UNDERSTAND WHAT FEEDS YOUR ENGINE
Some fuels the engine. The rest must return to the tank while the regulator holds pressure. See the whole balance, from a quiet idle to your chosen boost level.
Fuel reaching the rail at the operating pressure.
Fuel the engine consumes at your chosen load.
Surplus the regulator and return path need to pass.
Start with ten Evo X configurations. Mix and match the pump, rail and regulator. Then change the fuel, boost and engine demand to see how the estimates respond.
Interactive estimates, with assumptions and source data included.
Ten mix-and-match Evo X configurations, calculated at your fuel pressure and engine demand. All flow results are estimates at the target pressure.
38.0 psi rail · 13.5 V · 2.0 L/h engine use. FPR + return capacity is unverified.
10% flow reserve, current boost and BSFC. Pump supply only; injectors and engine limits are unverified.
Petrol · 450 crank hp · 25.0 psi boost · 13.5 V · 10% flow reserve target
| Build | Pump | Rail / FPR | Rail supply L/h | Engine L/h | Return L/h | Idle return L/h | Supply result |
|---|---|---|---|---|---|---|---|
| Stock OEM Curve not available | Stock railStock FPR | — | 164.4 | — | — | OEM pump curve required | |
| AEM 320 (legacy) Legacy graph estimate | Stock railStock FPR | 247.9 | 164.4 | 83.5 | 316.6 | Margin available | |
| AEM 320 (legacy) Legacy graph estimate | AMS Evo X railStock FPR | 247.9 | 164.4 | 83.5 | 316.6 | Margin available | |
| AEM 320 (legacy) Legacy graph estimate | Stock railAEM 25-302BK | 247.9 | 164.4 | 83.5 | 316.6 | Margin available | |
| AEM 320 (legacy) Legacy graph estimate | Radium Evo X railRadium DMR-RA | 247.9 | 164.4 | 83.5 | 316.6 | Margin available | |
| DW65c Manufacturer table | Stock railStock FPR | 214.4 | 164.4 | 50.1 | 260.3 | Margin available | |
| DW300c Manufacturer table | AMS Evo X railAEM 25-302BK | 264.7 | 164.4 | 100.3 | 329.8 | Margin available | |
| 450 · F90000267 Manufacturer table | Radium Evo X railAEM Hi-Cap 25-305BK | 330.5 | 164.4 | 166.1 | 409.5 | Margin available | |
| 450 HP · F90000274 Manufacturer table | Stock railAEM Hi-Cap 25-305BK | 342.6 | 164.4 | 178.2 | 412.7 | Margin available | |
| 450 HP · F90000274 Manufacturer table | Radium Evo X railRadium DMR-RA | 322.3 | 164.4 | 157.9 | 396.2 | Margin available |
All rows share the operating-point inputs. The first nine start with an OEM-style feed/return arrangement; build 10 includes a current Radium hanger and revised plumbing. Every pressure-loss value is an editable assumption. “Margin available” assesses supply only; it does not certify FPR bypass capacity or fitment.
Change parts independently. Matching the hardware does not automatically change the assumed hydraulic losses.
Pump: Legacy 320-E series, 13.5 V. Digitized graph shape normalized to 320 L/h at 43 psi. Not the gasoline 50-1000 or a substitute for every current 340 revision. Needs an appropriate Evo X installation kit or matched hanger. Source
Rail: Retains the factory rail. Pressure loss is not known from a verified installed test. Source
FPR: Uses the separately entered measured OEM base pressure. No assumed L/h bypass limit. Source
Selected build. Engine power/duty and all other inputs stay fixed during this pressure sensitivity sweep.
Lines stop where reference data stops. Missing curve segments are not zero flow. Pump losses are solved again at each boost point; return lines assume the FPR can regulate.
Flow capacity and pressure regulation are different checks.
The pump must overcome base pressure, boost and feed losses. A pump’s “320” or “450” name is not its delivery at 25 psi boost. A rail upgrade can reduce a restriction, but this report does not multiply pump flow by marketing claims.
Low engine consumption leaves more fuel for the FPR to bypass. The Evo X return hose and in-tank jet can raise return backpressure. An adjustable FPR cannot necessarily correct a restriction farther downstream. Radium’s Evo X notes.
If demand exceeds capacity, the target pressure cannot be maintained. The displayed shortfall is at that target pressure; the report does not predict the resulting lower rail pressure, AFR or engine output. A zero-return result is not adequate sizing headroom.
Use measured rail pressure minus manifold pressure, pump-terminal voltage and fuel consumption at load. Confirm low-load pressure and return behavior too. The report does not establish injector capacity, compatible fittings, filter choice or a complete installation bill of materials.
Pressures are gauge psi, flow is L/h. Both K values are user-assumed pressure losses at 300 L/h. Zero tank pressure and negligible static head are assumed. The rail is treated as one pressure node; injector-to-injector pulsation and pressure gradients are not resolved.
The solver finds the intersection of the pump curve and the feed-loss curve. Internal supply diversion recirculates in the tank; it is not engine consumption or FPR return. Actual FPR return equals this result only when the target pressure is held.
1 hp = 0.745699872 kW. Density is kg/L and BSFC is lb/(hp·h). Preset density and BSFC are editable assumptions. E85 composition, temperature and tune vary. Fuel selection changes demand assumptions, not the manufacturer pump curve’s test fluid.
Duty is a fraction in this equation. Injector ratings must match the fuel being evaluated. The square-root correction assumes the FPR holds constant differential pressure. In injector mode the calculated demand can change with the chosen regulator’s base pressure.
The factory regulator’s nominal 329 kPa (48 psi) pressure is the starting base value. Replace it with the measured reference-off value for your car. Manufacturer tables are interpolated linearly in pressure. TI data is also interpolated between 12 and 13.5 V. Other voltage values use the optional approximation (enabled by default): Q(V) = Q(Vref) × [1 + slope × (V − Vref)]. It is a sensitivity assumption, not a motor model. The optional derating is then applied once. No pressure extrapolation is displayed.
The reserve-adjusted power ceiling divides available rail flow by (1 + reserve) before converting it to engine power using the selected fuel and BSFC. It is not a validated horsepower rating for the car. The idle check uses its own pressure, voltage and measured/assumed consumption.
The measured idle bypass limit is checked only at the recorded idle rail pressure and fuel density. Exceeding it flags a likely pressure-control failure; the report does not cap the calculated return and pretend pressure remains correct. Unknown bypass capacity stays unknown.
AEM 320: legacy 50-1200/50-1205 series data, not a substitute for every pump sold as AEM 320/340. The gasoline 50-1000 is not modeled. The 2015 AEM chart’s gasoline 0.5-BSFC series was digitized, then its relative shape normalized to 320 L/h at 43 psi. This reconstruction avoids assuming an undocumented test-fluid density. The plotted pressure range is 35–80 psi at 13.5 V. The AEM test included its filter and FPR, so it is an assembly-curve proxy; added losses represent further assumed installation losses. Display rounding does not imply measurement precision.
The current AEM product page says 340 L/h at 40 psi and lists an 80 psi relief point; its linked revised manual says 340 L/h at 43 psi. Those differing ratings are not merged into the legacy curve. Confirm the exact revision and curve for your pump.
DW65c and DW300c: numeric tables from DeatschWerks’ linked manufacturer sheets, revision 12 October 2023, at 13.5 V. The DW300c is not the larger DW300; their curves differ.
TI/Walbro: exact F90000267 and F90000274 manufacturer tables. Test fluids and dates differ from the DW and AEM data. Small numerical differences are not a controlled cross-brand comparison. F90000274 is the higher-relief-pressure version; do not interchange these curves.
OEM: no flow curve is supplied. All-stock means the three named parts, not a complete factory vehicle calibration. User-supplied pump data is explicitly identified. FPR bypass capacities, installed feed losses and rail-specific pressure drops were not established from the retrieved sources.
| Pressure, psi | 35 | 40 | 43 | 45 | 50 | 60 | 70 | 80 |
|---|---|---|---|---|---|---|---|---|
| Flow, L/h | 326.9 | 326.5 | 320.0 | 315.7 | 304.7 | 283.1 | 261.5 | 240.3 |
| Pressure, psi | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
|---|---|---|---|---|---|---|---|---|
| Flow, L/h | 280.0 | 265.0 | 250.0 | 235.0 | 220.0 | 210.0 | 190.0 | 170.0 |
| Pressure, psi | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
|---|---|---|---|---|---|---|---|---|
| Flow, L/h | 360.0 | 340.0 | 320.0 | 295.0 | 275.0 | 260.0 | 240.0 | 220.0 |
| Pressure, psi | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
|---|---|---|---|---|---|---|---|---|
| Flow, L/h | 400.0 | 375.0 | 349.0 | 323.0 | 298.0 | 273.0 | 232.0 | 155.0 |
| Pressure, psi | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
|---|---|---|---|---|---|---|---|---|
| Flow, L/h | 455.0 | 430.0 | 405.0 | 381.0 | 355.0 | 328.0 | 268.0 | 206.0 |
| Pressure, psi | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 | 110 |
|---|---|---|---|---|---|---|---|---|---|
| Flow, L/h | 405.8 | 378.9 | 355.5 | 332.7 | 309.3 | 286.9 | 262.7 | 238.9 | 216.1 |
| Pressure, psi | 38 | 50 | 60 | 70 | 80 | 90 | 100 | 110 |
|---|---|---|---|---|---|---|---|---|
| Flow, L/h | 436.1 | 409.2 | 386.5 | 364.5 | 341.4 | 318.0 | 294.5 | 270.7 |
| Part | Use / limitation | Evidence |
|---|---|---|
| Stock rail | Retains the factory rail. Pressure loss is not known from a verified installed test. | Source |
| AMS Evo X rail | AMS.04.07.0006 series, includes a feed line and pulsation damper. Factory FPR can be retained. Aftermarket FPRs need the correct rail adapter and plumbing. | Source |
| Radium Evo X rail | 20-0112-12 rail, 8AN ORB ports. OEM FPR retention needs the plumbing kit/adapter. A compatible DMR can mount directly. | Source |
| Part | Use / limitation | Evidence |
|---|---|---|
| Stock FPR | Uses the separately entered measured OEM base pressure. No assumed L/h bypass limit. | Source |
| AEM 25-302BK | Universal remote-mount 1:1 regulator, -6 ports. Requires a bracket, suitable rail outlet adapter and complete return plumbing. | Source |
| AEM Hi-Cap 25-305BK | Universal remote-mount 1:1 regulator. 40–130 psi base adjustment. Return flow capacity has not been established for the complete Evo X return path. | Source |
| Radium DMR-RA | Direct mounting suits a compatible 8AN ORB port. Other rails need a compatible adapter/remote arrangement; check clearance. 150 psi is a conservative report scenario ceiling, not a manufacturer DMR maximum. | Source |
All combinations are planning configurations. Use a vehicle-specific pump installation kit or a hanger explicitly matched to the chosen pump. Universal pumps, universal FPRs and arbitrary rail/FPR pairs do not become direct-fit parts simply because they can be selected here. When replacing the OEM module, provide the required downstream filtration. Match fuel compatibility across hoses, seals, filter, injectors and regulator.
Primary manufacturer documents and product information retrieved 9 September 2026. AEM’s historical PDF is manufacturer-authored and hosted by a distributor. Links are for evidence; the calculator itself runs offline.
Manufacturer service manual hosted by an Evo X manual archive. Nominal regulator pressure: 329 kPa (48 psi); test range 45–50 psi with reference disconnected and about 38 psi connected at idle. Use your measured base pressure.
Manufacturer-authored manual, pages 2–3. The 320 L/h at 43 psi anchor and 13.5 V test conditions underpin the reconstructed 35–80 psi curve.
Current 340 L/h at 40 psi rating, fuel compatibility and 80 psi PRV listing. This current rating is not substituted into the legacy 320 curve.
The linked manual uses 340 L/h at 43 psi. This conflict with the product page is retained as a revision/data limitation.
Official sheet linked by DeatschWerks, Rev 10-12-23. Flow table: 30–100 psi; reference voltage 13.5 V.
Official sheet linked by DeatschWerks, Rev 10-12-23. 340 L/h at 40 psi; full table is used, not the larger DW300 curve.
Authoritative index for both DW pump PDFs. Evo X DW300c application kit is 9-307-1026; confirm the exact kit for your model.
21 May 2019; Stoddard test fluid; 12 and 13.5 V. The model uses the unambiguous 30–100 psi tabulated points, including the marked high-pressure flow drop.
15 January 2019; Solvent 142-66; 12 and 13.5 V. US gallons/hour converted with 3.785411784 L/US gal. Ambiguous repeated low-pressure samples are omitted; conservative model overlap is 38–110 psi.
Factory-line/FPR compatibility, included feed line and pulsation damper. Flow-area and marketing improvement claims are not applied as whole-system multipliers.
8AN ORB ports. The 20-0112-PK plumbing kit provides an OEM FPR adapter and factory-feed connection.
1:1 pressure reference, 20–120 psi adjustment and -6 ports. No matched Evo X bypass-capacity curve was retrieved.
1:1 reference and 40–130 psi adjustment. A large return orifice is described; it is not assigned an invented L/h capacity here.
1:1 vacuum/boost reference, direct 8AN ORB mount and remote-mount option. Minimum pressure 18.5 psi; maximum depends on the pump/system.
OEM return/jet restrictions; current jet consumes 15–45 L/h. The 8AN feed and OEM-feed-as-return conversion are described. A current hanger is explicitly distinguished from earlier designs.