i just got a 94 z28 with 53k miles. It has a vortec supercharger around 4-5psi, 52mm throttle body, full exhaust. Has 2 fuel pumps adjustable pressure regulator, Crane Hi-6r ignition. I know the lt1 came like 10.25:1 stock and supposibly the supercharger does a number on the motor. I am wondering if i can run a shot of nitrous. i ran a 04 vette the other day and stayed right with him. i want an edge over them things. Nitrous is the cheapest to go. My question is what usually blows up. Being winter now should i pull the heads off and put some new better head gaskets? Is the botom end up to the task. The motor is in great shape, allways been run with synthetic oil. I drive the car and do not want to kill gas milage. Also what kinda extra power is expected in porting stock heads? or maybe 1.6 rockers.

Thanks in advance, Ian

 

The ring lands on the stock Hypercrap pistons are what let go under boost. If you keep it at the boost level your at you should be OK as long as you have a good tune and are not getting any detonation, But you might as well start saving for a rebuild because it just a matter of time before you will have to with FI on a stock motor. As far as adding nitrous to that set-up you would probably be pushing it. Heads and cam are where you will see the most gains in power . You can have the stock heads ported and put 2.02 1.6 vlaves in them and they will flow pretty good as long as you have a decent head porter. Any time you start doing some serious modding you are probably going to lose some mileage especially if you change the cam and rockers . I didn't buy my car for mileage but with my blown 385 I get 13mpg around town and about 18-20 mpg on the highway.

 

As stated above, your piston ring lands will not handle blower and nitrous. As far as gas mileage is concerned, I'm running 10# of intercooled boost (Vortech) on a 9.7 compression motor and get 25 mpg on open highway (M6).

A small shot of nitrous on a blown motor works out well. The cooling affect of the nitrous helps to counter the heat generation of the blower.

 

Blower and nitrous on a stock LT1?



If I were you I'd work on my valvetrain and heads to get some better flow. A cam with higher lift wouldn't help either. If you get the heads out and make the chambers bigger you can crank up the boost, or else add some nitrous.

 

I agree, reduce the restrictions in and out of the motor before adding more pressure (nitrous some call blower in a bottle)