Running Ex Bosch 044 W/o A Surge Tank?

[Shockster0429]

Well I'm going to be need more fuel for my new setup this year. However I really don't want to run a surge tank it seems like a hassle and not entirely needed at least from what I think.... could be wrong. I've been searching for a few hours now and am having trouble finding someone whose running their fuel pump(s) like this.

Using my currently intank walbro 255 as the lift pump, but not using a surge, and off that same feed line, running the 044 bosch then to the fuel filter, the fuel rail, into the FPR and back into the tank for return. Any issues with this setup type of setup? heres a shitty drawing I did in paint for it.

thanks.

[GeeTR]

That setup should be fine.

You haven't mentioned what fuel tank your putting it in. Most Skylines seem to get away without a surge tank, if they're 1/3 full.

044 is rated at 600hp, which is about 350rwkw.

In reality, a tank and some line wont cost that much extra if you fit it under the car. Once you go in the boot, you'll have to use hardline or teflon braid to limit fuel weepage and cabin smell.

Edited February 23, 2008 by GeeTR

[Shockster0429]

Its actually in an s-13 chassis, using the stock fuel tank. The rear of the car is gutted, and car has a 6 point cage it in. The car is daily driven so I do place items in the hatch (one reason I don't want a surge tank).

I'm under some time constraints currently to getting the car finished and moved out so a surge tank can always be an option for under the car at a later point.

I'm aware of the 044's output however are you saying that because the power outputs don't add to each other? I understand that there will be loses with this setup so it will never see the full potential of both pumps, but it should be able to make over 600hp since the walbro is aiding it as well?

[GeeTR]

S13 chassis - nice, I almost bought a 180 with a RB20 in it 3y ago.

No sorry - I was just rambling off the output, as you hadn't mentioned a turbo, or power goal

Correct, having the ass of the 044 fed a positive pressure will undoubtedly help it reach its "on paper" spec.

180 or Silvia? As if 180, the boot isn't sealed from the cabin, so you cant legally fit a s.tank setup in there ne way. you'd have to enclose all the gear in a box, or just stick it under the car. My vote is for a carefully designed under floor setup. It means you can use ordinary EFI hose with worm clamps, and don't need to be fussed with fancy stuff to prevent smell.

[Shockster0429]

S13 chassis - nice, I almost bought a 180 with a RB20 in it 3y ago.

No sorry - I was just rambling off the output, as you hadn't mentioned a turbo, or power goal

Correct, having the ass of the 044 fed a positive pressure will undoubtedly help it reach its "on paper" spec.

180 or Silvia? As if 180, the boot isn't sealed from the cabin, so you cant legally fit a s.tank setup in there ne way. you'd have to enclose all the gear in a box, or just stick it under the car. My vote is for a carefully designed under floor setup. It means you can use ordinary EFI hose with worm clamps, and don't need to be fussed with fancy stuff to prevent smell.

Lol, well I'm from the states, and around here theres no emissions testing or anything, so no worries. Its a s-13 hatch with chuki front end. I think for the moment since its cool to run the pump like that, I'll just use my stock lines and nipple adapters.

Setup is 2.7 liter stroker with forgies of course, 8.5 to 1, 35r T4 hot sided tons of other goodies too much to list. Looking to make close to 500rwhp with pump gas here. I shall see. This setup should be plenty for that.

[R31Nismoid]

The walbro wont be "aiding" the bosch at all, the bosch flows a truckload more so its pointless having the walbro there at all IMO.

[Shockster0429]

The walbro wont be "aiding" the bosch at all, the bosch flows a truckload more so its pointless having the walbro there at all IMO.

good point, I know in fluid systems like for water plants and such, running pumps in parallel doesn't allow them to flow their max do to line sizing and so forth.. I shall see, basically the walbro will just be hanging out then if that ends up being the case. I'll know more when I'm making pulls and watching my fuel pressure.

[BHDave]

I tried the exact same thing. The 044 was cavitating with that setup, it just couldn't get enough fuel in.

If you want to run an external pump then add a surge tank with a decent size feed into the back of the 044, otherwise get an 040 and replace the in tank walbro and run one pump.

[GeeTR]

...the bosch flows a truckload more...

The Bosch does indeed, but the Walbro's issue is suppling flow at high pressures, which isn't occurring here as its not pushing onto a FPR and making 60psi, its pushing into the back of the intake of another pump; Its pushing into negative pressure area. hence Id think It'd be fine.

Don't get me wrong, im not a fan of the setup either, but I know ppl that do run it like that, and its fine. The things you can get away with are amazing.

Dave, were the two pumps close to together?

PS: Nice sounding setup Cory, but wtf's a Chucki?

Edited February 24, 2008 by GeeTR

[BHDave]

the 044 was in the back corner of the boot walbro in the stock location in the tank, so maybe 800mm between them by the time the hose wound it's way into the boot.

to be honest i think the 044 just didn't like a 5/16 feed line as i had the same problem when i initially installed the surge tank and maintained the same 5/16 fitting on the inlet of the 044. I upsized to 3/8 (i think) or maybe 1/2inch, can't remember, and the problem went away.

[Risking]

Its not feeding a negative pressure area at all. Thats why you need a lift pump to feed it. The old VL turbo pumps needed a lift pump due to this same reason.

If it did produce a neg area behind the feed there would be no need for a surge tank or a lift pump as the 044 would generate its own fuel supply.

Dave is correct the 044 will always cavitate when being feed by something like a walbro with a 5/16ths line. A 3/8ths feed should be fine for that pump. You really need to do it properly and run a surge tank gravity feeding into the 044. Or use an intank 040 and all your problems are covered with an intank solution.

[GeeTR]

Its not feeding a negative pressure area at all. Thats why you need a lift pump to feed it. The old VL turbo pumps needed a lift pump due to this same reason.

If it did produce a neg area behind the feed there would be no need for a surge tank or a lift pump as the 044 would generate its own fuel supply.

Dave is correct the 044 will always cavitate when being feed by something like a Walbro with a 5/16ths line. A 3/8ths feed should be fine for that pump. You really need to do it properly and run a surge tank gravity feeding into the 044. Or use an intank 040 and all your problems are covered with an intank solution.

Confusions My point was that a Walbro, pushing against no restriction (or think of it, as having its output sucked from it by the 044) should keep up with a 044.

An 044 (roughly 040 sized i thought) into a S13 tank while not technically hard, isnt a simple affair I'v found; which is why people supplement the setup with a external 044, simply using the smaller Walbro to force feed it (and give it that head of pressure your talking about)

[Shockster0429]

My 044 will be mounted in my engine bay, so there will basically be the length of the car's distance between the two. I think your pumps might have been too close together? OR maybe it was too small of a line. In theory you would think the fuel would be sucked through the walbro more with the 044 since they are hooked to the same line it would be aiding.. Maybe I'll call bosch tomorrow or a company that sells these pumps and uses them to see what they think.

GeeTR this is a chuki front end and my car...

[GeeTR]

ooooh, you mean a Onevia!!

[Shockster0429]

ooooh, you mean a Onevia!!

not quite its a hatch back lol. 89's here came with Zenki or pig nosed front ends, 91-94's came with what you see above called a Chuki.

[GeeTR]

Ahh thats right. A mate owned an older KE24 240 while in the US.

Outa interest, who coined the terms Chuki and Zenki?

[Shockster0429]

Ahh thats right. A mate owned an older KE24 240 while in the US.

Outa interest, who coined the terms Chuki and Zenki?

The Japanese I do believe, and its KA24 .

[Wheezy]

The Japanese I do believe, and its KA24 .

We call them a Onevia in Aus. The opposite of Sileighty.

Thus your Chuki is a 180sx in Japan, with a 2.4L making 240, sucks to be a yank I guess

Edited February 25, 2008 by Wheezy

[BHDave]

chuki is an sr 180 front end, zenki is the ca 180 front end, as far as Aussies and Japanese are concerned.

type x front ends have a different name again, but i can't remember it as i've only seen it mentioned once.