95 LT1 Piggyback Engine Management Options
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From: Marianna FL
95 LT1 Piggyback Engine Management Options
Looking for options for tuning my 95 383, Procharged LT4. I've heard AEM has a piggyback controller and I think Accell has one as well. Any experience with these for a forced induction application?
Thread Starter
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From: Marianna FL
Apparently its not that simple. Apparently on the later LTx, GM began using the MAP sensor to see ambient atmospheric pressure and when the computer sees the low ambient (half voltage on the 2 bar MAP), it sets a code. I am really just looking into options right now. A similar setup to mine has been tuned well without the computer 'seeing' the boost, so I may try it there first and re-evaluate later.
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From: Glenbeulah Wi
Use a 2 bar map sensor and modified program from tunercat and the stock computer. I have done this twice so far and it works well, you loose a little resolution at but in general everything works well.
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From: Glenbeulah Wi
Thread Starter
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From: Marianna FL
All the tunercat FI stuff I have found is converting to speed density and running open loop. Do you know where I can get a copy of the modified definition file? I'd like to take a look at it.
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From: O'Fallon Missouri
Thread Starter
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Joined: Jul 1999
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From: Marianna FL
Yeah, I've read that thread about a million times. He says its closed loop, but the files he references are named "open loop". I wanted to leave the MAF in place, but maybe deleting it is the right thing to do?
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From: D / FW
I'm using the Accel Generation 7 laptop tuning computer on my 95 383 with LT 4 based engine and after having hardware issues I sent it in for the latest upgrade and got the USB tuning cable .
The only access issue is you have to use a older Windows based system, Vista and up is not supported.
It has provisions for whatever you intend to do in the future .
Boost , three stages of nitrous .
It is a two bar system and it also has Torque Converter , fans , A/C Idle and tables for Air Fuel .
My old ECM still controls the dash gages and the transmission shift points.
Yep I'm running a Automatic .
The Accel EFI system ain't too shabby once you get the hang of it.
The only access issue is you have to use a older Windows based system, Vista and up is not supported.
It has provisions for whatever you intend to do in the future .
Boost , three stages of nitrous .
It is a two bar system and it also has Torque Converter , fans , A/C Idle and tables for Air Fuel .
My old ECM still controls the dash gages and the transmission shift points.
Yep I'm running a Automatic .
The Accel EFI system ain't too shabby once you get the hang of it.
Melting Slicks
Joined: Jul 2004
Posts: 3,277
Likes: 32
From: Mission Viejo California
Apparently its not that simple. Apparently on the later LTx, GM began using the MAP sensor to see ambient atmospheric pressure and when the computer sees the low ambient (half voltage on the 2 bar MAP), it sets a code. I am really just looking into options right now. A similar setup to mine has been tuned well without the computer 'seeing' the boost, so I may try it there first and re-evaluate later.
Also, currently I'm running without the PCM seeing boost. We change the performance enrichment vs rpm. The downside is that if my belt slips, it runs rich. I have a base tune but we never did get things finished/finalized.
