Intake Manifold Prep
Disabling VRIS
Now that you will be boosting in the range that the VRIS normally operates, you will no longer need them. You can either tie them to the open position as pictured, or you can remove them completely, cutting out the butterfly valves they operate inside the intake manifold.
Spark Plugs
The spark plugs you use will depend on the engine setup you have. To cold of a plug will blow out spark, too hot of a plug can cause pre-ignition.
Below is a chart that you can use to select spark plugs for your application. The best plugs to use on these engines are NGK V-power copper plugs, gap them to .32-.34, This will help against blowing spark out.
| Compression Ratio | Engine | Stock Plug | Recommended Boost Plug |
| 9:2.1 | KLDE | ZFR5F-11 | ZFR7F-11 |
| 10:1.1 | KLZE | ZFR6F-11 | ZFR7F-11 |
| 8:5.1 | KL | ZFR5F-11 | ZFR6F-11 |
Turbo Drain Line
The turbo will need to be able to gravity drain back into the oil pan for circulation.
Remove the Oil pan and tap it using a weld on bung of your choice. It is best to tap the pan at his highest point to allow good oil flow thru the drain line.
PCV System
The PCV valve may cause problems, under normal conditions these should prevent boost from entering the crank case, but I recommend removing them completely and plugging the vacuum line, or getting a metal style pcv that’s designed for boosted cars. You can also use a one way vacuum check valve that will prevent boost from entering the crankcase.
Additionally, a oil catch can be installed in-route of the PCV system, but isn’t required.
EGR System
Remaining Emissions
Now that you have disabled the VRIS, you do not need the vris valves, nor do you need the EGR valves, these all can be removed and the main vacuum line to them plugged. The Charcoal canister can also be removed if you want more room in the engine bay. If you wish to keep cruise control then the vacuum chambers under the intake manifold will need to remain. King6fab offers a EGR block off for the removal of the oem valve.
Oil Options
Engine Oil & Filter
Changing the oil to synthetic will help prevent the oil from “coking” inside of the turbo from extreme temps. You can also add a 1995 Corvette ZR1 oil filter that is a direct replacement and allows more oil to be used in the engine
