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.

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.

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'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.

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.

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.

:scratch:

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.

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 :icon_tdow

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.

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.

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.

^ Are you serious??

Did you not read the two posts where we explained why it wouldn't do that?

i'm sure he is, cause no one actually reads anymore.

someone will probably ask the same question following this one.

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:blush:

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.

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?

Nope. The NA pump will flow more than enough for your needs.

guess I'll be unwiring mine and putting it up for sale then.

thanks for the reply

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!