boost question??

[13guest13]

hey guys im having problem with my turbo 420. im running 10 psi on stock internals. i just bought a godspeed wastegate and worked fine boosting at 10 psi for a day. then the next at 7 then 6 and then 5 so i thought the vac line to the turbo was bad. but it was good so i thought there was a leak somewhere. no leaks.then when i was going to check my blow off valve the adjustment screw got stripped. so i stripped a bigger thread in but now my blow off valve doesnt sound the same. its very quiet could it be compressor surge?? or its leaking from the blow off valve. maybe low compression in pistons?? when i step on the gas it starts boosting at -5 vaccuum. it doesn't even get to 0 before boosting. and it boost alot later like 4000 rpm instead of usual 2500 rpm. its alot slower now and only boosting to 6 psi right now. im driving it real slow right now because im scared i might mess something up. any help i would appreciate it please....

 

[LD25Delta9]

Sounds like it's either your wastegate leaking or your BOV. Do a BLT with a regulated pressure source going to the inlet on top for the BOV. For the wastegate, hook up a regulated pressure source to the bottom inlet, and make sure that it is opening at the rated psi.

 

[LiquidX]

Boost leak test

 

[13guest13]

i did both test and they seem fine. but now their is white smoke coming from the exhaust. and i did a compression test on the pistons and they are fine......sounds like a blown turbo???

 

[LD25Delta9]

Could very well be, but if it was fine before.......

 

[Carter_95RS]

Is it smoking all the time or just in boost?

 

[13guest13]

it smokes all the time. it started a few days ago. after that it never boosted the same. could it be too much oil? i never ran an oil restrictor. its a journal bearing. not ball bearing. could that have blown out the turbo?

 

[LiquidX]

It's very well possible your blew out the oil seals depending on what the oil pressure is at the inlet of the turbo. Check for shaft play both lateral and horizontal.

 

[Haase]

it smokes all the time. it started a few days ago. after that it never boosted the same. could it be too much oil? i never ran an oil restrictor. its a journal bearing. not ball bearing. could that have blown out the turbo?

yes... no restictor could definitely have blown the seals in your turbo... i fried mine by not having a big enough return line for the oil so now whenever the car is running its issuing out blueish white smoke, maybe check that as well?

 

[Carter_95RS]

Check for shaft play, sounds like blown seals in the turbo.

 

[13guest13]

i hdo have some shaft play. and the turbo came with a really really small oil restrictor but i made it bigger. it seemed too small for me