fuel pump/surge tank questions/idea's

**JZA70 R** · 06-01-2010, 02:34 PM

Still a few questions unanswered in the first post im hoping to clarify... for anyone still not conviced a single 044 with suffice, for arguements sake ill use two 044's.

**DrNick** · 06-01-2010, 04:19 PM

hey Todd have you thought about using a Denso 1020 fuel pump as your lift pump. This is the USDM JZA80 pump which flows buttloads of fuel and should fit nicely into your stock hanger. I got mine recently for $150 so its pretty cheap and I would always trust Denso quality.

**JZA70 R** · 06-01-2010, 04:40 PM

nah i havent, what fuel pumps im gonna use isnt really my biggest concern... which way im going to power the pumps and the effect that has on heating the fuel is really what im trying to find out here...

**2jzhilux** · 06-01-2010, 09:20 PM

Just power them up with constant 12v through a circut opening relay so if you crash it wont pump fuel everywhere.
The difference with the heat of the fuel through the pumps wont be enough to make a difference.

**Draven** · 06-01-2010, 09:22 PM

re: the alternate power ... when I was looking at my options I decided to go for constant power because of a few things I'd read (on TEH INTAHWEBS!), and also the 044 is a noisy bitch no matter where you put it, and if it kept changing pitch I think I'd end up crashing my car into a telegraph pole to end the pain.

imho ideally you'd have a high volume low pressure lifter into the surge tank. That way you can have the engine return back into the tank (rather than the surge tank) to minimise the effects of overheating (a bit).

That said, Ed ended up going for a fuel cooler, which is not such a silly idea when pushing large-ish numbers

**JZA70 R** · 07-01-2010, 01:19 AM

i thought you NEED to have fuel returning to the surge tank otherwise the 044 (or even worse 2x 044's) would pump the surge tank dry... you would need a pretty impressive lift pump to offset that. the lift pump would have to outflow the main pumps 100% of the time or your stuffed...

regarding fuel heating, the return to the the surge and the return to the fuel tank are both at the top of the surge tank, so once its full - in theory hot fuel returning to the top of the surge tank should be pushed straight back into the fuel tank via the outlet on the top of the surge tank. leaving cool fuel at the bottom of the surge to be sucked by the main pumps...

**Draven** · 07-01-2010, 01:22 AM

yep.

get yourself a lifter designed for a big F-off american style engine.

realistically I'd go JZA80 lifter, 044 main pump, fuel cooler, and be happy.

My fuel only really complains toward the end of a track day

**JZA70 R** · 07-01-2010, 01:25 AM

orright ive pretty much got the info I need thanks everyone for your input.

**Mr Ed** · 19-01-2010, 10:50 AM

Curious about a couple things with this setup:
1. Where did/do you anticipate mounting an external surge tank? What sort of design is the tank itself?
2. Do you have a safety cut out for the pumps? (Ie. if the engine shuts off)
3. Do you have an aftermarket fuel reg? (Cant remember reading about one) If not, budget for one, youll need it soon enough.

My opinions:
I agree with you the a single 044 should be fine for the moment. If it is insufficient then it will easily be picked up during tuning, in which case you could fix it up then. True its good to back 2 pumps as a back-up in case one goes, but this train of thought can lead to you getting carried away pretty quickly. I would design the surge tank with 2 main pumps in mind though, not the sort of thing you want to have to remove and modify should 1 pump not end up being enough.

I think your nuts not replacing a 20yr old lift pump though. Its a pain in the arse job to replace but is a very cheap part (comparitively), the tank is going to be out anyway while youre mucking about with lines, best to just get it over and done with then.

If your stock lines end up being too restrictive, just run a new low pressure line for the return and use the stock return line as a 2nd fuel supply line. I really doubt youll need to do this though.

**JZA70 R** · 19-01-2010, 02:11 PM

no worries, although just to clarify first, this is all theory and research (as it should be) before I actually start physically creating this fuel system... hence there are a lot of specifics not yet finalised.

1. I am yet to get under the car and search for suitable locations to mount a simple 1 - 2L surge tank.

2. The pumps WILL (just like factory) be wired in a legal, safe and practical configuration. I have a personal friend (talented auto-electrician) looking after this part of the project for me and trust he will find the best solution.

3. I dont have an aftermarket fuel reg and dont plan on getting one until it becomes a restriction OR I require one just so I can mount a FP sensor in it for my aftermarket ecu... even then i would consider modifying the stock rail to include a boss/provision for a fuel pressure sensor/sender.

I believe aftermarket fuel pressure regulators are designed to give you control over fuel pressure (which i dont need) I also believe they provide less restriction (depending on the unit) - which I also dont need as people have proven the stock reg to hand high horsepower fine.

The main reason I want to keep the stock lift pump is because you wont find a better scavenger of the tank, and after the last pump I had which had no pickup, I dont want to have that hassle again. I also have the urge to see how long (even a stock pump) will last when it has no work to do (no load)...

Thats a good idea with the stock fuel lines, ill keep that in mind, thanks.

**Mr Ed** · 19-01-2010, 02:24 PM

Cool, cheers. Very interested to see what your mate comes up with for the safety cut off, although I suspect yours might be a bit simpler than mine due to your aftermarket ECU (Im working something out to work with my stock ECU)

I 100% agree that an external surge tank is the way to go. Ive never been in a car with an internal surge tank in the cabin somewhere (ie. any supra) without having major fuel smell problems. The only thing Ive seen that fixes it is an entirely new fire wall over the whole fuel system. Finding a spot to mount the tank externally might be tricky but its still a shitload better than internally.

The reason I suggested an aftermarket fuel reg isnt to do with tunability or power restriction, the problem is at the low end of the scale. Youll find that unless you run low voltage to the pumps at low RPM your pump will be flowing full fuel flow to a rail that is not injecting very much fuel. On many cars this results in too much flow for the stock reg to bleed off so fuel pressure increases higher than it should and you end up with a stalling car or shitty idle. Ive seen a single 044 do this on a stock 2JZ before, double 044s would certainly do it.

**JZA70 R** · 19-01-2010, 03:58 PM

that should be directly reflected in the fuel pressure reading... if the reg cant bleed enough fuel, pressure will build and you will see it when you take a pressure reading.

i plan on tuning the car from scratch so if base fuel pressure was affected by maybe 1 or 2psi i wouldnt be so worried as i can tune around that.

i find it hard to believe this would be a likely outcome as there are that many people running 044's now with their stock regs and you dont hear much about it... thanks for the heads up though.

**Mr Ed** · 19-01-2010, 04:11 PM

You could tune around it and it likely wouldnt cause any major problems (no load after all) but it is kind of a band aid fix. As you said though, youll find out if you have the problem soon enough.

People dont get the problem? 2JZR31 and 60TJZ had the same problem, seen it a few other times too. I cant think of one that doesnt. (Id go to SF and have a look around but it seems people are scared of me there