Zfan

Which pump is better, I am going to be installing the fuel system in my 240Z next week. It will need enough to support my L76 and maybe a 150 wet shot.

I have heard very little but what I have heard is Bosch makes a good pump and the Walbro 255 has had it's share of failures.

Thanks
Mike

tennerv8

iTrader: (7)

The bosch will out flow the walbro by far. Way better pump.

Zfan

10-4, thanks!

stevieturbo

The Bosch is superior in every way.

But the Walbros are great little pumps too and very reliable.

2000RATA

Which of these 2 draws fewer amps? I'm running e85 and need a quiet pump. My MagnaFuel 4303 is noisy. I pulled my fuel cell and will modify to run either the "quiet" pumps or the 4303 depending on my driving intent.

papermushrooms

the Bosch 044's are not "quiet" pumps, im running two of them and they are pretty rowdy, but ill never have to worry bout running out of fuel press.

2000RATA

Thank you. I assumed, incorrectly it seems, that any of the stock appearing pumps are quiet. So are the walbro pumps quiet?

stevieturbo

The 255 draws less current, but then it also flows less than an 044.

In reality at a sensible working pressure, the Walbro will be closer to 200lph, whereas the Bosch will be up around 250lph at almost any pressure

My pair of Bosch pumps draw 22A at 60psi, rising to a max of around 26A at about 85-90psi.

The newer range of pumps like the 340, 400, 450 or whatever all draw huge amounts of current. Far more than the 044, but in reality once fuel pressure is up around 70-80psi, they dont really flow any more than an 044.
The only one that continues to perform well beyond 80psi is the 044.

It's one of the oldest fuel injection pumps out there, and still the best IMO.

It is crappy having to run multiple pumps to get the job done...but IMO there really arent any big single pumps that perform like an 044, and for street use are reliable as an 044.

As for noise. Of course they arent silent, but they are quieter than most pumps. Certainly the noise isnt obtrusive at all. Once the engine's running I cant hear mine. An A1000 I had used a few years before was far louder.

2000RATA

I am going for quiet if possible. I have started wiring a switch to toggle between the pumps. I run about 63 psi when at max boost. I am looking for a "driving down the interstate" pump. I run full exhaust (dual 3") and my car is pretty quiet. The only noise I hear besides road noise is the fuel pump. If I get that fixed my car is perfect. It's just shy of 1000 rwhp, a/c blows cold and the car still has less than 5000 original miles on it. The nagging pump is my only gripe. Thank you for the help and advice.

stevieturbo

Noise will depend a lot on how and where the pumps are mounted.

Obviously with Walbros and similar, when submerged in-tank, that kills a lot of noise.

My fuel tank sits in the trunk, and the 044's just below the tank, also in the trunk. Ive also dual 3" pipes, with a pair of 9x4 Magnaflows in the middle and a pair of 8x5x14" magnaflows at the rear.

I wouldnt say the car is quiet by any means, but when driving etc it really isnt too bad. At idle etc the loudest thing is my blower, but when cruising it really isnt too bad. Pumps....I certainly dont hear them
They are both rubber mounted which will help some too, but that's just normal practise.


2 x 044's will support the 1000rwhp no problem on normal fuel. E85 I dont know. But I know a pair wired and installed properly will flow approx 500lph. At least that's what mine flow tested at as installed on mine, although I only use pump fuel.

But then I'd also question how well the Magnafuel copes with that power on E85.
A friend in the UK has a twin turbo 3.6 engine making about 1200 flywheel HP and his 4303 is struggling at that point, and that's just on race fuel.
Some of that may be down to dynos reading different, but those big pumps claim big things at low fuel pressures....but at real efi working pressures, their flow drops off dramatically.

2000RATA

The 044 looks like what I'm after. I want to mount them outside the tank. My MF is in tank. I was thinking rubber mount like I read yours are. I googled images of the 044 and it has threaded fittings like what I wanted. Thank you. Looks like I should order a pair and see how they sound. Do you know if they have a check valve in them so if I "Y" my big pump with them it won't back flow through the 044's?

stevieturbo

If you retain the fitting on the pump outlet, then yes. But it will be restrictive.

Are you intending to run the 044/044's and the 4303 ??

If you just want pumps to run for normal street duty, then you could really just use a single pump. It would be cheaper and less complicated.
I can see little reason to run a pair of 044's AND the 4303.

IMO your cheapest and simplest option might just be to run say a Walbro GSS392 in-line pump in parallel with the 4303.
Except wire the 4303 to turn on when it is needed, but leaving the in-line pump running all the time.

How the system will cope with the surge of fuel when the big pump powers up, I dont know, but it might only last for a split second.

I thought you were looking to get rid of the 4303 and just use a pair of 044's

stevieturbo

Some googling revealed this

Now to me, at 60psi that's only about 550lph which is barely 10% higher than I tested my 044's at.
Turn that up to 80psi and they're flowing about the same, perhaps the Maganfuel a little less than the Bosch pair would.

As I say, these big pumps claim huge numbers, but seems they only apply to low pressure n/a installs. Crank up the pressure and they fall apart.

2000RATA

You are correct I am only looking to use these to drive around on and lower boost stuff. But kick the big single on for racing. I want to keep about the same fuel volume so my base fuel pressure is the same fearing a sizable difference in pump or pumps would cause me to have to readjust fuel pressure at the regulator.

2000RATA

If you hold an 044 in your hand and put 12v to it does it sound like an electric razor or the motor on an ice cream maker you use at home?

stevieturbo

TBH I'd just get rid of the 4303 and run a pair of 044's

Cant say I have an ice cream maker lol.

All of the typical efi pumps just make a buzzing sound, 044 is no different.

2000RATA

I will get a couple coming tomorrow. I have put less than 200 miles on this build and I am ready to drive it a little.
Where is the best place to get the Bosch pump?

stevieturbo

I'm in the UK, so no idea about US suppliers.

If the noise is the only concern with the 4303, and you are happy it will be street reliable. Why not just invest some time and money insulating it to try and eliminate the noise ?

ie suitable rubber mounting, and some sort of sound deadening enclosure ? It would be a hell of a lot cheaper and less hassle.

2000RATA

I have thought about that and to quiet it down I would have to bury it at least 2 meters underground. I can hear it clearly over open down pipes. Even on the highway. Turning the power off to it guarantees me it is quiet. It is a spur gear style pump and it sounds like it. Just gear on gear noise. It has ruined the street fun factor for me. I am going to do what you have suggested and try the 044's.

stevieturbo

My A1000 was loud, that thing must be horrific !

The Bosch pumps really are hard to beat. At a push if they didnt flow enough for you, a BAP would certainly give you the headroom needed and ditch the 4303 altogether.