60mm turbo, doesnt build as much boost anymore..

[SkyMarauder]

i used to build boost at about 2500 rpm and i could see my boost gauge hit 8-9psi easily..

lately (last 2 or 3 months), my turbo starts to boost at about 3000 rpm and its a hair away from 5psi....

anyone else with a hp performance 60mm have this problem? if not does anyone know where to start looking? thanks in advance.. thi has been bugging me..

 

[Charlie Sheen]

http://s197forum.com/forum/showthread.php?t=22897

 

[SkyMarauder]

yeah i dont have that problem. i dont have cats

 

[Charlie Sheen]

Leaking gauge line?

 

[SkyMarauder]

hmmm... could be. should i just take them all off and inspect for cracks? or blow air through them maybe?

 

[ChevyKiller]

Start with checking your wastegate...

 

[SkyMarauder]

Start with checking your wastegate...

i checked it. its there..... lmao. what would i need to check? im new to turbos and the fine details. sorry bout being a PITA

 

[5.SLOW]

am new to but am having problem with it raising boost above set point and i got the hp kit to.

 

[jroc07gt]

try a leak down test to check for boost leaks

 

[SkyMarauder]

try a leak down test to check for boost leaks

how do i do that?

 

[Charlie Sheen]

Leaking gauge line?

hmmm... could be. should i just take them all off and inspect for cracks? or blow air through them maybe?

Which gauge are you using?

 

[ROUSH STAGE 4]

Check all your band clamps and also check the intercooler to see if maybe a rock hit it... There are quite a few things that could cause it to not build boost. Look for the obvious first...

 

[SkyMarauder]

im using a mechanical boost gauge

 

[Timbostang]

Do you have a boost controller on the car? Wastegate spring could have weakened. I don't know how hard your wastegate is to get to but you can pull it off and check the valve inside for any damage. Has the sound of the turbo changed? If so it could be something stopping up the housing. You can pull your inlet pipe off the turbo and make sure that the shaft doesn't have excessive play and make sure it spins nice and smooth. You also need to check your blow-off valve and make sure it is seating. Other than that it would have to be loose exhaust connection not allowing it to spool the turbo or a boost leak at any of the charge connections or intercooler.

For what it's worth, boost controllers are priceless. Takes away the weak spring in the wastegate factor.

 

[jroc07gt]

first thing you should always do on a turbo car is check for vac/boost leaks cuz the can be in the most discrete places. get you a 3" pvc end cap, drill a hole in it, install a tire valve stem in the drilled hole. place a rubber coupling in between the pvc end cap and turbo housing. now use a air compressor and pressurize throught the pvc end cap. if there is leaks then you will hear them.

now the easiest way is to get a smoke machine.

 

[SkyMarauder]

no boost controller yet.. but supposed to be getting one though.

i will check out what you guys have suggested. thanks again

 

[Timbostang]

first thing you should always do on a turbo car is check for vac/boost leaks cuz the can be in the most discrete places. get you a 3" pvc end cap, drill a hole in it, install a tire valve stem in the drilled hole. place a rubber coupling in between the pvc end cap and turbo housing. now use a air compressor and pressurize throught the pvc end cap. if there is leaks then you will hear them.

now the easiest way is to get a smoke machine.

Good idea!

 

[AutoXRacer]

First question to answer is, have you felt a difference in power?

Next thing is to check your gauge...make sure that one is working correctly first. Are you getting correct vacuum? Are you using that nylon tubing (get rid of that crap; get copper tubing or stainless braided lines)? They are prone to cracking in the engine bay (heat). Just inspect the portion in the engine bay. If its brittle, it will snap off.

If still no luck, inspect every single coupling and clamp along with all vacuum lines, then blow-off valve, and finally the wastegate. Just look for something that may be loose or disconnected.

Let us know what you find.