Tune for altitude

[mortimersnerd]

Anyone know if any of the tunes out there do a better job of dealing with altitude? I'm in the foothills east of Denver, live at 6000' and ski many weekends during the winter, so the car sees a fair amount of high load driving (big hills at freeway speeds) above 8-9000' feet. Longevity is a higher priority over outright powers, as I'm happy with the car's power now and mostly want to improve low end response. One local shop told me that APR's tunes tend to blow up turbos up here, but I've got no idea if that's actually the case. Any info is appreciated.

[skis4hire]

I've seen people recommend Avalon motorsports in Denver for tuning with altitude in mind. Looks like they are an APR dealer.

To hit published performance numbers the car has to be able to deliver the ECU's requested boost. At 6-9000 feet you have to make up 3-4psi vs sea level to hit that.
The car can do this by increasing the wastegate (N75) duty cycle at a given RPM, assuming there is head room.
If the tune would go close to 100% duty cycle at sea level for a specific RPM, then you will not hit the published performance #s at that RPM.

If you look at the APR Dyno Charts, there is a large increase in torque from ~2000 RPM which will give you low-end improvement.
To understand if you will get the published numbers, you'd have to see boost logs at sea level vs elevation, and if there is a reduction in boost at altitude, it may be explained by N75 duty cycle logging.

That is my understanding at least. You can read some interesting info about it here:
http://www.audizine.com/forum/showth...Boost-Duty-Map

[mortimersnerd]

Thanks! Your understanding reflects mine. I'm wondering if my car is already tuned. I've been doing some boost logging and am routinely seeing 15-16 psi. My understanding is that the stock tune runs around 11-13 and I'm seeing APR's tunes running around 19psi. At 5500' where I've been doing most of the logging, that could well translate into the numbers I'm seeing. Doubly true since all our premium gas is 91 octane, so it could be a conservative tune.

[jjvwg]

You're probably stock. These cars seem to run higher peak boost than the older Audi motors. I bought mine CPO so there is no chance of a tune and I peak 17psi, hold 14-15 to redline here in Denver. I would goo with apr or if you want a custom time done here at altitude talk to Bluewater performance is commerce city/Thornton about a united motor ports tune.

[Alex1188]

I didn't care for APRs tunes while I lived out in the foothills in Loveland. If I was you I would I wouldn't waste the money on just a tune. The performance difference at that high of altitude wasn't worth it. Ya you'll gain a little low end grunt but nothing crazy. I would just save your money and do a K04 conversion or something custom like others have said.

I went through two stock turbos on APR software out there. I then decided to just run the car stock tuning until I moved to MN now the tune is almost as fun as when it was when. I initially got it when I was stationed out in NC.

[mortimersnerd]

As much as I'd love it, a k04 isn't in the budget at the moment since I just bought the car. Current plan is a HFC and tune, with k04 maybe if I blow up the stock turbo down the road. Need to get some maintenance items taken care of first before I spend that kind of $$.

[AWDLover]

I ran APR Stage 1 tune on my 2010 A4 in Denver and went to the mountains often. I could tell a noticeable difference and enjoyed it. Had it on for about 30k miles before I traded it in for a truck. Never had any issues with the turbo, though did upgrade some of the piping and the diverter vallve. Blue Water was the shop I used for tuning, but at that time you had to remove the ECU and bench flash. Now that most of them can just plug in and tune, I'm sure any shop is fine.

Logging in the Golden area, I was hitting peak boost levels in the low 20's.