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Discussion Starter · #1 ·
I think of converting my LT1 to a EFI Connection 24X conversion with the LS2 coil-on-plug setup.

To all users of the EFI Connection setup, the LTCC and the Deltec how much more juice if any does the LSx multiple/coil on plug setup has over using a MSD 6AL box with the stock Opitspark or even the Accel 300??

Did you guys get any increase in driveabiltiy and/or power with the coil on plug setup?

My mechanic say that a MSD 6AL tends to burn out the Opti's cap and rotor over time and I have heard other users said that this is the case.
 

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There is an improvement in driveability at low throttle transitions with LTCC. I doubt there is much of a performance increase.

There is huge difference reliability wise for high revving engines. With the stroker, the opti exploded in a matter of months. LTCC gave me no problems for almost 5 years. I used a custom cap on the opti, cut off the rotor blades and siliconed everything (no vent harness).
 

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Discussion Starter · #3 ·
Thanx Dmitry for the reply,

One reason I considering the EFI Connection conversion is that I want to set the stage for my eventual 383/396 LTx stroker rebuild. Even though I the MSD advertises more spark energy than the stock ignition, I was told that the LSx ignition is great for high rpm, nitrous and forced induction applications. I want know exactly how much more spark energy the LSx setup has over the stock LTx ignition and also what is the energy advantage it may have over traditional capacitive discharge Ignition(CDI) systems like the MSD 6AL and the Accel 300+.
 

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My mechanic say that a MSD 6AL tends to burn out the Opti's cap and rotor over time and I have heard other users said that this is the case.
I have had a 6A on for 13 years...and not experienced any ill effects to opti. I am not saying a MSD or other ignition box is "better" than a EFI multi coil set up

on a dyno day I did do pulls with and without the MSD box. No HP/TQ difference beyond typical +/- 1-2 HP between runs. It did show a "slightly" smoother graph in the upper RPM range with the MSD box.

It is my understanding with those who convert to the multi coil thing is they have positive results in more stable RPM's above 6k over a opti set up
 

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Like Dmitry stated.
With the stock engine I had no problems with the Mallory and Opti. Just run bigger wires to run the ignition box then to the coil. The stock engine still has the original Opti on it 115000 or so. Nitrous racing, etc. So they can last.
Heads and Cam I had problems, 2 Opti's pretty quick. LTCC so far has been great. 7000 a few times and no problems. Both looked like a lightening storm inside. One the rotor had already started to crack, so that one was about to explode.
Stock engines I think are fine. But some have had no problems with the Opti in built engines, but I think the reliability drops off also if you want to drive them more than a track car.
 

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I converted to the LTCC, because I was blowing up rotors, shifting at 6500 plus. Since, converting, I've had no issues.

I do think the stock opti is very reliable, until you start revving over 6000.

I had to do something, and so far, the LTCC eliminated my problem.

I might switch over to the 24EFI, one of these days. It is pretty pricey. I'll wait until the engine is out, though. Lot easier to do all that electrical plumbing, with an empty bay.:D
 

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Each person has to state what has happen to them so anyone that has stated problems with the Opti I believe.

I can say if you do the following the Opti works fine even at high RPM.

1. Use only a GM Parts Opti, not a Summit or other brands.
2. Change the GM cap and rotor to an MSD cap and rotor. The GM rotor had issues and will cause failures if not discarded.
3. Lock tight the rotor screws. The MSD comes with tape on those scews but it's not the same as lock tight.

Do those things and you can bounce them at 7200 RPM's all day long.

The issue with the high RPM firing was addressed by GM in 1996 production. Above 3000 RPM's the computer switches to the crank sensor to fire the car. This was done because the number of pulses in the timing wheel for the opti was too much at high RPM. So anyone that is not running the 96 crank trigger, even with an OBD1, could have an issue at higher RPM.

One more secret why I don't have the issues others do. If it helps others than I fine with it.
 

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Most people stated that the rotor exploded at high rpms.

I have seen the screws that come with the MSD cap/rotor kit and they about the same as screws that hold PC motherboards. Maybe locktite helps, but I do not see how they can reliably hold an unbalanced rotor at 7000 rpms.

Wouldn't there be a separate PCM table if the crank trigger was used at higher rpms?? The common knowledge is it is used to detect misfires.
 

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Have not seen the screws come out if lock tight applied. The tape on the MSD will come loose. If someone could make a reliable sensor for the Opti then if would never fail. Thats all that goes wrong at this point with those units. By the way, the cam/Opti is only spinning half as fast as the crank so it's really not that big of RPM's.

I had a problem about 4 years ago that was dropping the #4 cylinder out above either 3K or 4K RPM's. I could see this because I can see each cylinder with the 8 channel wide band. The car ran fine and made power at WOT but just not the power it should and you could see that cylinder drop out. I changed the injector. checked the wiring, changed the computer, changed the Opti, changed and replaced everything I could think of but still it dropped that cylinder. For the first time I was ready to junk it all and put in a FAST system. I am lucky had have a few friends that work with the GM engineers in Detroit so I called in a favor to see if he could find someone that worked on the OBD's that could tell me what was going on.

The GM Engineer said he didn't know. What I did get out of him was the 1996 Impala's were scheduled to come with an OBD1 and was changed to the OBD2 at the last minute. The crank trigger was to solve a problem in the computer had reading the Opti at high RPM because of the number of pulses it put out in the 94/95's. This meant the OBD1 was able to see the crank trigger even with the fact no OBD1 ever had this as a factory setup. I connected the dots and thought it could affect the timing or fuel so I unplugged the sensor for the crank. The motor screemed again and that #4 cylinder didn't drop out. Replaced the sensor and it's been fine.

That crank sensor does exactly what the GM Engineer said it did and a bad sensor will drop a cylinder but only above 3 or 4K RPM and the average person would only know the car is not making the power it use to be still good. I wounder how many Impalas have a crank trigger issue but don't know it. I wounder how many people that put a OBD1 in a 1996 Impala left the crank trigger unpluged because they thought it doesn't have any affect other than a misfire detection.

I saw what it will do and that it's a contributing factor in higher RPM's. I think this is one more reason why this motor will fire perfectly at 7000 RPM's with 20 pounds of boost on top of that.

the GM setup is pretty darn good, except for the optical sensor in the Opti, if you understand it.
 

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Discussion Starter · #11 ·
Jeff,

I wonder why that it is not more known that the ODB2 crank sensor is also a crank trigger(at least for above 3000 RPM's). To think that how many people spend big bucks for aftermarket crank trigger setup and here is OEM setup that is not taken advantage of.

To think that the ODB1 conversion to sold as a performance upgrade.
 

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If I had not had that problem a few years back I still would not know what was going on. The lesson on this one is put a 96 timing chain cover on your 94/95 and hookup the crank sensor or make sure you keep it if you put an OBD1 in a 96.

A MSD 6 box and MSD coil firing 20 pounds of boost on a stock GM LT setup and it works. Pretty good stuff and you don't need to change everything, or spend the money, to have an system that would fire even 14 to 1 motors. I'm guessing it's firing about 17 to 1 in my motor and thats clean at 7000. People may not know this but a digital 6 box is hotter than the old AL10's we ran in our race cars 20 years ago and they fired whatever we threw at them back then. The only bad part is still the optical sensor in the dist. that seems to go bad about every three years. Still not terible but it would be nice to only need to change the cap and rotor and thats it. A coil pack is still better from never needing to do anything to it. For the guy looking for every pound of weight in a car the coil packs are adding almost 8 pounds or more to your nose over the stock setup.

Thats what I know at this point but still learning.
 
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