# e46 injector & fuel pump question



## jankyl29 (May 12, 2008)

I'm going to be turbo'ing my 01 330i this winter, and I will be assembling the parts myself. My last 2 cars were honda's which I assembled and turbo'ed myself.

I already have a system and a tuner local who can tune the car. What I am having a difficult time figuring out is if the injectors are saturated or peak and hold and what supplier has them for our bmw's? I imagine RC or Bosch has to make a set for the 330i? I would be looking for 440's-550's since I am only shooting for 350ish whp.
Also, will the stock fuel pump suffice? whats the flow rate on the stock pump and at what hp level should it be upgraded?


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## Black-Out (Nov 1, 2008)

jankyl29 said:


> I'm going to be turbo'ing my 01 330i this winter, and I will be assembling the parts myself. My last 2 cars were honda's which I assembled and turbo'ed myself.
> 
> I already have a system and a tuner local who can tune the car. What I am having a difficult time figuring out is if the injectors are saturated or peak and hold and what supplier has them for our bmw's? I imagine RC or Bosch has to make a set for the 330i? I would be looking for 440's-550's since I am only shooting for 350ish whp.
> Also, will the stock fuel pump suffice? whats the flow rate on the stock pump and at what hp level should it be upgraded?


Take a look at resistance values on the injectors themselves from the leads.
Pull the connector off the lead injector and use a DVOM to measure the resistance

Peak Hold: 2-5 ohms of resistance across the coils

Saturated: 12-16 ohms of resistance across the coils

RC Engineering is a great company to go through to get injectors from because they send you a balance sheet with the injectors telling you what each one flowed after service and thier quality is great. They can even repair and re-flow your injectors to your desired specification if you don't mind downing the vehicle for a while so check them out on the web they do good work.:thumbup:

The stock fuel pump should be tossed for a higher volume pump just to make sure your fuel rail is not dropping off pressure from the lack of volume at wide open throttle. If you run out of fuel from the lack of volume under boost you will either burn valves or melt pistons and the pistons are usually the first victems in the motor. stock pumps usually cant hold up to the fuel demands beyond 4-5psi
BTW we hit 350whp on the shops twin turbo E34 535i on 6psi.....do the larger fuel injectors (550cc) and upgrade the fuel pump and let your tuner shoot for 400 I have no doubts you'll hit it and retain the drivability and reliability you have now with a proper tune and 93octane in the tank......


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