I recently purchased T1R UICP and LICP for my 2012 GSR, installed it, and noticed a difference on how boost comes on.. the car doesnt seem to hit boost as hard, I dont feel the sudden surge of power compared to my stock U/LICP's, It also feels like my car is turning Naturally aspirated . Only other mod is a Cat back exhaust and cobb panel filter but no tune yet.

I thought maybe the ECU needs to adjust itself so I ignored the issue.

Few days later my AP3 arrived but i did not flash the ecu yet and ive been monitoring the boost pressure in PSI.
At idle, my vacuum is around -8PSI to -12PSI depending on the temperature.

At full boost in third gear, the highest ive seen was around 14psi to 16psi through out WOT to redline. Not sure if I have a boost leak or not.. On the forums, ive been comfused with the correct boost pressure numbers because people stated vacuum should be at around -18 to -22 and peak pressure should be at around 17-25, but they didnt specify in inHg or PSI... Can someone explain this to me please?

I may have loosened the boost pills during the UICP installation but I don't see how that would cause me to underboost in anyway..

any suggestion or advice is appreciated!

 

That boost up to redline for stock is about right. You could always double check for leaks with soapy water along the joints of your piping to make sure there is no leaks!

 

its correct but even through out the powerband it doesnt peak higher than 14psi to 16psi. Like, at full boost its 14psi-16psi, and doesnt taper down at all.

 

IC well yea there is deffinitly something up there then. It should Peak in the 20's then taper down. Well the only thing you have messed with it sounds like is the intercooler pipes so its got to be a boost leak somewhere in there.

 

bumping for interest

 

Consider this--- the new piping is larger in diameter in all locations (from what I have seen) and while you thought that was a good idea (removing restrictions) it cuts air velocity thru the intake and that my friend slows response from the turbo moving the power band to the rt. check for boost leaks and get it retuned. As a general rule when it comes to engines bigger isnt always better as your finding out. Good luck.

 

30 in/hg is equal to 14.7 psi. If your boost gauge is reading vacuum in psi just double that figure to quickly mentally calculate in/hg (you'll be really close).

It sounds like you're idling in the right neighborhood.