Installing a Turbo Kit

It is profoundly unnecessary to know anything about the science and engineering of turbocharging to competently install a well-designed aftermarket turbocharger system. The installer need only be a competent hobbyist mechanic. The experience level is about equivalent to that of changing a dutch or removing and replacing an intake manifold.

A German proverb clearly states the problem of accomplishing such a job: The devil is in the details.' To illustrate the accuracy of this proverb, it is easy to imagine that most people could install an exhaust manifold correctly. Yet a simple air hose not properly attached to a fuel pressure regulator can keep an otherwise faultless system from functioning correctly. Therefore, thoughts about one's competence to install such things should center around how conscientiously one can do the details.

This chapter is a walk-through of the installation of an aftermarket turbo system into a Mazda Miata. The vehicle is stock. The system carries the CARB EO number D-349.

Follow instructions faithfully. When a system has a street-legal exemption order, it is absolutely necessary to follow instructions to the letter to maintain the legal status. Furthermore, the installer should presume the designer knew what he was doing.

There is some logic to the process. Read the instructions and make notes of questions, if any, to pose to the kit maker. It is both easy and natural for instruction writers to gloss over many points of the installation, since they know all the pieces and processes intimately Service is supposed to begin after the sale. You purchased a kit in good faith and were told that with modest ability, you could properly install it. You will likely need many points of the instructions addressed before and during the installation.

Fig. 18-1. Clean the engine compartment prior to starting an installation and the experience will be more pleasant.

It is entirely fair to require the kit maker to give you guidance on the procedure where necessary. Clearly, this form of feedback also improves the writer's ability to create proper instructions.

Familiarize yourself with the parts of the system. Learn the name the writer has given each part. Inventory the parts with respect to the packing list, to be certain all items were included. Call the manufacturer for shortages at the earliest opportunity.

No kit maker should be shipping parts less than spotlessly clean. However, it is a serious error to assume they are clean and ready to install. Any installer worth at. least his weight in salt will insure that every part is perfectly clean.

The vehicle subject to the installation need not be in perfect condition, A proper installation on a 90% vehicle will, however, yield only 90% results. While clearly superior to stock, 90% is not the objective of this book or what this writer perceives as the objective of the fellow hard-core enthusiast. If something is mechanically amiss, fix it before the installation.

Prior to starting the installation, fill the fuel tank with gasoline of the octane suggested in the instructions. Do not dilute with lesser octane fuel already in the tank. If necessary, drain the tank. Never use octane boost as a testing aidit will mask many critical characteristics, such as air/fuel ratios and ignition timing controls.

It is convenient to establish directional references with respect to the instruction writer's viewpoint. If unspecified, consider left and right from the position of the driver,

Alter the installation has begun, the best procedure is to complete the entire job prior to driving the vehicle. Certainly the job can be broken up into segments, like installing the boost gauge, fuel pump, heat shield, etc. The catch is, one cannot install only the turbo and associated pipes and then set out to see how fast it will go. That will surely prove a disaster.

Always read the statement of warranty prior to starting the installation. If questions of policy exist, this is the best time to discuss them.

The speed with which you accomplish the installation is not of any consequence, A few extra hours mean nothing.

Tools and Equipment

A reasonable selection of hobbyist mechanic's tools is all that's required for a successful installation:

Metric open/box combination wrenches.

Metric socket set.

SAE open/box wrenches.

Assorted slot and Phillips screwdrivers.

Electric drill and assorted bits.

Ignition timing tight.

Sealing compound.

Never-Seize compound.

Loctite #271.

Spray can of cleaning solvent.

Oil filter and oil change.

Teflon tape.

Safety wire.

Clean rags.

Floor jack.

Jack stands (4).

Factory shop manual.

Preliminary

Position the car on four jack stands. Check the shop manual for the suggested hard points. Be certain the car is supported by all four stands.

Disconnect the negative battery cable. Consult the manual for any special precautions,

Keep the removed parts organized, especially the nuts and bolts.

Major items to remove:

Air filter and flowmeter assembly. When removing the electrical connector, do not pull the wires.

Flowmeter from filter box.

Cross tube to the throttle body.

Intake resonator/silencer box below the throttle.

Exhaust manifold heat shield.

Oxygen sensor from exhaust manifold. Avoid touching the element end of the sensor.

Exhaust manifold.

Cruise control actuator and mount. (Leave cable attached to linkage and place actuator on valve cover.)

Valve cover breather tube at left forward corner.

Lower splash pan and black radiator inlet duct.

Exhaust pipe hanger bolt attached to left lower side of transmission.

Fuel filter cover beneath car (on passenger side, about 2 feet forward of differential.)

Bracket beneath flowmeter/air filter box. This bracket will unbolt from front gusset at strut tower.

Miscellaneous

The water bypass tube located beneath the exhaust manifold must be repositioned slightly to clear the turbo exhaust pipe. Anchor the tab to the second-from-rear exhaust stud by sandwiching the tab between two nuts. This will force any bending to take place aft of the tab. With a suitable pry bar, bend the bypass tube aft toward the firewall. Bend the end of the tube approximately 3/4 inch.

Wrap the heater hose located aft of the exhaust manifold with insulation. Safety-wire the insulation securely in place.

Wrap the brake line at the left side of the frame rail in a similar manner.

Auxiliary Fuel Pump Installation

Attach the high-pressure auxiliary fuel pump to the left rear frame rail, approximately 4 inches in front of the shipping anchor, as follows. At the filter, the fuel lines are rerouted to and from the pump,

NOTE : Remove the fuel tank cap to let pressure outless fuel will be spilled.

Install the banjo hose barb and connecting bolt onto the fuel pump. Use the copper sealing washers. Add the short segment of hose and the p/n 21009 adaptor.

The fuel pump will hang inside the segment of rubber hose. The pump is retained in the hose with a large hose clamp. See Fig. 18-3.

Fig, 18-2. The auxiliary fuel pump is suspend ed in rubber and placed at the rear of the Miata to reduce noise.

Fig. 18-3. A stainless steel hose clamp holds the fuel pump within the rubber hoop.

The pump/hose assembly will hang from the frame rail by a bolt positioned from inside the rear deck. A piece of tape covers a hole through which the bolt can be inserted. The bolt head must be downward. Use washers on all faces.

Install the pump/hanger assembly. Use the 5-inch bolt.

Remove the fuel line from the inlet side of the filter and route to the new pump inlet.

Route the new pump outlet to the fuel filter inlet.

Route the fuel lines over the cross member and anchor with tie wraps. Keep the lines away from heat, road debris, and any moving parts. Replace standard clamps with higher-strength spiral-lock clamps. See Fig. 18-4.

CAUTION : Fuel spillage will occur on removal of the fuel lines from the filter.

Wiring the Fuel Pump

Roll back the carpet on the shelf behind the seats. Remove the service-hole cover. This is the cover anchored by six Phillips-head screws. See Fig. 18-5.

Locate the blue wire with the red stripe. Splice into this wire with the connector provided. This wire allows the OEM rollover fuel pump cutoff to be extended to the second pump.

Fig. 18-4. The higher-pressure fuel system reqiures replacing standard fuel-line clamps with higher-strength spiral-lock clamps.

Fig. 18-5. The power-wire to maintain the rollover fuel pump cut-off to the second pump in accessed through the shelf behind the seats.

Route a 7-foot segment of wire downward between the tank and chassis. It is helpful to pull this wire through with a straightened coat hanger.

Replace the fuel tank service cover and carpet.

Add suitable end terminals to the power and ground wires. Crimp these carefully and test with a firm pull.

The fuel pump negative wire must be grounded. The rear bumper retaining bolt is a suitable location. Note the terminal designations on the pump.

Exhaust Manifold

Inspect the inside of the exhaust manifold for casting debris. Clean as necessary.

Install the two lower mount studs into the manifold with Never-Seize compound on the threads. Use the double-nut jam method. The front lower stud must be the shorter of the two. See Fig. 18-6.

Install the exhaust manifold onto the engine. Reuse the old gasket. If using a thin-walled box end wrench, the original center nut may be reinstalled. Otherwise, the center nut must be replaced with the thin nut provided, since wrench clearance is minimal. Reuse the remainder of the old locknuts. Attach the water tube bracket to an exhaust stud, as it was originally configured.

Fig. 18-6. The turbo is held to the manifold by two studs and two through-bolts. The studs must be wrenched into place by the double-nut jam method.

Fig. 18-7. The exhaust manifold's compact dimensions require a slim-profile nut for the center fastener.

Turbine Outlet Pipe

Install three studs into the lower end of the turbine outlet pipe. Use Never-Seize compound. Reuse the original gasket. See Fig. 18-8.

Fig. 18-8. Preparation of the turbine outlet pipe is limited to installation of the studs needed to fasten to the stock Miata exhaust header pipe.

Unhook the oxygen sensor wire from its anchor at the bell housing spacer plate.

Insert the turbine outlet pipe into position. Leave the nuts loose until the pipe is attached to the turbine.

Attach the oxygen sensor to the tailpipe.

Reattach the exhaust clamp at the transmission bracket. Leave the bolts loose.

Fig. 18-9. The turbine outlet pipe must be placed into position before the turbo is installed.

Turbocharger

Attach three silicone signal-line hoses to the fittings on the turbo vane actuator. The center fitting 'vent' will be the short line.

Remove the top fitting from the turbocharger oil reservoir. Add 120 cc of oil to the reservoir. Do not overfill. Replace the plug. Inspect the plugs in the oil reservoir to assure that the air breather plug is the uppermost of the two. These are pipe threads and need only be tightened until snug.

Fig. 18-10. Preparing the turbo for installation by adding signal lines to the vane position actuator

Fig. 18-11. The oil reservoir is sealed with a special sintered brass 'breather' plug.

Fig. 18-12. Turbo prep includes filling the reservoir with 120 cc of the special aircraft turbine engine oil.

Attach the turbo to the exhaust manifold. The upper bolts must be inserted from the engine side. Use the mechanical locknuts.

The mechanical locknuts are critical, since engine vibrations tend to loosen fasteners. Use the gasket provided. Leave the nuts finger tight.

NOTE : When the turbo is in position, the compressor outlet should point straight up and the actuator downward and inboard. The actuator needs only adequate clearance to other objects. If the positions are incorrect the turbo must be returned to the kit manufacturer for adjustment.

Fig. 18-13. Note protection of the compressor outlet while the turbo is being fitted to the manifold. Every fastener must have a washer under the head and nut.

Temporarily cover the compressor outlet with something- for example, the fuel pressure regulator baggie. Any foreign particle dropped into the compressor outlet will likely damage the turbo. Also stuff a clean rag in the compressor inlet. (Do as I say, not as I do in the photo.)

Attach the outlet pipe to the turbine. Insert the studs through the flange, placing the gasket in position, and anchor with the double-nut method. Use Never-Seize compound on all related threads.

Tighten all related fasteners: outlet pipe to turbo first, outlet pipe to tailpipe second, transmission anchor third, and turbo to manifold last.

Fig. 18-14. With the turbo in place, fit the turbine outlet gasket and secure the fasteners to the outlet pipe.

Intercooler

Install the intercooler in front of the cooling system radiator and mount it at two pointy. Attach one mount to the lower bolt of the vertical support bracket for the hood latch. Use the longer bolt provided. For proper alignment without binding, it may be necessary to add a spacer between the mounting plate and lug.

Fig. 18-15. The intercooler is positioned in front of the cooling system radiator and AC condenser. The bottom is angled outward to cause the least blockage of airflow to the cooling system.

Fig. 18-16. As installed, the intercooler receives substantial airflow through the standard air inlet.

The second intercooler attachment is the frame end of the body support rod. Place the intercooler bracket between the support rod and the frame. Use the original fasteners.

NOTE : Do not replace the splash pan. This pan inhibits air flow to the radiator.

Intercooler Tubes. Install the 10-32 hose barb into the aft side of the throttle body inlet casting. Seal with Loctite. Be very careful with the small threads, as they can easily strip in the casting. Do not permit Loctite to clog the hose barb.

Install the throttle body inlet casting. Point the casting inlet straight down.

Attach the hose from the idle air-control valve to the throttle inlet casting. Secure with the original clamp.

Assemble the remainder of the intercooler tubes. Leave all joints loose and adjust the position and fit of tubes for clearance and appearance, then tighten all hose clamps.

Fig. 18-17. With the turbo and intercooler in position, the interconnecting tubes can be installed.

Fig. 18-18. Tightening hose damps on pressurized tubes should, be done with a ratchet wrench. Screwdriver tight will almost assure a tube's popping off under boost.

Be certain each hose properly overlaps the inside tube and that the retaining clamp is completely over the tube.

CAUTION : The compressor outlet tube can rub the hood when the engine rocks if the tube is not pushed into the compressor outlet until it touches the compressor outlet boss.

NOTE : Do not replace the plastic inlet duct.

Compressor Inlet

Install the brass fittings for the valve cover breather into the compressor inlet casting. Use a 90 el and point the hose barb upward.

Install the rubber 0-rings into the grooves on the turbo. Lubricate the O-rings with a small amount of grease.

Remove the rag guarding the compressor inlet. Press the inlet casting onto the turbo and swivel the inlet to point directly outboard.

Air Filter Box

The filter box will attach to two points. One is a tab on the aft sheet metal gusset for the left front strut mount. This point is immediately below the front end of the brake master cylinder. Install the rubber isolator onto this tab. Use the nylon locknut and appropriate washers. Leave finger tight.

The second mount is an existing hole located 3-1/2 inches forward and 4-1/2 inches outboard of the left strut center line. Drill this hole to 1/4 inch. Install a second isolator at this point.

Install the small hose barb into the threaded hole adjacent to the rear mount of the filter box.

Attach the flowmeter to the filter box. Reuse the original gasket, studs, and nuts.

Fig. 18-19. The air filter bottom case serves as the airflow meter mount.

Fig. 18-20. The flow-meter/filter case assembly mounts to the Miata'a structure with rubber isolators in allow for engine rock.

Press the filter element into the filter box. Bolt the upper and lower box halves together with the stainless steel cap screws. Position the cap such that the air inlet faces outboard

Slip the 2 3/4-inch-diameter hose onto the compressor inlet casting.

Place two hose clamps onto the hose and leave them loose.

Attach the wire harness connector to the flowmeter. The wires are best routed beneath the filter box.

Insert the flowmeter into the hose on the inlet casting and position the filter box.

Attach the air filter assembly to the inner fender well at the two isolators. Adjust the position until all alignments are correct. One or both isolators may need spacing up. Use the nylon locknuts and appropriate washers. Check hood clearance prior to closing the hood.

Tighten all related clamps and fasteners.

Miscellaneous

Remove the restrictor from the original valve cover breather hose and place inside a 6-1/2-inch-long segment of 5/16-inch hose. Use a small amount of lubricant on the hose barbs for ease of assembly.

Route this hose from the hose barb on the compressor inlet casting to the valve cover breather

Attach the heat shield to the cylinder head. Use suitable washers under the bolt heads.

Fig. 18-21. The valve cover breather has a smalt restrictor inside that must be placed inside the new breather hose. The breather must be placed before the turbo to avoid pressur-izing the crankcase.

VATN Actuator Signal Lines

The line from the lower fitting of the actuator (small end) is the boost-pressure signal. This signal originates at the hose barb on the aft side of the throttle body inlet casting. Check this hose barb for possible Loctite blockage by blowing through the hose.

The upper fitting on the actuator is the vacuum signal, This line will get its signal from the hose exiting the top of the intake manifold approximately 1 inch after the throttle body. Sever this hose and insert the brass tee. Attach the actuator signal line to the leg of the tee.

The center fitting on the actuator is a breather only. It is connected to the fitting at the aft bottom of the air box.

CAUTION : Check these lines carefully, if they are not correct, the turbo will be subject to overboosting. This may overrev the turbo and cause damage.

NOTE : Prior to final assembly, blow through all actuator signal lines and fittings

to assure that none are blocked, crimped, or otherwise plugged.

Relocation of Cruise Control Actuator

Vehicles equipped with cruise control must have the control actuator moved. A convenient location for the actuator is the small cavity just in front of the clutch master cylinder, A mount bracket is provided that attaches to the out-board master brake cylinder mount. Keep the actuator cable as straight as possible.

Fuel Pressure Regulator

Attach the regulator to the bracket.

Install the two fuel-line hose barbs. Use thread sealant. Do not use Teflon tape. These fittings should only be tightened snug.

CAUTION : Do not excessively tighten the hose barbs, otherwise the casting may crack.

Mount the regulator and bracket assembly to the firewall at the position shown. Assure clearance to the hood.

Fig. 18-22. The rising-rate fuel pressure regulator conveniently mounts to the firewall.

Drilling the mount holes accurately requires a drill dimple.

Remove the original equipment fuel injection return line from the steel return line on the frame of the car. Route this line to the side fitting on the regulator. This line then connects the output of the stock regulator to the input of the new regulator. Secure with proper hose clamps.

CAUTION : Fuel spillage will occur.

Install a segment of the new high-pressure fuel line from the center fitting of the regulator to the steel line at the frame. Secure with proper hose clamps.

NOTE : These two preceding steps have inserted the regulator into the EFI return line.

Fig. 18-23. Once the regulator is in place, fuel and signal lines complete its hookup.

Locate and sever the vacuum signal line to the stock fuel pressure regulator.

Place a white plastic or brass tee in the signal line and route a vacuum hose from the leg of the tee to the new regulator. Insert the small plastic restrictor into this signal line.

Add the one-way check valve to the exit of the needle valve. This check valve eliminates vacuum leaks yet allows adjustment of the regulator by boost-signal leakage.

Assemble a brass tee from the items provided. Install this fuel pressure check gauge tee into the fuel rail inlet hose at the frame connection. This is the lower fuel line on the right side of the engine,

CAUTION : The fuel intet line will be under pressure and fuel will spill. Spillage can be reduced by using fuel-line clamps.

Tape the fuel pressure check gauge to the windshield such that it can be observed while driving the car. Route a piece of the high-pressure fuel line from the brass tee to the fuel pressure check gauge.

Fig. 18-24. For reasons of safety, the fuel pressure gauge, which is needed to complete the tuning process, should not be placed inside the cockpit. Tape the gauge to the outside of the windshield at a convenient location for viewing while driving.

Boost Gauge

Attach the boost gauge and cup to the lower left windshield pillar. Use the sheet metal screws provided.

Route one wire to the red wire with black stripe at the dimmer switch. The switch pulls out of the dash easily with a screwdriver. The plug may be disconnected to ease splicing.

NOTE : If you prefer the gauge light to vary brightness with the instrument lights, wire it to the rheostat according to the factory manual.

Route the other gauge wire to a convenient black wire or ground. The pressure line to the gauge can easily bo routed through the firewall by making a small hole in the grommet located to the left of the throttle cable. A sharp hit turned slowly will make a hole in the grommet. Route the gauge line to the capped fitting located aft of the throttle body, atop the plenum.

Fig. 18-25. The signal line for the boost gauge passes through the firewall at the speedometer cable grummet. A sharp bit turned slowly will make a hole in the grommet.

Ignition Retard

Install the MSD ignition retard unit in accordance with MSD's instructions.

Miscellaneous

Reconnect the battery. Clean the terminals if needed.

A vacuum check valve must be inserted into the hose to the vacuum canister. The canister is located 2 inches outboard of the throttle body. The check valve goes into the smaller of the two hoses. Sever the hose and insert the check valve with the white end toward the canister. This check valve permits a vacuum to be drawn on the canister, but the canister will not be pressurized under boost.

Testing

Start the engine and check for vacuum and fuel leaks. Correct as required.

Set the ignition timing to l0 º BTDC. Open the connector on the wheel well on the driver's side and place a jumper between terminals 'GND' and 'TEN.' Attach the timing light to the number one plug wire. Change timing by loosening the bolt on the right side of the crank angle sensor at the rear of the intake cam. Rotate the sensor until the 10 º advance is achieved, as checked at the front engine pulley. When the timing is correct, tighten the bolt and remove the jumper wire.

Fig. 18-26. The char-coat canister must he protected from boost pressure. A one-way valve placed in the vacuum line, allows the engine to purge the canister while blocking boost pressure.

Several objectives must be met in the testing procedure:

Ascertain fuel pressure rise rate as a function of boost pressure. The needle valve is the fuel pressure adjustment Adjust in one-twentieth-turn increments until the desired fuel pressure is achieved according to the following table:

Determine that no combustion roughness or engine knock occurs when operating at maximum boost

Boost pressure should be between 4 and 6 psi at full throttle at 2000 rpm. If less than this, call the manufacturer for consultation.

Maximum boost pressure should bo 7 to 8 psi.

CAUTION : Due to the sparse sound insulation on the Miata, knock is difficult to hear. Pay careful attention to the sound of detonation, as it is very damaging to the engine.

If knock is detected, lift off the throttle immediately.

Drive the car a few miles prior to applying boost. If all systems are operating normally, proceed with the testing. Generally, use third or fourth gears, to keep events at a slower pace. Apply boost in small increments, so that no sudden changes occur.

Circumstances can combine to make the Aerocharger either less or more responsive than desired. If either case is perceived during testing, call the kit manufacturer for further guidance.

When the engine runs smoothly to the redline in fourth gear at 7 to 8 psi boost pressure, with correct fuel pressure and no hint of detonation or rough combustion, the installation may be considered complete.

Fig 18-27. When testing and tunning are done, remove the fuel pressure gauge. The installation may be considered complete.

Remove the fuel pressure check gauge.

CAUTION : Fuel spillage may occur.

Review the instructions and installation for any details overlooked, and correct as required.

General Rules of Operation

Use 92 + fuel at all times. Higher, if available.

Do not apply maximum boost for more than 15-second durations.

If any sounds of rough combustion occur, cease using boost until the cause is identified and corrected.

The oil must be checked every 10000 miles in the turbo reservoir. Do not overfill. Oil refill interval will be 20000 miles.

Mobil Oil synthetic SHC630 is the only acceptable oil for the Aerocharger. This is available from the kit manufacturer or a Mobil Oil products distributor.

Use extreme caution when driving the vehicle on wet pavement, as the rate of boost rise can cause an unexpected loss of traction.

The foregoing procedure is typical of the installation of an aftermarket turbocharger system. There are many reasons to respect the process. There are none to fear it.