Supra fuel pump or a walbro 255 fuel pump?

[Inverted540]

What fuel pump is a better pump to go with? (supra fuel pump or a walbro 255 fuel pump)
I am going to be running 780cc injectors and a 50 trim turbo. I am wondering what you guys think and if anyone has had experiences with both pumps. Thanks

 

[weith1111]

I have the supra pump and it's a beast. It outflows the 255 pump by quite a bit. I'm still getting all my fuel problems solved, so I don't know if the pump is making it more difficult or not.

 

[95blackGsTurbo]

I have friends who have used both and there isn't a whole lot of difference. If you go with a 255 high pressure you will need a FPR but if you are running that big of injectors you need one anyways. This actually just come's down to what you want to buy. I would go with the 255 because you can buy it new. A supra pump will most likely be used and used is never the way to go if you are planning on making big power. You can get a new Supra pump but they are like $400.00 so I would just save the money and go with the 255. There really isn't any difference. The Supra can support more horsepower but you can to get pretty big numbers to max out a 255hp.

 

[munguiaoh]

walbro 255 fuel pump, you dont need an aftermarket regulator.

 

[95blackGsTurbo]

walbro 255 fuel pump, you dont need an aftermarket regulator.

How do you figure. I doubt seriously he plans on running 43psi of fuel pressure on a 50trim with 780cc injectors...he would hit fuel-cut at 17psi if he was lucky.

 

[oldman]

walbro 255 fuel pump, you dont need an aftermarket regulator.

Yes he does, mind explain how you get around fpr overrun?

I doubt seriously he plans on running 43psi of fuel pressure on a 50trim with 780cc injectors...he would hit fuel-cut at 17psi if he was lucky.

Fuel cut is triggered by air count, not fuel supply. Please explain.

 

[95blackGsTurbo]

I just said that because when I had my 2g with a 50trim that is when I hit fuel-cut was 17psi.

 

[oldman]

I just said that because when I had my 2g with a 50trim that is when I hit fuel-cut was 17psi.

Like posted above, fuel cut is triggered by a pre-program air flow value to guard mainly against run away boost and have nothing to do with your fuel pressure. Your problem was probably related to something else like boost leaks and such. Sorry to break your balls again, I believe you were the one who called for back up this time.

 

[steve]

walbro 255 fuel pump, you dont need an aftermarket regulator.

That's a pretty controversial statement. Do you have personal proof like fuel pressure readings before and after to back that up?

Steve

 

[95blackGsTurbo]

Like posted above, fuel cut is triggered by a pre-program air flow value to guard mainly against run away boost and have nothing to do with your fuel pressure. Your problem was probably related to something else like boost leaks and such. Sorry to break your balls again, I believe you were the one who called for back up this time.

Your KILLING me here. I called for reinforcement's and they turned on me! I wasn't 100% on the technical standpoint of fuel-cut but now I know Because knowledge is POWER!!!

 

[munguiaoh]

steve, i dont have any proof, i honestly dont see the need for it. if the gentleman wants it, get it.

 

[95blackGsTurbo]

If you don't see the need you shouldn't have posted in the first place. You need to increase fuel pressure in order to get more fuel into the cylinder. A FPR keeps the fuel in the rail longer and builds more pressure so when the injector open's more fuel can be injected into the cylinder. Boost and fuel pressuer are directly related. The more you turn the boost up the more you need to turn up the fuel pressure to get more fuel into the cylinder because more air is being injected.

 

[oldman]

If you don't see the need you shouldn't have posted in the first place. You need to increase fuel pressure in order to get more fuel into the cylinder. A FPR keeps the fuel in the rail longer and builds more pressure so when the injector open's more fuel can be injected into the cylinder. Boost and fuel pressuer are directly related. The more you turn the boost up the more you need to turn up the fuel pressure to get more fuel into the cylinder because more air is being injected.

You're KILLING me , I will leave this one to uncle steve.

 

[steve]

steve, i dont have any proof, i honestly dont see the need for it.

If you had measured the base fuel pressure with a stock pump and regulator and then with a 255 l/h pump and the stock regulator you most likely would see the regulator being overrun. Since the injector activation code in the ECU depends on the fuel pressure difference between the rail and intake being constant so the injectors always deliver the same amount of fuel per unit of time, overrun and the fuel pressure spikes it causes throws off the A/F. Some people say you can tune that out but the problem is tied to the amount of fuel the car is using. When the IPW is low the regulator overruns and when the IPW is longer the car uses the extra fuel that the regulator couldn't dump back to the tank and the pressure falls back onto the 1:1 line. Part throttle operation is hit the most since you on and off the throttle and one secons the regulator is works and the next it's spiking.

It's much easier to fix the problem by using an aftermarket regulator that can handle the return flow of these big pumps or get a smaller pump that doesn't outflow the regulator return port. Most people here don't really need a 255l/h pump much less the HP one.

Steve

 

[steve]

You need to increase fuel pressure in order to get more fuel into the cylinder. A FPR keeps the fuel in the rail longer and builds more pressure so when the injector open's more fuel can be injected into the cylinder. Boost and fuel pressuer are directly related. The more you turn the boost up the more you need to turn up the fuel pressure to get more fuel into the cylinder because more air is being injected.

Wow. A little bit of this is right but the rest is all mixed up.

Our fuel pumps are what's called a constant displacement pump. The pump doesn't make pressure it makes volume. The FPR restricts the flow creating pressure in the fuel lines and rail. The diaphragm and spring hold the return port closed until the fuel pressure forces the diaphragm to compress the spring and open the port releasing some flow back to the tank and dropping the pressure until the port closes or the pump replaces the fuel. So far we have a constant base pressure based on the pump delivering enough fuel to keep the port partially open. If he pump delivers more fuel than the return port can flow fully open then the fuel pressure rises. This is FPR overrun.

The reference nipple on the FPR is used to increase or decrease the effective spring pressure by using manifold pressure to push or pull on the diaphragm. Our regulators are set up so that a change in 1 psi at the reference port equals 1 psi change in fuel pressure. Other regulators like the ones used for turboing NT cars have different rates. We use a 1:1 rate so that the injectors always deliver the same amount of fuel per unit of time at 20 in hg vacuum as they do at 25 psi boost. If we didn't track manifold pressure the vacuum would suck fuel from the injectors at idle and slow it to a trickle at full boost.

You don't need to change the base pressure to run more boost. If the injectors are large enough to begin with the ECU will increase the amount of fuel delivered by holding them open longer. It's when the injectors aren't big enough that you might want to increase the pressure to make them act bigger.


Hopefully that clears up the major misconceptions in what you posted.

Steve

 

[munguiaoh]

steve, that is what i was thinking.

 

[Inverted540]

OK so can we get back to the original question i asked? If i am running a 50 trim and plan on running 25psi, What pump do i go with?

 

[oldman]

OK so can we get back to the original question i asked? If i am running a 50 trim and plan on running 25psi, What pump do i go with?

It was already answered I thought, either one will be fine along with an afpr.

 

[Inverted540]

Thanks for the help guys!

 

[Ultimatedsm]

Supra pump out flows the walbro 255LPH. Its been proven that a walbro 255LPH doesn't actually flow that much, its more like 238LPH. Supra pump flows 260LPH. Anyway you would be needing AFPR for any of those pumps. Only way you can get away with not getting an AFPR is if you got the walbro 190.

 

[tstkl]

OK LETS ANSWER THE GUYS QUESTION WITH CORRECT INFO

the supra pump flows 290, and can be bought new for 235 from diamond star motorsports.... its a denso style pump which means it is a direct, exact drop in replacement for the stock fuel pump, while the walbro requires an install kit (most come with it anyways, and i believe it isnt that hard anyways...)

BOTH require an aftermarket fuel pressure regulator, no matter what anyone else tells you, either pump will rape your stock fpr and theres no way of getting around that....

both should be fine for the 50trim, but in the long run the supra will get you farther...(no duhhh...)

 

[steve]

its a denso style pump which means it is a direct, exact drop in replacement for the stock fuel pump, while the walbro requires an install kit (most come with it anyways, and i believe it isnt that hard anyways...)

This is true on a 1G where the stock pump is a 50mm denso unit. On a 2G the stock fuel pump is 34mm IIRC so the walbro is closer to a direct fit.

Steve

 

[Inverted540]

It will be going into a 2g with a 6 bolt swap. Is the supra pump a direct fit for a 2g and if not what do i have to do to make it fit?

 

[steve]

It will be going into a 2g with a 6 bolt swap. Is the supra pump a direct fit for a 2g and if not what do i have to do to make it fit?

One great thing about DSM's is how much information exists online in the form of VFAQ's or can be found with a simple google search in less time that it usually takes to get an answer here.

http://www.vfaq.com/mods/pump-DENSO-2GAWD.html
http://www.vfaq.com/mods/pump-WB-2GAWD.html

Steve

 

[weith1111]

One great thing about DSM's is how much information exists online in the form of VFAQ's or can be found with a simple google search in less time that it usually takes to get an answer here.

http://www.vfaq.com/mods/pump-DENSO-2GAWD.html
http://www.vfaq.com/mods/pump-WB-2GAWD.html

Steve

I feel like you have this saved on your PC so you can just copy and paste it. I've seen this somewhere before....like 100 times.

So true though...