So something I just came to learn is not really being discussed here on the M2 forums, but can be found elsewhere, and I wanted to make a thread about it.
I am having my fuel system upgraded today to support my Pure Stage 2 setup. I went with the XDI-35, Flex Fuel Kit, and Walbro 450 Stage 2 LPFP. While I read that the OEM LPFP was sufficient to support my power goals and sub E50 blends, It was recommended by a friend running full E85 in his M2 that I get the LPFP to support the corrosive nature of any corn fuel blend. So I bought a used pump from a forum member last week confident this was the safest move for my car.
I had to call Tuning Tech FS to acquire a part that was missing for my hpfp, and got to talk to the owner Frank about my setup and expectations. He promptly informed me that the Walbro 450 draws more amperage from the stock harness at certain flow rates than the oem harness can handle. The oem design limits the factory fuel pump draw and thus is unable to drive high capacity aftermarket fuel pumps without overheating. This can cause the LPFP to crash which can take out both the LPFP and HPFP potentially and cause misfires.
<9amps max is what I'm told the oem harness can handle, and the Stage 2 450 harness can require upwards of 14amps with full E85 in the tank. This is problematic obviously as it will fry the oem EKP Module along with the LPFP as I already stated.
So I have two options:
1) Do not exceed blends of E40-50 (working with Cary Jordan on my custom mapping this week, who is well aware of the issue)
OR
2) Purchase a upgraded or "virgin" EKPM for the lpfp and have the ability to run E85
So based on other tuners experience and feedback from Frank, the power increase from say E50 vs. E85 is pretty insignificant, maybe 5% (I'm told) and not really worth it in my opinion. So I will be sticking with lower blends with my current setup. I have a bluetooth analyzer so I can monitor the ratio in my tank.
My question for the community and for people looking to run full E85, is which EKPM does one purchase for the F87 M2? I cannot find anything specific to this platform online. I found this plug and play solution and was curious if there are any other more affordable solutions in the market currently? Im already $3k into fueling mods that no-one will ever know is there, so Im not looking to sink more money into the setup given my modest goals. But the reliability would be nice so I'm not ruling it out completely. Thanks everyone
https://www.eospeed.com/products/bpm...ump-controller