[Main Performance Bulletin Board | BBFAQ | Prev by Date | Next by Date | Post Followup ] Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos Re: Bigger picture. Like This Post: - Subscribe to Daily Digest for this Bulletin Board Posted by Kevin K [Email] (#374) [Profile/Gallery] (more from Kevin K) on Thu, 16 May 2002 10:36:39 In Reply to: Bigger picture., Coolknight, Thu, 16 May 2002 09:08:15 Alert me when someone posts in this thread: Members do not see ads below this line. - Help Keep This Site Online - Signup

I would like to see back pressure data thru the rpm range. In most cases, I don't think it would be dramatically less at mid range vs top end, same boost, as u imply. The turbine presents itself as a variable orifice, based on turbine speed, so the backpressure curve would be flatter than u implied, imho. Once the basic port sizes become limiting, boost will drop.

Regarding downpipes, my limited test data suggests that backpressure due to the downpipe is very low during transients, when response is an issue. My conclusion was that flow dynamics was the more likely player. This is a big issue when the wg opens, esp with old T3's.

My post focused on pumping losses related to back pressure. Another thing that becomes more difficult with high backpressure is chamber evacuation, which reduces the net VE of the engine. Both of these negative qualities do not exist with supercharged engines.





posted by 52.128.3...

• Turbo Backpressure Hp Loss, Kevin K , Wed, 15 May 2002 15:03:29
  • Bigger picture., Coolknight, Thu, 16 May 2002 09:08:15
    • Also note..., Coolknight, Fri, 17 May 2002 11:30:46
      • Don't forget..., Alex, Sat, 18 May 2002 14:11:29
    • mid-range?, Ed S, Thu, 16 May 2002 12:51:19
      • definitely think about 9000IC, dave n, Thu, 16 May 2002 13:51:34
    • Re: Bigger picture., Kevin K , Thu, 16 May 2002 10:36:39 <-- Viewing This Message
    • this is my problem right now, and why I *think* I need, WASSAAB, Thu, 16 May 2002 09:38:25
      • upgrade options, TE05-16G, Kevin K , Thu, 16 May 2002 17:56:04
        • awesome info, again, WASSAAB, Thu, 16 May 2002 22:42:54
          • consider goals .., Kevin K , Fri, 17 May 2002 10:56:00
            • Re: consider goals .., Marko A, Sun, 19 May 2002 05:34:45
      • maybe the two of us can get one, dave n, Thu, 16 May 2002 13:47:10
  • crap shoot, dave n, Wed, 15 May 2002 23:10:57
    • Re: crap shoot, chrisx, Thu, 16 May 2002 00:02:27
      • garrett, dave n, Thu, 16 May 2002 08:52:54
  • Re: Turbo Backpressure Hp Loss, Brad, Wed, 15 May 2002 18:31:08
  • does anyone here have a C900 with an extended red line?, WASSAAB, Wed, 15 May 2002 16:20:58
    • Re: does anyone here have a C900 with an extended red line?, jvanabra, Wed, 15 May 2002 17:39:31
      • Oops.... (^ was me ^), Justin VanAbrahams , Wed, 15 May 2002 17:40:35
    • Re: does anyone here have a C900 with an extended red line?, kooch, Wed, 15 May 2002 17:10:32

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