question about boost spike/creep

[sexystover]

im running a big16g on my talon and it stays at 8psi till around 5500 and then climbs till about 20-22 psi, is this normal or is something wrong. someone said maybe a boost leak but this is my first turbo car so im not sure. ill be making a boost leak tester this week

 

[LiquidX]

It's called boost creep. Either port the turbine housing or tune your car to the psi it's creeping to. It happens from a free flowing exhaust system causing the turbine wheel to be the path of least resistance over the wastegate outlet.

 

[gsxkid81]

do you have a boost controller?if so what is ## boost set to

 

[sexystover]

i was running a line straight from the intercooler pipe to the wastegate, the car is tuned for the boost creep running 10.5-11.0:1 AFR from 3k-redline. now i have a manual boost controller installed and im limiting the creep to 20psi. im just going to deal with the creep. but is there a reason im only building 8psi until 5000ish? its just a 16g i thought full spool was around 4k full spool isnt till 5500 or so on my setup

 

[sexystover]

bump any reason for my slow spool or is it normal?

 

[gsxkid81]

its not normal.a big 16g shouldnt creep.even with stock ported wastegate hole.you need to double check that you have no boost/vacuum leaks.

post your whole setup

 

[sexystover]

big 16g, fmic with 2.5" piping, 3" gm maf with maft, SAFC2, wally 255 rewired, AFPR, 660cc injectors, arp head studs, bc 272s, 2.5 or 3 inch exhaust including dwnpipe (cant remember bought the car with it),no cat, 2g o2 housing, 2g exhaust manifold

 

[SlowChild3]

Port, port, and port some more. When you think your done porting, port some more. I had to Do my small 16g 3 times. Lol.

Sent from my DROIDX using Tapatalk

 

[sexystover]

so if i get a tubular o2 housing and just port the turbo/manifold i should be good?

 

[JayRolla]

You really need to port the turbo housing too allow better flow to the wastegate. So make sure its ported correctly to stop the boost creep. In my case I just decided to run e85 and set the boost too 30psi and ported to MAKE the turbo creep so I can hold better boost.

As for the slow spool, that is NOT normal at all. I hit 30psi on my 16g at 3600-4000rpms, you should get 8psi by 3200 rpms. Do a boost leak test!!

 

[sexystover]

did a boost leak test , no major leaks, biggets leak i think is a throttle body seal maybe, its in that area but i cant tell, ran outta time, found out my wastegate line had a split in it, i repaired it and now it doesnt creep to 20+ anymore, holds strong at 15 now