HuD 91gt's 1971 240Z Turbo Build "Project Crush"
1971 240z - Project Crush
Photo: 1971 240z - Project CrushTurbocharged L28-powered 1971 240Z, built and refined over several years
HuD 91gt documents a long-running turbo conversion of a 1971 Datsun 240Z, moving from carbureted L-series engines through EFI and finally to a turbocharged, Haltech-managed L28. The thread covers engine building, wiring repairs, a custom 3 inch exhaust build, suspension alignment tooling, and an experimental twin-scroll exhaust manifold.
Specs
As stated in the original write-up.
- Engine
- L28 with 0.040 overbore flattop pistons, fully balanced, ARP hardware throughout
- Cylinder head
- P90 head, ported and polished by Whitehead Performance
- Camshaft
- Colt Cams c.542s (.491 lift, 280 duration) with Kameari adjustable cam gear
- Ignition
- 60-2 crank trigger (VR), LS2 ignition coils, Jeep CAS for sequential
- Fuel system
- 240sx throttle body, Pallnet fuel rail, 440cc injectors
- Turbo system
- HX35w turbo with 12cm housing, Tial MV-R 44mm wastegate, ported turbo manifold
- Exhaust
- 3 inch downpipe, custom 3 inch exhaust with cat replacing resonator, vibrant super quiet resonator (original build) and magnaflow muffler
- ECU
- Haltech Platinum Sport 2000
- Rear axle
- R200 with OBX LSD and Techno RT diff mount
- Suspension
- T3 rear control arms, Silvermine aluminum front control arms, Ground Control coilover sleeves, Tokico Illumina struts, larger sway bars
- Wheels
- Konig Rewind 16x7
- Tyres
- Continental Extreme 225/50r16
- Brakes
- Stock brakes with Portafield pads/shoes and Tacoma booster/master cylinder
- Interior
- Porsche Boxster seats reupholstered in black leather
Parts used
Parts named as used in the original write-up, grouped the way the Parts page groups them. Where one of the shops we index lists the same thing for this car, it is shown underneath with a link to the shop.
Engine 7
- L28 engine block with 0.040 overbore flattop pistons
Fully balanced with ARP hardware throughout
In the shops
Piston & Ring Set for Datsun 280ZX L28 (1980-83) ↗
JDM Car Parts· $1,299.99 USD
Piston Ring Set (L28 Engine) ↗
Z Car Depot· $79.99 USD
Flat Top Piston Set for L28 Engine ↗Z Car Depot· $429.00 USD - P90 cylinder headWhitehead Performance
Ported and polished for the build
In the shops
Cylinder Head Water Fitting - L-Series (L24/L26/L28) ↗
The Datsun Depot· $57.00 USD
Cylinder Head Gasket Set (Rover V8 Carb) ↗
bpnorthwest.com· $59.99 USD
Water Pump Housing to Cylinder Head Gasket ↗bpnorthwest.com· $0.69 USD - Colt Cams c.542s camshaftColt Cams
Fitted with Kameari adjustable cam gear
In the shops
Camshaft Sprocket to Cam Bolt ↗James Paddock Ltd· £3.75 GBP
- Ported intake manifold
Hacked open and rewelded for more flow
In the shops
Intake Manifold Assembly for L28 Engine ↗JDM Car Parts· $999.99 USD
OER Complete 45mm Carburetors & Intake Manifold Kit for L6 Engine ↗JDM Car Parts· $2,299.96 USDOER Complete 47mm Carburetors & Intake Manifold Kit for L6 Engine ↗JDM Car Parts· $2,469.96 USD - Ported turbo manifold
Used to feed the turbocharger
In the shops
Gasket, exhaust manifold, rolls Royce 1965-94 non turbo ↗Moss Europe (UK)· £4.25 GBP - HX35w turbocharger with 12cm housing
Core turbo for the conversion
- Tial MV-R 44mm wastegateTial
Controls boost pressure
Fuel & Ignition 9
- 60-2 crank trigger (VR)
Used for ignition timing reference
In the shops
36-1 Toothed Crank Trigger Wheel ↗
C Bradley Motorsport· £39.50 GBP
Ford Duratec Ø146mm Crank Pulley & 36-1 Trigger Wheel ↗C Bradley Motorsport· £162.50 GBP
Ford Duratec Ø164mm Crank Pulley & 36-1 Trigger Wheel ↗C Bradley Motorsport· £178.00 GBP - LS2 ignition coils
Used for ignition system
In the shops
LS2/LS7 Ignition Coil Relocation Harness ↗Z Car Depot· $51.00 USD
Lucas Ballasted Ignition Coil ↗bpnorthwest.com· $31.99 USD
Ignition Coil Non Ballast System ↗bpnorthwest.com· $20.99 USD - Jeep CAS
Used for sequential ignition triggering
- 240sx throttle body
Fitted to the intake system
In the shops
240SX Throttle Body Spacer Adaptor (280Z/280ZX) ↗Z Car Depot· $24.99 USD
Throttle Body ↗
Moss Motors – Triumph TR6/TR250· $1,145.63 USDThrottle Body, X-Type ↗Moss Motors – Triumph TR6/TR250· $454.77 USD - Pallnet fuel railPallnet
Part of EFI fuel delivery
- 440cc fuel injectors
Sized for current tune, with plans to upsize for more boost
In the shops
DeatschWerks 440cc Top-Feed Fuel Injectors (6-Pack) ↗
JDMuscle — Mazda MX-5· $499.00 USD
DeatschWerks 440cc Fuel Injectors, Set of 4 [Civic Si, S2000, RSX/TSX] ↗JDMuscle — Mazda MX-5· $329.00 USD - VW recirculating valve
Used in the boost/vacuum system
- Bosch 2-wire idle valveBosch
Used for idle control
In the shopsBosch Fuel Pressure Regulator ↗Retroford (Gloucester)· £73.17 GBP
Bosch Aerotwin 26" Wiper Blade ↗C Bradley Motorsport· £19.00 GBP
Bosch Aerotwin 24" Wiper Blade ↗C Bradley Motorsport· £18.00 GBP - Haltech Platinum Sport 2000 ECUHaltech
Manages fuel and ignition for the turbo setup
In the shops
Haltech Multi-Function CAN Gauge ↗
MiataSpeed· $426.00 USD
1968 Buick Gran Sport 400/Skylark Custom Panel Vinyl (Platinum) ↗
Legendary Auto Interiors· $93.00 USD
1969 GS Sport Coupe Package Tray with Speaker Cut-Outs - Platinum ↗Legendary Auto Interiors· $119.00 USD
Gearbox & Drivetrain 2
- R200 differential with OBX LSDOBX
Required extensive machine work including correcting a warped ring gear mounting surface
In the shops
R200 Differential Cover Gasket ↗JDM Car Parts· $50.00 USD
R200 Differential Mustache Bar ↗JDM Car Parts· $498.00 USD
R200 Differential Side Seal Set ↗JDM Car Parts· $59.00 USD - Techno RT diff mountTechno Toy Tuning
Used to mount the differential
Suspension & Steering 4
- T3 rear control armsT3
Fitted to the rear suspension
In the shops
Rear Upper Control Arm Bushings (Set of 6) ↗
Flyin' Miata· $189.00 USD
Rear Lower Control Arm Bushings (Set of 8) ↗Flyin' Miata· $229.00 USD
Control Arm Bushing (XJ) ↗Moss Motors – Triumph TR6/TR250· $6.85 USD - Silvermine aluminum front control armsSilvermine Motors
Fitted to the front suspension
In the shops
Front Upper Control Arm Bushing Set ↗Flyin' Miata· $149.00 USD
Lower Front Control Arm Bushing, S-Type ↗Moss Motors – Triumph TR6/TR250· $41.99 USD
Front Lower Control Arm Bushings (Set of 4) ↗Flyin' Miata· $149.00 USD - Ground Control coilover sleevesGround Control
Used with Tokico struts for coilover setup
In the shops
Skunk2 Racing Adjustable Sleeve Coilover Kit (88-00 Civic, CRX, del Sol) ↗JDMuscle — Mazda MX-5· $288.56 USD - Tokico Illumina strutsTokico
Paired with Ground Control sleeves
Brakes 2
- Portafield brake pads/shoesPortafield
Fitted on stock brakes
In the shops
Brake Discs/Drums/Shoes/Pads Kit ↗ - Tacoma brake booster/master cylinder
Used for improved braking performance
In the shops
OEM Tokico Brake Master Cylinder Cap (240Z/260Z/280Z) ↗Z-Services· €29.00 EUR
Brake Booster to Master Cylinder Engagement Tool Gauge ↗Z Car Depot· $13.99 USD
Tokico Master Cylinder Cap ↗The Datsun Depot· $29.00 USD
Wheels & Tyres 2
- Konig Rewind wheels 16x7Konig
Fitted wheels
In the shopsKonig Rewind Wheel Kit, 16x7" (Matte/Satin Graphite) ↗Motorsport Auto (The Z Store)· $699.87
Triumph Shield Konig Rewind Wheel Centre Caps ↗
baulycars.com· $99.00 USD
Konig Rewind Centre Caps ↗baulycars.com· $165.00 USD - Continental Extreme tyres 225/50r16Continental
Fitted tyres
In the shops
225/50R15 91V Toyo Proxes TR1 Tyre ↗C Bradley Motorsport· £129.00 GBP
225/45R13 84V Toyo Proxes R888R Tyre ↗C Bradley Motorsport· £142.80 GBP225/45ZR15 91W Toyo Proxes R888R Tyre ↗C Bradley Motorsport· £142.80 GBP
Body & Trim 1
- 3 inch custom exhaust system
Built from fresh pipe with fabricated hangers and tips, replacing the old 2.5 inch MSA system
Interior 1
- Porsche Boxster seats
Reupholstered in black leather in a 240z/911 style
In the shops
Blackline Porsche Boxster 986/987 2.7 Audi 01X Gearbox Limited Slip Diff (HLF184) ↗Newman Cams· $932.00 USDBlackline Porsche Cayman/Boxster S 987 3.4 G87 Gearbox Limited Slip Diff (HLF183) ↗Newman Cams· $932.00 USD
Blackline Porsche Boxster S 986/987 3.2 G86/G87 Gearbox Limited Slip Diff (HLF182) ↗Newman Cams· $932.00 USD
Electrical 2
- CSS 140 amp alternatorCSS
Higher output alternator contributed to wiring wear
In the shopsAlternator, A127 70 Amp, 1990-96 ↗bpnorthwest.com· $165.52 USD
Alternator, 60 Amp (Spitfire 1973-80) ↗bpnorthwest.com· $149.99 USD
Alternator, 60 Amp (Spitfire 1971-1972) ↗bpnorthwest.com· $163.28 USD - Stock 280z voltmeter
Replaced the original ammeter
In the shops
Stock Style Exhaust Muffler System (240Z/260Z/280Z) ↗Z Car Depot· $725.00 USD
Stock Replacement Radiator (280Z 1975-78) ↗Z Car Depot· $379.00 USD
Photos
26 pictures collected from the write-up, in the order they were posted, shown from 1971 240z - Project Crush. A picture opens larger here, with the way through to the page it is on.
HuD 91gt · 2020-10-02T15:20:06Z 2this post at 1971 240z - Project Crush ↗
HuD 91gt · 2020-10-02T15:51:39Z 6this post at 1971 240z - Project Crush ↗
HuD 91gt · 2020-10-02T16:35:10Z 2this post at 1971 240z - Project Crush ↗
HuD 91gt · 2020-10-15T04:38:56Z 1this post at 1971 240z - Project Crush ↗
HuD 91gt · 2020-10-22T03:44:55Z 4this post at 1971 240z - Project Crush ↗
HuD 91gt · 2020-10-28T04:38:13Z 5this post at 1971 240z - Project Crush ↗
HuD 91gt · 2020-11-03T15:19:15Z 3this post at 1971 240z - Project Crush ↗
HuD 91gt · 2020-11-12T00:28:36Z 2this post at 1971 240z - Project Crush ↗
HuD 91gt · 2021-04-19T02:26:05Z 1this post at 1971 240z - Project Crush ↗
How it was done
History of the build
The car has gone through several engine iterations over years, starting as an L24 with an E31 head and SU carburetors, then an L28 with an N47 head, then a P90 head, before EFI was added and finally a turbocharger with a Haltech ECU. The owner describes it as finally reliable after six years of work.
Electrical and interior work
The owner found the original 10 gauge charging wire fried from age and alternator load, so new wiring was run including a 4 gauge wire through a 100 amp breaker to the starter. A stock 280z voltmeter replaced the ammeter. The interior got reupholstered Porsche Boxster seats and an aluminum glovebox housing gauges and switches.
Suspension alignment
After installing coilovers, the owner built a string alignment fixture mounted to the car itself, using a cube inclinometer for camber, allowing repeated adjustments without needing to realign strings each time.
Exhaust build
The original 2.5 inch MSA exhaust was replaced with a custom 3 inch system to suit the turbo, including a catalytic converter to replace the resonator. The owner fabricated hangers and exhaust tips, fighting fitment issues around the front differential mount.
Differential rebuild
Fitting the R200 with an OBX LSD required extensive machine work after the ring gear mounting surface was found warped, causing inconsistent backlash. A machinist friend corrected it on a lathe. The owner notes he would consider an M-tech or Super 8.8 kit if doing it again.
Experimental manifold and dyno session
The owner began fabricating a true twin-scroll turbo manifold adapted from the original 240z exhaust manifold, using a single 44mm wastegate, but paused the project to reorganize the shop for a new lathe and reinstalled the old manifold to drive the car. A first dyno run produced a baseline pull despite ignition issues at 6500 rpm.
A summary in our own words. The full account, with all its detail, is in the original write-up: read it at 1971 240z - Project Crush ↗
Worth knowing
- Checking backlash before and after rotating the ring gear 180 degrees can reveal a warped mounting surface
- Stretching OEM-style exhaust hangers horizontally helps secure the system but makes alignment harder
- If rebuilding a differential again, an M-tech or Super 8.8 kit may be a smarter route especially when also replacing brakes and CVs