ive been getting mixed answers on which one to go off of when tuning. recently i was working on a car that would read 10psi solid on the new aem boost gauge but in the logs in s300 it would creep up to 15.5psi thru the hondata 4bar map sensor. obviously this greatly effects the tune and i just want to see what others opinions are.

 

it isnt so much which to trust but which is correct. it could be neither. bottom line the tune runs of the map so get that straightened out. is the map sensor scaled properly in s300? have you tried another sensor or gauge?

 

It also depends on where you are getting the readings from physically.

 

im useing a aem 50psi boost sensor taped into my edelbrock manifold. tial mvs gate with 10 psi spring. wastegate line tapped into charge pipe. hondata 4bar map sensor and im useing the preset settings in the hondata s300.

 

Well if the map sensor isn't reading a steady value then it sounds like you need a new one. You should always use the map sensor to tune but the boost gauge should be reading exactly the same thing.

 

both are new purchused and installed the same day.

 

Just because they are new doesn't mean they work... <FACT.

-J

 

Yeah, if your boost gauge is reading a constant pressure and the MAP sensor is freaking out then it doesn't matter if it was crafted by the president of space, it's broken.

 

I have a hard time believing that the new map sensor it broken. The only reason why we moved to the 4bar map sensor was because the stock sensor would hit boost cut which was set at 10psi. It would cut before 5k rpm. I should have some more time with the car soon, I'll have to do some more testing.

 

I am not saying that your issue is for SURE a "faulty" new sensor. But I have come to learn a lot in the last 13 years of building and tuning cars that putting 100% of my trust in "new" parts, or any part for that matter is just ignorant and time consuming...

Checking your map sensor calibration takes about 10 minutes, don't be so quick to waste time chasing your tail.

-J

 

I guess I shouldn't be so quick to say that it's broken since it could be a wiring/calibration issue but also don't always assume that since something is brand new that it works (although 99.9% of the time it does).