[ChrisN]

Hi guys - more advice needed please.

I'm still working on putting the G13B GTI into my 89 Sierra SWB. I was planning to use a surge tank like this one pictured below ...



... along with a Facet pump as lift pump and an EFI pump downstream from the surge tank. The Sierra has standard springs and no body lift (and at this stage I plan to keep it pretty stock), and I'm worried about clearance between the diff housing and the surge tank on full bump with a passenger in the back.

I can probably work around it, but it brings up the question - is a surge tank needed? What happens if you just have the low-pressure pump feeding direct into the EFI pump? Does the Facet pump simply stop pumping when it comes up against downstream pressure? I'm assuming the Facet pump can provide all the flow required (specs say 15 gallons/hour).

I guess the easiest work-around might be to mount the surge tank backwards (with the deep section towards the front), and remote the EFI tank to a different location (and trim off the pump mount).

Thanks - have a great weekend!

Chris

[shep]

I was able to fit 2 pumps, surge tank the same as the photo and a cav fuel filter under my swb sierra and none of it was in the way of a moving part.
I just sat under the car with all the bits and moved them around until I was happy with how it all fitted

[JrZook]

ChrisN wrote:

I can probably work around it, but it brings up the question - is a surge tank needed?

Quite a few of us have been running EFI engine with just a HP VL pump. No surging issues or problems off road until you get real low on fuel like <5L or so.

[Gwagensteve]

Surge tanks are terribly unsuited to a 4wd application. The evidence is in that photo- look at how muddy everything is around that tank, and consider all the hoses, hose connections, wires, motors etc all dangling down there in the mud/water/sticks

Use a coil sierra tank, mod a leaf sierra tank to take a swimmer pump, mod the mounts to make a vitara tank- I'd be doing anything to run a swimmer pump over an external pump or external lift pump/surge tank/HP pump

For a huge horsepower track car I understand the point of a surge tank- the stock in tank swimmer pump can't flow enough fuel at rail pressure, so use it to feed a HP pump, but for 100HP it's a lot of $$ and complexity that's not required.

[shiv]

i have a surge tank in the back on my tin top in an electical box. works well there

[UBZ]

JrZook wrote:

ChrisN wrote:

I can probably work around it, but it brings up the question - is a surge tank needed?

Quite a few of us have been running EFI engine with just a HP VL pump. No surging issues or problems off road until you get real low on fuel like <5L or so.

I used a BMW E30 pump for my G13B conversion .
No issues off-road , just factory pickup in tank .

[ChrisN]

Thanks for the input folks. I can see the pros and cons for the surge tank versus the in-tank pump. For hard-core work the in-tank approach would be hard to beat. And some folks have had success with a more simple approach.

Plenty to think about here!

[Gwagensteve]

There are pros to a surge tank?

[droverdave]

The pro's are due to the fact that an external pump doesn't like sucking fuel. They will do it but its not their favorite hobby.

That's why the external VL pump that everyone loves, in a VL also has a lift pump inside the tank to prime the main high pressure pump.

I too have used an external vl pump for a 4age conversion in my corolla, and it worked, but over time the pump got noisier and noisier. I then installed an intank pump with surge tank, which gave some positive pressure at the inlet of the vl pump, and from then on the pump was silent.

Any car that uses an external fuel pump, im fairly sure all of them have an internal submerged fuel pump to prime the external pump.

Perhaps a external pump that is designed to suck prior to the external HP pump could be an option. (without using a surge tank)

[JrZook]

droverdave wrote:

That's why the external VL pump that everyone loves, in a VL also has a lift pump inside the tank to prime the main high pressure pump.

I too have used an external vl pump for a 4age conversion in my corolla, and it worked, but over time the pump got noisier and noisier. I then installed an intank pump with surge tank, which gave some positive pressure at the inlet of the vl pump, and from then on the pump was silent.

This was one of my main concerns when I mounted the VL pump in mine. So to give it the best chance I mounted it very close to the tank. First pump I had (s/hand unknown k's) lasted over 3 years and only died because it sucked up some crud and jammed the pump mech. It was very quiet. The pump I have now is a $40 fuel miser VL pump. Again very quiet and no issues what so ever over the past couple of years. I have heard noisy pumps in sierras. I believe this is due to them being mounted a bit too far away from the tank and a too small of a feed line. Both factors enhancing the chance of cavitation and noise/short life.

[tanshi]

mine even ran the J20 happily without issues and no surge tank

[droverdave]

Fair enough.

But if the OEMs use a lift pump, i think its best to use a lift pump.

[Gwagensteve]

20 years ago maybe. Not many external electric fuel pumps any more- all swimmers, which is my point.

Steve.

[ChrisN]

Just to follow up on this question: I've now got the car running, using a Facet pump as lift pump, then a high-pressure EFI pump. This seems to be working OK for on-road use. Haven't had the car on the tracks yet. The pumps were very noisy initially but have quietened down a bit now - running in I guess.

[Jazzor]

I was under the impression that non-efi fuel filters didn't provide enough flow?, have you tried it without the pre filter? (unless thats an efi plastic pre-filter)

FYI I don't have a surge tank and have no issues when there is fuel in the fuel tank. The noise also might be nothing to worry about, got anyone else nearby running one to compare?

[ChrisN]

Thanks for that idea - I'll give it a run without the pre-filter and see if it makes any difference.