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@#$^*&!! Trifecta!!!!!!!!!!! (Resolved)

11386 Views 48 Replies 18 Participants Last post by  Sonic
This is my last attempt to be nice with trifecta. I installed a boost gauge. In both eco mode and perf mode i see 22psi. I purchased a select a tune. Correct me if im wrong but should i not see 12-14 psi in eco mode (with cruise control enabled)? Vinces response was "its your elevation". Omfg so you are telling me that because i live at 4000ft ill get 22 psi even though you told the pcm to only boost 14?! Please tell me if im wrong because im about to cause problems for vince. Im so sick of this! Sent from my Galaxy S3
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This is my last attempt to be nice with trifecta. I installed a boost gauge. In both eco mode and perf mode i see 22psi. I purchased a select a tune. Correct me if im wrong but should i not see 12-14 psi in eco mode (with cruise control enabled)?

Vinces response was "its your elevation".
Omfg so you are telling me that because i live at 4000ft ill get 22 psi even though you told the pcm to only boost 14?!

Please tell me if im wrong because im about to cause problems for vince. Im so sick of this!

Sent from my Galaxy S3
I am at basically zero feet but mine never strays above 14psi with the cruise control on.

Sent from whatever I want. .
 

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This is my last attempt to be nice with trifecta. I installed a boost gauge. In both eco mode and perf mode i see 22psi. I purchased a select a tune. Correct me if im wrong but should i not see 12-14 psi in eco mode (with cruise control enabled)?

Vinces response was "its your elevation".
Omfg so you are telling me that because i live at 4000ft ill get 22 psi even though you told the pcm to only boost 14?!

Please tell me if im wrong because im about to cause problems for vince. Im so sick of this!

Sent from my Galaxy S3
Here is a question for him. If its all about elevation, then why isn't you 22psi tune boosting higher than it should as well?

Sent from my XT912 using AutoGuide.Com Free App
 

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Boost control works off the TQ management tables.

The ECU is programmed to make X TQ. When the air is thinner it runs more boost to make that amount of TQ. This is why stock cars will run 15psi in the summer and 10psi in the winter at the same elevation. The actual output in hp/tq is the same in winter/summer, where as most cars make much more power in winter. The DA (density altitude) can vary by 5,000 feet when the car is really at sea level, based on the temp and atmospheric conditions. I frequently see +3000DA in the summer and -2000DA in the winter living at sea level.

It does have to do with your elevation levels. Mine will go up to about 19psi in eco mode. Where i live is about 400ft above elevation.

400ft isn't enough to do anything.
 

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In addition to what Hoon said, the turbo in the Cruze can only output enough to generate a certain amount of boost. I don't know what it is, but Hoon and [email protected] probably do. When you go up your turbo has to work harder to get to the same boost because the starting air pressure is lower. There's a good chart of this drop at Air - Altitude, Density and Specific Volume. Scroll down for the chart. At some point it doesn't matter how good your tune is because you will hit the mechanical limits of the turbo in our cars.

I guess the real question to ask Vince is for a altitude based "max boost" chart for the Trifecta tune.
 

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Titan,

Go to this site and a site that has your local weather.

Where it says track elevation in the middle box, enter all your info for your home town and the current weather.

Post up the results.

DA Calculator - Density Altitude Calculator - DragTimes.com



For comparison, my current DA is -1400, which is the equivalent of being 1400ft BELOW sea level in "normal" conditions. In this air my car will make mid 9.x psi sustained. Spikes into the low-mid 10.x....unless it's on a dyno where it will hold 12.5psi for reasons i still don't fully understand.
 

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It does have to do with your elevation levels. Mine will go up to about 19psi in eco mode. Where i live is about 400ft above elevation.
I've seen the same thing in mine in the "eco" mode on occasion. It happens more on hot/humid days than on colder, drier days.

Sort of OT, but the other night when it was 6*F out the "sport" mode only got up to 18 PSI. The car was pulling like a champ, though.
 

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Discussion Starter · #13 ·
Thanks. Ill check the stock tune.

I dont want to hear anything about elevation 1) it isnt relevant here 2) ive already proven to vince that there is little difference between my car at 0ft, 2000ft and 4000ft. Have logs to prove it.

I will retune stock and report back.


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elevation.I've seen the same thing in mine in the "eco" mode on occasion. It happens more on hot/humid days than on colder, drier days.
I am definitely seeing the same as Sciphi, with ECO mode. Hot 90+ temps seeing 21-22 psi peak boost. Since it has been cooler more like 18 psi peak in ECO mode.
 

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Thanks. Ill check the stock tune.

I dont want to hear anything about elevation 1) it isnt relevant here 2) ive already proven to vince that there is little difference between my car at 0ft, 2000ft and 4000ft. Have logs to prove it.

I will retune stock and report back.


Sent from my Galaxy S3
I really wouldn't expect elevations below 4,000 feet to have much difference given that my stock tune ECO MT doesn't start showing signs of shortness of breath until it's over 10,000 feet. There is a lot of head room in that turbo for compressing lower density air.
 

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Discussion Starter · #17 ·
Confirmed, stock tune produces no more than 14psi both at 2000ft and 4000ft.

Sending my email now.

titan2782- if I were you, I would re- flash to stock & just drive the SRT-4 when I get the urge for some fun. Am sure the wife won't mind ;)
Well, 1) I already paid for a tune that I can't return for a refund 2) The wife says no.
 

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Discussion Starter · #19 ·
Hmmm, that is odd. Sorry buddy I don't know what is wrong! I guess the question is.. does it FEEL like it is pushing 22 psi in eco mode?!
Feels exactly the same in both modes. After I switched back to stock tune, I noticed a huge difference in drivability. I tried to pull out into traffic and almost died. Ok, maybe not almost died, but I certainly didn't get the response from the car that I have come to expect.

So having said that, I would expect eco mode to be similar to stock tune as far as feel.

Either way, the gauge reads 22psi in both modes with tune and 14psi with stock tune.
 

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Feels exactly the same in both modes. After I switched back to stock tune, I noticed a huge difference in drivability. I tried to pull out into traffic and almost died. Ok, maybe not almost died, but I certainly didn't get the response from the car that I have come to expect.

So having said that, I would expect eco mode to be similar to stock tune as far as feel.

Either way, the gauge reads 22psi in both modes with tune and 14psi with stock tune.
Well, that just seems like a problem with getting "eco" mode to work. Eco should be 14 psi and be slightly weaker than stock.
 
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