Anyone heard of this? Opti Alternative

[WICKED LT1]

Called the Dynaspark. Made by a company called Dynotech.

Dynotech

Seems a little pricey, but it looks like a CNC machined Opti with revised compoments. Any thoughts?


-Paul

[Rob B (shoebox)]

They have been around for a while, but not long enough for anyone to give any long term results (not that I know of, anyway). There are some people on CamaroZ28.com that have bought one. It has some improvements, but is still the basic opti.

[KnightFire]

WHEN my opti dies, I'll probably just go with a multi coil setup...I believe it to be a far superior setup.



KnightFire

[Detroit_Bird]

Here's a question -

they sell carb intakes for LT1's- how does the opti run without all the FI? I'd think the computer would be really confused. Does someone make a kit to run a standard distributor or are these guys getting a stand alone spark CPU.

[Injuneer]

You've got it backwards.... the Opti does not need the fuel injection.... the fuel injection needs the Opti. The Opti serves 2 distinct functions. The optical section feed cam and (psuedo) crank position information to the PCM. The PCM uses the low resolution (cam position) signal to fire the injectors. It uses the high resolution pulse to provide extremely high accuracy, low scatter ignition timing. The stock PCM can NOT function without the Opti. It requires the low resolution pulse to activate the fuel pump. Without the low res signal, it shuts off the pump and the injectors. The other function of the Opti is a simple cap & rotor high voltage distributor.

In order to run without the Opti, you need a synthesized pulse signal. Electromotive briefly made such a system. I had one of the first ones they made, about 5 years ago. My car ran for 2 years without an OptiSpark. Unfortunately the E'motive SDI/Opti-Eliminator was not "perfect".... it lacked a true cam position signal, so it was possible to synch the synthesized low res signal 360-deg out of phase. With OBD-II, the resulting crank speed irregularities caused the crank position sensor misfire detection to go haywire.

If you swap to a carbed intake, you don't need the low res pulse from the Opti. But you keep feeding the signals from the Opti to the PCM to control the spark. You would need to put 15ohm resistors in the injector harness connectors to simulate the injectors.

If you use a "conventional" distributor with the carbed intake, you don't need the Opti at all. You don't even need the PCM. You would just need to provide a way to control the fuel pump, and a way to feed the VSS signal to the speedometer.

You could also use the MSD CPC igntion computer, using a "cam stub" from a conventional SBC setup to provide the required cam and crank position signals.

You would only use an aftermarket ECU with a full fuel injection system. These can be driven from the Opti, or with a crank sensor in batch fire mode, or with an add-on cam sensor in full sequential mode. I run a MoTeC M48Pro, using the optical section of the Opti for cam and crank position signals, MoTeC's IEX 8-channel ignition driver, and 8 LS1 coils in direct fire mode.

There are also two other "black box" systems that use ONLY the optical section of the Opti. Bob Bailey's LTCC "box" uses the stock PCM to control 8 LS1 coils. The Delteq "box" allow you to use the NorthStar 4-coil lost spark coil pack and control module. Delteq claims to have a box that completely eliminates the Opti "almost ready" for production.

Getting the high voltage function out of the Opti case seems to extend the life of the unit. George Baxter used the Opti/MoTeC system for over 4 years, ultimately making over 1,100HP and winding the engine close to 8,000RPM. My system has been running for 3 years now with no problems.

[TruckMuddr]

When I build my 383, I'm gonna get the dynaspark for it.