1 Bar to 2 Bar Map?
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Joined: Sep 2004
Posts: 61
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From: Las Vegas Nevada
1 Bar to 2 Bar Map?
Just wondering if the stock ECM (1991) will read a 2 map sensor if installed? I have a lot of engine goodies including a procharger, would like to go to a 60lb fuel injector and my tuner wants to use a 55lb injector... Any thoughts?
Safety Car
Joined: Apr 2011
Posts: 3,660
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its not so much a matter of the ECM reading the MAP, its the "tune" parameters in the PROM that need to "know" that the range has doubled. I would think the tuner would know about this and how to tweak the tune for a wider air-flow/pressure range.
I am not sure where the 2bar sensor starts its ranging minimum...at 1.0 bar or if it has the full range of 0.1 bar to 2.0 bar....I kinda doubt that it has that full range otherwise they would ALL be 2 bar sensors... So, the min of the 2 bar sensor is the question that the tuner needs to figer out.
Why map? MAf is so much more precise and easier to work with.
I am not sure where the 2bar sensor starts its ranging minimum...at 1.0 bar or if it has the full range of 0.1 bar to 2.0 bar....I kinda doubt that it has that full range otherwise they would ALL be 2 bar sensors... So, the min of the 2 bar sensor is the question that the tuner needs to figer out.
Why map? MAf is so much more precise and easier to work with.
Thread Starter
Advanced
Joined: Sep 2004
Posts: 61
Likes: 0
From: Las Vegas Nevada
Vette is set up with Map (speed density) instead of the MAF. Was trying to figure out (and understand) why 55lb and not 60lb injectors? Must be the limitation of a chip tune I guess... Can't wait till I get (afford) a XFI FAST,,,
Melting Slicks
Joined: Mar 2001
Posts: 2,149
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From: Timra, Sweden
Some 20+ years ago I did something similar on my 1984 (also MAP based). I converted to a 7747 ECU and used a 2-bar MAP. I compressed the fuel an spark tables more or less by deleting every second row. Then I put values in the top half of the tables by interpolating. That way I got more or less the "stock" tune compressed to the 0-2.5 volt range, and the top half for boost.
