http://cgi.ebay.com/ebaymotors/ws/e...&category=33558

i'm spending wayyyyyy too much time on ebay!

in gm high tech performance's project magnum series, they used a harness special harness which let them use a dfi for engine management and the factory computer for the smog control.

couldn't you do something similar with a 4bbl tbi setup? the aftermarket computer would offer much better tunability, wouldn't it?

 

You'd be suprised how much tunability is built into the stock computer. There are more tables and constants in a stock computer to control basic engine features then in even the most concurent dfi kits. One example: A/C on desired idle speed, AFR in open loop vs coolant temp, choke, and manifold vacuum, there is also highway mode and complete TCC control. The only advantage to a aftermarket is that they usually have a few little extras like shift light and real-time higher refresh rates.
The 8746 ecm and the 7747 (any c3 for that matter) can use the lockers diy'er project to get 15+fps of data AND has extra A/D inputs for stuff like oh say a wideband o2 .