Turbo noise increase with altitude

[AbwTCU11]

Back in july I moved to Colorado from texas. I have noticed an extreme increase in turbo noise. My car is still stock. Is this increase in noise normal due to high elevation, or do yall think that something might be loose?

[nsibanez]

could be normal? maybe because the turbo can spool faster with thinner air? i dont really know for sure but if its still stock, then that would be the only reasonable explanation. try asking people in your region too.
how many miles are on your car?

[Ingo]

I'd suggest to get a tune. I live in Colorado Springs, did a road trip to Iowa. Now, mine is a stage2 and tuned for that. At the way lower altitude my car overcharged very hard. Once even blew the piping to the front mount intercooler apart. Everything back to normal once back to the Springs. Just had to drive carefully and keep it out of too much boost. But it happened very drastically. So you are looking at the reverse, and I'd think a re-tune would fix you right up. While the ECU does learn over time, it is more geared towards ignition timing and fueling rather than atmospheric adjustments, I believe.

[nsibanez]

ya youre right. the ecu lears over time to adjust just that. valve timing, fuel trim, but not performance i believe.
even my lancer i did a cai and cbe...had check engin lights, but eventually they went away on there own. all for bank 1 system too lean

[SKI.WRX]

As altitude increases air pressure decreases. So the turbo has to work harder to compress the air to the specified boost level i.e. spin more/faster. Boost leaks can be very loud depending on the size but from the two that I've heard they don't sound like a turbo should. So I would say check all fitting and hoses on the intake tract and If they are good, the noise is likely the turbo working harder to compress the thinner air.

[Donkey]

ya youre right. the ecu lears over time to adjust just that. valve timing, fuel trim, but not performance i believe.
even my lancer i did a cai and cbe...had check engin lights, but eventually they went away on there own. all for bank 1 system too lean

All cars are different. You can't always compare one directly to another. Also the ECU doesn't have an infinite amount of adjustability. Car manufacture's can only predict so much as far as the ECU compensating variables for all situations.

OP: I would get the car retuned. Not just for performance sake,but for driveability and reliability.

[nsibanez]

As altitude increases air pressure decreases. So the turbo has to work harder to compress the air to the specified boost level i.e. spin more/faster. Boost leaks can be very loud depending on the size but from the two that I've heard they don't sound like a turbo should. So I would say check all fitting and hoses on the intake tract and If they are good, the noise is likely the turbo working harder to compress the thinner air.

yay!! I was part...kind of right...I think

[nsibanez]

All cars are different. You can't always compare one directly to another. Also the ECU doesn't have an infinite amount of adjustability. Car manufacture's can only predict so much as far as the ECU compensating variables for all situations.

OP: I would get the car retuned. Not just for performance sake,but for driveability and reliability.

I know this is true. Every car is different but I figured this may have been similar too. Like I'm sure every car's ECU will tune itself for short term and long term fuel trim?

[Donkey]

Like I'm sure every car's ECU will tune itself for short term and long term fuel trim?

The ECU doesn't tune itself for short term and long term fueling. Short term and long term fueling is data used for the ECU to compensate for changing fuels and tired MAF/O2 sensors in closedloop fueling. And the ECU can only adjust the trim a certain percentage. In Openloop fueling the ECU has basically no control/ability to compensate for fueling targets as no O2 sensor feedback is used. This is the part people don't understand. Just because your CEL went away doesn't mean there still wasn't a problem. The closedlooop fuel trims might have fixed the closedloop fueling but not the openloop. There are very few cars that run completely closedloop fueling. Some VW's and Audi's do but they run they run the Bosch LSU 4 wideband sensors.

[nsibanez]

All that lost me lol. I'm gonna have to re read up on that E-module