Opti delete option! Help!

[383racecar]

Well just had my 5th opti of the year go bad last night, witch caused a nitrous backfire and who knows how much damage to the engine,I tried 2 summit optis 2 Accels the last one was a GM, What should i do now? does anyone make a opti worth buying? whats the best way to delete the opti can i do a crank trigger wheel? Im spinning the engine to 7100rpm.

[wrd1972]

First off the Accel's are $hit. I had one and sparks were shooting out the cap.

What is breaking on the Opti's?

[mdacton]

how can you go through so many......


I ran the factory one for 8 years or longer with no issues.

[383racecar]

Originally Posted by wrd1972

First off the Accel's are $hit. I had one and sparks were shooting out the cap.

What is breaking on the Opti's?

3 with rotor problems, 2 with no physical damage just now more spark...

[rock1501]

I run a rear mount distributer with crank trigger for timing and spark but I still need the opti for the fuel signal to pulse the injectors.
I only spin mine to 7k due to the stock computer but once I get big stuff I can go higher since that cam makes power upto 8500

[cnorton]

A crank trigger eliminates most of the problems that occur with the Opti. We run them routinely on NHRA stockers. There are still issues with the durability of the rotor but they can be made to twist 7500 regularly and still live. A major factor in durability is making sure that the venting system is in place and functioning. Beyond that, it's helpful to reinforce the rotor with epoxy, to replace any plastic rivets with brass and, in some instances, to completely replace the rotor with a brass component that extends closer to the terminal pole inside the cap.

[Airbornec507]

I recomend dynaspark. These are picey but since Delteq has gone out of business this would be the next best bet unless you can find a complete LTCC setup for an LT1. Here's the link for the Dynaspark: http://www.dynaspark.net/products/

[383racecar]

Originally Posted by Airbornec507

I recomend dynaspark. These are picey but since Delteq has gone out of business this would be the next best bet unless you can find a complete LTCC setup for an LT1. Here's the link for the Dynaspark: http://www.dynaspark.net/products/

I have no problem spending the money on the Daynaspark IF that will stop all my problem... Any one else running a daynaspark??

[CGrant]

i did the ltcc and my car has never ran better, do a search and you will find my thread when i did the install.
you still use the opti but just for the timing trigger, i used a teflon washer on the opti instead of the rotor just to keep the timing wheel on the opti and i have taken it to 7k with no issue, i kept tearing up the rotors on my opti's and the ltcc has resolved my issues.

[Injuneer]

Originally Posted by cnorton

A crank trigger eliminates most of the problems that occur with the Opti. We run them routinely on NHRA stockers....

What are you using for an ECU, without the optical sensor? Did you switch to bank-to-bank injection? Can't see how you could maintain full sequential injection without cam position info.

[cnorton]

Fred,

In our specific application, we dump the stock ECU at the outset. The vast majority, if not all, Stock Eliminator FI cars are running aftermarket systems such as Accel Gen VII, Holley, F.A.S.T., or BS3. The primary distinction between the systems seems to be based on convenience and familiarity.

On LT1 motors the crank trigger replaces the optical sensor and the stock distributor function of the Opti is intact (as per the rules). The fuel injection operates in a batch-fire mode.

One of the Holley engineers told me that, during their development of the system, they found that sequential injection produced little if any improvement on the time slip. That may or may not be true. I have no empirical data to compare but the cars seem to run well using speed density tuning and batch fire injection.

c

[Injuneer]

The main difference when you delete the optical sensor is the loss of the cam position, which eliminates the ability to fire sequentially, and to direct fire ignition with 8 coils. I went in the opposite direction, with the MoTeC ECU, but kept the optical sensor, and ditched the high voltage function in the Opti, using the MoTeC IEX 8-channel ignition driver for 8 LS1-style coils. Not sure NHRA stock would allow the 8 coils though.

Getting the high voltage out of the Opti case seems more beneficial than eliminating the optical sensor..... no rotor problems, no RPM limits, no ozone to rust the internals, etc. The shop that did my work was adapting the MoTeC to a Viper V-10, with 10 LS1-style coils.... it was impressive. They remain convinced that the sequential injection offers an advantage. But they also subscribe to running huge injectors, supplying the fuel for dry nitrous, keeping the duty cycle very low to allow the injectors to fire almost totally while the intake valve is open, not allowing fuel to puddle in the intake valve. I think when you use that approach, the sequential firing and the MoTeC's ability to adjust the injector timing relative to valve timing may offer some advantages. But I've never seen their data to support that idea.

[cnorton]

Rules specify that the stock TYPE distributor and stock number of coils be used. We've tried most of the aftermarket units that are out there and have basically found that a Delco Opti with a reinforced rotor works as well as anything else. One hugely important thing to include is the vented Opti system. Sealing the vents resulted in a disintegrated rotor in less than 50 runs. When I say "disintegrated" I mean exactly that. The plastic was honey-combed and brittle that quickly. Venting eliminates that problem and even helps mitigate the accumulation of moisture and rust. Rotors usually need to have the rotor tip up-graded to one that extends a little closer to the terminals. Also, the plastic rivets are replaced with brass screws and the whole unit gets a reinforcing bead of JB Weld. They last several seasons when they're set up this way, twisting 7500 if needed.

The issue of sequential injection is one that I've discussed with the Holley engineers on several occasions. I've always thought I could make it work since we operate within a specifically narrow power band, essentially between 5,000 and 7,500 RPM on the stockers. The head engineer at Holley was adamant that they had tried it on the dyno and couldn't find much advantage to it in dedicated drag racing applications. Street driving and road racing was another story. I'd like to have some definitive answers just to satisfy my own curiosity.

For the purposes of our kind of racing, I prefer to handle my tuning with Alpha N maps to avoid having the ECU change the tune-up between runs or at half-track during a long day or weekend at the track. It's hard to dial the car when the tune-up changes without warning.

I suspect my remaining time in the sport will run out before a lot of these questions are answered.

c

[slp223]

I was having a problem going through optis. I bought a dynaspark and it has worked for years but the car gets driven very little.

[77amc]

I was reading a thread from several years ago and one person said that he had replaced a few and gave the mileage at those changes.

The last three were after 150K and up to 230k something.. Could it be that whatever drives the opti is the real reason for all the problems??

I don't know what does. I'm used to the old stuff that only needed 2-3 wires to run.
Again, after reading ALL THESE threads you would think that you all should have mandated that GM do a recall on these. Probably a couple million units around the world by now.
Just my .02