3 Bar Map questions

[Grimster]

If you swap to a 3 bar map will the stock boost gauge still work? (yeah I know it's not accurate but I still want it to work).

I tried a search but "bar map sensor" seems to discard the bar and map and search only for sensor resulting in far too many results, since bar and map are 3 letter words.

 

[wagon]

Yes.


Map sensors put out 0-5v (or really close to 0 and really close to 5)depending on the boost/vacuum.
A one bar map puts out ~0v at 14.7 in Hg., and 5v at 0 in Hg, which is also 0psi

A two bar map puts out ~0v at 14.7 in Hg., and 5v at 14.7psi

A three bar map puts out ~0v at 14.7 in Hg., and 5v at 29.4psi

Your gauge doesn't know what is plugged into it. It just reads the 0-5volt output, and uses that to light up the little lights on your dash. I've done it before.

So, to answer your question again. Yes, but it won't be accurate.
Are you thinking what I think you are thinking? Because I've thought that too. I just haven't done it yet.

 

[pacecarta]

the stock 2Bar map is good to 1 Bar pressure (~15psi) , 1 bar vac
the 3Bar is good for 2 Bar pressure (~30psi) , 1 bar vac

both use 5v reference but because they run in a different range they have different meaning for their output voltages

on a 2bar 2.45v is about 0psi , lower than 2.45v is vacuum and higher is boost
on a 3bar 1.65v i about 0psi , lower than 1.65 is vacuum and higher is boost

in stock configuration replacing a 3bar for the stock 2bar does nothing for performance , it will mess up the analog dash LED boost gauge

if your led gauge worked before, with the 3bar map it will still work but because of the voltage output diference explained above it wont read accurate to the stock scale numbers , now when it does light the first led it will be at approx 6psi and the last LED(full scale ) at ~30 psi, you could do an overlay over the stock to show this

the main reason to add a 3bar is for
alkycontrol alky kits . it uses the map to determine boost to regulate the alky amount needed
aftermarket ecu like fast , dfi ,xfi , bigstuff that use speed density to regulate the fueling and log boost
or for dataloggers like power logger and others to log boost over the 15psi

 

[Grimster]

I'm thinking I want to know what boost I have going on and I'd like to log it Pretty sure the upgraded turbo is pegging more than 14.7psi easily. And I don't want my pretty dash boost gauge to quit working even if it is off by a lot Wonder if anyone makes an overlay for that gauge so it shows 0-30 psi.... hmmm

 

[pacecarta]

and before Id' add a $75 sensor to make the totally useless stock indash reflect over 15psi i would install a reputable boost gauge

mark at TRcustoms ( buickgn.com ) could do anything you want on the overlay
and it wont show 0 , min boost required is 6psi

 

[Grimster]

I mostly want 3 bar so my powerlogger will properly log true boost. I'll probably use a mechanical boost gauge in a 2 pod console gauge holder.

 

[TurboBob]

If you don't have a boost gauge yet?????

 

[Grimster]

I've only had the car a short time, I'm slowly getting it into proper order so I can keep it in top running shape, one piece at a time. Right now I'm trying to get all the logging and data collection and gauges set up so I can see where I am sitting mechanically/electrically/etc before I start throwing parts at it that I may or may not need or may or may not be what I need.

Mechanical boost gauge is sitting in the closet, just need to run a T and hook it up and mount it.

 

[TR Custom Parts]

and before Id' add a $75 sensor to make the totally useless stock indash reflect over 15psi i would install a reputable boost gauge

mark at TRcustoms ( buickgn.com ) could do anything you want on the overlay
and it wont show 0 , min boost required is 6psi

Something like this?

 

[Grimster]

Something like this?

Yeah that looks pretty nice

Frankly I don't care what the #'s say as long as my computer is logging the boost properly!