LT4 coil on LT1 question!
Thread Starter
Drifting
Joined: Feb 2004
Posts: 1,485
Likes: 2
From: Champaign, IL
St. Jude Donor '05
Once the rod bearing went and the motor had to be pulled all bets were off. 
I found the forum and started getting all these crazy ideas ... 
you guys know the rest of the story
I found the forum and started getting all these crazy ideas ... you guys know the rest of the story
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
Just get a Moroso Pro Coil F
I have one and it works good, as long as you don't mind the color blue under the hood of your Chevy. It has the longest spark duration of any *aftermarket* coil, and it still delivers the juice @ 6000rpm unlike a stock 92 - 95 coil.
I have one and it works good, as long as you don't mind the color blue under the hood of your Chevy. It has the longest spark duration of any *aftermarket* coil, and it still delivers the juice @ 6000rpm unlike a stock 92 - 95 coil.
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
The '96 LT1/LT4 ignition system is supposed to be much more than just another "hot coil."
The combination of the new ignition coil and ignition control module make up what is known as a smart coil. The coil does carry more primary current, however, this setup varies the amount of dwell depending on the rpm to make it efficient.
Compared to a standard ignition control module, at low rpm, in order to not saturate the coil for extended periods and cause heat buildup from the primary current, the dwell time is decreased. While, at high rpm, the dwell time is increased to allow a hotter spark where it is needed.
Aftermarket "hot" coils simply have less primary resistance/inductive-reactance and carry more current causing more heat at all rpms.
With the '96 ignition system, GM has tried to give the hottest coil that is considered reliable, while, at the same time, using the control module to cut back on current when not needed to keep the primay of the coil in a save zone from heat.
The idea here is to have the best compromise between reliable higher rpm and reliability that the coil primary won't burn out from excess heat -- I can already see the replies of how some have hot coils that didn't burn out yet.
Think of the coil primary like a light bulb, the less current you put through it the longer it will theoretically last. GM wants that reliabilty -- they are concerned of their reputation. And, yes, I have an Opti-Spark too, so what about that reputation, huh?
If you want something better, solve both problems (Opti-Spark high-voltage section and better spark at high-rpm) by going multi-coil distributor-less.
Let' not even talk about the reputation with the key-less hub......
Tom Piper
The combination of the new ignition coil and ignition control module make up what is known as a smart coil. The coil does carry more primary current, however, this setup varies the amount of dwell depending on the rpm to make it efficient.
Compared to a standard ignition control module, at low rpm, in order to not saturate the coil for extended periods and cause heat buildup from the primary current, the dwell time is decreased. While, at high rpm, the dwell time is increased to allow a hotter spark where it is needed.
Aftermarket "hot" coils simply have less primary resistance/inductive-reactance and carry more current causing more heat at all rpms.
With the '96 ignition system, GM has tried to give the hottest coil that is considered reliable, while, at the same time, using the control module to cut back on current when not needed to keep the primay of the coil in a save zone from heat.
The idea here is to have the best compromise between reliable higher rpm and reliability that the coil primary won't burn out from excess heat -- I can already see the replies of how some have hot coils that didn't burn out yet.
Think of the coil primary like a light bulb, the less current you put through it the longer it will theoretically last. GM wants that reliabilty -- they are concerned of their reputation. And, yes, I have an Opti-Spark too, so what about that reputation, huh?
If you want something better, solve both problems (Opti-Spark high-voltage section and better spark at high-rpm) by going multi-coil distributor-less.
Let' not even talk about the reputation with the key-less hub......
Tom Piper
Last edited by Tom Piper; Dec 2, 2004 at 07:05 AM.
Safety Car
Joined: Feb 1999
Posts: 3,504
Likes: 4
From: Mexico Beach FL
Originally Posted by tkrussell
Is the 96 LT4 Coil/Module compatible with a MSD 6 multidischarge box?
Would the MSD offer any improvement?
Would the MSD offer any improvement?
The problem with CD is the short spark duration -- at low rpm and temperatures the short spark duration of CD is inferior to the stock inductive discharge. That is why they make them multi-strike....hopefully one of the sparks will do the trick. You can think of it as a poor attempt at a longer spark duration to mimic the original inductive discharge. There really is a reason that manufacturers never got on the CD bandwagon.
For the LT1/LT4, here is my order of preference -- best to worst:
1) multiple coil system -- this has the added advantage of getting the high-voltage out of the Opti-Spark. Good from start/low-rpm to unimaginable rpms.
2) '96 coil and ignition module -- good to at least 6400
3) stock pre-'96
If you were buying everything new, by the time you buy the '96 coil, ignition module, and any CD system, you could buy the multiple-coil system.
Tom Piper
