4agze TMIC vs FMIC Boost levels

**Poggy** · 09-07-2007, 10:26 AM

Hey everyone, i recently took my ARC topmount off my 4agze and put on a FMIC, with the ARC i was running between 14-17psi, now with the FMIC i'm running a constant 13-14psi, is this normal to lose a few psi due to the longer piping and larger intercooler size?

Also, when really hammering it, when you take your foot of the throttle sometimes it will keep reving for a split second, any light on that?

Cheers.

**celicapain** · 09-07-2007, 10:53 AM

yeah thats normal, cause youve gone to a less restrictive core.
remember boost is half air quantity x half air temperature(shuddup physicists) so your new front mount is cooling the charge more which will drop the pressure, as well as being less restrictive.

**celicapain** · 09-07-2007, 10:54 AM

p.s at a guess that 1/2 sec of free reving would be the engine using up boosted air in the plenum?

**Poggy** · 09-07-2007, 11:01 AM

Originally Posted by celicapain

p.s at a guess that 1/2 sec of free reving would be the engine using up boosted air in the plenum?

yeah i was thinking that, more air in all the pipes etc.

**MRMOPARMAN** · 09-07-2007, 05:53 PM

just throwing out a theory here.. feel free to shoot me down in flames..

where is the boost reading taken from? if its after the intercooler (ie inlet manifold) wouldnt that mean the intercooler is more restrictive than the old cooler?

and if the boost reading is taken before the intercooler, wouldnt the above readings mean the intercooler is flowing better.

also do you have the ability to read TPS voltages while driving? is the throttle body sticking or being held open under boost, or the throttle cable sticky maybe?