help only 12lbs of boost

[supercarkiller]

just hooked up boost guage today and realized im only making 12lbs of boost with steg stage 5 port, 4lb lower and 2.76 upper and i belive i should be making 17lbs (also have 60lb injectors, cold air intake, sct mass air flow and a tune) ( oh forgot full exhaust and headers too)

 

[Posi]

Belt slip or your lines for the gage are leaking. You have an aux idler?

 

[03cobra#694]

Belt slip or your lines for the gage are leaking. You have an aux idler?

+1
Where did you hook your sending unit up?

 

[supercarkiller]

to the factory tellow boost guage line and yes i have and aux. pulley and thanks for the quick responses

 

[Posi]

How loose is the belt? Below the upper pulley on the left you shouldn't be able to move it left to right hardly at all. Maybe a 1/2" tops and 1/2" is loose to me. Just use your hand and if it moves that much easily I'd get a new belt.

 

[96stanggt]

What size belt are you running.

 

[03cobra#694]

If the belts slipping,there is probably a lot more dust than normal on the pulley.
Is this vac/boost or boost only?

 

[supercarkiller]

the belt is very tight and its brand new

 

[96stanggt]

Didn't ask if it was tight, what size is it? A belt that is even an 1/2" too short can feel tight, but be loose enough to cause a nice bit of belt slip.

 

[supercarkiller]

its a napa belt 25-080780

 

[03cobra#694]

if the belts slipping,there is probably a lot more dust than normal on the pulley.
is this vac/boost or boost only?

hey!!

 

[supercarkiller]

boost only guage

 

[03cobra#694]

boost only guage

Ok,If it was vac/boost i was just curious what the vac reading was at idle to see if the guage was working correct!Sorry i couldn`t help:shrug:

 

[supercarkiller]

no problem i really do appreciate the input though

 

[mike302]

Ok,If it was vac/boost i was just curious what the vac reading was at idle to see if the guage was working correct!Sorry i couldn`t help:shrug:

Not trying to high jack, but Im having a similar problem where should the vac be at???

 

[96stanggt]

Do you have just the 100mm aux idler pulley, or all 4 idlers? Stock alt pulley or the 3.2"?

 

[supercarkiller]

just the axuliary idler all the rest of them are stock

 

[96stanggt]

With that combo I ran a 77" belt on my car. I saw about 15lbs of boost peak with headers and no cats, occasionally I'd see 15.5lbs in 4th gear on a cool night. Aside from that belt being too lose have you checked your boost bypass?

 

[supercarkiller]

boost bypass is brand new

 

[96stanggt]

Was it preloaded and installed correctly?