Ive been reading about people modifying the encoder wheel in the opti to provide a cam sync with their crank trigger. But all that I saw were people trying to use the LS1 style coils with their aftermarket management systems...

I wonder why no one has tried modifying the wheel in order to run sequential injection with the opti still doing its entire job, but for an aftermarket ECM? I'm sure most are just dead set on not using the opti for spark distribution... But couldn't the opti's High and Low Res "Pulse" signals be understood by an aftermarket system? Assuming that you can manipulate the wheel to provide the correct number of pulses.

The DFI computer needs a x4 wheel for the crank (and already gets it from the opti when running batch fire), and x1 for the cam location... Seems I could manipulate the DFI settings to work with most anything. But I dont really know anything about the opti's output signals. If one is compatable with DFI the other should be as well, correct?

Also, anyone thats modified their opti wheels, what did you use and did it last?

My car doesnt go through opti's very much being that it really only sees track duty. So a wheel and wiring modification would be a CHEAP way to go full sequential for me. Which would just be cool!

 

The MoTeC ECU's accept the stock Opti high and low res pulse patterns, with no alterations or interface requirements. The injection is full sequential, with adjustable injector timing and fuel trims for each cylinder. I've been running a MoTeC M48Pro for 8 years, with the Opti optical sensor as the input, full sequential injection, and a MoTeC IEX 8-channel ignition driver with 8 LS1-style coils. I believe there are other aftermarket ECU's that will interface with the Opti signal. I think the Kinsler catalog has a summary of aftermarket ECU features, including the cam position signal interface options.

 

That's cool that it can be done with the Motec, but I've already got Accel DFI. This does give me hope though. And I will try to find that Kinsler catalog to glean any information possible.

Ive drawn up a pair of wiring diagrams on AutoCad, which I'll try to get printed to PDF on my break and post up. Not to sure whether I still have a hosting account or not though.

Anyway, it seems that due to the outputs on the opti itself; the crank and cam signals would have to share a ground path. So I'm starting to think it wouldn't work. Even though the opti's reference signal is carried on the positive path... Anyone have any insight as to this? Or could recommend a more Accel DFI specific forum that I could ask in?

 

My hosting account expired, I'll have to post the drawings after work...

 

Ok, Ive found most of the information needed elsewhere... I cant find any way to modify the wheel (block out windows) that seems any kind of reliable. The only thing I saw that someone tried was some metal tape (kinda looked like AC stuff), but there were no results posted as to whether it worked and held up or not. I cant see that stuff handling any kind of heat at all.

Anyone KNOW if whatever is used needs to be reflective or not? I'm really needing suggestions on blocking the openings. So that when I get an answer from the DFI tech guys about sharing the ground path for the signals I can proceed.

 

I thought about building a LS1 signal converter. Such a device would use the opti signal(360x 8x) and convert it to an LS1 signal(24x 1x). Do you guys thing there would be a demand for such a device?

-Sean

 

As long as there's not a cheaper way to just modify the wheel or even have a new one made...

 

I was thinking $100-200, this device would allow you to use many more after market systems, even an LS1 PCM.

 

Yes there would be a big demand for such a converter box, if you can do it that would be a break through. Lets put it tis way, I sold my 95 Trans AM heads/CAM but prior to selling it I was soooo close to putting on an LS1 computer, I bought the wheel that mounts on the back of the crank already and all the sensors such as the Crank & CAM position sensors, was trying to build a bracket but ended up selling the car.

I do still have and will keep for my next project the wiring harness & PCM for 2002 M6, if there was a converter box that would take care of the signal, we could easily also have something for the CAM sensor as its just a FLAG type to say cylinder 1 or 6 firing position, I'd do it on the 383 I'm working on, but builidng a bracket etc.. was kinda messy.

 

Cool, let me finish the opti decoder for diyefi.org( http://www.diyefi.org/forum/viewtopic.php?f=8&t=71 ) then maybe I'll throw together a PNP converter.

-Sean

 

It would be a plus if you could not only PNP, but have the same box put out all different types of signals. For example; if your not running LS coils, you dont need an LS output configuration. Alot of guys will probably want to keep the opti in place to use as the cam and crank sync so they can run aftermarket EFI in sequential injection. For an app like this you'd need it to put out the 4 crank pulses and 1 cam pulse.

Anyway, I just talked with Eli or something like that at Accel DFI's tech line... He suggested using the opti as the crank trigger and using one of those MSD universal Hall effect sensors in the timing cover to read a magnet mounted to the cam sprocket.

Oh well, I think Im just gonna stick to running staggered batch for now, and worry about sequential injection if/when I ever go to a single plain intake with an old school dizzy.

 

Yeah, maybe add dip switches for different output modes 60-2,36-1, 24-1 and so on. Sequential doesn't have too much of an advantage anyway. I'm running batch mode too.

 

If you design it put me down on the list for immediate payment

 

Will do

 

Agreed, just thought I was onto something easy that would increase the cool factor a bit