Dumb Fuel Pump/ Injector Question

[Urameshi.Ibn.F10M5]

Been doing a little research on parts that are interchangeable from the F90 to our F10 M5's. My car is a completely stock 14 CP M5, I'm not the most mechanically inclined individual but the beauty of life is that everyday is a new day to learn

So my question is, if I were to upgrade the HPFP from a F90 to my F10 would It behoove me to change my Fuel Pump to the F90 one as well? Or maybe an aftermarket upgrade or should my stock one suffice?

Thank you all in advance for your input.

[SCD-1983]

Originally Posted by Urameshi.Ibn.F10M5

Been doing a little research on parts that are interchangeable from the F90 to our F10 M5's. My car is a completely stock 14 CP M5, I'm not the most mechanically inclined individual but the beauty of life is that everyday is a new day to learn

So my question is, if I were to upgrade the HPFP from a F90 to my F10 would It behoove me to change my Fuel Pump to the F90 one as well? Or maybe an aftermarket upgrade or should my stock one suffice?

Thank you all in advance for your input.

Mechanically, the F90 HPFP will fit your engine. I have a sleeved and forged engine, running the F90 pumps, just the wiring to the pumps must be corrected due to different plugs (quick solder job, cut off old plug and connect to new plug or get a full kit). A change of the fuel pump is not required, but I would tend to say that a software adjustments is needed. The F90 HPFP can dumb a lot of more fuel and it doesn’t make sense to install them without increased power levels.
So in a nutshell: they will fit and no further mods required, but IMHO a useless mod without proper software and power increase.

[ajm55]

Originally Posted by SCD-1983

Mechanically, the F90 HPFP will fit your engine. I have a sleeved and forged engine, running the F90 pumps, just the wiring to the pumps must be corrected due to different plugs (quick solder job, cut off old plug and connect to new plug or get a full kit). A change of the fuel pump is not required, but I would tend to say that a software adjustments is needed. The F90 HPFP can dumb a lot of more fuel and it doesn’t make sense to install them without increased power levels.
So in a nutshell: they will fit and no further mods required, but IMHO a useless mod without proper software and power increase

I'm currently looking into this as well. Some say one should not go into boost on the F90 pumps unless the tune has been adjusted to account for the extra pressure. Others say that running the F90 pumps without adjusting the tune causes no problems at all (even though adjusting the tune might offer more in the way of performance gains). Do you know which of the 2 conflicting views is correct?

[SCD-1983]

Originally Posted by ajm55

I'm currently looking into this as well. Some say one should not go into boost on the F90 pumps unless the tune has been adjusted to account for the extra pressure. Others say that running the F90 pumps without adjusting the tune causes no problems at all (even though adjusting the tune might offer more in the way of performance gains). Do you know which of the 2 conflicting views is correct?

Based on the statement of my very experienced engine builder, the F90 HPFP will not run properly without software adjustments. And there’s a risk of dumping too much fuel, uncontrolled.
I can’t proof either concept, I just followed the advice of my tech and the engine is running great so far 👍🏻

[ajm55]

Originally Posted by SCD-1983

Based on the statement of my very experienced engine builder, the F90 HPFP will not run properly without software adjustments. And there’s a risk of dumping too much fuel, uncontrolled.
I can’t proof either concept, I just followed the advice of my tech and the engine is running great so far 👍🏻

Noted, thanks.

[Urameshi.Ibn.F10M5]

Originally Posted by SCD-1983

Mechanically, the F90 HPFP will fit your engine. I have a sleeved and forged engine, running the F90 pumps, just the wiring to the pumps must be corrected due to different plugs (quick solder job, cut off old plug and connect to new plug or get a full kit). A change of the fuel pump is not required, but I would tend to say that a software adjustments is needed. The F90 HPFP can dumb a lot of more fuel and it doesn’t make sense to install them without increased power levels.
So in a nutshell: they will fit and no further mods required, but IMHO a useless mod without proper software and power increase.

That makes perfect sense. I was thinking about tuning it regardless but would like to have the fuel pumps on so I can knock it all out at once. I was just curious because I know there are ALOT of similarities between the new M5’s and our previous Gen’s.

I’m thinking of getting a custom tune versus an OTS . When I dyno’d it my fuel dump around like 6k. I’d like to have steady pressure throughout the entire pull.

[m5rosco]

You can fit the f90 HPFP's without changing software. Yes the f90 pump makes more pressure, but there is a regulator so the rail pressure, and therefore injected quantity will remain the same.

On a tuned car, at high load and high RPM's the f10 pumps can find their limit, the f90 pump stops things from tailing off if that makes sense.

[Urameshi.Ibn.F10M5]

Originally Posted by m5rosco

You can fit the f90 HPFP's without changing software. Yes the f90 pump makes more pressure, but there is a regulator so the rail pressure, and therefore injected quantity will remain the same.

On a tuned car, at high load and high RPM's the f10 pumps can find their limit, the f90 pump stops things from tailing off if that makes sense.

Gotcha! That makes sense, so hypothetically speaking, just to throw some arbitrary numbers out there for my example.. lets say the F10 HPFP is like 300 bar and when it gets to 6k RPM's it drops to like 220 bar... would the F90 HPFP basically keep the pressure sustained at 300 all the way through the pull to 6k and above?

I know these aren't exact numbers but just as an example for my understanding.

[m5rosco]

Originally Posted by Urameshi.Ibn.F10M5

Gotcha! That makes sense, so hypothetically speaking, just to throw some arbitrary numbers out there for my example.. lets say the F10 HPFP is like 300 bar and when it gets to 6k RPM's it drops to like 220 bar... would the F90 HPFP basically keep the pressure sustained at 300 all the way through the pull to 6k and above?

I know these aren't exact numbers but just as an example for my understanding.

Yes, exactly that! I don't know what the exact figures are either!

[ajm55]

Originally Posted by SCD-1983

Based on the statement of my very experienced engine builder, the F90 HPFP will not run properly without software adjustments. And there’s a risk of dumping too much fuel, uncontrolled.
I can’t proof either concept, I just followed the advice of my tech and the engine is running great so far 👍🏻

The disparate views persist, it seems. Mike Benvo at BPM (whose tune I'm running) tells he has never had to accommodate for the upgraded pumps in any of his tunes so can't help with this. I am surprised but it's no major as I'd already decided to fit new f10 pumps and be done with it. As a matter of interest, which tuner do you and/or your engine builder use?

[m5rosco]

Here Tommy talks about using the f90 HPFP's on the f10 from 8:00 onwards.

[ajm55]

Originally Posted by m5rosco

Here Tommy talks about using the f90 HPFP's on the f10 from 8:00 onwards.

Thanks for this. Tommy seems to be one of the most knowledgeable tuners on this platform and I'd be guided by him. Only issue, based on my experience, is customer service.