ideas on twin fuel pumps????
Originally Posted by silverofs
does anyone have any details on this pump??? what version is it?? any wiring involved like rewire or anything??
mr buschur?? any comments on your pump???
mr buschur?? any comments on your pump???
Originally Posted by silverofs
does anyone have any details on this pump??? what version is it?? any wiring involved like rewire or anything??
mr buschur?? any comments on your pump???
mr buschur?? any comments on your pump???
but I do have a few observations about fuel system basics that might provide a background for this discussion.1. Stock fuel pumps flow enough for stock, and perhaps 20% higher HP before they're marginal;
2. With replacement (upgraded) fuel pumps, you get what you pay for. Walbros are not stock OEM quality fuel pumps. Why is that important? Because manufacturers of stock OEM quality pumps have to build them to last at least the warranty period. Denso and Bosch pumps ARE OEM pumps. The Denso 1020 is the Supra T.T. stock OEM pump, and outflows the Walbro, as well as being much quieter. I've never heard of a Denso 1020 pump failing; in contrast, Walbros fail regularly. The Bosch 044 inline pump is another high quality factory Porsche Turbo pump. Both flow substantially more than a Walbro, are quieter, and more reliable. They cost more than a Walbro, too, but you usually only have to buy them once
3. With any replacement fuel pump, increased voltage means increased pumping capacity. Why would you pay a significant amount of money for an upgraded pump and not give it the current it needs to perform? Rewiring is cheap in terms of performance gains. Under bigger load, the issues with lack of current make both factory and aftermarket pumps underperform. Rewire and get the stability and performance the pump is capable of.
4. Increased boost must be matched by increased fuel pressure in order for your injectors to spray the same amount of fuel that your ECU is calculating. In other words, the boost pressure in the manifold must be overcome by the pressure in the fuel injector in order for anything to come out. The higher the boost, the greater the manifold pressure the injectors must overcome. The fuel pump must be capable of delivering the amount of fuel your engine demands at the pressure that is necessary to compensate for the boost you're running. If your base pressure is 42 lbs. for example, and you run 20 lbs of boost, your pump needs to provide 62 lbs of pressure to "break even" and flow the fuel that your ECU is using for its computations. Make sure the pump you buy is rated for the flow you need at the pressure you're going to need it. See No. 5.
5. Fuel pumps pump LESS than their maximum flow as the pressure increases. You can have very high fuel pressure and VERY LOW flow at the far end of the boost curve. Run lean, buy a new motor. That's why it's useful to know what your fuel system is capable of flowing at the pressures you're going to run. That includes both fuel PRESSURE and fuel VOLUME.
6. Fuel lines from the pump to the rail are often a bottleneck. Too small ----> not enough volume of fuel. With high HP motors, go to an AN-6, AN-8, or AN-10 line from the pump to the rail, and the next size down for the return line.
7. Once you know your fuel lines are adequate for the fuel VOLUME your engine will demand, then install an electric fuel pressure gauge and you'll be able to monitor whether your fuel pressure is rising at a 1:1 ratio with your boost. If you have Defi BF gauges, the controller also has a mode where it will compare the two. That's cool!
Now you know exactly what the fuel is doing compared to the boost...8. Upgraded (in volume) fuel rails and Adjustable Fuel Pressure Regulators are recommended if you're making sure your fuel system is adequate for your engine's needs. As for the AFPR, see No. 4 above. While factory FPRs may suffice, why would you save $150 and risk your engine? Rails can be a limitation, too, and can also exacerbate fuel pulsing when you're using high volume fuel injectors. Bigger internal rail volume and cutting out the flow restrictions of the factory fittings are other (+) factors in replacing the rail. Not just the bling here, guys.
8. Single pump systems can fail. If they do, your car stops running because it has no fuel, hopefully before your engine is damaged. Dual pump systems can fail, too. If only one pump fails, and the other keeps pumping, your motor can keep running. If you're not in it, you may be OK. If you are, the continuing fuel supply may cause you to run lean. That's not good.
Hope this helps some understand how the fuel system components interrelate.
Last edited by CO_VR4; Jul 9, 2006 at 08:47 PM.
Originally Posted by CO_VR4
I'm not Dave Buschur. but I do have a few observations about fuel system basics that might provide a background for this discussion.
1. Stock fuel pumps flow enough for stock, and perhaps 20% higher HP before they're marginal;
2. With replacement (upgraded) fuel pumps, you get what you pay for. Walbros are not stock OEM quality fuel pumps. Why is that important? Because manufacturers of stock OEM quality pumps have to build them to last at least the warranty period. Denso and Bosch pumps ARE OEM pumps. The Denso 1020 is the Supra T.T. stock OEM pump, and outflows the Walbro, as well as being much quieter. I've never heard of a Denso 1020 pump failing; in contrast, Walbros fail regularly. The Bosch 044 inline pump is another high quality factory Porsche Turbo pump. Both flow substantially more than a Walbro, are quieter, and more reliable. They cost more than a Walbro, too, but you usually only have to buy them once
3. With any replacement fuel pump, increased voltage means increased pumping capacity. Why would you pay a significant amount of money for an upgraded pump and not give it the current it needs to perform? Rewiring is cheap in terms of performance gains. Under bigger load, the issues with lack of current make both factory and aftermarket pumps underperform. Rewire and get the stability and performance the pump is capable of.
4. Increased boost must be matched by increased fuel pressure in order for your injectors to spray the same amount of fuel that your ECU is calculating. In other words, the boost pressure in the manifold must be overcome by the pressure in the fuel injector in order for anything to come out. The higher the boost, the greater the manifold pressure the injectors must overcome. The fuel pump must be capable of delivering the amount of fuel your engine demands at the pressure that is necessary to compensate for the boost you're running. If your base pressure is 42 lbs. for example, and you run 20 lbs of boost, your pump needs to provide 62 lbs of pressure to "break even" and flow the fuel that your ECU is using for its computations. Make sure the pump you buy is rated for the flow you need at the pressure you're going to need it. See No. 5.
5. Fuel pumps pump LESS than their maximum flow as the pressure increases. You can have very high fuel pressure and VERY LOW flow at the far end of the boost curve. Run lean, buy a new motor. That's why it's useful to know what your fuel system is capable of flowing at the pressures you're going to run. That includes both fuel PRESSURE and fuel VOLUME.
6. Fuel lines from the pump to the rail are often a bottleneck. Too small ----> not enough volume of fuel. With high HP motors, go to an AN-6, AN-8, or AN-10 line from the pump to the rail, and the next size down for the return line.
7. Fuel rails and Adjustable Fuel Pressure Regulators are recommended if you're making sure your fuel system is adequate for your engine's needs. As for the AFPR, see No. 4 above. While factory FPRs may suffice, why would you save $150 and risk your engine?
8. Single pump systems can fail. If they do, your car stops running because it has no fuel, hopefully before your engine is damaged. Dual pump systems can fail, too. If only one pump fails, and the other keeps pumping, your motor can keep running. If you're not in it, you may be OK. If you are, the continuing fuel supply may cause you to run lean. That's not good.
Hope this helps some understand how the fuel system components interrelate.
but I do have a few observations about fuel system basics that might provide a background for this discussion.1. Stock fuel pumps flow enough for stock, and perhaps 20% higher HP before they're marginal;
2. With replacement (upgraded) fuel pumps, you get what you pay for. Walbros are not stock OEM quality fuel pumps. Why is that important? Because manufacturers of stock OEM quality pumps have to build them to last at least the warranty period. Denso and Bosch pumps ARE OEM pumps. The Denso 1020 is the Supra T.T. stock OEM pump, and outflows the Walbro, as well as being much quieter. I've never heard of a Denso 1020 pump failing; in contrast, Walbros fail regularly. The Bosch 044 inline pump is another high quality factory Porsche Turbo pump. Both flow substantially more than a Walbro, are quieter, and more reliable. They cost more than a Walbro, too, but you usually only have to buy them once
3. With any replacement fuel pump, increased voltage means increased pumping capacity. Why would you pay a significant amount of money for an upgraded pump and not give it the current it needs to perform? Rewiring is cheap in terms of performance gains. Under bigger load, the issues with lack of current make both factory and aftermarket pumps underperform. Rewire and get the stability and performance the pump is capable of.
4. Increased boost must be matched by increased fuel pressure in order for your injectors to spray the same amount of fuel that your ECU is calculating. In other words, the boost pressure in the manifold must be overcome by the pressure in the fuel injector in order for anything to come out. The higher the boost, the greater the manifold pressure the injectors must overcome. The fuel pump must be capable of delivering the amount of fuel your engine demands at the pressure that is necessary to compensate for the boost you're running. If your base pressure is 42 lbs. for example, and you run 20 lbs of boost, your pump needs to provide 62 lbs of pressure to "break even" and flow the fuel that your ECU is using for its computations. Make sure the pump you buy is rated for the flow you need at the pressure you're going to need it. See No. 5.
5. Fuel pumps pump LESS than their maximum flow as the pressure increases. You can have very high fuel pressure and VERY LOW flow at the far end of the boost curve. Run lean, buy a new motor. That's why it's useful to know what your fuel system is capable of flowing at the pressures you're going to run. That includes both fuel PRESSURE and fuel VOLUME.
6. Fuel lines from the pump to the rail are often a bottleneck. Too small ----> not enough volume of fuel. With high HP motors, go to an AN-6, AN-8, or AN-10 line from the pump to the rail, and the next size down for the return line.
7. Fuel rails and Adjustable Fuel Pressure Regulators are recommended if you're making sure your fuel system is adequate for your engine's needs. As for the AFPR, see No. 4 above. While factory FPRs may suffice, why would you save $150 and risk your engine?
8. Single pump systems can fail. If they do, your car stops running because it has no fuel, hopefully before your engine is damaged. Dual pump systems can fail, too. If only one pump fails, and the other keeps pumping, your motor can keep running. If you're not in it, you may be OK. If you are, the continuing fuel supply may cause you to run lean. That's not good.
Hope this helps some understand how the fuel system components interrelate.
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From: KL,Malaysia
Originally Posted by CO_VR4
I'm not Dave Buschur. but I do have a few observations about fuel system basics that might provide a background for this discussion.
1. Stock fuel pumps flow enough for stock, and perhaps 20% higher HP before they're marginal;
2. With replacement (upgraded) fuel pumps, you get what you pay for. Walbros are not stock OEM quality fuel pumps. Why is that important? Because manufacturers of stock OEM quality pumps have to build them to last at least the warranty period. Denso and Bosch pumps ARE OEM pumps. The Denso 1020 is the Supra T.T. stock OEM pump, and outflows the Walbro, as well as being much quieter. I've never heard of a Denso 1020 pump failing; in contrast, Walbros fail regularly. The Bosch 044 inline pump is another high quality factory Porsche Turbo pump. Both flow substantially more than a Walbro, are quieter, and more reliable. They cost more than a Walbro, too, but you usually only have to buy them once
3. With any replacement fuel pump, increased voltage means increased pumping capacity. Why would you pay a significant amount of money for an upgraded pump and not give it the current it needs to perform? Rewiring is cheap in terms of performance gains. Under bigger load, the issues with lack of current make both factory and aftermarket pumps underperform. Rewire and get the stability and performance the pump is capable of.
4. Increased boost must be matched by increased fuel pressure in order for your injectors to spray the same amount of fuel that your ECU is calculating. In other words, the boost pressure in the manifold must be overcome by the pressure in the fuel injector in order for anything to come out. The higher the boost, the greater the manifold pressure the injectors must overcome. The fuel pump must be capable of delivering the amount of fuel your engine demands at the pressure that is necessary to compensate for the boost you're running. If your base pressure is 42 lbs. for example, and you run 20 lbs of boost, your pump needs to provide 62 lbs of pressure to "break even" and flow the fuel that your ECU is using for its computations. Make sure the pump you buy is rated for the flow you need at the pressure you're going to need it. See No. 5.
5. Fuel pumps pump LESS than their maximum flow as the pressure increases. You can have very high fuel pressure and VERY LOW flow at the far end of the boost curve. Run lean, buy a new motor. That's why it's useful to know what your fuel system is capable of flowing at the pressures you're going to run. That includes both fuel PRESSURE and fuel VOLUME.
6. Fuel lines from the pump to the rail are often a bottleneck. Too small ----> not enough volume of fuel. With high HP motors, go to an AN-6, AN-8, or AN-10 line from the pump to the rail, and the next size down for the return line.
7. Once you know your fuel lines are adequate for the fuel VOLUME your engine will demand, then install an electric fuel pressure gauge and you'll be able to monitor whether your fuel pressure is rising at a 1:1 ratio with your boost. If you have Defi BF gauges, the controller also has a mode where it will compare the two. That's cool! Now you know exactly what the fuel is doing compared to the boost...
8. Upgraded (in volume) fuel rails and Adjustable Fuel Pressure Regulators are recommended if you're making sure your fuel system is adequate for your engine's needs. As for the AFPR, see No. 4 above. While factory FPRs may suffice, why would you save $150 and risk your engine? Rails can be a limitation, too, and can also exacerbate fuel pulsing when you're using high volume fuel injectors. Bigger internal rail volume and cutting out the flow restrictions of the factory fittings are other (+) factors in replacing the rail. Not just the bling here, guys.
8. Single pump systems can fail. If they do, your car stops running because it has no fuel, hopefully before your engine is damaged. Dual pump systems can fail, too. If only one pump fails, and the other keeps pumping, your motor can keep running. If you're not in it, you may be OK. If you are, the continuing fuel supply may cause you to run lean. That's not good.
Hope this helps some understand how the fuel system components interrelate.
but I do have a few observations about fuel system basics that might provide a background for this discussion.1. Stock fuel pumps flow enough for stock, and perhaps 20% higher HP before they're marginal;
2. With replacement (upgraded) fuel pumps, you get what you pay for. Walbros are not stock OEM quality fuel pumps. Why is that important? Because manufacturers of stock OEM quality pumps have to build them to last at least the warranty period. Denso and Bosch pumps ARE OEM pumps. The Denso 1020 is the Supra T.T. stock OEM pump, and outflows the Walbro, as well as being much quieter. I've never heard of a Denso 1020 pump failing; in contrast, Walbros fail regularly. The Bosch 044 inline pump is another high quality factory Porsche Turbo pump. Both flow substantially more than a Walbro, are quieter, and more reliable. They cost more than a Walbro, too, but you usually only have to buy them once
3. With any replacement fuel pump, increased voltage means increased pumping capacity. Why would you pay a significant amount of money for an upgraded pump and not give it the current it needs to perform? Rewiring is cheap in terms of performance gains. Under bigger load, the issues with lack of current make both factory and aftermarket pumps underperform. Rewire and get the stability and performance the pump is capable of.
4. Increased boost must be matched by increased fuel pressure in order for your injectors to spray the same amount of fuel that your ECU is calculating. In other words, the boost pressure in the manifold must be overcome by the pressure in the fuel injector in order for anything to come out. The higher the boost, the greater the manifold pressure the injectors must overcome. The fuel pump must be capable of delivering the amount of fuel your engine demands at the pressure that is necessary to compensate for the boost you're running. If your base pressure is 42 lbs. for example, and you run 20 lbs of boost, your pump needs to provide 62 lbs of pressure to "break even" and flow the fuel that your ECU is using for its computations. Make sure the pump you buy is rated for the flow you need at the pressure you're going to need it. See No. 5.
5. Fuel pumps pump LESS than their maximum flow as the pressure increases. You can have very high fuel pressure and VERY LOW flow at the far end of the boost curve. Run lean, buy a new motor. That's why it's useful to know what your fuel system is capable of flowing at the pressures you're going to run. That includes both fuel PRESSURE and fuel VOLUME.
6. Fuel lines from the pump to the rail are often a bottleneck. Too small ----> not enough volume of fuel. With high HP motors, go to an AN-6, AN-8, or AN-10 line from the pump to the rail, and the next size down for the return line.
7. Once you know your fuel lines are adequate for the fuel VOLUME your engine will demand, then install an electric fuel pressure gauge and you'll be able to monitor whether your fuel pressure is rising at a 1:1 ratio with your boost. If you have Defi BF gauges, the controller also has a mode where it will compare the two. That's cool!
Now you know exactly what the fuel is doing compared to the boost...8. Upgraded (in volume) fuel rails and Adjustable Fuel Pressure Regulators are recommended if you're making sure your fuel system is adequate for your engine's needs. As for the AFPR, see No. 4 above. While factory FPRs may suffice, why would you save $150 and risk your engine? Rails can be a limitation, too, and can also exacerbate fuel pulsing when you're using high volume fuel injectors. Bigger internal rail volume and cutting out the flow restrictions of the factory fittings are other (+) factors in replacing the rail. Not just the bling here, guys.
8. Single pump systems can fail. If they do, your car stops running because it has no fuel, hopefully before your engine is damaged. Dual pump systems can fail, too. If only one pump fails, and the other keeps pumping, your motor can keep running. If you're not in it, you may be OK. If you are, the continuing fuel supply may cause you to run lean. That's not good.
Hope this helps some understand how the fuel system components interrelate.
I have a customer from NYC who mdae 623whp running one intank 255hp pump and another inline 255hp pump. Only thing was he didnt run them in succession. He drilled a hole in the fuel pump assembly on the top and ran a 2nd pickup. Then he used a T to connect the 2 lines. He said he has done this on a few cars and had no problem
Originally Posted by Smogrunner
I've recently had arguments with people that believe that runing two inline 255 pumps doesn't do any better than one. I disagree, and am doing the inline approach. I'd like to hear others opinions.
Originally Posted by Steve@NoLimitmotors
I have a customer from NYC who mdae 623whp running one intank 255hp pump and another inline 255hp pump. Only thing was he didnt run them in succession. He drilled a hole in the fuel pump assembly on the top and ran a 2nd pickup. Then he used a T to connect the 2 lines. He said he has done this on a few cars and had no problem
We use two walbro pumps for any applications over 450whp. You can get more flow out of your walbro pump by direct wiring but not a whole lot more.
As for Buschur's pump I'm really curious also. The Walbro pump is an internal / external spur gear pump, so unless they are remachining the gears or changing the motor armature I'm not sure how they are getting more flow out of the pumps.
Cheers,
Gary
Gruppe-S
As for Buschur's pump I'm really curious also. The Walbro pump is an internal / external spur gear pump, so unless they are remachining the gears or changing the motor armature I'm not sure how they are getting more flow out of the pumps.
Cheers,
Gary
Gruppe-S
Originally Posted by silverofs
does anyone have any details on this pump??? what version is it?? any wiring involved like rewire or anything??
mr buschur?? any comments on your pump???
mr buschur?? any comments on your pump???
Walbro pumps can be bought just about anywhere. Their external pumps are quite similar to their in-tank pumps. Any of the dealers on this list could order them for you -- AMS offers them in thier kit (and could order them separately); so could RRE, etc.
They're offered on E-Bay, for example, http://cgi.ebay.com/ebaymotors/ws/eB...tem=8013443054 $125 up.
Whatever Buschur does with the in-tank pump could also be done to the external, I'd guess, if you'd like that option.
They're offered on E-Bay, for example, http://cgi.ebay.com/ebaymotors/ws/eB...tem=8013443054 $125 up.
Whatever Buschur does with the in-tank pump could also be done to the external, I'd guess, if you'd like that option.
Where do people usually mount their in-line walbro's... or is there a write-up anywhere for it?
Also, at what power lvl will the stock fuel lines and stock bore fuel rail begin to choke? How much power on top of that will methanol add into the mix?
Been considering upgrading my fuel system lately although I don't know exactly how far I can push my current one...
Also, at what power lvl will the stock fuel lines and stock bore fuel rail begin to choke? How much power on top of that will methanol add into the mix?
Been considering upgrading my fuel system lately although I don't know exactly how far I can push my current one...
if you have one intank walboro and one external 255lph walboro hooked up one in front of each other isnt the flow going to be the same at 255lph....unless you run them parallel? 
or maybe im missing something on how it works 
or maybe im missing something on how it works
Last edited by Derek888; Jul 23, 2006 at 08:15 AM.