Fuel, How Much 60-1 plus 75 direct wetshot

[BlackHawkAWD91]

Ok, heres the deal. I got a 60-1 uninstalled and zex wet direct port also not installed. Smallest shot 75 in this kit. I would also like the option to later use a larger shot.

Question is, fuel requirements. I have a walbro intank 255, stock fuel lines, buschur bolt on fuel rail FPR. I have 780cc injectors that should be fine for 30psi area on 60-1. When I add the shot, will the 255 not be enough? I have read about guys using inline pumps along with the intank. What are the thoughts on that idea. Do I need to replace my stock fuel lines?

Thanks, Rob

 

[1990EclipseGSX]

I am in a similar position as you, and I don't feel a single 255 will keep up with the amount of fuel I need. I am running a FP3052 and have a single fogger NX kit. I want to run 25-30 PSI with a 75 shot. My intake manifold has direct port bungs, and I would like to upgrade to a direct port setup eventually.

I have heard you can mount the Bosch -044 pump in tank in 1g's with minor modifications.

"Capable of providing 300 LPH free flow and 200 LPH at 5 bar (or 72.5 psi) for up to 685 BHP. In comparison, the Walbro GSS341 255 "high pressure" fuel pump can support 390 BHP Note: Values calculated at 12V, 3 bar (43.5 psi) base fuel pressure, 2 bar (29 psi) boost pressure, 1:1 fuel pressure regulator ratio."
http://www.jayracing.com/products.htm

I think I am going to go with one of these with a -8AN line from the tank, if I can find some more info on installing the pump in tank.

I have read of people running dual Walbro's in-tank in parallel, and in series with one in line also. Both setups seem to work well.

Regardless of what you go with, you will probably want to upgrade the fuel lines to at least -6AN. 30psi with a 100 shot is going to require a lot of fuel.

 

[herostar]

One thing to mention is that the walbro 190 pump has supported over 400whp, and who knows how many people are running 500-600hp on walbro 255 pumps....


How much horsepower are you realistically thinking you'll be making?

 

[Slippi84]

I have a walbro 255hp and I'm gonna get the zex inline fuel pump which only increase pressure with boost to keep it up to where it should be. I only plan on a 40-50shot with my gt14 though

 

[hairybeanbag]

One thing to mention is that the walbro 190 pump has supported over 400whp, and who knows how many people are running 500-600hp on walbro 255 pumps....


How much horsepower are you realistically thinking you'll be making?

it's not about HP, he's asking if a 255 can still manage 35lb of fuel pressure with 720's possably at 80% duty cycle and a .28 fuel jet.

I guess the only way to tell is to monitor your Fuel pressure with a electric gauge in your car from the rail, I run a 60-1 with a 50 shot and have not had any problems with fuel pressure yet, but we all know ever car is diffrent.

 

[Kevin Jewer]

I realize this is an old thread, but I might as well ramble on anyway. The injectors are cutting it close. Even if the 780s flow 780 (the x80 injectors tend to end up flowing more like x50 injectors), with a base pressure of 43 psi, fuel specific gravity of .724 (race gas example), and target AFR of 12:1, they support around 58-59 lbs/min of airflow. Not enough for the 60-1 on it's own, nevermind the nitrous.

a 255LP at 30 psi with the same variables above will support 57 lbs/min, again not enough. The HP is good for 68 lbs/min which is enough for the turbo, but even with a 50 shot I don't feel there is enough headroom to be comforable with it. The Supra pump in contrast supports 76 lbs/min under the same conditions.

Note that in these example it is assumed that the turbo will be maxed out. That is done purposely, to cover the scenario where boost gets away from you and the turbo goes to max aiflow. Also note that a 2 liter at 30 psi will have a hard time maxing out a 60-1, but a 2.3 will do it at around 25 psi (which makes the fuel pump a little "bigger").

 

[Slippi84]

Most people say that a walbro 255hpl is good for about 500whp. WHat are you spray guys doing for extra security when you push it to the limit cause I have a turbo that realistically will do 60lbs/min and spray and I only need about 500whp ball park but I have a feeling 500 with just boost is diffrent than like 450 and 50 of spray.

 

[Kevin Jewer]

It should be roughly the same as far as fuel requirements, provided that your AFR remains the same. I really try to avoid looking at it in terms of power output, since there are so many variables regarding how much power you make from a given amount of fuel it's ridiculous. Since I do all fuel system sizing in terms of compressor flow in lbs/min, I attribute 1 more lb/min capacity for each 10 HP added by the nitrous. If AFR remains the same, this should be more than accurate enough for our needs.

To apply that to your situation, with a 2 liter, I would not trust a 255hp to be enough. With a stroker, you'll hit that turbo's max capacity of 65 lbs/min at 29-30 psi on most setups. A LP will not be enough just for that alone. The HP is JUST enough with capacity for 67 lbs/min at 73 psi, fuel SG of .724, and target AFR of 12:1. Since a 2 liter will require more boost, the pump will get smaller. The turbo plus the nitrous again requires more than the HP can provide. Now, on a 2 liter you are likely to end up with more like 55 lbs/min at 30 psi, which will leave enough room for the nitrous, but if boost gets away from you it will get ugly (some quick math says you'll end up around 14:1). So wether or not a 255 HP is enough depends on your idea of "enough," and your risk tolerance.

 

[Slippi84]

It should be roughly the same as far as fuel requirements, provided that your AFR remains the same. I really try to avoid looking at it in terms of power output, since there are so many variables regarding how much power you make from a given amount of fuel it's ridiculous. Since I do all fuel system sizing in terms of compressor flow in lbs/min, I attribute 1 more lb/min capacity for each 10 HP added by the nitrous. If AFR remains the same, this should be more than accurate enough for our needs.

To apply that to your situation, with a 2 liter, I would not trust a 255hp to be enough. With a stroker, you'll hit that turbo's max capacity of 65 lbs/min at 29-30 psi on most setups. A LP will not be enough just for that alone. The HP is JUST enough with capacity for 67 lbs/min at 73 psi, fuel SG of .724, and target AFR of 12:1. Since a 2 liter will require more boost, the pump will get smaller. The turbo plus the nitrous again requires more than the HP can provide. Now, on a 2 liter you are likely to end up with more like 55 lbs/min at 30 psi, which will leave enough room for the nitrous, but if boost gets away from you it will get ugly (some quick math says you'll end up around 14:1). So wether or not a 255 HP is enough depends on your idea of "enough," and your risk tolerance.

I got ya. The thing is i'm playing with fire right now cause this is all on stock block with just MLS hg and arp studs . I know I'm crazy but I figure I'll push it a little bit at a time and by the time I get toward the end of the blocks life I"ll have enough saved up for a build. BUt thats why I keep using 500whp cause that's the ballpark estimate of when a stock 6 bolt goes POP! I ave dsmlink so I should be able to keep the afr where I need it to avoid blowing the engine before I have another ready to go.

 

[Kevin Jewer]

Sounds like a plan. DSMlink makes running 500 whp on a stock 6 bolt relatively safe. The fact that it turns off the nitrous when you get more than some predetermined amount of knock has already saved my motor.

 

[Slippi84]

Yeah that's what I was thinkin. I love the link. I think it will take me into the high tens with a setup that only took a year to piece together.

Edit: anyway back on topic any othe reasons to pick one over the other when going for 50whp abouts?

 

[Slippi84]

http://cgi.ebay.com/ebaymotors/WALB...ryZ33555QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

WHat you guys think of this for fuel security. For that price it's worth it just to not have to worry about ever going lean but I read on another thread that one pump can starve the other and cause not enough pressure or something like that. This sound like a legit argument or just bs??

 

[Kevin Jewer]

Some poeple have had good succes with another inline pump, while others have reported less than stellar results (another 50hp capacity). I tend to aggree with the latter, in theory anyway, since both pumps are the same size. Parallel installation will double flow at the same pressure, but series installation will keep flow the same but add pressure capacity. Since the over pressure relief valves still open at the same pressure I don't really see any real advantage here. Some people have tried the pumps in parallel and also found that they don't behave as you would expect, and all kinds of theories about pulse cancelation etc were tossed around. When I was going to try the dual pump setup I planned to run them in parallel and run seperate feed lines to the motor to provide more surge volume and pulse dampening, perhaps dual feeds at the rail with center outlet. But alas, I never got around to trying it.

 

[Slippi84]

I don't really make discisions based on theory though even thought they make sense on paper they don't always hold true in reality. Lets just make it easy people makin over 500whp with spray what is your fuel setup?

 

[XakEp]

I don't really make discisions based on theory though even thought they make sense on paper they don't always hold true in reality. Lets just make it easy people makin over 500whp with spray what is your fuel setup?

A1000 pump, 950s and FP at 45 psi. I have been able to flow a reliable 53 lbs/min on 91 octane and zero knock, and I have running nitrous (50 shot) on top of that.

 

[Kevin Jewer]

For what it's worth, the A1000 at 73 psi will support 90 lbs/min worth of airflow. With a 75 shot, that's going to be about 80 lbs/min. I'd say the aeromotive is sufficient for most poeple.

 

[XakEp]

For what it's worth, the A1000 at 73 psi will support 90 lbs/min worth of airflow. With a 75 shot, that's going to be about 80 lbs/min. I'd say the aeromotive is sufficient for most poeple.

My only real problem with it is its loud as hell. Make sure you put it somewhere that will help deaden the sound.

 

[NosLaser]

With a wet kit the nitrous is going to supply it's own fuel, so it's no longer about volume at this point but pressure. If you start to experience pressure drop, you'll know you'll need more pump and/or an inline pump to keep pressure up. Don't worry so much about overanalyzing duty cycles, and BSFC and all that jazz. Nitrous is basic, and the way it works is basic.

Regards,

 

[Slippi84]

NOSlaser do you really use a 150 dry shot on your laser .

 

[NosLaser]

NOSlaser do you really use a 150 dry shot on your laser .

What am I 9 feet tall too?

I used an 80 shot dry on the Laser. In retrospect a wet kit would have been a better choice, but it's what I had at the time, it worked, so I used it.

Regards,

 

[Slippi84]

What am I 9 feet tall too?

I used an 80 shot dry on the Laser. In retrospect a wet kit would have been a better choice, but it's what I had at the time, it worked, so I used it.

Regards,

"NOS systems 150 shot dry kit"


That's what it says in your profile

 

[NosLaser]

"NOS systems 150 shot dry kit"


That's what it says in your profile

Is that the only thing you read?

Vehicle

1987 Mustang LX Notch

Bolt-On Mods

K&N air filter, Ford Motorsport 1 5/8" shortie headers, H-pipe, 2 chamber flowmasters, Walbro 255lph HP fuel pump, Steeda underdrive pullies, adjustable FPR, short belt, NOS systems 150 shot dry kit

Suspension Mods

Pony wheels w/ 245/50/16 Steeda Sport Springs, HD Upper rear control arms, HD sway bar end links, Urethane SB bushings, Urethane rack bushings, Steeda Aluminum CC plates, G Trac Bar, Strut tower brace, tubular sub frame connectors, urethane tranny mount

I'll give you the benefit of the doubt and take for granted that you didn't know that Ford Motorsport shorty headers weren't for a DSM, but under vehicle it says '1987 Mustang LX Notch.'

I actually sold that car and have a '96 GT now.

Regards,

 

[Kevin Jewer]

With a wet kit the nitrous is going to supply it's own fuel, so it's no longer about volume at this point but pressure. If you start to experience pressure drop, you'll know you'll need more pump and/or an inline pump to keep pressure up. Don't worry so much about overanalyzing duty cycles, and BSFC and all that jazz. Nitrous is basic, and the way it works is basic.

Regards,

Pressure is a result of volume flow vs restriction, so this statement seems odd to me. I know what you are trying to say, but I think this is a misleading way of expressing it. With nitrous, you get more power without raising fuel pressure, so more volume is required at that pressure. Pressure may drop due to lack of volume flow. Perhaps it's all in the wording and I'm just being an anal touchole as usual.

 

[NosLaser]

Pressure is a result of volume flow vs restriction, so this statement seems odd to me. I know what you are trying to say, but I think this is a misleading way of expressing it. With nitrous, you get more power without raising fuel pressure, so more volume is required at that pressure. Pressure may drop due to lack of volume flow. Perhaps it's all in the wording and I'm just being an anal touchole as usual.

If fuel went straight from the tank into the combustion chamber like a hose, then yes, you'd have to worry about it more. But it doesn't. It stops at the injectors and there is plenty of fuel that isn't being used that finds it's way back into the tank. A wet kit supplies it's own fuel independant of the injectors, so as long as the pump supplies enough pressure to keep the motor happy with the amount of fuel "lost" to the nitrous fuel line, then you don't have to worry about it. A wet kit is pretty self sufficient. If you get pressure drop from adding a wet kit, chances are your pump was pretty near maxed out already on 'motor.'

Regards,

 

[Slippi84]

that's the whole point of this thread is to figure out at what point your max out your fuel setup? A wet kit isn't self suffecicent it piggybacks off your cars exsisting fuel system. If you put a second intank pump that went straight to the nitrous kit then yeah it would be self sistaining