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In Reply to: Re: I keep forgetting to talk about the compressor wheels.., John Williams [Profile/Gallery] , Fri, 9 Dec 2005 14:00:12

Again about the airplane example, can it compesate with more rpms like a turbo can? If you run a turbo with a deasent pressure ratio at sea level, you will have 20-30% more rpms in "reserv" to compensate for the increased pressure ratio. This is easy to read from the comprssor map...

"My turbo is pushing less air here than at sea-level, this means a loss in pressure, it cannot duplicate sea-level pressure at the same rpm, its basic physics"

please share this simple physics with the rest of us, since I cant get to the bottom of what you mean. Of course you'll loose slitly on the rpm where the turbo spools... but reffering to your old post you wrote that our boost 3psi higher at altitude = same manifold absulte pressure since boost gauge measures agaist ambient.

And what comes to the dyno results in general at altitude, both the stock viggen and STI clearly indicates that numbers with SAE correction will be to big for those cars having left over capasity in the turbo. IHMO the uncorrected values for the STI and stock viggen are really close to what one should expect. For instance the sti will dyno around ~230whp at sea level, uncorrected at MAC auto was 225whp.

Also like I once wrote, your feel to believe who ever you want and what ever wicked formulas for altitude correction you like, it is your car not mine, but suggesting values for altitude losses with out any facts what so ever is just as good as guessing.

posted by 81.197.81...

• john williams pulls only change 9 psi base boost, jak , Thu, 1 Dec 2005 10:47:40
  • JAK...., Vigge, Mon, 5 Dec 2005 03:24:44
    • I know you love me :-), jak , Tue, 6 Dec 2005 20:13:50
      • Re: I know you love me :-), Vigge, Tue, 6 Dec 2005 23:34:03
        • Im gona get some viggen #s from 5000 ft if possible, jak , Wed, 7 Dec 2005 06:04:12
          • Re: Im gona get some viggen #s from 5000 ft if possible, vigge, Wed, 7 Dec 2005 12:13:51
          • It's all about pressure ratios, SteveW, Wed, 7 Dec 2005 07:48:54
            • Re: It's all about pressure ratios, Vigge, Wed, 7 Dec 2005 11:33:12
              • I keep forgetting to talk about the compressor wheels.., John Williams , Wed, 7 Dec 2005 21:37:05
                • Re: I keep forgetting to talk about the compressor wheels.., vigge, Fri, 9 Dec 2005 02:42:09
                  • Re: I keep forgetting to talk about the compressor wheels.., John Williams , Fri, 9 Dec 2005 14:00:12
                    • Re: I keep forgetting to talk about the compressor wheels.., vigge, Sat, 10 Dec 2005 11:12:22 <-- Viewing This Message
              • Turbo car and pressure..., John Williams , Wed, 7 Dec 2005 21:12:55
                • some more, vigge, Fri, 9 Dec 2005 05:39:10
                  • Sounds about right, I just pulled the specs at 300hp., John Williams , Fri, 9 Dec 2005 13:44:33
                    • Re: Sounds about right, I just pulled the specs at 300hp., Terry, Fri, 9 Dec 2005 21:12:12
                      • Also....., Terry, Fri, 9 Dec 2005 21:47:24
                        • Thanks Terry, thats the answer I was looking for...., John Williams , Sat, 10 Dec 2005 10:06:48
                          • A/F, vigge, Sat, 10 Dec 2005 11:14:15
                            • Re: A/F, John Williams , Sat, 10 Dec 2005 16:32:03
                              • Re: A/F, vigge, Sun, 11 Dec 2005 03:39:50
                                • Yea too many variables, John Williams , Sun, 11 Dec 2005 04:05:03
                                  • Re: Yea too many variables, Vigge, Sun, 11 Dec 2005 04:26:06
                                    • Re: T-5 compensate for a Mile high?, John Williams , Sun, 11 Dec 2005 09:31:34
                                      • Re: T-5 compensate for a Mile high?, vigge, Sun, 11 Dec 2005 10:06:33
                                        • Re: T-5 compensate for a Mile high?, John Williams , Sun, 11 Dec 2005 14:41:26
                                          • about the altitude, vigge, Sun, 11 Dec 2005 21:44:39
                                            • Re: about the altitude, John Williams , Mon, 12 Dec 2005 13:21:10
                              • Where are you measuring?, Drew in Houston, Sat, 10 Dec 2005 20:08:08
                                • Re: Where are you measuring?, John wiliams, Sun, 11 Dec 2005 03:33:54
  • also just to be clear, jak , Fri, 2 Dec 2005 08:11:38
  • what I know is on there?, jak , Thu, 1 Dec 2005 15:50:21
  • Re: john williams pulls only change 9 psi base boost, nathanb, Thu, 1 Dec 2005 10:59:49
    • Re: john williams pulls only change 9 psi base boost, John Williams , Thu, 1 Dec 2005 16:58:28

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