I recently purchased a 92 Corvette with a Vortech kit already installed. I noticed the Carrol Supercharging name on the installation manual, but I'm not sure what the relationship with Vortech was back then.

Anyway, I want to go over the engine and make sure everything was done right, and tweak some extra power if possible. The kit was professionally installed, and came with injectors, fuel boost pump, fuel pressure regulator, Crane Hi-6 with boost retard, etc. To my knowledge, no internal engine mods were done, and no ECM programming. I was told it dyno's right at 400RWHP.

The Crane system was installed with factory coil. I think this could be a weak spot and I'm planning on replacing ASAP. What is recommended?

I would like to get a custom EPROM and have the ability to look into the injector duty cycle, temps, etc on a laptop. Are there decent "off the shelf" chips available?

The throttle body is stock. I am looking at a BBK 52mm. Would this be a good step? Will it require any additional ECM tweaks?

The car has functional side pipes (very low backpressure), but factory exhaust manifolds. Would headers give a big improvement?

Over the winter I'll probably do a rebuild and stick in a cam designed for the blower. What are my choices?

I've seen many people running 1.6 rocker arms. Does this still provide good valve clearance with the factory cam?

Sorry for the barrage of questions.

Thanks.

 

Carrol used a couple different brands of blowers back then, they even used a Paxtons as well. And its a good thing you got a Vortec instead of one of them ball bearing drive Paxtons which has short lifespans.

As for your coil, don't underestimate that stock GM coil. It is a very good coil. If you want to upgrade, get GM coil for a 1996 LT4, that was a even better coil. If you go aftermarket all you will be getting is a reboxed coil from GM that maybe blue or red. If you go the LT4 coil route you will need a new coil wire because the coil side has the same termination as the distributor side. Also you will need a new adapter harness to connect to your Crane box. It has a flat 4 pin connector vs your old style dual plug coil.

There are no off the shelf proms that I would trust with your combination. It is best you go and have a custom tune done on a dyno to identify any lean areas. If you want to view the operations of the ECM you need to get some scanning software for your laptop. One choice is to download Datamaster from:

www.ttspowersystems.com

Then you will need a cable to communicate with the ECM and those are available from Andrew at AKM Cables:

www.akmcables.com

With datamaster you can use it twenty times before having to register it. Its about $90 and if you need a tool like this its well worth it. Andy can also take care of registering it as well and its cheaper from him rather than from TTS. Plus his customer support is 10x better than from the Author (TTS).

For headers, my car loves the Exotic Muscle long tube headers. You gotta remember an engine is just a air pump, what goes has to come out. The easier you let the engine breathe the more power you will get. Also the stock CATs can and should be replaced with some high flow units like a set of Dynatech Headers 3" bullet CATs.

A 52mm body wouldn't be a bad idea, but a 58mm would be better. Remember its all about flow, installing a 58 will require removiing the intake to port the throttle bores to match the TB. Some say you can do it in the car, as for me I don't relish the idea of having metal chips in the intake. A TB will not require custom tuning on your chip.

1.6 rockers will give you a little gain. The problem is with stock springs that are tired you may experience valve float at high RPMs. It is best to replace the springs to accomadate the higher lift. You could use a set of the LT4 springs, or better yet change them out to a set of the new beehive style single springs from Comp Cams. These are very similar to the LS1/6 style springs and these are good up to .650" lift depending on the spring and the final installed height.

For a cam, you should go with a relatively mild cam for your "Stock" engine. A good choice would be the LPE/Accel blower grind part number 74220 with 215/220 intake/exhaust duration. Its lift is .530/.560, this is a good cam and I personally used it in my car until I went with a larger cam. In a LPE test mule a 383 with this cam under 8 PSI of boost made over 575Hp Granted that test mule had ported heads and a ported Super Ram intake you can see that it makes serious power. Also it offers excellent streetability and will pass emissions.