Convert MAP to Boost?

[sdgoat]

Is there a way to convert MAP to boost? I have an LS2 with a Maggie supercharger, and I would like to display boost. Can I calculate the boost based on the MAP? I was reading through http://www.hptuners.com/forum/showthread.php?t=4084. When I create a user defined field, I choose "Manifold Absolute Pressure" for the Sensor, psi for the units. Do I then need to build a function? [SENS.30] appears to be the MAP. Or am I not even on the right track? Will I need to purchase a boost sensor that can send voltage to the EIO?

Thanks!

[devildog9999]

I dump mine to excel and insert a column called boost. Then use this formula : =SUM(L8/6.894)-14.5 (L8 being map) and it will get it pretty close.

[miker2]

the nice folks at hpt give you the ability to right click on the gages or charts and select properties-then change from kp to psi and set your max limit.you can do this on old logs as well.note that as you move the bar to view your chart history,the gages will stay in sync. see attached sample

[miker2]

or you can just use this config.

[sdgoat]

the nice folks at hpt give you the ability to right click on the gages or charts and select properties-then change from kp to psi and set your max limit.you can do this on old logs as well.note that as you move the bar to view your chart history,the gages will stay in sync. see attached sample

Wouldn't this be listing MAP in PSI? MAP isn't necessarily the same thing as boost, is it?

[redhardsupra]

the popular term boost is pressure relative to atmospheric. so if absolute pressure (psia), which is what MAP sensor measures, reads 2bar (if you have 2barMAP that is) then it's 1bar of 'boost'. boost is also called gauge pressure (psig)

psia = psig + baro

[TTZ06]

the nice folks at hpt give you the ability to right click on the gages or charts and select properties-then change from kp to psi and set your max limit.you can do this on old logs as well.note that as you move the bar to view your chart history,the gages will stay in sync. see attached sample

what's up with the 8knock and 2.5advance in this log?

[devildog9999]

I saw that too.....Glad I was not the one who pointed it out!

[miker2]

just finished the install and trying to sort it out. found the problem today,the used whipple was apparently set up for high boost on a 6.0--mine is a 5.3. i ordered the larger blower pulley today.

[miker2]

plot thickens --whipple is shipping me a 4 3/8" pulley, i now have 2 7/8" or a 50% overdrive. no wonder i had a wee bit of knock.nothing in the install manual about pulley sizes.

[jimmyblue]

MAP-BARO is your boost/vac value. There is (or may
be in your setup) also a manifold vacuum PID / "sensor"
that might (or not) give a negative value for boost.
But you need a 2-bar MAP sensor for anything over
105kPa or so, to read right (and the OS to match).