GM TPI This is the instruction for the GM TPI Plate systems.
Nitrous is especially compatible with the TPI Engine. The stock fuel pumps used on most carburated engines at times do not deliver enough fuel pressure or volume to keep up with some nitrous systems.
By contrast, the high pressure fuel system on all TPI engines is capable of supplying enough fuel for both the fuel injection and nitrous system!
INSTALLING THE TPI PLATE
To install your injector plate, remove the four bolts holding on the throttle body. Install the injector plate with brass hookup fittings on the PASSENGER SIDE with TOP stamped in the plate FACING UP. Be sure that a throttle body gasket is on BOTH sides of the injector plate!
Spacing the throttle body forward requires cable modiifications. Install the supplied linkage bracket to move foward to make up the difference. If cruise control needs more length, there is an inch of adjustment available at the other end of the cable.
WARNING: DO NOT OVER TIGHTEN ANY BOLTS!
LOCATING YOUR DIAGNOSTIC FUEL TEST PORT
The GM Tune Port Engines have a perfect place to tap in for your nitrous oxide system fuel supply. There exists a diagnostic test port somewhere along the engines fuel injector rail. By using the diagnostic test port, it eliminates any need to splice into any of the stock lines.
Now is the time to find it, and it's easy. Just follow the fuel line to the fuel injector rail and look for a fitting covered with a screw on cap.
Special Note: If locating the fuel diagnostic port becomes a problem, call Compucar's technical assistance line for help....(803) 442-9206 M-F 9-6 EST.
Modifying your fuel diagnostic test port
Inside the fuel test port fitting there is a core plug which must be removed. This is accomplished with a Shrader (tire valve) tool.
Hooking up your fuel solenoid
Locate in your nitrous hardware the fuel solenoid. It will have a "G" stamped on the underside to distinguish it from the nitrous solenoid.
Locate in your hardware the attachment line which connects the fuel solenoid valve to the modified fuel test port (the fuel line is the one with the larger diameter).
Tighten the fuel line onto the modified fuel diagnostic test port and the other end to the fuel solenoid valve port marked "IN".
Which Horsepower is for me?
Your Compucar TPI kit provides you with 2 different horsepower levels; 90 and 150 horsepower jets are included in your kit.
For 305 TPI Engines use 90 HP jets:
Gas jet-39 Nitrous jet-59
For 350 TPI Engines use 90 or 150 HP jets:
Gas jet-59 Nitrous jet-76
These jets are placed in the spray bar outlets on the passenger side of the injector plate. MAKE SURE THE GAS JET GOES IN THE OUTLET MARKED "G" AND THAT THE NITROUS JET GOES IN THE OUTLET MARKED "N"!
INSTALLING THE SOLENOID OUTPUT LINES
1: Locate in your hardware the four brass fittings. Install the smaller fittings in the outlet side of each solenoid. Install the larger fittings in the inlet side of each solenoid.
Note: We recommend using a soft set pipe sealant compound (pipe dope) NOT TELFON TAPE!!
2. Locate in your hardware the two smaller braided steel lines. Attach them to the injector plate outlets. DO NOT FORGET YOUR JETS!
3. Connect the remaining side of the line feeding the "G" outlet to the outlet side of the gas solenoid.
4. Connect the remaining side of the line feeding the "N" outlet to the outlet side of the nitrous solenoid.
Slip the 2 mounting brackets onto the bottle with the taller bracket toward the front of the bottle and place the unit in it's mounting position. This is usually in the trunk or rear hatch area. Where ever you mount it, make sure you have access to the bottle valve, hose connections, and bracket wing nuts to facilitate bottle changing.
Using the hole in the bracket base as a template, mark and drill 4 holes to secure the mounting brackets to the mounting surface. We recommend 5/16" bolts, washers, and nuts for a secure installation. The bottle position in the bracket is VERY IMPORTANT! The bottle valve end MUST be HIGHER and the bottle output adapter pointing STRAIGHT DOWN. Tighten the mounting bracket wing nuts.
SUPPLY LINE INSTALLATION
Install the long braided stainless steel supply line. It MUST be routed under the vehicle. Locate and drill a 5/8" diameter hole near the bottle valve in the sub flooring. Securely fasten the AN nut on the line to the bottle adapter. You may also want to use some silicone or a split grommet to keep the line from possible harm. Install nitrous filter at this time in the engine compartment keeping in mind the flow direction of the filter. Install the 1 foot line supplied in the kit to the other end of the filter, this will then go to your solenoid.
INSTALLING NITROUS SUPPLY LINE TO SOLENOID
Before installing the main nitrous supply line, BLOW OUT THE LINE BY OPENING THE BOTTLE VALVE FOR 4 SECONDS! This blows out any foreign matter in the line. Immediately tighten main nitrous supply line onto the nitrous solenoid valve inlet marked "IN".
IMPORTANT SAFETY NOTE: WHEN BLOWING OUT THE MAIN NITROUS SUPPLY LINE, ANCHOR THE END SO IT WILL NOT WHIP AROUND AND STAND CLEAR!! THE EXTREMELY COLD HIGH PRESSURE BLAST EMITTED FROM THE OPEN END OF THE LINE COULD CAUSE HARM OR EXTREME FROST BITE!!
Disconnect the battery ground cable!!
Your 12Volt source should be taken from the fuse panel marked accessory. This will ensure the nitrous oxide system is activated only with the switch turned on. Be sure all connections are well insulated to avoid possible shorting.
Select a location within easy reach of the driver and mount the "ARM" toggle switch and the "ACTIVATE" push button switch. The push button is a momentary type and must be held down to operate the system.
Connect a piece of electrical hookup wire from 12Volt source to either terminal on the toggle switch. Connect a piece of hookup wire from the remaining terminal on the switch and connect it to a terminal on the push button switch.
Connect one wire from the nitrous solenoid valve and one wire from the gas solenoid valve to the other terminal on the push button switch. Connect the remaining wire from each solenoid to a solid chassis ground.
FINAL SYSTEM CHECK-OUT
With the electrical wiring completed, open the bottle valve fully and check ALL nitrous connections for leaks and tighten as necessary. Start the engine and check ALL fuel side connections for leaks and tighten as necessary.
Now start you engine and allow the motor to warm up to normal operating temp. If the engine idles and runs smoothly, open the bottle and head for the nearest test area. WITH THE CAR IN DRIVE AND UNDER WIDE OPEN THROTTLE ONLY!! PRESS THE ACTIVATION BUTTON AND ENJOY THE COMPUCAR EXPERIENCE!! SPECIAL NOTE: COMPUCAR solenoids have a bubble tight seal, however as an added precaution, close the nitrous bottle when the engine is not running.