Focus Fanatics Forum banner

1 - 20 of 44 Posts

·
Registered
Joined
·
363 Posts
Discussion Starter #1
for those of you who know what a fuel surge system is then here is my questions

can i not use the existing fuel line going from the tank to go to the fuel rail? snf use the evap line for the return off the fuelrail? doing this could cut some cost to keep everything in the trunk area and using the existing lines would they be too small? im just looking into it i saw 700hp posts on his but i do not have enough room under the hood like where he put his but i could do a battery relocate do you think this could work or would the fuel line be too small
 

·
FF Affiliate
Joined
·
31,096 Posts
You can use the stock line all the way up to where it connects to the hose that goes to the fuel rail , you have to go from there to the surge tank then from the surge tank through your secondary pump and to the fuel rail , then from the end of the fuel rail you can use the evap line back to the tank but you will need to do some modifying at the tank to get the fuel back into the tank

Tom
 

·
FF Affiliate
Joined
·
31,096 Posts
I would stay far away from that RobbMc surge tank , there is no way that cannister with a pump inside taking up 30% of the 5 x 8 size that it will support a 500HP engine unless your stock fuel pump can support about 400HP already which we know the Focus cannot , you need roughly 2L to support a 1/4 mile pass making 500hp with the stock Focus fuel pump

It isnt going to do much good to add a surge tank that gets sucked dry half way down the track

Tom
 

·
Registered
Joined
·
1,269 Posts
I would stay far away from that RobbMc surge tank , there is no way that cannister with a pump inside taking up 30% of the 5 x 8 size that it will support a 500HP engine unless your stock fuel pump can support about 400HP already which we know the Focus cannot , you need roughly 2L to support a 1/4 mile pass making 500hp with the stock Focus fuel pump

It isnt going to do much good to add a surge tank that gets sucked dry half way down the track

Tom
The math is simple... your response is hillarious. Try again!
 

·
FF Affiliate
Joined
·
31,096 Posts
Please show us the math , which part am I off about ? you dont have to be an azz about this , what I posted was from many years of building 300-500+ HP foci and knowing there demands on the stock fuel system

The stock fuel system can only get you to on average 300-320HP and thats pushing it on a STD Focus , to add your tank which doing the "math " will hold about 1 to 1.25 quarts of fuel because of the fuel pump in it , with only another 150 hp ( 450hp ) fuel demand on the stock fuel pump 1.25 quarts of fuel will last about 8-10 seconds WOT , you cannot take into account that the return fuel system from the fuel rail going back into your surge tank because thats already fuel pumped by the stock pump and already calculated , so with my " math " you will starve your surge tank at about 12-13 sec in a 1/4 mile pass at best on a 500hp Focus because the stock pump wont be able to keep the small surge tank full enough and all this depends on how close to the bottom the fuel pump is in your surge tank , add a boost-a-pump and your will get more supply to the surge tank
Use a 2L or 3L like I built and have a external fuel pump pulling from the bottom of the surge tank and you will have plenty of fuel

Tom
 

·
Registered
Joined
·
1,269 Posts
Please show us the math , which part am I off about ? you dont have to be an azz about this , what I posted was from many years of building 300-500+ HP foci and knowing there demands on the stock fuel system

The stock fuel system can only get you to on average 300-320HP and thats pushing it on a STD Focus , to add your tank which doing the "math " will hold about 1 to 1.25 quarts of fuel because of the fuel pump in it , with only another 150 hp ( 450hp ) fuel demand on the stock fuel pump 1.25 quarts of fuel will last about 8-10 seconds WOT , you cannot take into account that the return fuel system from the fuel rail going back into your surge tank because thats already fuel pumped by the stock pump and already calculated , so with my " math " you will starve your surge tank at about 12-13 sec in a 1/4 mile pass at best on a 500hp Focus because the stock pump wont be able to keep the small surge tank full enough and all this depends on how close to the bottom the fuel pump is in your surge tank , add a boost-a-pump and your will get more supply to the surge tank
Use a 2L or 3L like I built and have a external fuel pump pulling from the bottom of the surge tank and you will have plenty of fuel

Tom
It's not drama, just math.

How much fuel does a 550 hp motor need per second?
This unit holds just under .5 gallons.
I'd say that alone is easily enough for 30 seconds.
 

·
FF Affiliate
Joined
·
31,096 Posts
Your the one that said my math is wrong , but your asking me so here you go

a 5x5x8 = 200 Cubic Inches , 1 gallon of water is 231 Cubic Inches , so even if the surge tank you posted about was square and not round it wouldnt even hold 8/10 of a gallon then put a good EFI fuel pump in there with hose and your down to about .6 of a gallon and thats still if your surge tank was square which its round and I dont feel like doing the math for round

Then you ask ME how much does a 500HP 2.0 Zetec engine use per second which is a ridiculous question , is that 1 sec at 3500 , 4500 , 5500 , 6500 , 7500 which one ?

Just for fun lets take 6500 RPM, One 60lb p/hr Inj at 6500 at 92% duty cycle will do 1 lb p/sec x4 inj is 4lb ps , sense fuel weights 7lb pg thats just over .5 of a gallon in 1 sec +/-, How is your surge tank looking now

Im made my statement judging off what I have done in the past , you said what I said was hilarious and that I needed to do the math

Im curious to see your math now ? I have been wrong before

Tom
 

·
Premium Member
Joined
·
44,595 Posts
I'm coming up with about a quart for 30 sec., so maybe a couple quarts (not all useable) would be adequate.

60 lb/hr x 92% / 3600 sec/hr x 4 injectors x 30 sec / 7 ppg = .2628 gal.

Check those assumptions anyone.
 

·
Registered
Joined
·
1,269 Posts
Your the one that said my math is wrong , but your asking me so here you go

a 5x5x8 = 200 Cubic Inches , 1 gallon of water is 231 Cubic Inches , so even if the surge tank you posted about was square and not round it wouldnt even hold 8/10 of a gallon then put a good EFI fuel pump in there with hose and your down to about .6 of a gallon and thats still if your surge tank was square which its round and I dont feel like doing the math for round

Then you ask ME how much does a 500HP 2.0 Zetec engine use per second which is a ridiculous question , is that 1 sec at 3500 , 4500 , 5500 , 6500 , 7500 which one ?

Just for fun lets take 6500 RPM, One 60lb p/hr Inj at 6500 at 92% duty cycle will do 1 lb p/sec x4 inj is 4lb ps , sense fuel weights 7lb pg thats just over .5 of a gallon in 1 sec +/-, How is your surge tank looking now

Im made my statement judging off what I have done in the past , you said what I said was hilarious and that I needed to do the math

Im curious to see your math now ? I have been wrong before

Tom

Fuel for 550 hp?
.5 gallon a second is your answer, that's pretty funny.

Tom, you were the one to baselessly slammed this product. When I ask you for the bases of your comment... you post information that illuminates your lack of understanding of the topic.
This is a well engineered product, made in USA, at a great price.
No, I am not associated with it in anyway.
 

·
FF Affiliate
Joined
·
31,096 Posts
I didnt slam the product , I said it wasnt big enough to do the job , so where is your math ? showing I am wrong

Sailor you may be correct just over 1 quart a sec at 6500 , his surge tank is still to small to do the job , it will suck the tank dry

Tom
 

·
Registered
Joined
·
1,269 Posts
I'm coming up with about a quart for 30 sec., so maybe a couple quarts (not all useable) would be adequate.

60 lb/hr x 92% / 3600 sec/hr x 4 injectors x 30 sec / 7 ppg = .2628 gal.

Check those assumptions anyone.
Looks good! I doubt a 550 hp focus would need more that 13 seconds for a 1/4mile blast. And that's with only the fuel it holds. More than adequate.
 

·
FF Affiliate
Joined
·
31,096 Posts
1 quart in 1 sec of fuel use and your tank holds less then 3 quarts and your saying a 12 sec pass it will be ok ? , where is your math ?

The stock fuel pump wont hold to make half a pass on the dyno in 1 gear so how is it going to keep a surge tank full that holds less then 3 quarts when an engine uses 1 quart in 1 second , again where is your math

Tom
 

·
Registered
Joined
·
1,269 Posts
I didnt slam the product , I said it wasnt big enough to do the job , so where is your math ? showing I am wrong

Sailor you may be correct just over 1 quart a sec at 6500 , his surge tank is still to small to do the job , it will suck the tank dry

Tom
Seriously? 1 quart a sec??
You can't do math or read. Hilarious.
 

·
Trump 2016
Joined
·
12,990 Posts
Your wrong ^^^^ Tom only takes 27 times to get a tune right on a stock car. Now that is bad math. Hilarious.
 

·
Registered
Joined
·
17,173 Posts
Not touching this one other than to say you always want far more fuel availability than you actually use in high-perf work..............you always shoot to oversupply there. Not doing so can make you look pretty stupid.
 

·
Registered
Joined
·
1,269 Posts
No drama just math, lets keep it on topic.

The real dynamics of the situation is likened to a bucket (with a hole) under a faucet.

For the sake of example, if the faucet is filling the bucket at 6 gal/sec and the full bucket is leaking at 8 gal/sec, how long will there be water in the bucket? But lets not even go there. That adds a level of complexity that we are not ready for. By the way the faucet filling the bucket (stock fuel pump) provides your ample margin of safety (overkill).

Think about it .....with this tank filled your stock pump can quit on the line, and you can still do a 1/4 mile pass with fuel to spare!

The simple question is can 1/2 gallon of fuel, supply a 550 HP car over the course of 1/4 mile? See you don't have to compute the volume of the tank, it's slightly less than 1/2 gallon and is now a given.

Tom's response is obviously flawed. Doesn't even pass the smell test. If a 550 hp motor needs .5 gallons a second can you imagine what size fuel tank a Hellcat with 707 hp would need to hold? 14 gallons would only last 28 seconds WOT at just 550 HP. Doesn't sound right now does it?

See if you can find the error in his computation.


Just for fun lets take 6500 RPM, One 60lb p/hr Inj at 6500 at 92% duty cycle will do 1 lb p/sec x4 inj is 4lb ps , sense fuel weights 7lb pg thats just over .5 of a gallon in 1 sec +/-, How is your surge tank looking now

Im made my statement judging off what I have done in the past , you said what I said was hilarious and that I needed to do the math

Im curious to see your math now ? I have been wrong before

Tom
 

·
FF Affiliate
Joined
·
31,096 Posts
In stead of taking pot shots at me why doesnt some one thats saying im wrong actually do the math and maybe we can all learn something including my self vs people like pasta posting silly crap that has nothing to do with this and 1/10 of what actually happened only to take a shot at me like he is 2 years old

Again show me the math ? why is that so hard to do what are we 2 years old

Tom
 

·
Registered
Joined
·
17,173 Posts
'...with this tank filled your stock pump can quit on the line, and you can still do a 1/4 mile pass with fuel to spare!'

Somebody seriously lost there, and 100% incorrect. Fuel is liquid and non-compressible and pressure as a result will drop like a rock as there is no big storage of pressure when compressing a solid, unlike a gas. The pressure will be too low to supply properly to the injectors LONG before the fuel is all expended as it will spread out to the gaseous space left by only a small amount of liquid fuel used there. By no means is the pressure drop linear or gradual, more like an ultra steep parabolic ramp. The more airspace there the faster it will drop.

Off topic? Think about brakes, you can raise brake pressure to a thousand psi on the fluid with only 1/4" of pedal movement on the M/C piston, back off pedal and only 1/4" and back to zero pressure. Think that's enough to empty the system?, look how much displaces ( a LOT more than the 1/4"!) with only one full length brake pedal pump while bleeding before the system has zero pressure................................not NEARLY all of it.

No math needed there.............and more comes into it than just the math.
 

·
Registered
Joined
·
1,269 Posts
In stead of taking pot shots at me why doesnt some one thats saying im wrong actually do the math and maybe we can all learn something including my self vs people like pasta posting silly crap that has nothing to do with this and 1/10 of what actually happened only to take a shot at me like he is 2 years old

Again show me the math ? why is that so hard to do what are we 2 years old

Tom
I'm not taking pot shots, not like your "AZZ" or "2 year old" comments.

You said the product couldn't hold enough fuel... but can't back it up. I think the burden of prove is yours. You have tried a couple times and your answers have ranged from ".5 gallon a second" to "just over a quart a sec".

Sailor posted his evaluation and I said it looked good. This should have given you all the clues needed to fix yours.

I posted yours was flawed and challenged everyone to look for the error. I thought if I could get 20 members working on a math problem (knowing Sailor's answer) it would be great and illustrate the need for kids to take an interest in the science. I was hopeful this morning the thread would be full of correct responses, but that didn't happen.

Soo.....

If you look at Sailor's compared to yours what is different?

Clue #1 Why did Sailor divide by 3600?

If you need to "PM a Friend" go ahead and PM Sailor.
 
1 - 20 of 44 Posts
Top