LT1 to LT4 conversion question
Thread Starter
Race Director
Joined: Feb 2003
Posts: 11,671
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From: Lake Wylie SC
LT1 to LT4 conversion question
I plan some day in the not too far future to upgrade my 92 LT1 to a LT4 top end, you know heads, intake, hot cam, 1.6 roller rocks, etc. My question deals with the fuel injection differences between a 92 LT1 and a 96 LT4. I have the fuel rail from a 95 which is different from my 92 fuel rail and will fit the LT4 intake correctly. Do the injectors of the 92 and 96 fire the same way? What changes should I make in my ECM? I'm slowly collecting all the parts for this project and don't want to be short on any parts or knowledge before I begin the surgery. Thanks guys. 
Drifting
Joined: Aug 2009
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From: Tampa Fl
I plan some day in the not too far future to upgrade my 92 LT1 to a LT4 top end, you know heads, intake, hot cam, 1.6 roller rocks, etc. My question deals with the fuel injection differences between a 92 LT1 and a 96 LT4. I have the fuel rail from a 95 which is different from my 92 fuel rail and will fit the LT4 intake correctly. Do the injectors of the 92 and 96 fire the same way? What changes should I make in my ECM? I'm slowly collecting all the parts for this project and don't want to be short on any parts or knowledge before I begin the surgery. Thanks guys.
Thread Starter
Race Director
Joined: Feb 2003
Posts: 11,671
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From: Lake Wylie SC
Race Director
Joined: Apr 2000
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From: Texas
The potential is far greater with the LT4 heads and intake. This has been proven to be a very successful combination. I'm not interested in re-inventing the wheel here. I'm just interested in the differences between the LT4 and LT1 injector sequences if any. Thanks for the come back.
Bolt the parts on and have a chip flashed that supports the mods and you're good to go.
Having said that, you'll find the stock '92 injectors will have a high duty cycle...nearing 100% around 6000rpm. If you just plan to play on the street or the drag strip it's fine and you can leave well enough alone. If you plan to use the car on a road course at all, I recommend you address the issue. You can address that a couple of ways...You can increase the fuel pressure effectively increasing what the injectors flow or you can buy new injectors. FWIW, the increase in flow versus fuel pressure is not linear.
Le Mans Master
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From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
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St. Jude Donor '12
IIRC the LT4 fires the injectors in sequence.
The 92 firs one bank at a time.
I asked this question of someone in another engine build thread and the concensus was the LT4 will run in batch mode. Just needs a good tune.
The 92 firs one bank at a time.
I asked this question of someone in another engine build thread and the concensus was the LT4 will run in batch mode. Just needs a good tune.
