gregs22

iTrader: (12)

hey guys I'm looking at purchasing a fuel pump for my s4 n/a to Turbo 2 swap, everything will be OEM. I'm considering getting the AEM 320 lph fuel pump. My main concern is passing CA emissions tailpipe test, do I have anything to worry about?

Thanks

Greg

RotaryRocket88

iTrader: (7)

Possibly. You're going to be using the stock turbo? Any plans of going for a lot more power in the near future? Because that's a very high flowing pump with high current demands.

https://www.rx7club.com/2nd-generati...4/#post9154530

High Flow In-Tank Fuel Pump - Wideband O2 UEGO, Water/Methanol, Stand Alone Engine Management, Piggyback F/IC, Tru Boost Controller, Gauges, Automotive Performance Electronics

At idle (2 bar/30 psi), that pump will flow in excess of 340 LPH. A stock TII pump flows 164 LPH at that same pressure (see link above, 13.5V test). And a walbro 255, which is known to overrun the stock FPR flows 284 LPH at this pressure. So it'll overrun the FPR even more, and it'll likely be more than the variable resistor or ECU are able to correct for w/ the 02 sensor input.

The stock pump also draws 5-7 amps, while this pump draws 12-15 amps. An upgraded alternator would be a good idea to keep up with it.

gregs22

iTrader: (12)

Yes planning for a turbo upgrade in the future, that's why I was considering this fuel pump, my concern is I have a smog test soon and from what I understand if the fuel pump is over run then it goes rich is that correct? If that's the case I think that may affect me passing California smog test.

Thanks for the info.

S4 Vert

I'm using the same AEM Fuel Pump now on my recent 13B T swap, maybe that explains why I use a lot of gas even when driving conservatively. I'm running everything stock egine and ecu wise. Could also be the reason my engine idles roughly.

Should I at least install an fpr?

Should I upgrade my fuel injectors?

What type of alternator upgrade should I perform?

I plan on staying with the stock turbo and intake system until I can afford to buy a Haltech Stand Alone.

RotaryRocket88

iTrader: (7)

The easiest way would just be to use a lower flowing pump until you actually need more. Or an adjustable FPR would take care of overrun issues (pressure increases, mixture goes rich).

FD alternator and taurus alternator swaps are two options.

gregs22

iTrader: (12)

i just looked up the fuel pump part #'s for the n/a and turbo model and they are the same. I will just stick with the OEM for now, thanks for the help!

RotaryRocket88

iTrader: (7)

An NA fuel pump is not the same as TII. It flows much less. Check the link I gave above for testing Higgi did. Post #9.

NA: 79 LPH at 3 bar (13.5V)
TII: 125 LPH at 3 bar (13.5V)

The TII fuel pump is also the weakest link the stock fuel system. If running above stock boost, a better fuel pump is needed. FD pumps are the simplest solution.

wthdidusay82

iTrader: (15)

With an fd fuel pump do you need a better alternator on s4, what's their lph rating?

I know walbros are 255lph so that's roughly double the output of the stock fuel t2 pump.

Rotary >Pistons

S4 Vert

Ah! Ok, got it . I will install an fpr and gauge to regulate fuel pressure, and look into buying an FD, or Taurus fuel pump.

gregs22

iTrader: (12)

That's so weird when I check part #'s for s4 n/a and turbo have the same part#, the s5 has a different part # from s4 but n/a & turbo s5 use the same part #

Thanks for the info.

jaggermouth

iTrader: (1)

A high flowing pump makes it run rich? I though thats what FPR's are for.

That AEM one looks nice and is a good price, I'll add that to my list

RotaryRocket88

iTrader: (7)

^ If you have a stock FPR, it will. They can't bypass enough fuel and pressure rises.

S4 Vert

I made a correction to the original post.