330i stock fuel filter and fuel pump

[stylinexpat]

Ayone here know what the maximum flow rate is for our 03 330i on our stock fuel pumps? What about our fuel filters? What is the next size up for better flow rate for our BMW'S?

[pei330ci]

I don't think replacing the entire fuel pump assembly is needed unless you are making sick amounts of power. The only way to find out is to start tuning on the dyno logging data with a fuel pressure gauge. If pressure starts to drop progressively as RPM increases, you've got a fuel supply problem. This doesn't nessessarily indicate that the fuel pump alone is in need of upgrading, you may have also reached the flow limits of the fuel lines. A common band-aid for Mustangs and Camaros with superchargers installed, is to install an in-line booster pump to ease the load on the in-tank fuel pump. Vortech makes one called the T-Rex that's fairly popular. Whether this would be needed in your application is only proven by logging fuel pressure as noted above.

Another question you should be asking: What is the limit of the stock MAF meter...

FYI, the fuel filter and fuel pressure regulator are one and the same thing in our cars. If you want to upgrade to a higher flowing fuel filter, you'll need to change some of the fuel line to accomadate this as well as add a return style fuel pressure regulator. (Usually in the engine compartment) That said, it's a good idea to change the fuel filter/regulator on a regular basis. I've heard of many other people commenting on a noticable increase in power when they put a new filter assembly in. North American fuel can be dirty...

[stylinexpat]

I don't think replacing the entire fuel pump assembly is needed unless you are making sick amounts of power. The only way to find out is to start tuning on the dyno logging data with a fuel pressure gauge. If pressure starts to drop progressively as RPM increases, you've got a fuel supply problem. This doesn't nessessarily indicate that the fuel pump alone is in need of upgrading, you may have also reached the flow limits of the fuel lines. A common band-aid for Mustangs and Camaros with superchargers installed, is to install an in-line booster pump to ease the load on the in-tank fuel pump. Vortech makes one called the T-Rex that's fairly popular. Whether this would be needed in your application is only proven by logging fuel pressure as noted above.

Another question you should be asking: What is the limit of the stock MAF meter...

FYI, the fuel filter and fuel pressure regulator are one and the same thing in our cars. If you want to upgrade to a higher flowing fuel filter, you'll need to change some of the fuel line to accomadate this as well as add a return style fuel pressure regulator. (Usually in the engine compartment) That said, it's a good idea to change the fuel filter/regulator on a regular basis. I've heard of many other people commenting on a noticable increase in power when they put a new filter assembly in. North American fuel can be dirty...

What would be a better flowing filter then the stock fuel-filter? I usually change my filter every 15,000 miles or so. Mine has 23,000 on the clock and was changed about 7,000 miles ago.What about the stock fuel pump? How many RWHP can that stock fuel pump supply fuel to? My fuel pump, fuel lines ( to my knowledge) and fuel filter are stock. I have upgreaded injectors from ESS for the Stage III Supercharger kit. I'm not sure if the kit now has a regulator on it.

[pei330ci]

What would be a better flowing filter then the stock fuel-filter? I usually change my filter every 15,000 miles or so. Mine has 23,000 on the clock and was changed about 7,000 miles ago.What about the stock fuel pump? How many RWHP can that stock fuel pump supply fuel to? My fuel pump, fuel lines ( to my knowledge) and fuel filter are stock. I have upgreaded injectors from ESS for the Stage III Supercharger kit. I'm not sure if the kit now has a regulator on it.

BMW uses pretty good parts right from the factory. Here's a hint: Go to Bosche's website and check out the price of their fuel regulators and fuel filters. Then check the price of your Bosche designed and supplied filter/regulator assembly for your 330. Changing to the separate filter and regulator doesn't mean that it's an upgrade, even if it's more expensive. In this case, your more likely to get a better product from BMW because it's designed specifically for your application.

Why change any of it if your engine has an optimal AFR? ESS does a pretty good job of getting that right.

[stylinexpat]

BMW uses pretty good parts right from the factory. Here's a hint: Go to Bosche's website and check out the price of their fuel regulators and fuel filters. Then check the price of your Bosche designed and supplied filter/regulator assembly for your 330. Changing to the separate filter and regulator doesn't mean that it's an upgrade, even if it's more expensive. In this case, your more likely to get a better product from BMW because it's designed specifically for your application.

Why change any of it if your engine has an optimal AFR? ESS does a pretty good job of getting that right.

It needs more fuel up on top...

[MarvelPhx]

The fuel regulator and pump are seperate on most, if not all, E46. I know for a fact that mine is. I believe the Z4 and X3/X5 have in-tank regulators.

If you change injectors or fuel rail pressure, your software will not know the change and you will fatten up down low as well as up high.

[stylinexpat]

The fuel regulator and pump are seperate on most, if not all, E46. I know for a fact that mine is. I believe the Z4 and X3/X5 have in-tank regulators.

If you change injectors or fuel rail pressure, your software will not know the change and you will fatten up down low as well as up high.

The software knows to pull back timing, doesn't it pull timing when it's short of fuel?

[pei330ci]

The fuel regulator and pump are seperate on most, if not all, E46. I know for a fact that mine is. I believe the Z4 and X3/X5 have in-tank regulators.

Yup, that is correct. All E46 cars run an in-tank fuel pump, and a return style regulator/filter. The regulator/filter is mounted on the driver's side frame rail across from the transmission under a protective panel. In the picture below, you can see 2 blue plastic fuel lines connected to a silver cylinder; this is the fuel regulator/filter.

http://i36.photobucket.com/albums/e29/PEI330Ci/CarProject130.jpg