[s-cars] 80tq: 20v Project Update, 415whp, 12.25, etc

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Dave:
It depends... That's the best answer you can propose.  As Javad points out, 'you' might see and increase, but others might not.  And certainly, putting a number correction claim will only have an 'n' of one.  Many times, as has been my shop experience of ASW customers coming to live in the midwest, lower altitudes overload the altitude tuning of the car.  I read Hap ran out of fuel.  Why?  Well he had more air density going thru his motor, all else being equal, and he needed more fuel he didn't have.

Turbo surge and choke are really where this argument will find limits in any given application.  My own thinking is the more you stretch the performance of a 2.3 motor with motronic, the more specialized you need to make the tuning of it.  The 034 boys (Javad et.al.) are finding that there are many variables that cause them to remap the fuel trims.  And there's more to it than just watch WB02, there's turbo efficiency and VE based on WB02 AND EGT's.  Without question 034 boys are just starting to come up on this.   

Motronic will have the same issues, the more you push the envelope and variables, the more it will need adjustment.  A lot of variables are changing with altitude changes: EGT, MAF, CATemp, CAflow, ICefficiency, Turbo efficiency, FPRpressures.  These baselines optimized for an altitude, can prove to be limitations at another altitude, or just cause overload of the various components as a whole = surge/choke.

The stock audi Motronic Box has Barametric sensor input as a safety feature, at 10,000 feet the WGFV is no longer operational.  But, to make the argument that means at -0- elevation it should be double 5000 feet (or some other number), just doesn't have validity.  I certainly believe those at lower altitudes might have better potential numbers, but attaining them isn't just a matter of driving down the hill a piece.  

HTH and my .02

Scott J




In a message dated 11/11/2004 2:04:57 PM Eastern Standard Time, Djdawson2 writes:


>Interesting... so not only are our cars getting the benefit of overcorrection 
>on the dynos, but the altitude is helping our turbos perform better???  C'mon 
>guys, give me a break.  Review your maps.  To run at the PR that we're 
>running (denominator is lower... therefore, PR is higher at altitude) we're crossing 
>the top of the map... certainly no improvement WRT compressor efficiency.  
>Let me know an acceptable sea level dyno, and I'll go give it a try.
>Dave
>