What matters most is the actual rail pressure is at that power level. If the rail pressure is dropping, so is fuel atomization and power/reliability along with it.


If you are using the stock return line and not getting a fuel pressure overrun at idle, that strongly suggests the pump is not getting full voltage. Stock lines should never be used with this pump.


Two important criteria that are rarely reported but speak volumes are (a) rail pressure at peak hp, and (b), voltage at the pump at peak hp.

 

Parting out my car, anybody need one already modded up

PM me if interested

 

I did leave out that i drilled my siphon out. I can't recall the bit size I used but iirc it was 9/64. I don't have a fuel pressure gauge either sink can't give readings just yet. I will have one installed in about a week and can report back if anyone is interested.

 

Even with the siphon drilled as described, if that pump is getting full voltage, it should overrun the factory return line. I would be more concerned if it weren't.

On the flip side, the factory feed line creates considerable friction losses, which are exacerbated with the ~30% increased demand of E85. There is a good probability that is starving the rail of pressure at 600+whp, but the pump is working much harder regardless due to the pumping losses through the line.

Make a way to check the FP at idle and at full load, and check pump voltage at full load, but the tiny OE lines are undersized for this application. I strongly advise upgrading them.

 

With proper selection of the full voltage transition load, its possible to use the factory return line without affecting fpr performance, even with upgraded wiring, at least for e85. I've done it and logged all the data. However, I'm not at max possible voltage because I'm using 10 ga wire and 2 relays, the latter of which is to duplicate the factory operational failsafes. I see about 12.9-13 V at peak power. If I used 4 ga wire and 1 relay, I'd probably be around 13.5 V. The story could be different for pump gas, and definitely different for anyone running a full time full voltage rewire (which I do not recommend).

I do fully agree on the supply line. Even a W255 on factory wiring will significantly benefit from a supply line upgrade.

 

yes i have. i drilled the syphon as well. i also made a true 6AN return setup for it so there was no backup/bottle neck affect. the feed's go from 6AN to a (WYE) to single 8AN to the rail. then to a FPR and full 6AN return. works awesome.

 

followed this and it works great just remember to drill the siphon

 

Where do you buy the fittings and what is the siphon?

 

bump X2 on where u got those fittings. also any more pics of ur dp setup?

 

Thank you for this tutorial, it made my life way easier having this as a reference. I'm about to get tuned on E85 tomorrow so I'll post on how it goes.

 

I followed this and it fit just fine. I now need to wire in a relay for the pump so that it can run at full efficiency, but I'm not sure how. Are they any write ups on how to do that, or can someone help me out with what to do?

 

https://www.evolutionm.net/forums/ev...e-circuit.html

See post #121.

 

First of all, great write up. Thank you.

I had a couple of questions.
I followed step by step and just wanted to see what others have done.
When installing the bottom part that holds the pump snug, did you reuse the rubber gromet at the bottom of the pump.
Additionally, is it required to trim the bottom of the plastic part to allow space for the sock to come through?

 

Awesome write up, thanks!

 

Im brining this back!

I followed all instructions on this forum, but I'm not sure exactly what's wrong...
I hooked everything up as followed but when I turn the key on (not cranking ) just turning it over the fuel pump does not prime what so ever? But if I unhook the relay and hard wore it to a battery the pump will kick on and run non-stop until you unhook it from a battery?
I did not mess with the stock fuel pump rely that come with the car from factory? Could that be the issue having the new relay and the factory relay hooked up at the same time? I'm not sure what's wrong! Any help would be greatly appreciated!