RmvBfrFlght
Well-Known Member
- Joined
- Sep 28, 2007
I did not post a picture of a stock buick distributor or any other distributor for that matter. I did not specify stock/msd/other either but I guess I should have. My question was aimed toward the running the distributor set ups that have become increasingly popular in the TSM class...whatever set up that might be. The orginal distributor question is quoted here.
You are correct that no picture was posted. I have one on my system that I looked at and the brain blended it all together as part of the thread.
The question: from what I can tell the stock ECM will run with a stock Buick distributor. I rang-out the ECM circuitry, checked some scope plots of the ref & EST signals, nothing looks to be inverted or otherwise changed from the standard GM way of doing things. Even the chip that handles the EST loop in the ECM is the same as many other GM ECMs with distributors.
However, in stock form the cam signal is lost. Which means no SFI. ECM will default to batch fire mode and light the SES. It will run like this.
I considered trying it just to see if it would work. Although looking at the engine, not a lot of room to fit a distributor in there.
GM put cam sensors in a handful of Caddy's (don't recall which ones, look for SFI and a distributor). Can pull the cam sensor parts out of one and install into the Buick distributor. Then need to buffer the signal. Easiest method would be to use the stock CCCI module (no coils required).
Need +12, ground, cam signal to ECM, and the three wires from the module to the sensor. For the electronics types can put together a simple circuit to provide power and to buffer the sensor signal. And eliminate the CCCI module entirely. Hall effect sensors are easy to work with.
OTOH, for full out racing does SFI buy you anything? It probably does help at low engine speeds as it halves the injector firing rate which increases the PW, which makes it easier to control the fuel when running large injectors.
Once the engine speed gets up to the tire roasting level SFI doesn't provide much benefit. This is one of those things where trying it and seeing how it works pays off.
RemoveBeforeFlight