Hey, I have been having a super bizarre issue that I cannot seem to diagnose and it is driving me crazy. Long story short, when I first start the car and start driving, the car will make target boost (17.4lbs) once the oil gets to 160f. After driving for a little bit longer the car will start to underboost to about 13-14 lbs with oil at 180f, and anything beyond that I will get 8lbs max. Coolant temps don't crack 185f the whole time.
So far I have smoke tested the charge air side for boost leaks, smoke tested the vacuum system for leaks, replaced all the small vacuum lines with thick walled silicone tubing, replaced vacuum solenoids, ensured the vacuum lines aren't kinking under heat, pulled downpipes to check shaft play and oil seepage (none present), manually moved both wastegates to make sure they weren't seized (turbos were cold so not super helpful), still no resolution to the issue.
Some relevant specs on the car; Pure600 turbos, ARM inlets, VRSF outlets intercooler and chargepipe w/ Turbosmart BOV, cooling system recently overhauled w/ CSF radiator, index 12s with new OEM HPFP, 6hp21 recently refreshed with trans cooler, custom tuned by CD919 w/ xHP Stage 3 91oct
I am driving myself crazy trying to figure out what could possibly be causing this issue. I am about ready to rip the twins out of the car and call it a day. Any advice is much appreciated.
I have attached two logs, one on the street one on the freeway.
Street: https://datazap.me/u/ajskalsk/street-underboost?log=0&data=3-21
Freeway: https://datazap.me/u/ajskalsk/freeway-underboost?log=0&data=3-21&mark=66
So far I have smoke tested the charge air side for boost leaks, smoke tested the vacuum system for leaks, replaced all the small vacuum lines with thick walled silicone tubing, replaced vacuum solenoids, ensured the vacuum lines aren't kinking under heat, pulled downpipes to check shaft play and oil seepage (none present), manually moved both wastegates to make sure they weren't seized (turbos were cold so not super helpful), still no resolution to the issue.
Some relevant specs on the car; Pure600 turbos, ARM inlets, VRSF outlets intercooler and chargepipe w/ Turbosmart BOV, cooling system recently overhauled w/ CSF radiator, index 12s with new OEM HPFP, 6hp21 recently refreshed with trans cooler, custom tuned by CD919 w/ xHP Stage 3 91oct
I am driving myself crazy trying to figure out what could possibly be causing this issue. I am about ready to rip the twins out of the car and call it a day. Any advice is much appreciated.
I have attached two logs, one on the street one on the freeway.
Street: https://datazap.me/u/ajskalsk/street-underboost?log=0&data=3-21
Freeway: https://datazap.me/u/ajskalsk/freeway-underboost?log=0&data=3-21&mark=66
