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Old 12-21-2009, 08:59 PM   #251
2006whitesti
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Originally Posted by D Money View Post
does a y fitting do the same as a distribution block? Answer Yes

The only reason I had to get two distribution blocks was due to the fact that I needed two -6's into one -8 and then one -8 into two -6's. All the y fittings I saw were the same size all around.
I know they make them both, let me see what I can come up with.
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Old 12-21-2009, 09:05 PM   #252
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Old 12-21-2009, 11:25 PM   #253
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I see a lot of systems with dual pumps, dual filters, etc. And I occasionally read about motors that popped when one pump died and the car ran on half the usual fuel.

We've got two fuel rails... So I have to wonder, if you're going to do a dual pump system, why not run one pump to each rail, each with its own FPR? If one pump dies, you'll have two cylinders seeing full fuel and two seeing none / hardly any. Stuff can still break at this point, but it seems less likely to kill the motor than running all 4 with half the usual fuel flow.

Is there a reason nobody does this?
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Old 12-21-2009, 11:47 PM   #254
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^^^^^

Not if u put a pressure switch into the line, so that if pressure drops below a certain value then you know theres something wrong with the pumps and the ecu will go into limp mode..
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Old 12-21-2009, 11:59 PM   #255
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I see a lot of systems with dual pumps, dual filters, etc. And I occasionally read about motors that popped when one pump died and the car ran on half the usual fuel.

We've got two fuel rails... So I have to wonder, if you're going to do a dual pump system, why not run one pump to each rail, each with its own FPR? If one pump dies, you'll have two cylinders seeing full fuel and two seeing none / hardly any. Stuff can still break at this point, but it seems less likely to kill the motor than running all 4 with half the usual fuel flow.

Is there a reason nobody does this?
I imagine it's because slight differences in fuel pressure from one bank to another would cause a hell of a time with tuning. If you have 1 fuel system, with its own peaks/valleys/resonances, you can tune out any fuel pressure irregularities with your MAF scaling (not ideal, but it works). If you have 2 fuel systems, each with their own peaks/valleys/resonances, you can't do anything about it unless you install 4 widebands, one on each cylinder (4 EGTs would help, but wouldn't be enough information IMO).

Say the motor in one fuel pump is slightly less efficient than the other and drops pressure by 3 psi instead of 1 psi at 60 psi. That's a half a point in AFR difference, one bank would be at say 11.3, the other would be at 11.8, that's pretty significant. Or say one fuel pressure regulator isn't as linear as the other, and instead of ramping up at exactly 1:1 it ramps up at more like .95:1. When your manifold pressure hits 25 psi, one bank will be at 68 psi, the other will be at 66.75, same problem as before. If the line feeding one bank is a different length than the line feeding the other bank, it could cause a resonance at a different IDC, which will cause one bank to randomly lean out at some RPM while the other doesn't.

Just throwing out ideas why people don't usually separate the fuel system like that.
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Old 12-22-2009, 12:02 AM   #256
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^^^^^

Not if u put a pressure switch into the line, so that if pressure drops below a certain value then you know theres something wrong with the pumps and the ecu will go into limp mode..
Where would you set that pressure? The fuel pressure changes dramatically with manifold pressure. With a 43 psi base, your fuel pressure can vary anywhere between 33 psi and 68 psi (depending on target boost), so where would you set the cutoff? 30 psi? If you're hitting 30 psi at idle that's a good place for a cutoff, but if you're hitting 30 psi at 25 psi manifold pressure your engine is already gone.

Of course this is all moot if you install a pressure sensor instead of a switch, and monitor fuel pressure - manifold pressure to check for a constant 43 psi differential. You would need a standalone ECU for that though.
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Old 12-22-2009, 12:33 AM   #257
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Or you could simply get a properly sumped fuel cell and run one pump. Weldon makes a hell of a single pump solution.
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Old 12-22-2009, 12:33 AM   #258
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nice find! I'm gonna scoop one up for when I do my top feed setup.
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Old 12-22-2009, 12:55 AM   #259
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i was just thinking about running 2 walbros in (paralel) i know spelled wrong. then into a single aeromotive regulator. then i would have double flow but equal pressure. right?

Quote:
Originally Posted by the suicidal eggroll View Post
I imagine it's because slight differences in fuel pressure from one bank to another would cause a hell of a time with tuning. If you have 1 fuel system, with its own peaks/valleys/resonances, you can tune out any fuel pressure irregularities with your MAF scaling (not ideal, but it works). If you have 2 fuel systems, each with their own peaks/valleys/resonances, you can't do anything about it unless you install 4 widebands, one on each cylinder (4 EGTs would help, but wouldn't be enough information IMO).

Say the motor in one fuel pump is slightly less efficient than the other and drops pressure by 3 psi instead of 1 psi at 60 psi. That's a half a point in AFR difference, one bank would be at say 11.3, the other would be at 11.8, that's pretty significant. Or say one fuel pressure regulator isn't as linear as the other, and instead of ramping up at exactly 1:1 it ramps up at more like .95:1. When your manifold pressure hits 25 psi, one bank will be at 68 psi, the other will be at 66.75, same problem as before. If the line feeding one bank is a different length than the line feeding the other bank, it could cause a resonance at a different IDC, which will cause one bank to randomly lean out at some RPM while the other doesn't.

Just throwing out ideas why people don't usually separate the fuel system like that.
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Old 12-22-2009, 01:02 AM   #260
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i was just thinking about running 2 walbros in (paralel) i know spelled wrong. then into a single aeromotive regulator. then i would have double flow but equal pressure. right?
Sure, but then you run into the problem that NSFW was bringing up. With one pump, if it up and fails you essentially go 100% lean, no fuel, which is basically just engine breaking. With 2 pumps, if one fails you go lean, but not so lean to prevent combustion. Basically it's a recipe for a blown engine.
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Old 12-22-2009, 01:11 AM   #261
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thanks egg. ^^^^but
im talking about 2 totally seperate lines clear from the tank/pumps to the rails, then if 1 pump dies then you basicly have one bank getting fuel and the other empty. i may hve to install check valves on the return lines just before the reg but i think it will work.
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Old 12-22-2009, 01:15 AM   #262
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nice find! I'm gonna scoop one up for when I do my top feed setup.

There are more on there, also check Jegs.com, they have better prices most times. Glad I could help.
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Old 12-22-2009, 01:44 AM   #263
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Quote:
Originally Posted by MartinSTi05 View Post
Or you could simply get a properly sumped fuel cell and run one pump. Weldon makes a hell of a single pump solution.
+1

this is what i'll do when I upgrade my fuel system
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Old 12-22-2009, 04:10 AM   #264
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Originally Posted by toyjunkie View Post
thanks egg. ^^^^but
im talking about 2 totally seperate lines clear from the tank/pumps to the rails, then if 1 pump dies then you basicly have one bank getting fuel and the other empty. i may hve to install check valves on the return lines just before the reg but i think it will work.
You'd definitely need check valves, otherwise you'll have one pump feeding both banks after the other pump dies, in which case you're no better off than the usual two-pump system.

A single regulator with check valves seems like a good way to work around the regulation problem that Eggroll brought up, though. Nice idea.
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Old 12-22-2009, 06:20 AM   #265
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Originally Posted by MartinSTi05 View Post
Or you could simply get a properly sumped fuel cell and run one pump. Weldon makes a hell of a single pump solution.
The problem with a cell is even with a huge sump and foam you still get a ton of slosh, if you run one with any sort of capacity. If you are drag racing you are fine, but you start throwing the car around and starvation becomes an issue once again. I have tried several different setups and no one setup is a end all solution. I just wish we could find a way to get away from the multiple pump setups. It just adds more complexity to an already overly complicated setup.
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Old 12-22-2009, 10:23 AM   #266
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Originally Posted by 2006whitesti View Post
The problem with a cell is even with a huge sump and foam you still get a ton of slosh, if you run one with any sort of capacity. If you are drag racing you are fine, but you start throwing the car around and starvation becomes an issue once again. I have tried several different setups and no one setup is a end all solution. I just wish we could find a way to get away from the multiple pump setups. It just adds more complexity to an already overly complicated setup.
What issues did you have with a surge? It should stay full constantly until you starve the pickup in the tank, full tank means no sloshing.
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Old 12-22-2009, 10:24 AM   #267
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Originally Posted by toyjunkie View Post
thanks egg. ^^^^but
im talking about 2 totally seperate lines clear from the tank/pumps to the rails, then if 1 pump dies then you basicly have one bank getting fuel and the other empty. i may hve to install check valves on the return lines just before the reg but i think it will work.
That might work with check valves
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Old 12-22-2009, 10:42 AM   #268
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What issues did you have with a surge? It should stay full constantly until you starve the pickup in the tank, full tank means no sloshing.
I only had problems when the fuel cell was not full. At about 1/2 tank in a high g sweeper I would get starvation. Take in to account that I was feeding a bosch 044 through gravity with this setup. I did not have a tank inside the fuel cell. Keeping the tank full is not always and option, especially for street cars, or track cars that do long duration runs, which was the case in my miata.
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Old 12-22-2009, 10:44 AM   #269
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I just don't like the approach of multiple pumps, even though it has been proven to work in a lot of cases. Like I said before it just makes the situation more complicated, and more of a risk of failure.
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Old 12-22-2009, 11:20 AM   #270
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I only had problems when the fuel cell was not full. At about 1/2 tank in a high g sweeper I would get starvation. Take in to account that I was feeding a bosch 044 through gravity with this setup. I did not have a tank inside the fuel cell. Keeping the tank full is not always and option, especially for street cars, or track cars that do long duration runs, which was the case in my miata.
Surge tank, not fuel cell

Fuel tank can be whatever it is (fuel cell or stock tank), lifter pump feeds a ~1.5L fuel cell (which almost always stays completely full), main fuel pump pulls out of that to feed the injectors.

Sloshing in the tank or fuel cell doesn't matter, because you have a ~1.5L buffer that can hold you over for at least 30 seconds to a minute in track use, plenty of time for the pickup in the tank to get fuel again and refill the surge.

It's not overly complicated, it's pretty cheap, and as far as I can tell it is an end-all solution to high-G fuel starvation.
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Old 12-22-2009, 11:51 PM   #271
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is this the proper way to wire a Bosch 044 fuel pump?
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Old 12-23-2009, 12:15 AM   #272
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You don't want to switch the relay with the line that feeds the factory pump. It's pulse width modulated at much too high of a frequency for the relay to keep up, and even if it could, the Bosch doesn't like to be switched. You want to switch the relay using the line that powers the stock fuel pump controller (goes hot when the key is switched ON for a few seconds, then goes cold until the vehicle is actually started).
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Old 12-23-2009, 08:24 AM   #273
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so should i switch 86 and 30?
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Old 12-23-2009, 09:11 AM   #274
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hmm found this on the web.
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Old 12-23-2009, 10:03 AM   #275
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check this out D

http://www.summitracing.com/parts/NOS-17840NOS/

I have one of that Y
That one would work, but I hate that it says "NOS" haha

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Originally Posted by 2006whitesti View Post
Damn dude, that would be perfect! Do you think that will do the same job as say, this distribution block?

http://www.summitracing.com/parts/EAR-100181ERL/

It's actually cheaper to go with the Earls, but that little aermotive y is pretty sick.

I need two of them. One to split the -8 feed into (2) -6 at the rails and one to split the (2) -6 from the pump to -8 feed line.
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