The V2 IS300 / GS300 twin fuel pump hanger has been shipping for a while now. This covers what changed from the original, and walks the assembly with the details that actually cause trouble.
It is the same price as the V1.
Watch the full walkthrough
What changed from V1 to V2
Studs instead of a bulkhead connector
This is the change that matters most.
The original hanger used a standard bulkhead connector, and that connector had an amperage ceiling. It is the reason ASE restricted V1 usage to the Walbro 450 and 485 — not because the hanger could not take more, but because pushing higher-draw pumps through that connector risked melting it.
V2 uses stainless studs instead. That removes the bottleneck almost entirely, so pump choice is no longer a decision constrained by the connector. Two Hellcat pumps are on the table if that is what your build calls for.
For context on what the old limit actually allowed: two Walbro 485s are still capable of supporting close to 1,400 wheel horsepower with appropriately sized injectors. The connector was never crippling the product. The change simply removes a decision customers should not have had to make.
Hardcoat anodized in house
Every hanger comes off the machine in a raw machined finish, which looks good on its own. All of them are then hardcoat anodized in house in the anodizing station at the back of the shop. That is done for longevity and E85 compliance rather than appearance.
Delrin isolators
The stud isolators are Delrin — not 3D printed, not general-purpose plastic. Delrin tolerates heat and is safe with gasoline, ethanol and other alcohol-based fuels.
Venturi machined into the pump bracket
On the original hanger the jet pump assembly for the siphon was a modified factory piece. On V2 the venturi is machined directly into the pump bracket. It is more compact, simpler to assemble, and it flows considerably more than the modified factory unit did.
Placement matters as much as flow: in this application the venturi drops fuel directly onto the filters low in the tank, which is what keeps cavitation and aeration down as the level drops.
You do not have to run two pumps
It is a twin hanger, but it is optimized for up to two pumps, not dependent on two.
If the goal is simply converting the car to a return system on a single pump, plug one of the two ports with a 6 ORB plug and run one. The plug is supplied.
Assembly
Pump adapters
Fuel pump adapters are available for most popular pumps on the market, including brushless options. Each adapter ships with its own instructions via QR code.
Fit the O-ring below the first barb with a little grease on it. Then fit the half-moon crescents underneath the barb, just above the O-ring.
Get one crescent seated and pull it up first. One side of the O-ring will still protrude slightly and that is fine — with one side secured the second is far easier. Use the second crescent to push the O-ring down into place, working pressure against the back side so the front stays where you want it. You will feel it snap under the barb.
A little lube goes a long way. Once fully assembled these get tight to rotate, and the necks of the pumps are plastic.
The eccentric outlet — read this before you tighten anything
The pump outlet is not in the center of the pump. It is eccentric, not concentric.
That means you cannot simply thread the second pump up into the manifold, because it will rotate around its center point instead of seating. Snug one fitting into the manifold, leave the second loose enough to still have threads engaged but rotate freely, then walk the pump into position and tighten the fitting up into the cavity using the hex, keeping the pump perpendicular to the base.
The screws
They are 3 mm. Start with a clean Allen key so you do not round the heads — these are not something you will find locally.
Take it slow and walk around the perimeter, pulling the assembly together gradually rather than tightening one screw down at a time.
Keep a set of cheap sacrificial Allen keys and trim one short. The screw tucked under the fuel manifold is genuinely awkward with a full-length key and takes seconds with a stubby one. The outer perimeter screws are easy either way.
Do not fight the final assembly. The pump necks are plastic, and a broken pump is an expensive way to save five minutes.
Hose routing
Loop the hose around the pump and then drop down. It is cleaner, more compact, and keeps the hose clear of the float bracket when you mount it.
Slide the pump mount on from the back side — away from the ring terminals.
Float bracket
Same bracket as the original. Keep it roughly parallel to the cavity up top, drop one screw in and hold it, then start the second.
The bracket is pliable, which is deliberate. Bend it for finger room while you start the threads, then bend it back once everything is snug.
Dropping it into the tank
Both pumps and the float go through the tank opening together. Angle it, fish the pumps through, and walk it in. It is a tight fit — the tightest part is usually getting the hose barb past the neck. A longer hose gives you more room to work if clearance is fighting you.
How the pumps should be wired
Pumps should be staged, not run together constantly. The car should start, idle and cruise on a single pump, with the second coming on only when demand calls for it. Staging keeps fuel temperatures down and extends pump life.
The ASE relay harness is not application specific — the same harness is used across every ASE hanger, because standard four-pin relay wiring is identical on any car.
A note on the dust seals
The supplied dust seals are for the outer connector only. They do not go inside the tank. They are neither fuel safe nor watertight, so they serve no purpose in there.
Proven capacity
The 8AN feed and 6AN return combination has been tested upwards of 1200 hp. That figure is the tested plumbing capacity of the system as configured, which is the number to build around.
Get one
Lexus IS300 / Altezza Twin Fuel Pump Hanger V2
Lexus GS300 / Aristo Twin Fuel Pump Hanger V2
Available as hanger only, or with the relay kit, AN or banjo fittings, and pumps pre-installed. Questions about your specific setup — email autosportsengineering@gmail.com or use the contact page.