[Dackz]

Does the GIAC still put out 13.5 psi at higher elevations as well? Or does it put out more then that kind of like how it does it at stock? I live at 5k feet here in CO and go to the mountains once in a while during the summer. Im wondering if it would do something like 14.5psi here or more at higher elevations.

Im worried about stressing the turbo's a tad, so was just curious. Otherwise, from what I have read it seems to be the tune for me.

Also, any improvement in highway cruising MPG's?

Fuel pump question: say it goes out at 62k, and its under warranty per BMW, but I have GIAC, can BMW deny me because I have a tune on the car even though it has happend to thousands of people without a tune?

[Andrew@GIAC]

Originally Posted by Dackz

Does the GIAC still put out 13.5 psi at higher elevations as well? Or does it put out more then that kind of like how it does it at stock? I live at 5k feet here in CO and go to the mountains once in a while during the summer. Im wondering if it would do something like 14.5psi here or more at higher elevations.

Im worried about stressing the turbo's a tad, so was just curious. Otherwise, from what I have read it seems to be the tune for me.

Also, any improvement in highway cruising MPG's?

Fuel pump question: say it goes out at 62k, and its under warranty per BMW, but I have GIAC, can BMW deny me because I have a tune on the car even though it has happend to thousands of people without a tune?

Hi Dackz,

Your boost should be a little lower at altitude just like it is at idle on the stock chip. We do not program for specific boost values, but rather condition based torque targets, just like your stock program. We will be checking some cars in Mexico City over the next week or so, if you send me your e-mail info I will send you the results.

The MPG's should be about the same. We leave all the part throttle maps alone.

The fuel pump scenario you describe could happen, as with any upgrade you make on your car.


Andrew.

[Dackz]

Thanks Andrew, check your PM

[lm1z]

To answer your fuel pump question: Yes. This could happen. This has been my only concern with modding my car. It happened to a guy who brought in his w/ his JB3 installed after he noticed he was having fuel pump symptoms.

If you have an issue, don't ever bring your car in to the dealer - even if you're tight with your SA. The issue goes way above and beyond your SA. BMW will try as hard as possible to blame the issue at hand on any modifications done to the car. As much as it sucks, It's just good business...

[cvc 22349a]

Originally Posted by Andrew@GIAC

Hi Dackz,

Your boost should be a little lower at altitude just like it is at idle on the stock chip. We do not program for specific boost values, but rather condition based torque targets, just like your stock program. We will be checking some cars in Mexico City over the next week or so, if you send me your e-mail info I will send you the results.

The MPG's should be about the same. We leave all the part throttle maps alone.

The fuel pump scenario you describe could happen, as with any upgrade you make on your car.


Andrew.

So, are you saying that at altitude your flash tune will make less boost than at sea level? I'm very interested in your tune and would like to know if it adapts/compensates for altitiude by raising boost pressure as the stock ecu does, and if so to what psi? Instead of emailing results of your testing in Mexico City, will you just post them here?

[JayKay335i]

Just as a BTW that may or may not be helpful for you I ran from NY to AZ and drove through CO over the Rockies and the whole 9 yards. From sea level to 10k elevation and back down. In Denver at around 5k the car performed OK. After that, it was pure crap. I was running the JB+ at 75% with 91 oct. I would have turned it down but I forgot to that morning and wasn't bothering once it was hot.

[Dackz]

Its just like I experienced stock out in Cali. At sea level, car has NO perceptable lag, car feels like a beast compared to here. Stock pre 29.2, not sure what it is but its pre 29.2.

Thats why Im wondering what a tune like this would do up here.

[cvc 22349a]

It sounds like other tunes ie. boost pressure does not increase at altitude as with the stock ecu, which increases boost pressure from 8psi at sea level to 11psi at altitude.

[marconi118]

the stock ECU increases boost with IAT to compensate for less dense hot air... Is this the same with giac?

It is impoerant to know this for methanol injection, to choose to place te nozzle before or after the TMAP sensor....