Max boost for 2 bar map?

[Fast SN-95]

I'd like to keep the 2 bar map for driveblility, but run 20-25psi of boost. Will this break the 2 bar map sensor? Obviously it won't read more than 2 bar, but I figured I could adjust the top row of the VE table for the added boost. Has anyone else done this? How is part throttle driveability with the 3 bar? Doesn't seem like you'd have much resolution to work with.

Thanks.

 

[bruce]

Originally posted by Fast SN-95
I'd like to keep the 2 bar map for driveblility, but run 20-25psi of boost. Will this break the 2 bar map sensor? Obviously it won't read more than 2 bar, but I figured I could adjust the top row of the VE table for the added boost. Has anyone else done this? How is part throttle driveability with the 3 bar? Doesn't seem like you'd have much resolution to work with.

On a Buick GN?
For the Turbo Buicks the MAP sensor just runs the boost indicator, it has nothing to do with engine management.

25 PSI won't harm it.

 

[Fast SN-95]

Ok don't throw anything, but this is on a mustang with a FAST system using a GM 2 bar map.

Thanks.

 

[Sleeper-6]

I personally have no clue, but you may want to check in with the guys in the Electronics section. There's a forum there dedicated to aftermarket engine management systems.

 

[bruce]

Originally posted by Fast SN-95
Ok don't throw anything, but this is on a mustang with a FAST system using a GM 2 bar map.

Oh one of them guys hahaha

Personally I'd go with the 3 and then turn up the fuel and back off the timing in too high of boost conditions.

 

[malibuick231]

fast sn-95 if you are going to run 25psi you need the 3 bar map for driveability. To answer your question it will not hurt the 2 bar buick guys do it all the time but theres does not have any thing to do with how there car runs. The map on your car takes the place of the mass air which tells the car how much air is going into the motor. Thats what tells it how much fuel it needs. Hope this helps.

 

[Fast SN-95]

I understand that I'll need to up the VE numbers in the highest row, since the MAP reading will be 15psi from 15psi on up to 24psi. I just wanted to make sure that 24psi wouldn't break the 2 bar map.

Thanks for the info...

 

[Reggie West]

Get a 3 bar MAP sensor.

1 bar = 14.7 psi
2 bar = 29.40 psi
3 bar = 44.10

You need the 3 bar to tune the VE tables correctly. If you think about it you are trying to tune the tables between 15 and 25 psi with only one row left on the graph.

You need the 4 or 5 rows to get the VE tables tuned correctly. I am no FAST expert yet, but if you have only one row left to tune for 10 psi on the top end of your motor, you are hoping that the ECM makes the right guess as to how much fuel to use when it sees 24 or 25 psi. If it leans out, pop goes the heads.


My 2 cents