Boost trouble

[tlo86]

i had just recently drove to denver from dallas and i noticed.... i was only getting 4 PSI max boost in denver.. opposed to almost 8 psi in dallas...(also taking a little longer to spool up) i am thinking i might have trouble with my wastegate as i have not heard it open up since ive gotten here...

the turbo seems pretty good itself, i checked all of my (stock) IC piping for leaks, car just hit 90,000 miles.

recent work: front sway bar, new radiator, transmisson cooler, exhaust manifold leak repair.

i also first thought i had another exhaust manifold leak but it looks fine up close.

 

[IHI-RHC7]

Denver is called the mile high city for a reason.
Air is really thin up there, three just isn't enough flow on the exhaust side of your setup to spool the super thin air to 8 psi.
Down in dallas, the air is nice and thick, and the turbo doesn't have to work as hard to make pressure.
I'm pretty sure it's normal.
-Jake

 

[tlo86]

i hear that a lot but.. gah is it just that though?

 

[IJ.]

I thought GTE's had a HAC?

 

[IHI-RHC7]

The hac doesn't up the boost, it just adjust the AFR.
With a stock downpipe, it will never make 8 psi @ 5000ft.

 

[IJ.]

Thanks !
(had no idea what it adjusted)

 

[tlo86]

i never did write my mods, intake, TMS 3'' downpipe (open elbow instead of stock), 3'' cat, 3.5'' cat back

 

[IHI-RHC7]

You have a pic of your downpipe?
You checked you cat recently?
You might still have an exhaust leak before the turbo.

 

[tlo86]

installed cat and downpipe maybe 3 weeks ago so they should be fine, i'll take a pic of the downpipe later today.

when it leaked before you could really hear the exhaust coming out of the manifold, took forever to boost and boost levels varied on how warm the engine was (gasket fluctuating), and there was no engine exhaust coming out of........ the exhaust.... if you know what i mean.... but the exhaust is nice and loud when i start up the car and stays the same until i shut it off, i'll recheck the turbo - > downpipe connection and take a pic, and look for any signs of a leak (the black stuff ) on the bottom of the manifold

 

[IHI-RHC7]

yeah, have you tightened the turbo to the manifold?

 

[tlo86]

tightened down manifold, manifold -> turbo, 02 sensor to downpipe (leaking a little ), turbo to downpipe (leaking a little), downpipe to cat (leaking.. yes)

im sure its my elevation... even i am short of breath up here

 

[jkbmkiii]

MY supra when it was stock pushed 7psi here in denver but with DP,HF cat, 3" cb exhuast boost went down to 5 psi. When I did my IC pipes it went 4.5 psi. My turbo spools pretty quick though. When I go to texas at 4.5 psi I get there and I get over eight.

 

[tlo86]

MY supra when it was stock pushed 7psi here in denver but with DP,HF cat, 3" cb exhuast boost went down to 5 psi. When I did my IC pipes it went 4.5 psi. My turbo spools pretty quick though. When I go to texas at 4.5 psi I get there and I get over eight.

i guess it sounds about right, boost should go back up once i go back down there

 

[jkbmkiii]

Do you have a boost controller? Bolth our cars have close to same set up and I have boost set at 10 psi now runs great! You can flange the waste gate for like a buck and 30 min of work!