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Drove NJFC3S TII today !!

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Old 03-05-02, 10:55 PM
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lets say you have a stock 89-91 T2...but you buy an FCD to put on it to be safe...(maybe for a very cold night) besides it being a $100 waste on a stock car, are you also starving the fuel system?

damn, my posts are just getting dumber and dumber...
Old 03-05-02, 10:56 PM
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Originally posted by Felix Wankel
I'm about to put a FMIC, some 720s, and a TO4B hybrid (just cause my turbo is shot) on my car. I'm not even gonna put a SAFC on it. If it blows up **** it, I want a half bridge anyway. I give you permission to point and laugh when my 150k+ mile motor finally pops.
Oooh oooh, wait until you're racing me to open it up all the way with all that extra **** on!

I'll make sure to have the tow line with me so I can haul your broke *** home.
Old 03-05-02, 10:57 PM
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you guys know the shop i goto has numerous cars with 300+ rwhp using the stock ecu right ? obviously with extra stuff but stock EMS!!!
Old 03-05-02, 10:58 PM
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Originally posted by Six Rotors
2.Mazda believe that the pressure sensor signal adjusts the fuel amount injected,according to their training manuals specifically the pressure sensor(or boost sensor) increases the amount of fuel over the base fuel map,and the atmospheric pressure sensor reduces it.I have never personally scoped the signals,but my money is on Mazda.
I'd like to see this Mazda training manual you allude to...
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.

This (*^#@$ is finally sinking in!&nbsp I've had too many arguments on FCD's and blown motors at this point.&nbsp I've seen the results, and it clearly shows that the boost sensor has nothing to do with fuel delivery - something the FCD nay-sayers have been hawking on for a long time.&nbsp It's the low voltage to the fuel pump that usually kills the motors, and it really has nothing to do with the FCD (sure, you can argue low fuel pump capacity and an advanced ignition is deadly, but you're overlooking the fact that the fuel pump is still the primary culprit).&nbsp Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...



-Ted
Old 03-05-02, 10:58 PM
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Maybe itll be like 25 outside and I can let it creep to about 20 psi without letting off
Old 03-05-02, 11:00 PM
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Originally posted by RETed

I'd like to see this Mazda training manual you allude to...
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.

This (*^#@$ is finally sinking in!&nbsp I've had too many arguments on FCD's and blown motors at this point.&nbsp I've seen the results, and it clearly shows that the boost sensor has nothing to do with fuel delivery - something the FCD nay-sayers have been hawking on for a long time.&nbsp It's the low voltage to the fuel pump that usually kills the motors, and it really has nothing to do with the FCD (sure, you can argue low fuel pump capacity and an advanced ignition is deadly, but you're overlooking the fact that the fuel pump is still the primary culprit).&nbsp Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...



-Ted
ted makes a good point. most of the modded cars probably have original fuel pumps and fuel injectors. they aren't getting enough fuel that is the most likely the real issue behind all these blown engines. making sure your getting how much fuel your supposed to !!!
Old 03-05-02, 11:08 PM
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just one simple question...

you have a stock T2
you put an FCD on

1) Does this FCD now mess with the rich/lean maps under 8psi?

2) or does it just take over when the car gets to 8psi (and plays no part under that reading) ...only takes over at 8psi (or whatever they advertise it for)
Old 03-05-02, 11:09 PM
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Originally posted by RETed

I'd like to see this Mazda training manual you allude to...
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.

This (*^#@$ is finally sinking in!&nbsp I've had too many arguments on FCD's and blown motors at this point.&nbsp I've seen the results, and it clearly shows that the boost sensor has nothing to do with fuel delivery - something the FCD nay-sayers have been hawking on for a long time.&nbsp It's the low voltage to the fuel pump that usually kills the motors, and it really has nothing to do with the FCD (sure, you can argue low fuel pump capacity and an advanced ignition is deadly, but you're overlooking the fact that the fuel pump is still the primary culprit).&nbsp Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...



-Ted
Learn something new every day. Thanks Ted, glad to see you're back.
Old 03-05-02, 11:10 PM
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Should only take over at 8 psi. I'll unplug mine tomorrow and cruise around town and see.
Old 03-05-02, 11:13 PM
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Hey guyz.. All these posts about fuel cuts and blah blahs are very interesting but I have to tell you, my car's almost completely stock except for the exhaust,FCD,K&N intake,NGK platinum plugs and 10mm Magnecor wires.. I guess my point is, would a Walbro fuel pump and the above mods enough for a daily driver? I don't bring my car to the track, 'coz dunno how to drag race.. And besides your occasional street racing every now and then, my car's just sitting in my driveway.. In other words, I wanna keep my car running as long as I can or until I can save up some dinero for another car.. Possibly the upcoming Mitsu Evo..
Old 03-05-02, 11:17 PM
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Originally posted by Mykl
The FD's computer can't even compensate for fuel and timing with a straight through turbo back exhaust, so it's not surprising that the FC has the same problem.
FD = speed density, FC = MAF... oops there goes your arguement.

As RETed said the pressure sensor has nothing to do with fuel delivery. Nor does it ignore timing with an FCD.

I've seen cars running FCD from 330-400rwhp. This isn't even worth arguing
Old 03-05-02, 11:30 PM
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Originally posted by NjFC3S
would a Walbro fuel pump and the above mods enough for a daily driver?
YES!



-Ted
Old 03-05-02, 11:34 PM
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Originally posted by 2DoritosOnAStick


FD = speed density, FC = MAF... oops there goes your arguement.

As RETed said the pressure sensor has nothing to do with fuel delivery. Nor does it ignore timing with an FCD.

I've seen cars running FCD from 330-400rwhp. This isn't even worth arguing
I'm not even going to try to have this conversation with you. The condescending tone pisses me off and I'll things I shouldn't. Be more polite when you make a point. I enjoy finding out when I'm wrong, and learning from it, but not in a way that's insulting to myself.
Old 03-05-02, 11:35 PM
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Originally posted by RETed

YES!



-Ted

Thanks Ted!
Old 03-05-02, 11:36 PM
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Originally posted by RETed

I'd like to see this Mazda training manual you allude to...
I've seen the oscope output myself, and I trust my eyes rather than a third-party comment at this point.

-Ted
Hey Ted, I'm curious as to how you performed the test. To my knowledge, the AFM input is used during operation below where the secondaries come on. Above that the ECU is open loop and goes from fixed maps which must have a MAP sensor input. If this is correct, then diddling the boost gauge at idle won't make a difference whereas diddling it above 4k would.

Henrik
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Old 03-05-02, 11:41 PM
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Originally posted by Mykl


I'm not even going to try to have this conversation with you. The condescending tone pisses me off and I'll things I shouldn't. Be more polite when you make a point. I enjoy finding out when I'm wrong, and learning from it, but not in a way that's insulting to myself.
Sorry. My day is reflecting on my posting
Old 03-05-02, 11:46 PM
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Originally posted by Henrik
Hey Ted, I'm curious as to how you performed the test. To my knowledge, the AFM input is used during operation below where the secondaries come on. Above that the ECU is open loop and goes from fixed maps which must have a MAP sensor input. If this is correct, then diddling the boost gauge at idle won't make a difference whereas diddling it above 4k would.
Good question!

Tenma O-scope, 2 channel - one primary and one secondary fuel injector channel was monitored
CAS spun manually off a Bridgeport vertical manual mill (if you can believe that) to 2kRPM - CAS runs 1/2 speed, so that's 4kRPM the motor "thinks" it's running at
AFM manually propped open - to simulate at least some air is going through
MAP sensor "fooled" with a MityVac hand pump - MityVac has an integral vacuum/pressure gauge built into it

MityVac pumped from vacuum to + pressure without any noticable trace of change of pulsewidth from the fuel injector channels.




-Ted
Old 03-05-02, 11:47 PM
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Originally posted by 2DoritosOnAStick
Sorry. My day is reflecting on my posting
It's all good.

I'm curious to see what Ted has to say about Henriks question.
Old 03-06-02, 06:13 AM
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here is a link i found explaining some FCD stuff although i'm not sure this is right either! LOL

http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm
Old 03-06-02, 07:16 AM
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Originally posted by RETed

Take a poll on how many 13BT's have blown up, and I put MONEY over 75% of them blew up at night...
You're right. 25F degree night, Slayer on the stereo, heater on and headlights on.

I think I AM going to start a poll!
Old 03-06-02, 09:23 AM
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Thumbs up fuel pump and rewire

Ted - you da man. Thats so far above what I understand it's scary but I'm glad you are around... and the rest of you techs for that matter.

I have a fuel pump question. With an aftermarket, walbro, racing beat, (I heard 90's ford ranger pumps work well too), should the rewire mod for the stock pump be done on an aftermarket one as well or does the xtra flow make the voltage changes a non-issue?
Old 03-06-02, 12:09 PM
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I am not surprised you did not see a fuel increase under those test conditions for the following reasons:
1.the pressure sensor is only used for fuel increase below 3600 rpm,above that a high speed correction is used.
2.the high speed fuel increase also uses TPS position as an input.
Old 03-06-02, 12:11 PM
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PS.You also need a simulated input from the thermosensor because different fuel mapping is used when cold.
Old 03-06-02, 12:29 PM
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I don't think a FCD leans out the fuel/air mixture. The car leans its self out by design.

As the boost goes past the factory cut off it continues to dump more and more fuel. Until the injector duty cycle approaches 100%. At or before that point there is no more fuel to give. If you go past that point you will run lean.

That is why people recomend upgrading the fuel pump. That simply insures there is all of the fuel there waiting to go into the engine that the injectors will allow or can flow. So it helps make your injectors do their job.
Install bigger injectors? Even better. It allows you to give the engine more fuel and boost even higher.

This is how it seems to work. If I wrong somebody correct me so I stop giving wrong info.

James
Old 03-06-02, 12:34 PM
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hey i have a 3 inch exhaust to the back...how bad is this as far as leaning out?

since i put it on, im scared to bring it up close or past redline cause i dont wanna break anything.

im still waiting for my air/fuel guage to get installed. but even after i get that in, it probably wont be acurate cause of my stock o2 sensor.

Mike
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