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| Le system |
Until a few hours ago I was planning to do a Toyota Supra mk3 fuel tank + 255 lph Walbro pump swap. However, I've just done some more reading on this particular "swap" but the guy who'd been claiming that he'd used the mk3 fuel tank hadn't been using the complete tank at all. Instead he'd been using it as a donor and swapping/welding stuff into the stock Z tank. Hmm, I almost spent €115 on a used tank which i wouldn't be able to install. Lucky me that those people from the junk yard had the day off today :)
After some more reading on available sump-options, I ran across this in-tank pump module from Tanks-inc:
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| PA-4 kit $235 |
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| installed |
The PA-4 kit comes with a 250 lph Walbro pump. The pump kit is adjustable for 6" - 10.5" deep tanks so it should fit my tank as well. Since it comes with a small reservoir tray that can hold enough fuel during hard cornering (or hard launches), I shouldn't have to worry 'bout designing and welding some baffle structure (which can always be done afterwards if the reservoir tray shouldn't suffice).
In the end, the price of this kit is about the same (a bit less) as that of the mk3 tank + the Walbro pump. The good thing is that no chopping and welding is required. Just drilling and flattening the flange. I'm glad the top of the Z tank is more or less flat so I shouldn't have to worry too much.
One thing I also have to do is to create an access panel at the boot to be able to access the pump unit without having to remove the complete tank. The pressure, return and vent connections are on top. This means that I'd have to route the lines through the boot and out again - not very elegant. My plans are to plug and shut off these connections and reroute the pressure line internally in order to use the tank's stock pump feed, return and vent connections.
[edit 25 January 2012] There's a hard line inside the tank that runs from the baffled centre section of the tank to the pump feed connection. I noticed this after removing the tank and peeping inside. So in order to use the pump feed conn. I'll need to remove this line.
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| stock tank connections |
The white tube on the pic above is the return line, so I think I should do something similar. I guess it's better to dump the return in the pump's fuel tray to keep it filled (in low fuel conditions that is). So route some hard line from the stock return to the tray.
After studying various pix of the Walbro in-tank pump, the pump outlet apparently is a barb-type connector where a 5/16 hose is clamped onto. I don't think a 5/16 barb to -6AN adapter will be necessary; clamping 3/8 hose to the pump should do.
Since the stock connections on the Z tank are mere pipes that you clamp a rubber hose on, these will either be closed off or ground off and replaced with a 3/8 barb to -6AN adapter from this Fragola kit. Summit did confirm that the barb/AN adapter fits onto the -6AN male/male bulkhead adapter. So I'd be needing two of these kits (outlet and return).
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| Fragola kit 900700 | typical Walbro kit 5/16 hose + ~35cm wire |
On the pic showing the Z's tank connections, it looks like the outlet and return nozzles are quite close to each other. If that's the case, I might interconnect them with some rubber hose to close them off, and insert two -6AN bulkhead fittings elsewhere. Option 2 is to weld in a plate with two -6AN bulkhead fittings.
DIY Pump kit design
Since I'm not planning to route outlet and return lines through the top plate, I thought it'd be better to make my own pump kit.
Why? First because I would have to do a lot of effort to close off the top plate (finding the right plugs) and it wouldn't look clean. 2) If you look at the top plate, there's apparently 16 bolts. Haven't found a 16-hole gasket anywhere. 12-hole (4.5 ID X 6.25 OD) seems more like the standard. Don't wanna limit my options. 3) And besides, I'll be saving a bit over $100, which can be spent on more useful stuff.
So the kit would basically consist of a 2mm thick 6.25" round plate + (4.5 ID x 6.25 OD) ring with weld-on nuts + L-shape tray welded to the plate. The tray size and height is yet to be determined once I've removed the tank from the car. I've already made a paper mock-up of the kit and it looks like it's gonna work just fine.
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| kit design | 4.5 ID x 6.25 OD ring/plate combo |
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| FPN009 kit |
The Walbro pump kit I have in mind is FPN009 from APEUsa.com - $110. It comes with a high pressure GSS342 type pump. I could in fact choose any kit but I think the foam pump sleeve could come in handy. These come in three sizes: thin / medium / thick which make the pump/sleeve diameter about 44 / 48 / 55 mm respectively (ref. APEUSA) . The GSSxxx pump diameter is 39mm if you'd like to know.
When it comes to attaching the pump to the kit frame, I'm thinking of something like this T-bolt style clamp, which is mucho more elegant than tie-wraps.
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| Aeromotive T-bolt clamp | $1 clamp :) |
Not planning on spending $22 on something as simple as this though. I've found a similar clamp less the "feet" for about a buck. Welding on two "feet" with mounting holes shouldn't be a daunting task. Of course I'll make a pair for the AEM hi-flo fuel filter as well.
The Walbro kit comes with about 35cm of electrical wiring which I hope is long enough to be routed to the alternative location.
Connector alternatives
Replace the pressure and return (at least the pressure connection) with a straight -6AN male/male bulkhead fitting.
From the pump outlet I could run 3/8 submersible fuel hose (Gates) ($20) to connect to a 3/8 barb to female -6AN adapter fitting ($6.39), which then connects to a straight -6AN male/male bulkhead fitting ($13). Sounds a lot like a puzzle and a roundabout way of doing things but it's cheaper than the ATL TF602 -6AN - 5/16 tank/bulkhead fitting, which can be found for $23 - $30. And 3/8 is less restrictive than 5/16.
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| barb to female AN | -6AN male-male bulkhead fitting |
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| or ATL's TF602 connector |
(guide) Lines
Pressure line
| Up to 250 HP | 5/16" or -4 AN |
| Up to 375 HP | 3/8" or -6 AN |
| Up to 700 HP | 1/2" or -8 AN |
| Up to 1000 HP | 5/8" or -10 AN |
| Up to 1500 HP | 3/4" or -12 AN |
Return line size based on fuel pump output:
(255 lph ~ 67GPH)
| Up to 45 GPH | 5/16" or -4 AN |
| Up to 90 GPH | 3/8" or -6 AN |
| Up to 250 GPH | 1/2" or -8 AN |
| Up to 450 GPH | 5/8" or -10 AN |
| Up to 900 GPH | 3/4"or -12 AN |
So, 3/8" (~9.5mm) will be the preferred size for my power goals.
Options:
- in-tank fuel hose 6" - 5/16 Chrysler spec $3 / SAE J30R10 spec 5/16 $1.75/inch (APEUSA)
- 25ft flex braided stainless steel fuel line $88 (Summit)
- 3/8 x .028 - 20ft SS hard line $54 (Summit) + Ridgid 377 37 degree flaring tool $102 (which can handle SS tubing up to .035") + Ridgid 3180365S tube cutter $63 + Ridgid 29993 SS tubing reamer $55
- 3/8 - 25ft Alu hard line natural $19 (or red anodised $48)
- 3/8 - 25ft PVF coated steel line AGS PAC-625 $28 (advanceautoparts)
-6 AN tube sleeves black $1.50 pair, red $0.95 ea., blue $1.50 pair
-6 AN tube nuts black $1.70 pair, red $1.95 ea., blue $1.70 pair
- Copper fuel line 3/8" - 25ft (7.6m) €78
According to this source: "..copper interferes significantly in the gum content of gasoline, because it is a catalyst of radicalar oxidation reactions and it accelerates peroxidation. Therefore, this metal must be avoided in any metal alloy that comes into contact with gasoline in the feeding system of engines."
Braided SS line is nice but I dunno yet if it's allowed to run it back to front. Have to check. SS hard line is actually my numero 1 but requires more expensive tools to get the job done properly :/ Copper is not an option if it's true what the research says.
I won't be driving the Z during winter conditions so that's either aluminium or the pvf coated steel line. I've read some good stories about the pvf coated lines so I guess I'll go with that. Tube sleeves and nuts red for pressure and blue for the return lines, for convenience :)
Tank vent
Rather than venting the tank directly to the atmosphere thru an open line, a two-way spring valve such as the TPV6 and TPV8 in-line valves from Newton Equipment are worth considering. The benefits are that valve is shut when the engine is switched off so there is no trace of fuel smells in the garage. The valve will open to allow ambient air into the tank when fuel is consumed (engine running). The valve will also open (to atmosphere) should any excessive pressure build up in the tank. This function safeguards the fuel system. Bit expensive though at ~$91.
But I guess I'll just stick with the stock vent system for now.
5/16 ID - 25ft rubber fuel hose $15 (Summit)
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| tank and vent lines |
FPR
Adjustable fuel pressure regulator allows manipulation of the stock fuel pressure. For the limited stock injectors, one can squeeze out more fuel by raising the fuel pressure a bit from stock base pressure. The regulator still retains the factory 1:1 boost dependent ratio.
Another benefit for changing the old regulator is that the old stock fuel pressure regulator can be sticking and creates problems such as hard cold/hot starts and excessive rich/lean conditions.
The Nismo Type-B FPR does not bolt to the end of stock fuel rail like the Type-A, but rather it can be mounted any place of choice inside the engine compartment. Type-B must be used with Tomei/Nismo FPR fitting.
Alternate tank solutions:
- 86-93 Supra mk 3 tank €90 with a 255 lph Walbro in-tank pump kit FPT005 $94 (high pressure version FPT006 $109) (APEUsa.com) IS NOT GONNA BE A DIRECT SWAP. You basically swap the internals of the Supra tank into the Z.
- ATL CFD600-HP 'Black box' kit (surge tank + 100psi in-tank pump) installed in the stock fuel tank ~$400
- or this external option from Aftermarket Industries with one or two Bosch 044 pumps:
Au$159
