04-2006, 04:40 PM
#8
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see the thing is I think that guy "popstoy" had a bad experience that was totally unique to him and now thinks that is the norm and feels the need to spread misinformation
but then again we could all be wrong but the facts that everyone else has seen kind of rules that out.
but then again we could all be wrong but the facts that everyone else has seen kind of rules that out.
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12-04-2006, 04:47 PM
#9
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I'm still running the stock fuel rail on my '99. I'm using a Walbro 255hp which raised the idle pressure from 60-61 with the stock pump to about 70 psi.
I also added a resrictor at the fpr and I'm seeing 80psi at idle, along with the RC650cc injectors. It runs fine and I don't seem to be running out of fuel at this time. Although I still may consider a dual feed.
I also added a resrictor at the fpr and I'm seeing 80psi at idle, along with the RC650cc injectors. It runs fine and I don't seem to be running out of fuel at this time. Although I still may consider a dual feed.
man, 650s...running close to 400rwhp with that thing?
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12-04-2006, 08:37 PM
#12
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I'm running ~205rwhp on a stock fuel system, just bigger injectors (310cc) and EMU, it runs fine and I have enough fuel. So what they're saying is that if I get a bigger fuel pump(190lph) I'll pick up more hp because I'll be able to maintain fuel pressure better? I'm totally lost here. And what's up with returnless fuel line on 99s, why is it so bad?
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12-04-2006, 09:12 PM
#13
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I think it is totally plausable.
The injectors source fuel from a pressurized rail. If the injectors remove fuel from the rail faster than the fuel pump can replace it, fuel pressure in the rail will drop.
<edit> the stock 99 injectors at 70 psi flow 8% more than at 60 psi. The stock ecu won't have any issue handling that.
The injectors source fuel from a pressurized rail. If the injectors remove fuel from the rail faster than the fuel pump can replace it, fuel pressure in the rail will drop.
<edit> the stock 99 injectors at 70 psi flow 8% more than at 60 psi. The stock ecu won't have any issue handling that.
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Last edited by Ben; 12-04-2006 at 09:29 PM.
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12-04-2006, 09:35 PM
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He's talkin about the post that you have in this thread that is irrelevant to the thread - You have copy/pasted about the keyless entry in this thread about "Know it ALL""
JUCRAZIMAN!!!! But we LOVE YOU
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12-04-2006, 09:40 PM
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Also, the NA ecu expects an increase in fuel rail pressure with high demand, so an injector squirt event doesn't necessarily have to lengthen in time to increase fuel delivery. But if rail pressure dropped, the squirt event can be lengthened to compensate. The NB ecu expects a constant fuel rail pressure and therefor must increase the length of the squirt event. The squirt event can only last so long, so if fuel pressure dropped, the motor won't be fueled properly.
I've never owned or worked on an NB. If I'm wrong tell me.
I've never owned or worked on an NB. If I'm wrong tell me.
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