BM3 Multimap FlexFuel

[Itt]

Does anyone know if the Multimap BM3 has increased HPFP pressure?

I heard that it raises the HPFP pressure from 2,800 to 3,400-3,600 PSI, so I’m concerned about its impact on fuel pump or injector longevity. Is it safe to use this kind of map long-term?

As far as I know, the stock injector's maximum operating pressure is 3,000 PSI. Maybe this is why many people running flex-fuel setups experience injector failures.

[mwpa71]

Yes it does increase as e is increased.

I had a custom flex tune done that doesn't push the injectors past 3100 psi.

Definitely pushing past this causing injector failures and possible engine failure.

[Itt]

Originally Posted by mwpa71

Yes it does increase as e is increased.

I had a custom flex tune done that doesn't push the injectors past 3100 psi.

Definitely pushing past this causing injector failures and possible engine failure.

Thanks bro
Who did the custom tune for you? Isn't it reliable? and What E you are running mostly?

[mwpa71]

Originally Posted by Itt

Thanks bro
Who did the custom tune for you? Isn't it reliable? and What E you are running mostly?

Gday advan sydney Australia.
If you want reliability don't push the injectors.
I put down a little more power then ots multi but with lower injector duty cycle (dc) with custom tune.
E ranges from 0-65 %
If you push past 23 psi the dc has to be increased to supply enough fuel for e.
Do some logs, that will tell you your dc psi. Each car is a little different.

[Sndmem3s]

Coming over here from another thread. Whatsup ITT

Looking at my logs I top out at 23 psi with HPFP around 3410 running 40% ethanol on 93 map (BM3 stg 2 multimap)

Is this really overwhelming the injectors? This should be around 530 whp from what I’ve seen.

Thought this was a good sweet spot for the S55 on stock fueling hardware. My shop didn’t seem to think I needed injectors and they have a lot of experience with tuning S55s