Fuel Pump Question
Rent me! per hour
Joined: 03-22-07
Posts: 24,161
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From: Still fixing others mistakes.
Cool, 9 pages to work that out but we did have fun and I have to admit I learned quite a bit researching for my posts.
There is an issue with the LSJ cooling system. The water pump feeds one side of the engine first and that doesn't give even cooling. Then the way the water recirculates via the thermostat setup. This causes the engine to run hotter in some areas than others and we addressed it when doing Ryan's build. He'll post a thread in a few days I'm sure as it's painted and looking all pretty now
There is an issue with the LSJ cooling system. The water pump feeds one side of the engine first and that doesn't give even cooling. Then the way the water recirculates via the thermostat setup. This causes the engine to run hotter in some areas than others and we addressed it when doing Ryan's build. He'll post a thread in a few days I'm sure as it's painted and looking all pretty now
also, the cooling system is not the cause of number 4 going blamo. keep trying!
Cool, 9 pages to work that out but we did have fun and I have to admit I learned quite a bit researching for my posts.
There is an issue with the LSJ cooling system. The water pump feeds one side of the engine first and that doesn't give even cooling. Then the way the water recirculates via the thermostat setup. This causes the engine to run hotter in some areas than others and we addressed it when doing Ryan's build. He'll post a thread in a few days I'm sure as it's painted and looking all pretty now
There is an issue with the LSJ cooling system. The water pump feeds one side of the engine first and that doesn't give even cooling. Then the way the water recirculates via the thermostat setup. This causes the engine to run hotter in some areas than others and we addressed it when doing Ryan's build. He'll post a thread in a few days I'm sure as it's painted and looking all pretty now
simple numbers and unnamed units for ease of understanding. based on the simple fact that as the fluid worms, it removes less heat energy from the air charge over the same amount of time, we have this scenario:
lets say the side by cyl #1-2 removes 4 units of heat, then the side by cyl #3-4 removes 3 units of heat, then the fluid must take the next laminova back to reach the end plate. The fluid will remove 2 units of heat by cyl#3-4, then continue down and remove 1 unit of heat from cyl #1-2
overall, the fluid has removed 5 units of heat from the path to cyl #1-2 and 5 units of heat from the path at cyl #3-4. The same would happen using a stock endplate, albeit a longer cycle.
A single pass IM however would definitely run into the problem of cooler IAT2 charges on one side opposed to another.
Really, zoomer was correct in that cyl #4 is not running lean, which is what some in here were trying to say, but area also agrees with zoomer in that this is not the case. Also, he was right in that a return style fuel rail is not a fix to this problem that apparently doesnt exist, solely because you dont need a return style to raise fuel pressures, which was zoomers whole point. you can just increase the pressure through whichever means he uses. returning the fuel will not aid in cyl#4 fueling
also, i dont think the physics forum is really bash worthy...he did say he'd have 3rd party evidence to support him..maybe thats what he was talking about? although it is still amusing at first glance, but whatever works.
of course the hostilities between everyone in this thread will continue, and i dont expect otherwise, so im not going to even bother, but again i would like to thank both sides of this debate for actually putting up a lot of raw information, theories, and test results to debate so that others like myself who are reading this thread can have a more clear understanding of all of the issues involved with our stock fueling system.
in my own defense, i am trying, as always, to remain neutral and unbiased, as i want to stay out of the bashing wars and just learn.
The pictures I have that were setup with the aquarium were from an old friend of mine who now works out west. They ran into a problem with the stock feed end of the rail being too restrictive and engineered a new rail. The pictures he sent me back then were from this tech article: http://www.wolfkatz.com/Articles/Wol...l%20Report.pdf
While doing a little online research for anyone with other models of vehicles that could also exhibit this problem I found that someone else flowbenched a rail from a stock 4g63 using only 450cc injectors @ 60psi and it too exhibited the same symptoms. While both setups are using a return fuel system, the difference between the two is minimal at high flow rates as the aftermarket regulator is near completely closed if the rail is already past its own flow capacity. That article can be found here: http://www.stevetek.com/R-FuelSys.html
The entire point I was trying to make which everyone seems to have forgot is that by changing from a returnless to a return style system you gain the ability to increase pressure thus increasing capacity of the rail especially at its critical restrictive point.
Also, if you didn't exactly know something here, no need to continue argueing a point you don't understand until you ask someone who might. I kinda giggled at this: http://www.physicsforums.com/showthread.php?p=2272398
While doing a little online research for anyone with other models of vehicles that could also exhibit this problem I found that someone else flowbenched a rail from a stock 4g63 using only 450cc injectors @ 60psi and it too exhibited the same symptoms. While both setups are using a return fuel system, the difference between the two is minimal at high flow rates as the aftermarket regulator is near completely closed if the rail is already past its own flow capacity. That article can be found here: http://www.stevetek.com/R-FuelSys.html
The entire point I was trying to make which everyone seems to have forgot is that by changing from a returnless to a return style system you gain the ability to increase pressure thus increasing capacity of the rail especially at its critical restrictive point.
Also, if you didn't exactly know something here, no need to continue argueing a point you don't understand until you ask someone who might. I kinda giggled at this: http://www.physicsforums.com/showthread.php?p=2272398
Witt, if the line from the pump to the front of the car is 5/16" and the smallest part of the rail is 9/16", how does the rail which will flow over 3 times what the line does become restrictive? That's like saying a guy with a 2.5" exhaust needs to replace his 4" tailpipe with a 5" one because the 4" one is restrictive.
The reason you found the information about the 4g63 Witt, is because that car has 3/16" fuel line in places and a 5.5mm fuel rail inlet. The Cobalt is already able to flow 3x what that car can. You can't just keep taking these examples that have nothing to do with the Cobalt and try and prove a point.
the physics forum is my 3rd party source which is something that a few people here may laugh at. For some reason physics is funny here and doesn't matter, nor can it be used as a source for evidence I guess.
As Hunter has pointed out, if you look at my original posts. I have been proven correct. Even by Witt. I don't expect Angel to admit this, nor Witt but it is in print and I will take this as a victory.
Last edited by Zooomer; Jul 16, 2009 at 10:33 AM.
Thread Starter
Senior Member
Joined: 08-09-07
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From: Columbus, Ohio
Actually in his defense, he didnt state this topic first, I did to someone else on this fuel pump topic that I had started, and I told the other individual about my upcoming ideas of a peltier cooler setup for our lsj's, and if he wanted to share ideas to make something work to pm me, so same for anyone else lets put are brains together and come up with something nice. Peltier coolers are used for over clocked graphics cards in a gaming or ect computer, and are not very big, not sure on exact messurements but they're not that big, and the 1 side gets any where from +10 degrees to -2 degrees F, wheres as the other side is visversue and gets extremely hot, and is powered by electricity. So I wanted to come up with a creative setup so I can get maximum coolent in my car......
<Off topic warning> I once got in a debate with a guy who said that a larger pulley would make more power, not smaller. He couldn't understand how something smaller would make the blower spin faster. It lasted quite a while. I wonder if we applied this forums logic to that debate and didn't allow science or outside sources how things would turn out....
Zoom you dumb ass, I put a smaller wheel on my car and guess what? top speed was LOWER!
Obiously higher gears make you go FASTER duh. That's why they call them HIGH gears. You're trying to argue that smaller gears make things spin faster. Idiot!
Zoom you dumb ass, I put a smaller wheel on my car and guess what? top speed was LOWER!
Obiously higher gears make you go FASTER duh. That's why they call them HIGH gears. You're trying to argue that smaller gears make things spin faster. Idiot!
I feel like saying something correct in this thread so here is what I have.
"The problem with the #4 cylinder is not the blinker fluid."
There are many other things that I could think of that are NOT the problem. This is too easy!
"The problem with the #4 cylinder is not the blinker fluid."
There are many other things that I could think of that are NOT the problem. This is too easy!
Rent me! per hour
Joined: 03-22-07
Posts: 24,161
Likes: 20
From: Still fixing others mistakes.
::looks at logs, and egt's::
mmmmm newp. at least from what i can see on my data i have from simple feedback devices.
if there was an issue, mine would have blown the **** up a long time ago. me and my 27psi of awesomeness.
Total fuel required is what's important. If you're injectors are large enough to supply fuel to the engine, you don't need larger ones. The HP that injectors will support is based on the pressure they are getting and the pressure they are spraying into.
At some point the fuel pump can't keep up with fuel demand. This normally doesn't happen with 4 60# injectors but could with larger if you were commanding a really high duty cycle.
The total volume the pump will put out is based on it's pressure. The higher the pressure, the less volume is available. So when you max a pump, pressure will drop. See the following chart from our FP rewire page:
http://www.zzperformance.com/cobalt_...1013&catid=144
Notice how at 100 psi the pump will only put out ~60 liters per minute but at 30psi the pump flows over 200lpm? (numbers do not mean anything other than comparison).
But when the pressure drops, the entire system is lower. Lines, rail, etc. Every injector will still flow the same as the others, just less.
