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Walbro 255lph on a stock N/A

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Old 01-28-10, 12:30 AM
  #26  
Sharp Claws

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yes, you obviously haven't listened to what we all have said. so ill say it a little bit differently


YOU DON'T NEED A FREAKING HIGH FLOW FUEL PUMP ON A NON TURBO CAR!

all it will serve to do is decrease your fuel mileage and add more carbon buildup to the engine because it will run too rich.
Old 01-28-10, 09:16 AM
  #27  
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Originally Posted by Karack
i've cranked out over 400 wheel horsepower on the walbro 255LPH pump, it can easily handle the boost of a stock turbo power output. if you don't have a way of adjusting fuel injector bandwidth then the pump can't be fingered as a problem. if you did in fact have a way of adjusting the fuel injectors output then you probably had old craptastic wiring to your brand new shiny high output pump. it is common after all and why many tuners recommend rewiring your pumps. i had one S5 turbo 2 with a T70 that was dropping voltage down to 6 volts! and it still was making well over 300 wheel horsepower at that point..

simply adding a pump to a near stock car isn't going to miraculously allow it to run safely at 14PSI on the stock fuel maps, the car isn't even meant to see 10PSI, that is why it has a boost cut built in.
400HP with stock injectors? My injectors are maxed out even with the walbro, and that's barely over stock boost level. Come on now, you had to have put in at least some big secondaries.

Although I'll agree, I do need to rewire the fuel pump. The wiring in the car's so old, I can easily see it dropping voltage everywhere. My goal eventually is to rewire the entire engine harness once I get a standalone. Piggyback controllers are ok, but to get some respectable power out of this car safely I'm going to need a good programmable ecu.
Old 01-28-10, 09:23 AM
  #28  
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Originally Posted by Karack
that depends if the stock FPR is installed still, some people leave it on and unplugged and use the aftermarket FPR to raise fuel pressure.
Yikes!

Originally Posted by asiandude15
So you could leave the stock fpr installed and disconnect it and then use an external aftermarket to keep the pressure in check? What is the pressure I am want to stay at?
No, NO and NO. If you install an aftermarket regulator, you need to remove the stock regulator for things to function properly.

And as stated earlier in this thread, the Walbro is massive overkill for an NA RX-7. Totally unnecessary and creates the problem of having to then control fuel pressure.
Old 01-28-10, 11:03 AM
  #29  
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Originally Posted by AGreen
400HP with stock injectors? My injectors are maxed out even with the walbro, and that's barely over stock boost level. Come on now, you had to have put in at least some big secondaries.
I'm fairly sure he just meant that the walbro worked fine in a 400whp build, and that it can help on a stock turbo / stock injector car that is running more boost (which is a bandaid really). Two separate cases.
Old 01-28-10, 01:01 PM
  #30  
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Originally Posted by AGreen
400HP with stock injectors? My injectors are maxed out even with the walbro, and that's barely over stock boost level. Come on now, you had to have put in at least some big secondaries.

Although I'll agree, I do need to rewire the fuel pump. The wiring in the car's so old, I can easily see it dropping voltage everywhere. My goal eventually is to rewire the entire engine harness once I get a standalone. Piggyback controllers are ok, but to get some respectable power out of this car safely I'm going to need a good programmable ecu.
who said anything about injector sizing? the fuel pump is only as good as the rest of the system. if you install a fuel pump as a band-aid to not having larger injectors then it is still a bandaid. you can't install a fuel pump and expect it to fix any lean running issues unless you have a way of adjusting the fuel going through the injectors. i simply was saying that you blamed a lean condition on the pump, which is nowhere near true unless the pump was having voltage issues.

Originally Posted by Aaron Cake
Yikes!



No, NO and NO. If you install an aftermarket regulator, you need to remove the stock regulator for things to function properly.

And as stated earlier in this thread, the Walbro is massive overkill for an NA RX-7. Totally unnecessary and creates the problem of having to then control fuel pressure.
i do tend to agree, since it can add another failure point but i also would have to say you probably haven't actually tried it. i have worked on some with both regulators and fuel pressure rises and falls just fine according to how you set the new pressure regulator. the only thing that leaves me weary is if the old pressure regulator decides to stick open which in turn allows more fuel to bypass the upgraded regulator, which so far i haven't seen a single stock FPR take a crap to date. i wouldn't make it a habit to do this though.

saying no like it won't work is false, it does work but it is lazy to not remove the old FPR in cases where you can't find a fitting to replace the old FPR.
Old 01-28-10, 07:21 PM
  #31  
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Originally Posted by Karack
i simply was saying that you blamed a lean condition on the pump, which is nowhere near true unless the pump was having voltage issues.


I didn't blame it on the fuel pump, I was only stating what you actually re-stated. Like I said, you can have a walbro 255, but it won't save you from leaning out if you crank up the boost on a stock car with stock injectors. (off the record, I was originally trying to utilize boost creep to my advantage to gain power, but I ended up porting the wastegate to prevent burning up my engine.)

ok... now we're all on the same page here.

Originally Posted by Karack
i have worked on some with both regulators and fuel pressure rises and falls just fine according to how you set the new pressure regulator.
Interesting, but I don't think I'll be trying that, nor recommending anyone do that for that exact reason. Sounds like a really cheap FMU, which is cheap and crappy to begin with
Old 01-28-10, 08:33 PM
  #32  
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It seems to me that when the oxegin sensor detects rich conditions that it will shorten the injector pulse. End results would be a shorter pulse but at a higher pressure. No?
Old 01-28-10, 10:05 PM
  #33  
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Originally Posted by Magpie57
It seems to me that when the oxegin sensor detects rich conditions that it will shorten the injector pulse. End results would be a shorter pulse but at a higher pressure. No?
That may be true in a modern car, not in the FC.
Old 01-29-10, 12:03 PM
  #34  
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Originally Posted by Magpie57
It seems to me that when the oxegin sensor detects rich conditions that it will shorten the injector pulse. End results would be a shorter pulse but at a higher pressure. No?
echoing what farberio said, these are not self adjusting cars. the oxygen sensor is a narrowband that hardly works at all even if all conditions are met and your car is in PERFECT working order. mazda was correct with this antiquated system to not have it rely on the O2 sensor for basic driving function. new cars heavily rely on their wideband O2 sensors for proper fuel mixture because they have 25 year newer technology.
Old 01-29-10, 06:43 PM
  #35  
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It seems to me that with higher pressure and more fuel the O2 senson would tell the computer to shorten the injector pulse. The end result would be the correct amount for the conditions. No? It seems the walbro is just overload for all components.
Old 01-29-10, 10:05 PM
  #36  
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^ Are you serious??

Did you not read the two posts where we explained why it wouldn't do that?
Old 01-30-10, 02:24 AM
  #37  
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i'm sure he is, cause no one actually reads anymore.

someone will probably ask the same question following this one.
Old 02-01-10, 09:21 PM
  #38  
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I was serious about my reptilian brain. And no I did not read the previous 2 replies. I will read them right now and stand corrected. All apologies
Old 02-03-10, 08:39 PM
  #39  
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Ok I got the point. I'm not using the walbro on an N/A. Thanks for the reply and for making this thread very interesting and full of info.
Old 08-17-10, 12:20 PM
  #40  
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Sorry to resurrect an older thread, but what if you have a ported N/A? Can the porting get large enough to warrant using the walbro?
Old 08-17-10, 02:23 PM
  #41  
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Nope. The NA pump will flow more than enough for your needs.
Old 08-17-10, 02:26 PM
  #42  
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guess I'll be unwiring mine and putting it up for sale then.

thanks for the reply
Old 08-24-10, 11:04 AM
  #43  
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While we're resurrecting old threads.... Does anyone have the flow rate for an FD fuel pump I have the walbro one but the FD numbers seem to elude me... And no I can't flow test it myself cause it is in my car which I daily drive...lol!
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