I did a search, but didn't find a complete answer:

If I get a Walbro Fuel Pump, will I be able to remove my Aux Fuel Pump on the SC?

If so, are there any dangers involved if I were to do things such as lower my pulley size (I am 3.25" now) or add a 50-shot of Nitrous?

Thanks!
IanS

 

I'll let you know when I get my 3.12" on

I think there are some other folks here that are running with this setup too with more power adders... I'll let them answer.

 

if you get the walbro, you don't need the aux fuel pump,just hook the fuel lines straight to the fmu

I think there are some other folks here that are running with this setup too with more power adders... I'll let them answer. [/B][/QUOTE]

 

If we change the fuel pump will we have to get different discs for the FMU? I know I have to re-adjust my afc right?

 

Note to everyone: I have a Cartech Adjustable FMU - doesn't use discs. Therefore, I don't care about the answer to PCGuRu2K's quesiton, and he needs to go start his own thread and stop Post Whoring.



IanS

 

the answer to the first question is no.....FMU connects to the fuel return from the engine. It works by delaying the fuel return, so fuel will stay in the engine longer when you boost the car. The role of the aux fuel pump is more simple, it will keep pumping fuel to the engine (if you have the hobb switch mod). FMU will be activated if it detects boost. swapping a new fuel pump does not require to change the FMU

I dunno the answer to the second question...I dun have a S-AFC.

 

Thanks!

 

I did a search, but didn't find a complete answer:

If I get a Walbro Fuel Pump, will I be able to remove my Aux Fuel Pump on the SC?

If so, are there any dangers involved if I were to do things such as lower my pulley size (I am 3.25" now) or add a 50-shot of Nitrous?

Thanks!
IanS

 

the answer to the first question, yes you can remove the aux pump. all you have to do is the line that connects to "I think is the top fuel rail" just run straight into the top fuel rail and your done. I have a Walbro sitting in my garage but have not installed it. There are no dangers, Matt (Mardigrasmax) is running this setup and you guys know he sprays.

One more time. Pull the fuel line from the top fuel rail that comes out of the aux fuel pump and the one that connects into the aux pump connect that one into the top fuel rail and your done. You may need to readjust your fuel settings with that cartech fuel regulator.

 

I believe so....I know BigDogJonx was running his 3.125 just with the Walbro pump.

 

Better get the high flow version Ian. That's the one I have. It holds the fuel pressure better when the boost comes in.

I should be putting it in shortly after getting my engine going.

Question is will the high flow 255lph Walbro overwhelm the stock VE FPR(ie running it with no boost)? I see some threads where it might?

 

It overwhelms the stock VQ FPR if that is any help to you Jeff.

You will need a FPR to drop the base FP a couple of PSI.

 

is this not true for the VQ?

 

Yes it is unless you want to run rich at idle, and part throttle

 

Why would it run rich? The ECM should adjust the injector pulse duration based on O2 sensor input. At least in closed loop mode.

 

It will run rich at WOT. When you are 4 psi too high at idle, most likely you will be 4 psi too high at WOT.

 

And if I have a S-AFC, whis will still hold true?

I'm guessing it will, because the S-AFC only works above 49% throttle, correct?

Guess I'll just have to floor it everywhere!

Seriously, what's a good FPR that installs easy?

 

All FPR's install easily... it's very similiar to an FMU.

sx7r Sells the SARD, it seems to be very popular here. I picked up a used Stillen off of Ebay.

You will also need the fittings, which you can locate, or just buy from sx7R for a nominal fee.

The AFC will only be useful in full throttle situations. So as you said unless your kicking it down to the metal everywhere your out of luck.

Tony, as far as Ian running rich up top, he can lean that out with his Cartech FMU (more adjustable than the Vortech Unit) or the AFC... the idle and part throttle response will require the additional hardware (FPR)

Stephen, The injector pulsewidth at Idle and part throttle will not vary dependant on pressure. The ECU has no way of monitoring Fuel Pressure. The only concievable thing that could happen is that the O2 sensors could force a compensation, but the Fuel Pressure in the max does not vary by much, going only up to 43 PSI @ WOT (under normal N/A conditions) it's pretty much an on/off situation. If the car is under load your FP jumps to 43 PSI, if not it rests @ ~35

 

From what BigDogJon told me the Walbro fuel pump will stand alone. You do not need the Aux pump with this setup. I installed it this morning and it took about 30 min, don't forget to buy the O-ring for the fuel pump from the dealer (it cost about $4-5) Install was real easy and took some miner changes to the pump to fit.
From the research I have done, I understand that your car could handle well into the 500hp range with this fuel pump setup.
Tahs my $.02