Thread: Cobb tune!
View Single Post
      12-02-2011, 06:53 PM   #54
E30M3Driver
Captain
E30M3Driver's Avatar
United_States
37
Rep
794
Posts

Drives: 2021 M2C, 97 M3
Join Date: Jan 2006
Location: Here, there

iTrader: (1)

Garage List
2007 BMW 335i  [8.00]
1989 BMW M3  [8.20]
Quote:
Originally Posted by ajsalida View Post
Yep, I routinely see 17.9 PSI indicated on stage 1 Cobb at low RPM at my elevation (~8k-12k). This puzzled me for a while, but then i realized what maps that target load meant. Essentially they target absolute manifold pressure, not some delta PSI above ambient. So if ambient is low due to elevation then turbos work a bit harder to hit it. They don't push any more air mass than at low elevation, but a larger portion of it needs to be compressed, ergo better FMIC is a real good idea.

I did not understand this before I bought the Cobb but I am glad it works that way.
Do you know what PSI you were seeing stock? I've been under the impression that at 5K feet the the full compensation that the stock programming delivers is less than the max it can do - in other words, that you see about 10.5psi and max occurs more around 8K feet?

Still have yet to meet anyone that has measured and volunteered boost numbers stock in Denver...
__________________


Performance Center Delivery, June 21, 2013: 2013 E92 335is | Le Mans Blue | Gray Leather with Black | 6MT | 19" Style 313's | Michelin Pilot Super Sports | BMW Carbon Fiber Rear Spoiler |
Appreciate 0