MAP Sensors vs SMEC cal... what would happen

[jonnymopar]

What would happen if I ran a 3-bar cal with a 2-bar sensor and/or vice versa? I'm trying to do some investigating. I've got my Daytona running on a stock TII calibration with the stock MAP sensor and it idles fine. When I switch to my 3-bar calibration and the 3-bar sensor, it runs rough, dies suddenly every so often, and throws a code 13. Both the calibration and the sensor are new.

[tryingbe]

Call the vendor you bought the 3 bar calibration from.

No, mixing 2 or 3 bar sensor with non matching calibration will make the engine run really poor and can even damage the engine.

[jim34]

Turn the fuel pressure down since the calibrations have to cover a wide variety of engine combo's from stock to fully built and ported they tend to err on the rich side.

[crazymadbastard]

Quote:

Originally Posted by jim34 Turn the fuel pressure down since the calibrations have to cover a wide variety of engine combo's from stock to fully built and ported they tend to err on the rich side.

Do not run it or turn the fuel pressure down, something is way wrong. I had this issue. The engine ran strong with the 2bar sensor even though it called for a 3bar. Whenever I plugged the 3bar sensor in, the engine would run like total sh!t, then I would put on the 2bar and it would run "right". So right that I did not suspect I would melt a piston, but I did.

call the vendor unless you enjoy fixing the car way too much. (I don't)

[jonnymopar]

Ok, thanks for the heads up guys. I'm definitely glad I didn't try experimenting with it now! I definitely don't want to ruin a brand new engine.

I'm trying to get in touch with the vendor. I won't say who because I've never had any problems at all with this particular vendor and I don't want to give them a bad name. I just need to find out if there's something else I need to change other than the MAP sensor when I switch computers.

[Sittn86]

Don't 3-bar cals require +40% injectors?
Just a thought.

[Sittn86]

Sorry, double post. Damn connection gremlins.

[mario03SRT]

A 2 bar map and a 3 bar map have different map voltage scales.

All analog sensors operate on a 0-5v scales. So a boost level @ 4.0 volts is less @ 2 bar than the boost at 4.0 volts on a 3 bar. Do not mix and match, use the one designed for your ecu.

FYI,
Marion

[jim34]

Quote:

Originally Posted by crazymadbastard Do not run it or turn the fuel pressure down, something is way wrong. I had this issue. The engine ran strong with the 2bar sensor even though it called for a 3bar. Whenever I plugged the 3bar sensor in, the engine would run like total sh!t, then I would put on the 2bar and it would run "right". So right that I did not suspect I would melt a piston, but I did. call the vendor unless you enjoy fixing the car way too much. (I don't)

So you ran a 2 bar on a 3 bar cal and you wonder why it blew up ?

[jonnymopar]

Quote:

Originally Posted by sittn86 Don't 3-bar cals require +40% injectors? Just a thought.

I have SRT Stage 1 injectors, which are 577cc (works out to roughly 55lb/hr). This is on a 2.4L. Also, I've only been able to idle the car because I still haven't put axles in it yet to take it for a test run. So I don't know how either calibration acts while driving. I know that the 3-bar that I have won't even stay running long enough anyway.

[xrattiracer]

Quote:

Originally Posted by sittn86 Don't 3-bar cals require +40% injectors? Just a thought.

They have nothing to do with each other. What matters is what the calibration was designed to use for each. Typically 3 bar cals are setup for larger injectors though, because there is usually a need for more fuel at the same time.

[tryingbe]

I have a 3 bar cal, and I have 83lbs injectors.

+40% is only 52lbs.

[crazymadbastard]

Quote:

Originally Posted by jim34 So you ran a 2 bar on a 3 bar cal and you wonder why it blew up ?

No, I know why it blew up. Silly!

[jonnymopar]

Ok, I talked to the vendor and they said that I could try the 3-bar cal with the 2-bar MAP just for quick diagnosis, but certainly not for a long time and definitely not while making a 1/4 mile pass. That way, I can see if it's a bad MAP or a bad cal. Thanks everybody.