Will a 4 Bar MAP sensor...

[NUTS4LC2]

provided far better readings over a 3 Bar MAP sensor on an XFI ? This @ over 30 #s boost, or can the 3 bar handle these boost levels ? Hope I made myself clear :redface: Thanks in advance.

 

[TurboDave]

A 3 bar map sensor will only read up to 3bars. That's 30# of boost plus atmosphere. Atmosphere=1bar and 1bar for each 15# of boost for a total of 3.

So basically, if you're going to be running more than 29.5# of boost, you'll need a 4 bar.

 

[Boost231]

1 bar is equal to 14.5 pounds so a 3 bar MAP is good for 43.5 pounds of boost.

 

[Chevota]

Yes, Dave is correct.:biggrin:

 

[TurboDave]

Dave i dont think that is correct. this is what i have always known

1 bar is equal to 14.5 pounds so a 3 bar MAP is good for 43.5 pounds of boost.

You're forgetting from 0 down one atmosphere.

There needs to be a way to measure below 0 boost (vacuum) at the manifold. Gotta reserve one bar for that.

 

[Boost231]

good call didnt think of that.

 

[bobc455]

How far over 30# are you going to go?

If you are only going to hit 31# or so, a 3-bar might give you better resolution and you can probably still compensate.

-Bob C.

 

[NUTS4LC2]

What I thought also...

How far over 30# are you going to go?

If you are only going to hit 31# or so, a 3-bar might give you better resolution and you can probably still compensate.

-Bob C.

I've got iron heads :frown: , but I expect to see no more than 35 #s . I think I should get the 4 Bar.

 

[norbs]

If you plan to run 35# on irons your only going to do it once. Stick with a 3 bar and limit it to 30 and it may live a few passes at least.

 

[1BADTT]

If you plan to run 35# on irons your only going to do it once. Stick with a 3 bar and limit it to 30 and it may live a few passes at least.

Didn't Roy Garcia run 9.3's with irons ? I doubt he kept the boost under 30#'s...also read it wasn't stroked either. Maybe someone can chime in & verify this.

 

[TurboDave]

Didn't Roy Garcia run 9.3's with irons ? I doubt he kept the boost under 30#'s...also read it wasn't stroked either. Maybe someone can chime in & verify this.

Hint: you don't always have to run big boost numbers, just move a LOT of air (translated: big turbo, ported heads, plus all the other parts to go with them).

 

[Otto J]

Call Hartlines they have a 3.5 bar that is good to 38#s and they have a file you can put in the calibrate it also