Could someone direct me to LT1 performance information? For example, what kinds of power/torque improvement can be expected for engine modifications of a '94 MY LT1? Is 450 hp realistic without new heads? Thanks in advance.

 

Yes, you can get 450 FWHP w/ ported LT1 heads and a healthy cam along with LT headers and a freeflowing exhaust. There's been plenty of discussion here about different combos for the LT1. The best thing is to check out some of the packages that have been put out by shops such as More Performance to get an idea of what is available and the cost.

 

Yeah, with enough cam and fully ported heads plus the other related goodies, you wouldn't even need to stroke it to get there or beyond.

 

I have a Supercharged 94 LT1 roadster with a 6 speed manual transmission and with the flowmaster exhaust. With the Vortech Supercharger it reportedly puts out around 435 hp and 450 hp. I think if I modified the chip and put on a bigger TB and long tube headers I'd get close to 500 hp. The thing is it drives like a stock car (with a nice whistle) until you put your foot in it. It's very reliable and still gets about 26 mpg.

 

Do you intend to port the stock heads, if yes then yes you can get there but not without extensive port work. A good stage three and an agresive cam and you can see 450+ FWHP with a stock bottom end.

 

all of this is very good info. Everything with power revolves around moving air. start with the intake-headers-exhaust and then move into the heads and cam. You want these to match each other so that you are not killing performance with a giant cam and heads that don't move enough air... and vice versus.

Check out Nathan Plemmons performance page that can be found in the tech FAQ sticky. If I remember, he is putting that power to the ground with very reasonable mods.

 

I was hoping to avoid porting the stock aluminum heads, although I am not opposed to it. I appreciate that power is proportional to volumetric efficiency for a given engine speed, with appropriate fuel delivery modifications. When you mention "not moving enough air," I presume you are referring to intake flow velocity that is important to throttle respone and misture preparation? We used to worry about killing low end performance with too little flow velocity due to large valves and high valve lift.

Years ago we used to port and polish cylinder heads for drag racing applications with a hand grinder. The effort was nearly totally empirical. I have been away from it long enough to realize that: 1) I don't have the expertise to optimize the flow of the aluminum LT1 head by porting it myself unless there are specific dimensions/templates that are generally recognized as appropriate targets/guides for porting, and 2) cylinder head modifications to increase volumetric efficiency have probably become much more defined, proven and automated with some clever CNC code to perform the surgery. Who are some of the suppliers of technology to improve the heads and camshaft, and to what do the code words "Stage II" and "Stage III" refer? What particular camshafts are the most effective for a naturally aspirated aluminum head LT1 producing 450 streetable FWHP?