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ECMlink E85 duty cycle ....

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SasaniFab

Proven Member
2,433
782
Dec 1, 2013
Mexico, Connecticut
So some of you know that I switched to e85.....I'm currently running the walbro 450 on fic 1650s, I understand that several factors dictate injector duty cycle. These factors include voltage to pump, fuel pressure... line size etc. I am currently on 6an lines front to back. On several pulls I am creeping up to 60lbs/min and my injector duty cycle is 95.4%. This is at 43psi for fuel pressure. Short of increasing fuel pressure is my setup at its peak regarding how much hp I can make reliably?
 
Keep going until you cannot control the fuel anymore and it starts to lean out. That shitty pump and just as crappy injectors wont give you much more.

once you can control fuel back it off and be happy where it is until further changes are made
 
Single, man pump. Don't sell yourself short on a junk dual pump setup and always have a crutch.
 
Your IDCs are a good indicator as to how much power your fuel system in its current configuration can support. At 95%, there's not much left in it.

Bottom line, you're going to need more pump, or to increase pump pressure. With the 450, you likely won't be able to increase pump pressure much without sacrificing flow. So, you need to get a pump(s) that will support at your power level. @Kapok6 can comment on pushing the Walbro 450, as I believe he's have very good luck with his.

I've gone through a similar situation recently myself, and have documented the process fairly in-depth. There are other solutions other than the one I came up with, but the principals outlined will apply to any fuel setup. At the end of the day, you need to find a fuel setup that will maintain flow within your operating ranges, according to your power level.

You need to start by calculating your pump requirements, and go from there. 99.99% of the information you need is already outlined here: http://www.dsmtuners.com/threads/gstwithpsis-galant-vr4-1837-2000.482807/page-10#post-153619672

Regarding biglady112's comments about the Walbro 450 and FIC 1650's being shitty/crappy, that's just simply not true. Although I'd certainly agree there's more than one way to solve your fuel problems, per the usual, I'd completely disregard his opinion/comments.
 
Single walbro 450, stock lines, stock filter, FIC 1550's, base fuel pressure like 42psi, e85, got me 130.75mph in the 1/4mi with IDC's never seeing 70%. AFR's were mid 11's on that setup. Boost was 29psi on a DSM76 HTA. Car weighed 3395lbs with me in it. I think avg AWHP per the calculators work out to something like 525awhp down the entirety of the track. As to what kind of crank hp that equates to, no idea. I'd guess upper 500's to 600, (though wisemen correct me if that assumption is wrong).

Where I started to see issues was in the mid 60's lbs/min on airflow and I had to run incredibly stupid rich afr's on the high comp motor. Going from 11.2afr to 9.2afr and going from upper 50's lbs.min to mid to high 60's lbs/min take a toll on the fuel system.

I drove for years on a single 450 and e85 with stock lines and never a single fueling issue.
 
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Haha. Ok, lets try not to get too far of topic.
Bring it around.....and we see..... Op needs a better system.

I forgot to ask, what are your goals. What kind of numbers are you shooting for. Be it 1/4 mile times or Dyno numbers? This will give us some data to work with. If your OK with mid 500hp numbers, then nothings needed. Again, its about your goals. State them and we can help further.
 
I'd be happy with 500 awhp but I don't want to be at the very peak of my setup..... I'm shooting for 10s. I'm close to 60lbs/min.....I want to fuel system that can handle that no problem
 
Well, 450, 1550's, stock lines/filter, and e85 got me there pretty easily.
I am pretty close to you in performance I feel. I haven't been to the track in a couple years now BUT I run an Aeromotive 340, stock lines, 1650's and now E85 and my car will walk away from a 11.3 GSXR600 bike that runs around here. Not bad but definately quicker than him and he runs at the track a hour from here.
 
I myself have been voted off of several islands due to my non desire to spoon feed and for stating what works and not allowing someones internet gossip/"research" to cloud my first hand knowlege of what works and what doesnt... that being said, you will find that the faster guys arent ones for splitting hairs or neccesarily coming off as "nice" but more to the point with no bs. Lets try not to be to hard on people that come on these types of forums and give FREE advice that they really dont have to give, on how to do things right and how to go faster, remember that alot of guys wouldnt give away their secrets for anything, lets act repectful and try to appear appreciative here ok?
 
@GST with PSI article on fuel pumps is a good read @amsrn13 if you haven't looked at it. Thanks for the Link Brett but the fuel pump calculator isn't working in it, fyi.
 
. Have any of you run a surge tank? Id basically use the walbro to pump into the surge tank and have an external pump to the rail.....
 
I will say it again , surge tanks are for non gravity fed mechcanical pumps. 100% unneccessary and unneeded on an electrical fuel pump car. Why complicate things by adding another pump, then add a stupid tank into the mix that does nothing for you? You might as well put two baby pumps in series or parallel and be happy.

And yes, I have experience with a surge tank in both mechanical and electric pumped cars. Super redundant in a car with an electrical pump .
 
No surge tank in my car. So far I am not leaning out up top so I don't think mine is running out of fuel. I could be wrong but the logs don't show it, although I suspect I am on the edge of the setup as it is now. DC's are high 80's maybe occasional low 90.
 
This thread has been cleaned up and warnings have been sent to those that participated. If you do not have anything productive to add towards the OP’s original question, don’t post it. If you have an opposing view on something please share it in a respectful manner to facilitate some useful conversation.
 
I actually thought the memes pertaining to me were funny. I should have screenshot them in retrospect.

Anyway, I've dabbled with double pumpers. I'm not a fan. Single 450 in tank or big external is what I'd prefer short of a mechanical.
 
I will say it again , surge tanks are for non gravity fed mechcanical pumps. 100% unneccessary and unneeded on an electrical fuel pump car. Why complicate things by adding another pump, then add a stupid tank into the mix that does nothing for you? You might as well put two baby pumps in series or parallel and be happy.

And yes, I have experience with a surge tank in both mechanical and electric pumped cars. Super redundant in a car with an electrical pump .

You're simply wrong once again. A surge tank isn't redundant, and it serves the same purpose whether the pump is mechanical or electrical. There are literally thousands of people who use surge tanks in conjunction with electric pumps. Here's a company who specializes in exactly that: http://www.radiumauto.com/Universal-Fuel-Surge-Tanks-C54.aspx

On my personal car, I added a surge tank between the lift pump that is in the stock fuel tank and the inline A1000 in order to reduce the working pressure the lift pump has to operate under. Since the lift pump only has to move fuel to the surge tank under low pressure, it can move that fuel at a much higher volume and sustain flow. It also ensures the pump is never starved under any condition. If you're considering running two pumps in series, adding a surge tank between the two is a great way to do it.

It took two in-tank 340's to feed the A1000 when the pumps were plumbed in series directly to one another. With the surge tank, I can easily go back to 1 in-tank pump next time I have to pull the hanger.




Have any of you run a surge tank? Id basically use the walbro to pump into the surge tank and have an external pump to the rail.....

That's how my car is currently configured. The fuel system works great, and my IDCs are super low. Check out the surge tanks from Radium in the link above. There are various other tanks available as well, many of which are cheaper.
 
The calculator works, thanks Brett. Nice little tool, appreciate the link!
 
One question that hasn't been asked - is your tune spot on, both from injector settings and SD table (assuming the mod list in your profile means you're on SD)?
Spot on, no...I'm was moving up to 60lbs a min at times at my peak injduty. I was basing the assumption on others experience with this setup. They claim that my fuel system is good for about 60lbs min with my turbo. Give or take 500whp on ethanol.
 
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