Autosport Labs

Brent - e-mail me at walterfricke@msn.com, and I can attach a copy larger than this website will accept. And the even larger video.

Jake - I was at Sebring (as a scrutineer). I used my system, but not on cars where an OBD signal could not be used. We could have compared notes. Oh, well.

Brent
photo too large for site. don't know how to make it right at 250k. vid way over that of course.
wish i knew jake at sebring. me too. heading home.

brent: my email walterfricke at msn.com. send me an email and attachments can be much larger. no websites, sorry.
walt

Brent - I tried the CoilX on a Porsche 911 3.2 liter Carrera. It uses the ECU to open and close the ground of the coil. The first data capture worked perfectly. But thereafter the data was junk - lots of missing counts. Attached are a scope picture, and - if it will send - a video. Oh, oh - file too...

We probed the coil positive. The coil negative, when probed (we were initially uncertain which was which, as the coil was mounted on the car, faces sort of down, and has a rubber protective cap over it), didn't seem to show much, if anything. I wouldn't have expected anything, since it is hard wired...

The large spike is negative, isn't it? Or is that an artifact of a scope setting? The goal is to have only one signal come out of the optoisolator I gather is at the other end of the circuit, and is what makes sure only a 5V or smaller signal comes out. Is the flyback pulse the positive "ringin...

Brent Here is an oscilloscope trace of the positive terminal of the spark coil used with a capacitative discharge ignition system, where the negative side is permanently grounded. The EE who took this had this to say about interpreting it: Below are the ‘scope screen captures of Drew’s 911SC CDI ign...

Brent - thanks for the quick reply. This is OEM. I don't want to use the tach signal because hooking up very quickly, then unhooking and going on to check the next car, is very important. From some research I did (Christopher Jacob's book on ignitions) it appears that make/break (or the equivalent) ...

Since Jake has a Porsche 3.2 Carrera (I am guessing from the wiring diagram in another discussion), his CoilX can be connected just as the diagram shows - to the coil negative. Because in that ECU equipped car the coil is grounded through the ECU. Which should mean it has current running through it,...