[KingLT1]

I don't think there is much you can do to get more fuel headroom out of that setup. Being that it will handle E60 tells me things have to be optimized pretty well.

The only reason you should drop rail pressure is if the HPFP will not hold commanded pressure. Then you lower it until it stabilizes, but that will cause IPW to increase. So you need to have enough IPW headroom in order to do that. For example, if your IPW is already at 5.8ms, then there is no room to lower rail pressure. If they are around 5.2-5.3ms but rail is dropping, then you would lower rail to keep that stable and IPW should still have some room to inject fuel on time.

That being said imo the LPE doesn't like 2900psi, it seems to work best no higher than 2500psi. That is where I normally run them with +30 XDI injectors. That doesn't mean it won't run 2900psi, it just tends to drop off a cliff fast when you close on its limits commanding that high of pressure.

Hoping to see if the new Katech Goliath pump is an improvement over the LPE. Because if it is happy @ 3200psi, then there should be some gains to be had as that will lower IPW and allow these bigger injectors to go further.