Supercharger install
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I'm cracking up myself, I just have a lot of more obvious questions... Where exactly is the data that indicates that the supra fuel pump is REQUIRED for low boosted 80? What fuel injectors are you running? What injectors are stock? How does the fuel pump resistor circuit work exactly?
I've installed a lot of big pumps, I just also use a pretty accurate worksheet that gives me an indication what is necessary. I don't believe big is better or always necessary. Does the addition of an adjustable fuel pressure regulator dictate another fuel pump?
I see a lot of folks using the supra fuel pump. I'm looking for the math on the 80 airflow and fuel demand. I'm more hesitant to do it just because, and more apt to do it because there's a demonstrated need.
ST
List is $3900 on the Kazuma. However, if you use your mud discount with cruiserdan, its a shade less than $3000. Installation, figure shop rate of 8 from someone who has done it before, or free if you do it yourself.
Pulling the trailor was a breeze with the supercharger. I didn't get pulled down to 35 MPH hour anymore, haven't tested it pulling a trailer over the mountain passes yet.
On the supra pump. I ran for a week without it and noticed the difference after installed. It seemed to me that the surge of power would last longer when flooring it going from 0 to merging on the highway. I have nothing other than that to offer. Just driving the exact same route for a week and then driving with the larger pump.
I do not have the additional Fuel Regulator. I may add that, just need to reserach it somemore. Don't plan on adding any more injectors.
I was REAL happy with the supercharger. Now that I have gone to 35's, I have lost some of the power and will re-gear over the xmas break.
I do not have the additional Fuel Regulator. I may add that, just need to reserach it somemore. Don't plan on adding any more injectors.
I was REAL happy with the supercharger. Now that I have gone to 35's, I have lost some of the power and will re-gear over the xmas break.
I don't thing more injectors is necessary, nor do I the fuel pump... Yet. If the line is the same size, the only difference is pressure, which is then taken care of by the FPR. If the FPR is stock, it should make no difference in terms of power. Where a larger pump comes into play is when the FPR is tweeked, or the rail runs out of fuel. I suspect from Christos post that if the Stocker can support two extra injectors, the rail isn't out of fuel.
Again, I'm not knocking anyone that's done it. I have a lot of experience in fuel systems, and I look for the *need* and numbers behind the mod. Normally, when I see a bigger pump, I see bigger lines (the pump can then support the increased flow). When I see the same size line, I just question whether the pump is doing what everyone thinks. If I run the numbers at 17psi boost pressure on the supra 3.0 liter motor, that's about what the I6 stock 4.5L pump needs to flow from increased displacement.
If the stock pump makes the grade, spend the money on the FPR. In your case Romer, IMO, you did it backwards. The stock fuel pressure will cause the injectors to run lean. Bell Engineering and others make Rising Rate Fuel Pressure Regulators that piggy back the existing for forced induction applications.
ST
Never said anything about "required" or "low boosted". Those appear to be constraints to the argument you've instilled. For me, I'll keep adjusting my boost and my fuel/air demands - and for that matter, pretty much everything on the truck from suspension, tires, electricals, etc. - until I get tired of it or die. I do; however, expect one or both of my children to continue the experiments...
Stock fuel injectors serviced by RC Engineering.
Stock injectors flow approx 310 cc's.
I'm not certain about this. I believe the voltage regulator output to the pump varies and the output of the pump varies according to the voltage it receives. In this case, the Supra pump puts out a larger volume and at a higher pressure at the same voltage compared to the Land Cruiser pump.
For who? You are good at asking blanket, primarily hypothetical, questions as if there is one explicit answer. Implicit in all of this is that by and large most people on this list will have a "special case" due to the odd combination of "add ons". For me, yes. I want to maintain a higher fuel delivery rate and pressure than what the stock pump I had - the one that came with the truck. I have no idea what the performance of a new stock pump would have done. But given that it was the same price for either pump and knowing what I wanted to do with the truck, I chose the Supra pump and am happy with it. I also purchased the BEGi 2025 rising rate fpr and have been happy with it as well. These along with a good electronic fuel pressure gauge allow me to monitor what's going on at the fuel rail to my satisfaction.
Do or don't do, Daniel-san. Makes no dif to me, just don't come off so authoritative. There is plenty of demonstrative evidence, experiential learning and solid manufacturer's specifications that show the two pumps flow at different rates and at different pressures. There is the same type of evidence that you can create fuel delivery issues with forced induction on the 1FZ-FE when relying solely on the stock fuel delivery components. How you solve that is up to you. Meanwhile I'm sure I'll see you in my rearview
Stock fuel injectors serviced by RC Engineering.
Stock injectors flow approx 310 cc's.
I'm not certain about this. I believe the voltage regulator output to the pump varies and the output of the pump varies according to the voltage it receives. In this case, the Supra pump puts out a larger volume and at a higher pressure at the same voltage compared to the Land Cruiser pump.
For who? You are good at asking blanket, primarily hypothetical, questions as if there is one explicit answer. Implicit in all of this is that by and large most people on this list will have a "special case" due to the odd combination of "add ons". For me, yes. I want to maintain a higher fuel delivery rate and pressure than what the stock pump I had - the one that came with the truck. I have no idea what the performance of a new stock pump would have done. But given that it was the same price for either pump and knowing what I wanted to do with the truck, I chose the Supra pump and am happy with it. I also purchased the BEGi 2025 rising rate fpr and have been happy with it as well. These along with a good electronic fuel pressure gauge allow me to monitor what's going on at the fuel rail to my satisfaction.
Do or don't do, Daniel-san. Makes no dif to me, just don't come off so authoritative. There is plenty of demonstrative evidence, experiential learning and solid manufacturer's specifications that show the two pumps flow at different rates and at different pressures. There is the same type of evidence that you can create fuel delivery issues with forced induction on the 1FZ-FE when relying solely on the stock fuel delivery components. How you solve that is up to you. Meanwhile I'm sure I'll see you in my rearview
Scott, the flaw to your argument is that you assume the lines are designed to handle the max output of the stock fuel pump and can't handle any more, if that were true, have another FPR wouldn't help either. I don't believe I did it backwards and I did notice a difference. Now if you have some data specifically on the fuel lines and fuel pumps, fine. Don't much care about all your experiance, only data.
A good analogy is plumbing. most homes use 3/8 or 1/2 inch copper. The water pressure into those standard lines varies by location. Increased pressure at the source (pump) provides increased pressure at the faucet (Injector).
A good analogy is plumbing. most homes use 3/8 or 1/2 inch copper. The water pressure into those standard lines varies by location. Increased pressure at the source (pump) provides increased pressure at the faucet (Injector).
I understand tweeking. I also understand how fuel systems work. I'm having more confusion regarding the supra pump. It *can* flow xxx gal/hr. Installed it may not get close. Isn't it the fuel pressure regulator that dictates pressure? Isn't it the engine that dictates fuel demand?
That sounds really high. Is this at the stock 43psi pressure?
But, if you use a stock FPR, it's the same volume, since you haven't increased line size or pressure. I see the head room on the bigger pump being higher (IOW, it will have a higher sustained operating pressure before cavitation) and suspect that's where it LPH gain is actually realized. I agree with your assessment of the voltage regulator, which means exactly that the pump output is dumbed down for less than some parameter. From the FSM, it appears there is a straight thru 12v feed as well. Trying to figure out if just eliminating the resistor will result in more fuel. Sure would appear that way.
Got no problem with that. I just question whether that pump is really doing anything 'more'. It has more rate potential, but unless the pressure rises significantly, or the line size is changed, the volume of flow isn't changed. I believe that fuel line flow is a cross sectional area at a given pressure. If it's more pressure for a given voltage that's one thing, but all that means is that the FPR is working harder.
I'm only trying to understand the fueling needs of the truck vs the pump output.
Do or don't do, Daniel-san. Makes no dif to me, just don't come off so authoritative. There is plenty of demonstrative evidence, experiential learning and solid manufacturer's specifications that show the two pumps flow at different rates and at different pressures. There is the same type of evidence that you can create fuel delivery issues with forced induction on the 1FZ-FE when relying solely on the stock fuel delivery components. How you solve that is up to you. Meanwhile I'm sure I'll see you in my rearview
I have no desire to race in my truck, I have 26psi quattros for that! I am only after the fuel issue. 29lb injectors seem really big to me, like almost double the engine demand at 5000rpm. If that is indeed the case, then the stock injectors should be more than fine. I also believe that if the stock pump is being dumbed down by voltage (in the audis we put relays at the fuel pump and run 10guage wire to them to maximize the continuous battery voltage), then the capacity of the stock fuel system has a bunch of head room in it.
Buying a new pump? Hey fine get the bigger one, it can't hurt. My quiery comes from the automatic upgrade logic. I'm not trying to inflame this, only understand a varying voltage fuel pump system with stock injector size that seems beyond logical.
ST
sleeoffroad
Supporting Vendor
> That sounds really high. Is this at the stock 43psi pressure?
Yes, as tested by RC Engineering on their reports. Around 305/310
Yes, as tested by RC Engineering on their reports. Around 305/310
This isn't how I understand fuel systems work. For given size line big pumps are rated at a higher pressure before cavitation.
I assume that the stock fuel pump can handle a significantly higher volume of fuel at a higher pressure without cavitation of the pump or the rail. The reason I think this, is that there is a resistor for fuel pump voltage, just up the voltage = more available pressure.
Your water example is not a good analogy. Fuel is a balanced and regulated feed system. You have system pressure, pressure in the line at a given 11volts of 50psi (supra) or 43psi (stock 80) thru a stock 5/16ths line. The stock FPR uses vacuum to determine that what is in the rail available to each injector is 43psi. Any extra fuel pressure = flow will return to the tank. The bigger supra pump then will just have more fuel returned to the tank.
Up to cavitation of the pump or rail, this is how fuel systems work. What the rising rate fuel pressure regulator does, is allow more fuel pressure into the rail based on boost, whereas the stocker doesn't know boost from adam.
What makes little sense to me is your claim of difference. The only way that can be Romer, is if there is backpressure on the fuel return line causing more pressure in the rail than the FPR allows. I might disagree that is a gain, or a good thing.
ST
Only to a point. As with any pump, it's ability to create pressure is governed by it's ability flow greater than the demand.
I don't know the specifics on our system, haven't got there yet. But what ever pump is installed it needs to flow fuel at a greater rate than consumption to maintain the pressure in the fuel rail. Having a rising rate regulator would seem to almost dictate that the pump be swapped out in order to be able to create that higher pressure in the rail during the large consumption periods.
At this point I think that removing the resistor is more of a band-aid if you need that greater flow. I'd sooner go with the Supra pump and allow it to run on the lower voltage during low consumption periods for greater life.
Right now this is my mind set and will hopefully prove/disprove it this summer.
Now your talking specifics, thats good. So your saying the FPR will prevent the additional fuel. But I believe my point about not having to change the size of the fuel line you are now agreeing with. My analogy was targeted at your comment on the fuel line sizing being a limiting factor. If you re-read my post you will see that I said if the line size mattered then changing to a FPR wouldn't make a difference either.
So Scott admit it, line size isn't a limiting factor.
I think you are trying to make the following point. The Supra Fuel pump can out put more fuel, the lines can handle that additional fuel pressure. However, the stock Fuel Regulator will only let so much fuel into the injectors no matter how much it receives at the input.
I am just trying to ensure we are clear on the bottle neck and the limiting factors. That makes sense. The only reason I can see that I felt any difference is if the stock pump I had was not able to keep up with the fuel regulator at max output.
Do you know for sure the stock regulators max output is the same as the stock fuel pump? Not exeperiance, but data for these parts.
So Scott admit it, line size isn't a limiting factor.
I think you are trying to make the following point. The Supra Fuel pump can out put more fuel, the lines can handle that additional fuel pressure. However, the stock Fuel Regulator will only let so much fuel into the injectors no matter how much it receives at the input.
I am just trying to ensure we are clear on the bottle neck and the limiting factors. That makes sense. The only reason I can see that I felt any difference is if the stock pump I had was not able to keep up with the fuel regulator at max output.
Do you know for sure the stock regulators max output is the same as the stock fuel pump? Not exeperiance, but data for these parts.
Not necessarily a given. You only need the flow rate of the pump and the size of the line. The rest is math. The reason IMO, the resistor is there, is to not overload the fuel return line (read: create backpressure on the fuel pressure regulator).
I'm very familiar with fuel pump operation. Lower voltage at the pump doesn't mean longer life, that's not a function of longer life. In tank pumps have a longer life if you don't allow the fuel to get down below the level of the pump. IOW, fuel pump life is increased by more cooling = keep your tank more full.
ST
Well I've measured the fuel pressure directly after the stock regulator under load (and boost - but that's another thing...) with the Supra pump and the stock regulator limits fuel pressure at that point to ~43 psi (this is a new regulator from Dan). The problem I encountered was that as you went from vacuum to boost there is a definite drop in fuel pressure as you go through the "zero" point (~= to atmospheric). Further, this jibed consistently with what the BEGi (& Mr. Bell) explained in the justification for the rising rate regulator. This was during a simple test and not under WOT. Under WOT it appeared the Supra pump was able to keep the fuel pressure at 43 psi or so, but it also appeared that the injectors can cycle at enough flow rate to demand more than that. Not pressure but volume (& yes I understand Charle's & Boyle's laws...) appeared not to be met. I'm sure the stock injectors are fine for a whole bunch of boost that none of us are hitting yet but there still seems to be not enough fuel entering the combustion chambers under a heavy foot. Christo and others are running extra fuel or water/meth injectors to meet this demand and can then stay into a rich vs a lean condition. I just don't see you doing that with just the stock fuel delivery components.
i don't have much technical to add to this thread. However, while my rig (naturally aspirated) sat on jack stands for a day while i had new control arm bushings pressed in, i drove my roommy's supercharged 95. To the best of my knowlege, it is just the supercharger with a new radiator/thermo.
The power off the line, to me, was dissappointing. Now, the power from about 1700 rpm up to 2500 rpm is awesome. Above that was a little dissapointing. I'm sure if he added a snorkle for more air, perhaps a smaller pully or an intercooler, things would have been different. I must say, i did enjoy the power, it's like the way the cruiser should have come from the factory. But it was not a "pin you into the seat" kind of power either.
I just thought i would throw out my judgement from someone who has been driving around my lifted 33's stock motor cruiser around for years, and finally got to tool around in a supercharged one.
The power off the line, to me, was dissappointing. Now, the power from about 1700 rpm up to 2500 rpm is awesome. Above that was a little dissapointing. I'm sure if he added a snorkle for more air, perhaps a smaller pully or an intercooler, things would have been different. I must say, i did enjoy the power, it's like the way the cruiser should have come from the factory. But it was not a "pin you into the seat" kind of power either.
I just thought i would throw out my judgement from someone who has been driving around my lifted 33's stock motor cruiser around for years, and finally got to tool around in a supercharged one.
Where you will feel the big bang is going up mtn passes, towing or not towing.
Sure it is. If you look for more flow for a given pressure, you need to increase the size of the line, btdt on the Bosch monster race pumps. OR you use a given size line and increase the pressure. What limits *flow* for a given pressure, is line size. Exhaust piping is the same, intake piping is the same, as is forced induction piping is the same.
I believe to make a few points here. Fuel line pressure can double, but flow won't necessarily double. The line can take the additional pressure up to and beyond pump cavitation pressure. The stock fuel regulator is dumb, it only knows vacuum or 1 atmosphere vs fuel pressure in the rail. It doesn't really care what's in the line to it. HOWEVER, if the return line is too small to handle the excess return, you will get a fuel pressure in the rail higher than the FPR is set for.
Not the only reason. You have increased the flow of system pressure, regulated by the FPR. However it has a feed and return. The return line is really small compared to the feed line. If you increased the system pressure (all else being equal in the rail), you have increased the return flow and pressure. IF that return flow creates backpressure on the fuel pressure regulator, you will have a higher fuel pressure in the rail. Increased system pressure *has to go* into the rail, or back to the tank Romer. Your FPR is a given. So, you either have a false high rail pressure, or you have no gain.
If the pump can't keep up with the FPR, then you get cavitation, either in the system line, or in the rail. I guarantee you don't have that, because if you did, there is no mistaking the symptoms.
According to the FSM the max fuel pressure at 1 atmosphere is 3 bar (43.5psi). Not sure what you are asking. Stock regulators max output has nothing to do with operating system pressure of the pump. Pumps are designed for a system pressure at xx volts at a given flow rate.
What I suggest you Supra pump guys do is do the FSM test for regulated fuel pressure (12volts to the pump) at atmospheric pressure. If it's higher than 44psi, your fuel return line is backfeeding system pressure into the rail = there is your increased performance. I see this all the time.
No question in my mind that if you haven't done these tests, the supra pump may or may not be helping at all. I also know that variable voltage pumps are used when fuel return line size is critical for a properly operating control pressure (fuel pressure regulator or rail pressure).
I'm not at all convinced this Supra pump thing is doing what anyone thinks.
ST
Rising rate FPR worked? The problem is the zero point in add-on forced induction. The FPR wasn't designed to recognize boost. Most production boosted cars use the same 'vacuum' profile, and a 1:1 or variable rate fuel pressure regulator under boost. What this does, is allow ~67psi of rail pressure for the injectors at 1.5pressure ratio.
I'd also venture that another Mr. T application FPR from a turbo car or truck, would bolt into the rail without spending the major bucks on the BEGI or others. You lose some of the adjustability in terms of fine tuning a variable rate regulator, but very few production cars use something other than 1:1 anyhow.
My fascination is in that fuel pump resistor circuit, that is triggered by the ecu. I suspect that testing it would show that it's either kicked by rpm or more likely by the WOT switch to go 12v. Using the Supra pump, don't you need to decrease fuel pressure during vacuum (since you are in essence a stock truck unless in boost), or live with the overfueling inherent to this supra fuel pump mod?
ST
Not exactly the FSM test, but the Supra pump w/BEGi 2025 will definitely let you put fuel pressure above 50 psi all the way through 8 psi in the intake manifold.
Still didn't hear me Scott. let me define. A bottleneck is the item that is currently athe limiting factor.
The Supra pump and a 50 PSI FPR work well with the stock fuel line and therefore, the fuel line is not a limiting factor here.
I was asking if it is possible that the stock fuel regulator can't keep up with the load (43 psi) with the stock pump, but that the Supra pump can keep up with the stock pump. Mike's said the same thing above.
I would agree in normal operation, the FPR is now the limiting factor (Bottleneck). If you want to improve something, you remove the bottleneck. There will always be a new bottleneck.
However, my discussions was were their times that the stock pump itself was a bottle neck for the supercharger. Based on my experiance and others here who strongly recommended the pump first and then the regulator second, that there are.
Like said above, what good will adding a FPR if you haven't added a larger pump to provide the fuel.
The Supra pump and a 50 PSI FPR work well with the stock fuel line and therefore, the fuel line is not a limiting factor here.
I was asking if it is possible that the stock fuel regulator can't keep up with the load (43 psi) with the stock pump, but that the Supra pump can keep up with the stock pump. Mike's said the same thing above.
I would agree in normal operation, the FPR is now the limiting factor (Bottleneck). If you want to improve something, you remove the bottleneck. There will always be a new bottleneck.
However, my discussions was were their times that the stock pump itself was a bottle neck for the supercharger. Based on my experiance and others here who strongly recommended the pump first and then the regulator second, that there are.
Like said above, what good will adding a FPR if you haven't added a larger pump to provide the fuel.
