i was in the lake tahoe area and my car started acting wierd. my car wouldn't boost when going up the twisties in the mountain. max boost was like around 3 pounds or so when i floor it in 4th and 5th. my bov also wouldn't vent for some wierd reason? could this be the altitude causing this? im worried something was wrong with my car but when i got home, my car was normal again. it would boost and the bov would vent. my mods are cobb st2 reflash, hks dp, gfb stealthfx bov, and hks catback.

 

yeah, but 3psi is pretty darn low even for up in tahoe.

 

I think this is common on high altitude areas. Its kinda like driving up a mountain range on highways/roads/streets.

When you drive on roads where the altitude is high, and you engage the turbo there isnt as much air for the turbo to force into the chamber. So, it feels lackluster.

(This sound right? I just want to get down to the real answer )

Kinda like driving fast on the grapevine in Los Angeles. You try to go faster up those mountain roads, the car doesnt go quite as fast because the turbo isnt as efficient when driving on lower elevations

Maybe someone else can give a better answer or explain it clearer.

 

If it boosts normally at lower elevations, your Rs were too low when going full throttle at the higher elevation in 4th and 5th. Downshift sufficiently to bring the revs above 4000.

--
0==WW==0
"…axles of evil…" - george w. bush

 

but even when i brought the revs up by downshifting to 4th, max boost pressure was about two or three "ticks" after the 0 on the stock boost gauge. my car was just so slow.

this didn't happen when going to lake tahoe during the day though, i also had to climb and stuff. it only happened when i was coming back where i couldn't boost.

does anyone else have experiences like this when they went to lake tahoe?

 

Yes, at higher elevations the air is less dense. A turbo helps offset the loss compared with a normally-aspirated engine but there is still a power loss for turbo engines, too. Witness the huge power loss for the WRC cars when running at over 7000 ft elevation in the Rally of Mexico.

--
0==WW==0
"…axles of evil…" - george w. bush

 

Yup, it was widely noted that most of those cars lost almost 100hp between service and the highest elevation stage.

 

high altitude doesn't affect boost that much

75% of my cars life has been spent above 7,000 feet

even at 11,000 feet it pulls like a champ

 

I don't have this problem, I go up to Tahoe or Truckee almost every weekend in the winter - I have no problem with power or boost in my car.

My only guess is that you don't have the RPM's high enough to boost, try downshifting.

 

Did you know the turbo was invented because of airplanes? Turbos were used to counter act the lack of oxygen when airplanes were flying.

To answer your question, no its not the thin air that makes your turbo lag/ underboost.