In Reply to: I keep forgetting to talk about the compressor wheels.., John Williams [Profile/Gallery] , Wed, 7 Dec 2005 21:37:05

I thought we already covered the fuel buring at the other place?
That would be true IF the so called thin air would not be pressurized, but as stated before you'll burn just as much fuel on top of everest or at sea level if the burning is done while this "thin" air pressurized to sea level(while temp etc remain same). The O2 ammount will be same...
I also asked you a guestion, how do we breath on airplanes? Thin air is pressurized right? No problem with breathing?
How do divers stay under water for hours with tiny bottles having absolute volume very small? = high pressure = lots of breathable air trough regulator.

The airplane propeller exemple is some what lacking, since the engine operates during take off near max rpm already at sea level. ie revs can be lifted. What about the turbo, it can spin faster...

your text
______________________
I understand the turbo tries to get back to sea-level manifold pressure, but you cannot convince me a turbo turning 22psi at sea-level will be the same as a car boosting 24-25psi a mile high
-------------------------
The boost gauge, though, reads pounds of boost over ambient pressure. So for the same manifold absolute pressure you will see higher boost gauge reading at altitude. So at 5000' you should see ~2.5psi higher reading, just like you stated. And why would the turbo try to make up for the loss? It is a MAP system = target absolute pressure, it does not know you're car is a sea level or at the top of hiroshima, it will still try to boost the same...

If manifold air temp does not change, you'll roughly have the same airmass...

Yes I know the real life and theore does not work 100% together always, but failing to understand the basics of ideal gas law isnt much to go after either.

Once again if you car looses big power with altitude your turbo is too small, ie. stressed to its max. at sea level, so there wont be any margin to compensate...

posted by 192.89....

• 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 <-- Viewing This Message
                  • 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
              • 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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