PI or HPFP upgrade?

RAT3DM · 03-13-2024, 09:21 PM

Quote:

Originally Posted by imperfectluck

Just wanted to chime in once more and nudge to get the fuel filter, can’t stress enough when Ian from Bend Calibration told me to look at the pics of when a cylinder leans out and the DME didn’t have time to react.

I’m running just about the same setup as astris as I saw the results and was impressed to follow suit. It was said earlier in this thread just wanted to once more stress this point so that you don’t end up making a thread about it as we’ve seen every now and then especially if you plan to run high E levels.

Agreed, I also ordered the bend filter kit as well, as I had an Eu5 injector go out (stuck open) with less than 800 miles ran hard with only e85 tune.

wheela · 03-13-2024, 09:32 PM

Quote:

Originally Posted by RAT3DM

Agreed, I also ordered the bend filter kit as well, as I had an Eu5 injector go out (stuck open) with less than 800 miles ran hard with only e85 tune.

How much injection pressure were you running? I've heard conflicting reasons for injectors sticking open between needing a fuel filter and running too high of injection pressure for the injectors. In the n55 world, you don't really hear about injector failure, but that's not the case with s55. Granted, most n55 guys aren't pushing the same power levels as s55, but the general rule of thumb over there is to keep hpfp minimum > 2000 psi to avoid misfire,
whereas it seems > 3500 psi seems common on these high-powered e85 s55 tunes. I'm guessing the higher pressure is needed to cram the necessary amount of fuel into the cylinder in the limited time available for injection when running 700+ whp on e85. I see Nostrum rates their injectors at 3625psi, I wonder what the max rating is for the M5 eu5 injectors?

astris · 03-14-2024, 01:33 AM

Quote:

Originally Posted by imperfectluck

Just wanted to chime in once more and nudge to get the fuel filter, can’t stress enough when Ian from Bend Calibration told me to look at the pics of when a cylinder leans out and the DME didn’t have time to react.

I’m running just about the same setup as astris as I saw the results and was impressed to follow suit. It was said earlier in this thread just wanted to once more stress this point so that you don’t end up making a thread about it as we’ve seen every now and then especially if you plan to run high E levels.

This! I’ve been running the Bend filter since day one. Wouldn’t run E85 without. I run some quantity of E85 nearly all the time and have had zero issues. No brainer safety net.

-Eidos · 03-14-2024, 01:36 AM

Quote:

Originally Posted by wheela

How much injection pressure were you running? I've heard conflicting reasons for injectors sticking open between needing a fuel filter and running too high of injection pressure for the injectors. In the n55 world, you don't really hear about injector failure, but that's not the case with s55. Granted, most n55 guys aren't pushing the same power levels as s55, but the general rule of thumb over there is to keep hpfp minimum > 2000 psi to avoid misfire,
whereas it seems > 3500 psi seems common on these high-powered e85 s55 tunes. I'm guessing the higher pressure is needed to cram the necessary amount of fuel into the cylinder in the limited time available for injection when running 700+ whp on e85. I see Nostrum rates their injectors at 3625psi, I wonder what the max rating is for the M5 eu5 injectors?

I have a N55 with 700+whp on E85. The M5 EU5 injectors should be ran at lower pressures for longevity - less than the Nostrum ones which are rated for 25mpa. That's the other big plus for the Nostrum injectors.

Hotflare · 03-14-2024, 01:43 AM

Quote:

Originally Posted by -Eidos

I have a N55 with 700+whp on E85. The M5 EU5 injectors should be ran at lower pressures for longevity - less than the Nostrum ones which are rated for 25mpa. That's the other big plus for the Nostrum injectors.

Wonder how these injectors handle smog checks

-Eidos · 03-14-2024, 01:21 PM

Quote:

Originally Posted by Hotflare

Wonder how these injectors handle smog checks

None of the upgraded DI injectors will handle SMOG well if the process involves checking for a stock tune.

With PI, you can run the stock tune and just not fire the additional injectors.

Hotflare · 03-14-2024, 02:06 PM

Quote:

Originally Posted by -Eidos

None of the upgraded DI injectors will handle SMOG well if the process involves checking for a stock tune.

With PI, you can run the stock tune and just not fire the additional injectors.

In other words, PI let's you have your cake and eat it too