I think you'll find that OEs time sequential pulses to fire when the valve is closed, ostensibly to reduce cylinder wash. This benefits wear rates, although at the expense of a bit of torque.

 

Even with 310* cams, you would have to be under 43% IDC to only inject when the valve was open.

I have heard spraying a closed valve does actually help atomize some of the fuel as the valve is hot and helps the fuel evaporate. It also helps keep the valve cooler. With that in mind, I would THINK you would want the end of the pulse to reach the valve right as it is closing.

Not exactly what you are after, but something I am mulling over. Bosch makes a HP version of the 044 pump. It is rated at 8bar. It matches up well with the EV14 injectors that are also rated for 8 bar operation. The HP version does about 200lph at 8 bar. This would mean a single pump would be about right for four 740cc injectors at 5.5 bar base fuel pressure and 2.5 bar of boost. This would make them about the same as 960cc inectors. This would probably be about right for a setup making around 550WHP when fully maxed out on boost. The benefit being they aren't modified injectors with crappy spray patterns, 100% OEM bosch. You can also match them up with a Bosch OEM FPR. I like the idea of OEM parts working together anyway.

 

I was talking about running 80psi all the time. Remove the boost ref from the FPR and set the fuel pressure at 80psi.

However who knows how fast that would kill your fuel pump. It would be drawing more amps at that level.

Anyhow cool results, I will be adjusting mine as well just to see how the car likes it.

The other guy that was talking about tuning injection angle, can you do that on the stock ECU. I am on an AEM EMS, and we have a full 3d map for Injector Phasing(RPM, Boost)

 

You don't want to do that. The vacuum/boost reference is needed to keep the pressure across the injectors constant.

 

Most definitely

IMO, the current angle is to steep. ok for low speed driving & emissions

Should be pointing towards the center of the valve. not so much the backside of the port, but the valve head itself & when i say center of the valve, im not referring to the stem.

yeah, there will need to be some injection timing adjustments made to maximize the angle change, but thats simple enough.

 

That does not make any sense to me. I might be special ed, but if your regulator is working it should be able to maintain the selected fuel pressure with out a pressure reference.

Or are you saying that as your IDC increases it will affect the FPR.

 

The job of the FPR is to maintain a set fuel pressure *across* the injectors. In order to do this, the FPR needs to reference the pressure at the outlet of the injector. This is why the vacuum/boost reference is needed. Definitely do not run without the vacuum/boost reference attached.

 

i am doing the same as you mrfred but on pump 93.... good info for sure

 

Got it that makes more sense.

 

I am wondering if the advantage mrfred is seeing is more of an e85 thing or if it would be just as beneficial on pump gas. Why I ask is because if there was a pump gas advantage, why would the oems stick with the 43 psi differential? Or is it due to the aftermarket, I.e. modified spray pattern, injectors.

 

Not just injection angle, but injection phasing as was touched on before.

 

Subscribed.

 

Update - I've been able to get some WOT logs, and pressure across the injectors is not holding at 58 psi at high fuel flow rates. I have fixed up the pump wiring as much as possible, and for my setup, about the best I can get is 13.1 V at the pump. With a switch from 10 gauge to 8 gauge power cable, I might be able to get it up to 13.5 V, but that's about as good as its going to get because I'm loosing roughly 0.5 V across each of the two relays that are in the power path. These are properly wired very high quality relays, so there's nothing to improve and not much to be gained even if I could improve it.

I really like the high base pressure for off-boost driving, so I'm going to have to figure out a way to make this work. I'll probably end up with a boost-a-pump to get pump voltage up to 17 V at high fuel flow. I may also look at an alternate way to connect the Walbro 416 to the factory housing to ensure I'm not loosing flow due to the grommet arrangement or due to the built-in filter causing a huge pressure drop.

 

Get that Squash double pumper and add another 416... It'll not only do your delta P of 58psi no sweat it'll also keep up during fast transients into boost.

 

I've already built my own double-pumper. Its pretty sweet actually. I was just hoping to be able to make it work with a single pump. If I install the double pumper, I'll have to redo the supply line and electrical. A boost-a-pump is not much more than connecting four wires. I'm lazy if I can be.