now why am i not worried about long trips with the optispark in my c4.....?

Hopefully all the puffing sac city does about their optispark with ring true and we will have a reliable alternative to the hard_to_impossible to find mitsubishi optical sensor oem units....

 

I don't know, but I've been known to worry too much. The guy that bought my other 93 C4 has put 6,000 miles on that opti. Still on the same opti

Install is looking nice

 

those brackets look sweet!

 

Thanks Guys! Turns out I only have about 1/2" of hood clearance between the passenger side coil packs and the underhood lamp. Think that will be enough room for engine movement when it torques up?

 

That is the nicest looking coil on valve cover mount I have ever seen, it's really nice looking-good work.

 

Thanks I appreciate it!

 

Magnecor should be your choice.

 

I ended up going with the Taylors again as that is what Bob recommend ed. Gave Jesse at Taylorvertex my measurements and he had custom wires made and shipped to my door in less than one day. Cost less than what it would to buy a kit and the proper crimping tool to make my own.

 

Spark plug wires came in. Still waiting on brain box and I still need to order or find some LS1 coil harnesses.

Edit- I tried to have Taylor make another set of wires for another car and they are not as helpful as they used to be! Definitely go with Magnecor now.

 

Results: Fired right up first turn of the key. Very smooth idle, a little smoother than the opti. I got to drive it for the first time last night. Not much of a difference compared to the Opti ignition. Drivability is the same, but there might be a tad more responsiveness when you hit the pedal. It is certainly smoother at wide open throttle.

Overall the install was very easy. I did spend a few weeks researching and probably read every LTCC thread from every forum that includes the LT1 (Camaro/Imapala/Buick,Corvette) three times over. Once you get the LTCC box it is probably only about a two hour install (including soldering). What took me the longest was finding a suitable location for the box and routing the wires to try and make it look somewhat factory, this is where I took my time.

First things first is trying to find a good location for the box. Andy (bogus) suggested mounting the LTCC module in the right front compartment of the engine bay near the coolant overflow. I used heavy duty 3M double sided tape to secure it to the body. This secures the box very well and also provides somewhat of a vibration barrier. Route the wires under the overflow tank and up next to the lower radiator hose, this will give you clearance for the rotating headlight.





Next run the harness ends where they need to go. One connector will plug in at the opti harness test port on the passenger side of the manifold. This intercepts the opti signal to send important timing and firing info to the LTCC brain. The other two harnesses are for the coil packs. Run the harness labeled “2468” to the passenger side, and run the harness labled “1357” to the driver side, I opted to run the odd bank harness under the trottle body in a similar manner to the way the factory coil wire was ran. Both of these harnesses have a ground for the coil packs, you can either use the one of the spark plug retainer bolts, or the fuel rail bolts on the intake manifold.. I opted to ground mine to the fuel rail bolts closest to the throttle body (Note: It is essential for extremely good grounding for proper operation).

Next, disconnect the factory ICM and Coil and remove them from the passenger side head, put them in a box and store them in your parts bin. Also remove all the spark plug wires and coil wire from the original opti. I just disconnected the spark plug wires from the spark plugs and left them hooked up to the opti just in case the LTCC box didn't end up working, once you confirm it fires up remove all optispark wiring except the hi/lo res signal harness.

Now you will notice there are two yellow wires, two white wires, and two pink wires coming out of the LTCC harness. The two yellow wires are for the activation of the two-step built in adjustable N2O / boost retard, the two white wires are for the EST signal and the Tach signal, and the two pink wires are to power the coils. The two yellow wires were not used in my application so I taped them out of the way.

One white wire has a black dot, this is the one that carries the tach signal, this wire you connect to the white wire on the gray connector that plugged into the factory coil. The two pink wires you solder to the single pink w/black stripe wire on the gray coil connector as well. On my 94 (and I assume it would be the same for 92'-94') I also cut the two white wires going into the tach filter and soldered them together to bypass the tach filter. The LTCC tach signal sends a nice square wave to the PCM for the tach signal, so a tach filter is no longer needed. At this point you can remove the tach filter from the factory harness entirely. It is a small rectangular black box taped to the harness. 95'/96' models I don't believe has a tach filter.









The solid white wire from the LTCC harness you connect to the solid white wire that is on the factory ICM connector.





You can tape the connectors to the harness if you don't want to completley remove them from the car, but they are no longer needed so I cut them out leaving plenty of wire in case for some reason I ever need to solder them back in.

That is it as far as any cutting or soldering goes, as stated above the rest is plug and play.

You need to fab or buy your own coil brackets, you will need 8 coils (LS1/LS6,LS2,LS3,LS7, & Truck coils without metal heat sink all work well). I went with LS6 coils and I bought two coil harnesses (one for each bank) from CBM motors, they are made for coil relocation and are a little longer than a factory LS1 harness. Then you will either need to make custom length spark plug wires or send your measurements to Taylor Vertex or Magnecor. As stated earlier in this thread, I went with Taylor and they had them shipped to my place within a day.

End result: profit. I feel like I breathed new life into the car. The PCM still relies on Hi/Lo res signals from the optispark, but the optispark is no longer a distributor, there is no high voltage passing through it which can lead to failure of the optical sensor. Essentially you are kind of turning the optispark into a crank position sensor of sorts. I feel this conversion is a worthwhile mod as genuine opti replacements with the mitsubishi sensor are getting harder and harder to find. Prolonging the life of the optical sensor is the goal behind this conversion. There are other pro's as well such as easier tune ups and access to the entire ignition system. I hope this thread helps anyone else considering the conversion. If there are any questions I will be glad to answer them. Big thanks goes out to Bob Bailey(Creator of the LTCC system), bogus, and Glenno

Here are some finished pics :

 

Awesome, if I decide to keep my C4, I'll do this. Very clean and neat install

 

Well-done!

 

Thanks guys I appreciate it! Loving it so far.

 

So you guys who have these conversations, how does the car drive compared to fully working stock opti+single coil system?

I haven't driven LTCC converted car so I have no idea how it compares, but in theory I dont see what difference would LTCC make in NA motor with working stock system.
Thanks

 

It drives the same. As stated above its a little smoother while at idle, but much smoother towards red line (and this is comparing it to a brand new working opti installed in December). If you have a highly modified engine, whether NA or not you can rev much higher without fear of a disintegrating optispark rotor. It is really helpful if you ever plan to boost or use N20. For a near stock engine, its more of a reliability/peace of mind mod than a performance one.

There are many theories why the opti fails. Ozone build up, moisture inside the distributor cap, rotor screws backing out, high voltage jumping across to the optical sensor causing a short, etc... The coil per cylinder conversion eliminates a lot of these problems. It removes Ozone, because now there is no high voltage passing through the opti, if the rotor screws back out, it won't leave you stranded or cause a miss, etc... My main goal is to prolong the life of the optical sensor as much as possible, because genuine Mitsubishi sensor optis are getting harder and harder to find. The LTCC mod just opens the door for other things in the future, and in my opinion makes the whole Ignition system much more accessible.

Right now I have a Petris Opti, and the LTCC conversion. Pretty expensive for what it is. However, the Petris opti is arguably the best aftermarket opti you can buy. Rotor screws come loctited, cap is sealed, and the retrofitted vent kit will now act as a cooling system for the optical sensor rather than a moisture/ozone vent. Then add the fact the LTCC removed the high voltage aspect from the optispark no longer making it a distributor. Hopefully, I should have a much more reliable ignition system.

Bottom line, if you are happy and content with a good working opti, then I wouldn't even bother. I kept having opti troubles about every year. So this eliminates some of the variables, including the single factory coil and ICM.

 

Looks great Torch. I went with the LTCC as well but I used some brackets that I found on ebay. I was looking for fast and easy. They were only 99 bucks and that was worth it for me just in the time it would take to make some.

This is a shot when I was installing the LTCC. I needed the car running asap as I had a small window to get it to the dyno and meet the tuner since I had made a number of other changes at the time. I have since routed everything a bit cleaner. I had a nightmare with 3 optis. Thought I would go with what I thought would be top shelf when I was doing the original build and went MSD. BIG MISTAKE!!! 2 MSD's failed on me in one week (they are JUNK people...DO NOT BUY ONE!) 1st one was arching all over the place when we fired the motor for the first time, 2nd one crapped out in 280 miles leaving me stranded in Chicago rush hour traffic in the left lane with NO SHOULDER.
So then I put my low mile 30K original back on and that one died that same summer. Anyhow, the car has never run better....money well spent. After seeing the inside of my CLEAN 30K opti after it died, I was immediately convinced that I needed to get rid of the ignition portion of the opti! What a complete POS design by GM. WTF were they thinking? I (nor anyone) will never know...

 

I've also read every LTCC thread, and it's always good to hear success stories. My LTCC is sitting in a box right now, since I still have other stuff to do first

 

huh... As I look back on this thread, I am more than a little surprised that I hadn't commented on the LTCC.

I have to be one of the early adopters... way back in 2003! The box has been back to Bob once, for a check up after a leak let water in, no damage.

I had one major failure caused by an exploding serp belt; took out the harness... ripped the sucker to shreds. New harness, new brackets... life was grand.

I use Taylors, make them myself. Each time, I get that much better. The latest set are MSDs and are doing very well. Also upgraded to LS2 coils.

I don't know for sure, but my email used to be at the end of the install manual... I rewrote it for Bob back in 2003.

Bob is a sharp guy. Really knows his stuff and the LTCC is a very nice product. I am pleased with it.

My next trick, run the LTCC brain into the glove box (92, no airbag).

 

LTCC convert here as well. Like others that have installed it, I have nothing but good to say. I went through several coils and ICMs and was still haunted by ignition problems. It hasnt missed a beat since the LTCC install and still using the original non vented opti. Think it has been on there for 4 or 5 years now.

 

Great Thread and install!

I too am considering going with this as I want to add a rev limiter and 2 step. I was all set to get an MSD 6AL-2 but after researching-it seems in many cases it can damage the rotor and cap. My opti is working fine so I may go this route.

What wires did you solder? I may of missed it.