This guide covers Mazda MX-5 Miata NA (MK1) and NB (MK2/MK2.5) models with 1.6L B6 or 1.8L BP engines being converted from naturally aspirated to turbo. Use it to match the vehicle application, engine oil-feed source, turbocharger, oil drain configuration, and coolant hose size to the correct GryphonTek line kit.
Identify the vehicle application first because Early NA models use a different engine-side oil-feed source from Late NA and NB models. Then select the exact turbo family because the oil inlet fitting, oil-flow configuration, drain flange, and coolant connections are not universal.
1. Identify Your Miata Application
GryphonTek Miata turbo conversion kits are divided into three vehicle application groups. This determines the engine-side oil-feed fitting and the coolant hose size supplied with applicable water line kits.
| Product Selection | Year / Engine | Oil Feed Source | Engine-Side Hardware | Coolant Hose Size |
|---|---|---|---|---|
| Early NA / MK1 | 1989–1993 1.6L B6 |
Exhaust-side engine oil port | Direct-fit M10 adapter | 8 mm / 5/16" |
| Late NA / MK1 | 1994–1997 1.8L BP |
Oil pressure sensor port | 1/8 BSPT sensor tee | 8 mm / 5/16" |
| NB / MK2–MK2.5 | 1998–2005 1.8L BP |
Oil pressure sensor port | 1/8 BSPT sensor tee | 10 mm / 3/8" |
Important: These are GryphonTek catalog application groups. Registration year, international-market vehicles, engine swaps, and modified blocks may differ. Confirm the installed engine and actual oil-feed source instead of selecting by chassis year alone.
How to Select the Correct Kit
- Identify whether the car uses the Early NA, Late NA, or NB oil-feed arrangement.
- Confirm the exact turbo brand, model, oil inlet, drain flange, and whether the center housing is water-cooled.
- Choose the required kit type: complete oil and water, oil feed and return, oil feed only, oil drain only, or water lines only.
- Confirm turbo position, manifold layout, oil-pan return connection, and available hose routing before installation.
2. Choose Your Turbocharger
Select the turbo family installed on the vehicle. The oil-feed configuration shown below refers to the corresponding GryphonTek kit and should not be applied as a universal specification to unrelated turbo models.
| Turbo Family | GryphonTek Oil Feed Configuration | Available Kit Types | Products |
|---|---|---|---|
| IHI VJ35 | Restricted oil feed with 1.8 mm inlet restrictor. | Complete Oil & Water Feed & Return Oil Feed Oil Drain Water Lines |
View Kits |
| Mitsubishi TD04 / TD04L | Restricted oil feed. Select the listed turbo oil inlet thread on the product page. | Complete Oil & Water Feed & Return Oil Feed Oil Drain Water Lines |
View Kits |
| Mitsubishi TD05H | Restricted oil feed with 1.8 mm restrictor. Select the listed turbo oil inlet thread on the product page. | Complete Oil & Water Feed & Return Oil Feed Oil Drain Water Lines |
View Kits |
| Garrett GBC20 / GBC22 | Calibrated restricted oil-feed configuration. | Feed & Return Oil Feed Oil Drain |
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| Garrett GT25R / GT28R | Restricted oil feed with 1.0 mm inlet restrictor. | Complete Oil & Water Feed & Return Oil Feed Oil Drain Water Lines |
View Kits |
| Garrett T25 / T28 | Restricted oil feed with 1.8 mm inlet restrictor. | Complete Oil & Water Feed & Return Oil Feed Oil Drain Water Lines |
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| Garrett T3 / T4 | Restricted oil feed with 2.0 mm inlet restrictor. | Feed & Return Oil Feed Oil Drain |
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| Holset HE221W | Full-flow, non-restricted oil-feed configuration. | Feed & Return Oil Feed Oil Drain |
View Kits |
| Holset HX30 / HX35 | Full-flow, non-restricted oil-feed configuration. | Feed & Return Oil Feed Oil Drain |
View Kits |
| Holset Super HX30W | Full-flow, non-restricted oil-feed configuration. | Feed & Return Oil Feed Oil Drain |
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| BorgWarner EFR 6258 / 6758 | Full-flow external oil feed fitting configured for the EFR internal oil-control arrangement. | Complete Oil & Water Feed & Return Oil Feed Oil Drain Water Lines |
View Kits |
| Precision PTE | Full-flow, non-restricted configuration used by the listed GryphonTek PTE kits. | Feed & Return Oil Feed Oil Drain |
View Kits |
3. Which Kit Type Do You Need?
Choose the system according to which parts of the turbo oil and coolant plumbing are being installed or replaced.
| Kit Type | Included Systems | Best Used For |
|---|---|---|
| Complete Turbo Oil & Water Line Kit | Oil feed, oil drain/return, and turbo coolant lines | Water-cooled turbo conversions requiring the complete plumbing package |
| Complete Oil Feed & Return Kit | Oil feed and oil drain/return systems | Oil plumbing installation when coolant lines are not required or are already installed |
| Turbo Oil Feed Line Kit | Engine-side adapter, -4AN PTFE feed line, and turbo fitting | Installing or replacing the pressurized oil supply to the turbo |
| Turbo Oil Drain Hose Kit | Turbo-specific drain flange, reinforced return hose, oil-pan fitting, gasket, and installation hardware | Establishing a high-flow gravity return from the turbo to the oil pan |
| Turbo Water Line Kit | Coolant hoses, turbo fittings, engine fittings, and hardware | Connecting a compatible water-cooled turbo to the engine |
4. Miata Turbo Oil Feed System
The turbo oil feed is a pressurized supply line. The engine-side connection changes between Early NA and later Miata applications, while the turbo-side fitting and flow configuration change according to the turbo family.
Early NA / MK1 1.6L B6
Early NA applications use an exhaust-side engine oil port. The corresponding kit supplies a direct-fit M10 adapter and a flexible -4AN PTFE stainless-braided oil feed line.
Late NA and NB 1.8L BP
Late NA and NB applications take the turbo oil supply from the oil pressure sensor location. The corresponding kit uses a 1/8 BSPT sensor tee and a -4AN PTFE stainless-braided feed line.
Turbo-Specific Oil Flow
The oil-feed fitting must match the listed turbo configuration. Some kits use a calibrated external restrictor, while other kits use a full-flow fitting because the turbo application requires a different oil-control arrangement.
Do not double-restrict the oil supply. Do not add a second external restrictor to a GryphonTek kit that is already configured for the selected turbo unless the turbo manufacturer or GryphonTek confirms that the additional restriction is required.
5. Miata Turbo Oil Drain and Return System
The turbo oil drain is a gravity-return system. Oil must leave the center housing freely and return to the oil pan without back-pressure, sharp bends, collapsed hose sections, or low points that can trap oil.
GryphonTek oil drain kits in this collection use a turbo-specific drain flange, reinforced high-flow NBR hose, gasket, oil-pan return fitting, clamps, and mounting hardware. The drain fitting must match the bolt spacing and outlet geometry of the selected turbo.
Oil-pan modification is required. Naturally aspirated NA and NB engines do not have the complete turbo oil-return connection used by these conversion kits. Installation requires a correctly positioned oil-pan return fitting.
Oil Drain Installation Requirements
- Position the turbo center housing so the drain outlet faces downward within the turbo manufacturer's permitted orientation.
- Maintain a continuous downward path from the turbo drain to the oil pan.
- Avoid hose kinks, low points, tight bends, and sections that rise before reaching the oil pan.
- Keep the drain hose away from the turbine housing, exhaust manifold, and sharp edges.
- Confirm that the oil-pan fitting, engine mount, air-conditioning hardware, and manifold do not interfere with the hose route.
6. Miata Turbo Water Line System
Water line kits connect compatible water-cooled turbos to the Miata cooling circuit. The GryphonTek routing bridges the thermostat-case and mixing-manifold connections to the turbo center housing.
| Application | Vehicle Group | Coolant Hose Size |
|---|---|---|
| NA / MK1 | 1989–1997 | 8 mm / 5/16" |
| NB / MK2–MK2.5 | 1998–2005 | 10 mm / 3/8" |
Water line kits are available only for the compatible turbo families listed in the turbo selection table. A turbo that does not use coolant ports does not require a turbo water line kit.
Route coolant hoses away from the turbine housing and exhaust manifold. After installation, refill and bleed the cooling system according to the vehicle service procedure before operating the engine.
Factory 2004–2005 Mazdaspeed Miata
This guide is for naturally aspirated NA and NB models being converted to turbo. A factory Mazdaspeed Miata uses different engine-side and installation hardware and should be matched through the dedicated Mazdaspeed Miata product collection.
View Factory Mazdaspeed Miata Turbo Line Kits →7. Pre-Order Fitment Checklist
Confirm the following information before selecting a kit:
- Early NA, Late NA, or NB application
- Installed 1.6L B6 or 1.8L BP engine
- Any engine swap or modified oil-feed port
- Exact turbo brand and model
- Turbo oil inlet thread or flange configuration
- Restricted or full-flow GryphonTek feed option
- Turbo drain flange and bolt spacing
- Water-cooled or oil-cooled center housing
- Oil-pan return fitting location
- Manifold position and available hose clearance
If the engine, turbo model, existing fittings, or manifold layout cannot be identified, send clear photos of the engine oil-feed source, turbo oil inlet, turbo drain outlet, coolant ports, and overall turbo position before ordering.
8. Frequently Asked Questions
Are these kits for a factory Mazdaspeed Miata?
No. This collection is designed for naturally aspirated Mazda MX-5 Miata NA and NB models being converted to turbo. Factory 2004–2005 Mazdaspeed Miata models should use the dedicated Mazdaspeed Miata collection.
Which application should I choose for an engine-swapped Miata?
Choose according to the installed engine and actual oil-feed source, not the body year alone. Confirm whether the engine uses the Early NA exhaust-side oil port or the Late NA/NB oil pressure sensor location.
Is a turbo oil return line the same as an oil drain line?
Yes. Turbo oil return line and turbo oil drain line describe the gravity-return path that carries oil from the turbo center housing back to the engine oil pan.
Does the oil drain kit require modifying the oil pan?
Yes. A naturally aspirated NA or NB engine requires an oil-pan return connection for the turbo drain. The fitting must be positioned to maintain a free downward return path while avoiding internal and external interference.
Does every turbo require an external oil restrictor?
No. The oil-feed configuration depends on the exact turbo. Some GryphonTek kits use a calibrated external restrictor, while other listed applications use a full-flow fitting. Select the kit by turbo family and do not add another restrictor unless confirmed.
Does every turbo conversion require water lines?
No. Water lines are required only when the selected turbo center housing uses coolant ports. Check the turbo compatibility table and the individual product page before ordering.
Why are the NA and NB coolant hose sizes different?
NA water line kits are configured for 8 mm / 5/16-inch vehicle-side coolant connections, while NB kits are configured for 10 mm / 3/8-inch connections.
Can I use a universal turbo oil line kit?
A universal kit may not match the Miata engine oil source, turbo inlet thread, oil-flow requirement, drain flange, coolant connection, or available routing. Match both the vehicle application and exact turbo family before installation.
Find the Correct Kit for Your Miata Build
Select your turbocharger from the collection or contact GryphonTek if your engine, turbo model, or existing fittings differ from the listed configurations.