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fuel pump capacity


Guest jt240z

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Guest jt240z

Is a Walbro 95PSI 190 litres p/hr capacity pump OK for my application?

 

I have a "stock" ;) 82 Turbo in a 240Z. The engine is still running the stock ECCS computer, but I've upgraded the following:

 

Rod Bolts--------- ARP 9mm

Main Bolts--------- New #13 Diesel Maxima Main

Rings-------------- Total Seal

Turbo-------------- T3/T04b (water cooled)

Intercooler-------- Skyline GTR rockon.gif

Throttle Body------ 60mm 240SX

Down Pipe---------- Scottie 2.5" 2thumbs.gif

Boost Control------ Dawes Devices Manual

Intercooler Pipes-- 2.25"

Boost-------------- ~15 PSI

BOV---------------- Eclipse 1st Gen.

POV---------------- 1" Pipe block off

 

My next upgrades will be:

ECU---------------- Haltech E6K or SDS 6F

Injectors --------- Benz 450sl 380cc/min

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No. The Walbro is junk. Even the "255" will not flow any real amount of fuel over 60psi (base fuel pressure + boost pressure). If you are going to be running over 15 psi (and with your list of goodies, I cetainly hope so), get an MSD or good Bosch pump capable of flow at high pressure. Some folks also recommend the Pierberg from Bell Engineering.

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My friend has a Walbro 190. Running on a L28 NA, p90, starion IC, stock turbo and 370CC injectors. Ran 13.4 @ 106 with 12psi of boost.

 

Here's some specs on the Walbro pumps...

From http://www.autoperformanceengineering.com/html/fuelpump.html#overview

 

Walbro has been making OEM pumps and aftermarket pumps for many years. A few years ago, they added in-tank high pressure pumps for fuel injected vehicles to their aftermarket line. Their two most popular aftermarket in-tank high performance pumps are their 190 ltr/hr pump and their 255 ltr/hr pump.

 

Their first FI pump was a 190 ltr/hr pump. It was created for the Mustang. It also fit in the Turbo Regals quite well. They recently created a modified version of the 190 ltr/hr pump so it can fit in many other pump hanger brackets (e.g. Probe, Miata, etc.). With a 12 volt power source, these pumps flow 190 ltr/hr at 0 psi, 155 ltr/hr at 40 psi.

 

Later, they created a 255 ltr/hr pump This pump has the same fittings as the original 190 ltr/hr pump. They later created another 255 ltr/hr pump to match the fittings of the Probe pump. Later, they discovered if the output fittings of the Probe pump were turned 180 degrees, that the pump would fit some other applications (RX-7, 1st-Gen DSM), hence a third 255 ltr/hr pump was born. These pumps flow 255 ltr/hr at 40 psi, and 285 ltr/hr at 0 psi.

 

Then, they put a different pressure-relief spring in a standard 255 ltr/hr pump. That raised the output of the pump above 50 psi of fuel pressure. Walbro builds all three versions of the original 255 ltr/hr pump in "high pressure" versions. Below is a table that compares the average flows of several pumps with a 12 volt source.

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Gee, just about every about powerful Turbo Buick on the planet uses Walbro. I am talking 500-600rwhp engine running 45psi base and 25-30psi boost.

 

We really need to stop staying a product, in general, sucks because of your own experience with it. No problem in saying you had a bad experience with. We have a lot of folks looking for advice and guidance and I believe that is the wrong impression to give of a product.

 

Sorry if that infuriates anyone.

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I was a bit too strong is classifying them as "junk" perhaps, but they are serious mis-marketed. The "255 liter/hour" number is achieved at approximately 20 psi fuel pressure. Nobody runs an FI motor, especially a turbo motor at 20 psi fuel pressure. When that particular pump is loaded with 60 psi, the flow drops to less than half their spec. To me, that is junk. A Bosch OEM pump will flow better than that for lots less money. Yes, the Walbro high pressure pump flows better up there, and is a more suitable pump for turbos, but folks need to look closely at pump specs - god knows they charge enough for them.

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The Pierburg that Scottie and I run is rated at roughly the same 255L/h as the Walbro unit. Scottie has had no problems with the pump, but I see that anything above 17psi and my fuel pressure starts to drop. Even with the filter removed this is a problem. On my buddies Honda race car the Pierburg supplied 420FrontWHP and would not flow anymore. GN cars use less fuel to make more power and that is why they can use this pump for 600hp. Hell, they tune the EGO voltages to .8V under WOT. Now, the Supra intank pump flow about 305L/h and is said to be good for an honest 600hp. To answer your question, do not use the 190L/h pump, go with the 255L/h and you should not have any problems. I am going to sell my single Pierburg and go with dual Walbro's or dual Bosch Units on my setup. I have also found that Python Injection makes a pump capable of 730hp that is used on all their Venom race cars. It is difficult to find a pump solution without spending big bucks or running dual pumps.

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GN cars use less fuel to make more power and that is why they can use this pump for 600hp. Hell, they tune the EGO voltages to .8V under WOT
That is an excellent point! 2 engines making the same HP, no matter what the displacement, theoretically will consume the same fuel. However, if one is tuned to run leaner it will consume less. The GNs now have a device that evens fuel distribution in the plenum and guys are now pushing the WOT O2 voltage down to .76. My EGT probe is in my exhaust header just before the turbo and I tune for 1600*F!!. All of that said, how many L28s are pushing 430+rwhp and need that much fuel at WOT?

 

One of the problems that folks are not aware of is the problem of pump voltage at WOT. When I ran the L28ET, I had no traction and ran lousy ETs but almost 111mph with the stock T3. I then switched to a hybrid and the 60' dropped from 2.1 to 1.74 just because the boost was more controllable. The car gained .26 in the ET as a result of the 60' but absolutely died on the top-end with only 105mph. No amount of SDS tuning helped. Long story to say I later discovered that the original fuel pump wire terminals was not only corroded but the gauge was too thin. Never measured it but I bet I did not have 10V at the pump at WOT!!! Most of the time when a pump is not delivering at WOT, it is because of insufficient voltage. Any turbo car looking to make HP with hi-po pump should run a 10-gausge + from the battery to the pump through a relay and use the original wire to trigger the relay and run the pump - with a 10-gauge directly to the battery.

 

Another thing you need to do is temporarily connect a FP gauge to the rail with a long hose that allows you see the FP at boost. Majority of the times those 2 are the problems folks face at high boost.

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Guest jt240z

Thanks guys,

 

It's good to here from those that have done it. Too often all you hear is arm chair tuning.

 

I think I'll try the Walbro 255 and keep an eye on the fuel pressure. You can't beat the price on the Walbro's. tongue.gif Seem like the best bang for the buck.

 

I like the suggestion on the higher guage wires and relay to the fuel pump. I've noticed from some of the flow curves that the current can peek at over 13 amps :eek: depending on the pressure.

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Guest jt240z

Does anyone have a good source for the Walbro 255 High Pressure inline fuel pump. I can't seem to find anyone who carries them. I tried their web site buy when I click on "Suppliers" :eek: I get "Under construction". cry2.gif

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What we have here is a classic case of misinformation. The Walbro pump used in that test was a GSS250 rated at 190lph. Walbro makes a standard and a high-pressure pump and the GSS250 is not a high-pressure pump. The pump the Zers want is the GSS392, high-pressure and rated 255lph.

 

If you want to see a more accurate comparison of pump performance, look at this link. the 3 Walbros listed are the 190lph GSS250, the 255lph standard pressure and the GSS392 255lph, hi-pressure. Note the performance of the 3 at 60 & 70psi, where it counts and then you see the advantage of the GSS392 above 70psi.

 

Again, before anyone jumps to the conclusion that someting "SUCKS", be certain you have the facts.

 

http://www.supras.nl/view.php?page=modsFuelPump.htm

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And the answer is...do your homework.

 

What irritates me, and generates my bias against the Walbro, is Walbro calls their pumps "255 liters/hour" pumps. Unless you are running a TBI, you will never get that flow. So you have to search the web and find pages that map the fuel flow versus pressure, because the manufacturers (not just Walbro) will not publish their data.

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I have the Peirburg and I like it. I have used a walbro, although I do not know what one, and we had problems with them dealing with higher fuel pressures, but they flowed more than a stock fp.

 

The wiring is a good idea, and I have found that a good ground at the fuel pump does a good job of improving performance. I think ZXT's control the fuel pump thru positive power, and 300ZXT's control it thru the ground. Not sure, but I think that is the case.

 

Another option is to get one of the voltage riser deals and wire it up back there and shoot 14 to 18 volts at the pump and see what it does.

 

I have had no problems with my peirberg, and at boost pressures up to 18 or so psi I was having rock solid fuel pressure at 60 psi or so. It also coped with my Cartech rising rate of gain FPR when I was using that route, the walbro would not deal with the pressures required.

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Sometimes we need to step back and understand better what our needs are and not get caught up the hype of which pump flows more, etc.

 

Nathan, I agree with you and unfortunately that is the nature of marketing, but lets take a look at this pump in more detail. How many L28ETs out there are going to run 70psi? That would mean you are running aftermarket injs with a base pressure of 43psi and 27psi boost! I am close, running 42psi base and 24psi boost on my Pierburg. Lets be a little more realistic and say you run 65psi (43 base + 22). The table says the hi-pressure 255lph pump is pushing about 190lph @ 65psi, which is 50.189 gals or 401.585lbs/hr. That can feed 6 67lb injs which can support 602hp at a conservative 80% duty cycle. That is why the Buicks use them and, yes, I know the Buicks use less fuel (more efficient? :D ..) but I hardly think the average hi-po L28ET is in danger of running out of fuel.

 

Even the "lowly" 190lph low-pressure pump at a more sane 60psi will support 6 42psi injs for 383hp. That of course leaves no margin for the big boys and therefore is not a choice.

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