Well, I am considering spinning a new motor over 7k and the stock computer will not accomodate I understand. What are my options and costs to replace the stock computer with something else? The car will be 90% race 10% street and will not need any emissions, abs, etc.

 

FAST is one of them, not too sure about the others.

 

Holley, F.A.S.T., Big Stuff3, Accel Gen VII. Pay your money and take your choice. With wide-band O2 you're probably going to spend around $2500.

If you choose Holley, PM me. I have programming information.

c

 

Do these systems plug into the factory harnesses or do they have their own?

 

I have seen some early Accel systems that seemed to plug into parts of the OEM harness. The Holley that I used required none of the original engine harness. For the sake of appearance and the hope of avoiding problems, I'd not use OEM wiring on any installation.

c

 

I prefer big stuff 3 to the others. You will need to consider that depending on what you get, you may have to leave the factory computer in if you have an auto trans or you want the factory gauges to work. Alot of times what people do is "piggy back" the aftermarket ecm with the factory pcm.

 

I don't plan on using the stock PCM for anything. I will probably sell it off. I will be running a manual fan and manually wire the fuel pump (somehow. probably will need help with that). I guess after doing some research in which I did not find a whole lot, my only concern is being able to plug into the factory opti and cost. I do not like the crank trigger system idea of the holley as the opti is raved about for its optical sensors. Its seems like a shame to give that up. I would like to keep it as simple as possible. I probably will be giving FAST and BigStuff a call next week. But I wanted to hear from you guys on this and be informed before giving them a call.

 

I know some very knowledgeable people who have good things to say about BS3. F.A.S.T. also seems to have some ease-of-use features that might help smooth out the operation of multiple-purpose applications. My experience suggests that, for dedicated drag racing applications, simpler is better and that some of the options that are desirable for smooth, economical, comfortable street driving really don't matter much. I think that being sure about what you want/need for your own satisfaction is important before spending the money.

c

 

While the stock PCM does not allow you to change some of the programmed values above 7,000RPM, it will still operate above that RPM. A knowledgable tuner can handle it. Keeping the Opti rotor intact may be an issue.

I run a MoTeC M48Pro, and its great for a huge dry nitrous system. But unless you can find one used, the price is prohibitive. Also make sure that the system you pick will accept the optical sensor data from the Opti. It provides an extremely precise cam position signal, allowing you to keep the full sequential injection, and adapt an 8-channel direct fire ignition driver using 8 LSx-style coils. IF the system can not handle the optical sensor signals, you need to add a crank sensor wheel, and switch to bank-to-bank injection, and a lost-spark ignition system (or a conventionally mounted distributor).

 

Really?? If I could push the factory computer to 7500 that all I need. Is that possible? Is there anything I can do for the rotor to make it survive at that speed?

 

One of the racers I'm acquainted with has had success by replacing the tip with a longer brass one that is easier to index accurately, melting out the plastic rivets and replacing them with brass screws, reinforcing the back of the rotor with JB Weld, and always running the complete vent system. NHRA stockers routinely reach 7500 RPM without loss of the rotor. On the other hand, sealing up the vents will destroy the rotor very quickly.

c

 

Well, i've got a brand new sealed opti for the 94. Will this give me issues? Is it something that should open up and replace the rivets? I would hate to screw something up.

Also, how do you make the factory ECM handel over 7k?

 

I believe that one of the secrets to keeping a rotor together is the vented housing. All of our Optis are vented. At one point along the learning curve I sealed the vent openings in the belief that moisture was being introduced through the vents. That unit lasted less than 30 runs before it literally disintegrated. The plastic of the rotor itself was honey-combed and brittle with we opened the unit to diagnose the problem. I attributed that to the ionization that occurs in a high-voltage environment and the effect of the charged atmosphere on the material of the rotor plus the high RPM that we were spinning it. That same phenomenon occurs in regular distributors and for years racers have addressed it by drilling ventilation holes in standard distributor caps. I'm certainly no scientist nor an engineer but since we've improved the rotor tip and vented all the units there have been no further failures.

There are no factory ECM's in our cars. Everything is aftermarket.

c

 

I guess I meant that the pre 95 optis did not have the vent tubes but I believe they do have ventilation holes from the factory, correct? I haven't looked at one in years. How or where do I get the parts to improve the rotor?

Oh and thanks for all the info. It's quite appreciated.

 

Chris, I must apologize for my lack of knowledge regarding the early Opti. I have changed one (on my wife's DD) but none of the race cars utilizes the early system so that's my only basis for comment. In theory, I believe that the vacuum-induced movement of air through the vented unit contributes to the extended life of the rotor and would provide superior ventilation.

c