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  • boosts on auto/tiptronics

    Well ive been paying more attention to my boost gauge to see what I'm hitting at different RPM's...... dry roads =) I get a 20 PSI boost spike. I hold around 14 PSI till 4200 RPM and then it drops to 12 and stays there all the way through till 6000 and levels out to around 10 at 6500 RPM.

    Im not sure if its because tiptronics/auto's are suppose to level off quicker or maybe I'm just too picky about my boost =) But only getting 12 PSI around 4200RPM's sounds quite low for a Upsoluted car.

    QuA
    Last edited by QuA; 12-03-2003, 02:55 AM.
    2008 BMW 135i | M Package | JB3 | DCI | BMW Performance Exhaust

  • #2
    Re: boosts on auto/tiptronics

    dude my stock chip spikes 14 in 4th and 5th and holds like 10-12 depending on my foot

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    • #3
      Re: boosts on auto/tiptronics

      Holds 10-12 throughout the whole RPM range? Give details! =) In 5th gear I spike up to 21 PSI. Its just not holding during the 4000-6000 RPM's its going back to stock boost throught that range. It might be my DV or my MAF.


      Originally posted by lsc2g
      dude my stock chip spikes 14 in 4th and 5th and holds like 10-12 depending on my foot
      Last edited by QuA; 12-03-2003, 11:23 AM.
      2008 BMW 135i | M Package | JB3 | DCI | BMW Performance Exhaust

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      • #4
        Re: boosts on auto/tiptronics

        well let me test it today coming home from work to give you a double check figure.. but its gonna be kinda hard to go full out in 4th and not speed crazy.. cuz i'll be doign 200+ by then

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        • #5
          Re: boosts on auto/tiptronics

          Didn't you make a post just like this a few months ago?
          KR
          Porsche 991 Carrera S

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          • #6
            Re: boosts on auto/tiptronics

            Yup but I wasnt maying much attention to how long I was holding the boost throughout my higher rpm's ... my 4500-6000 is PATHETIC. Kor help me... please! I saw you at the u of c today but I was helping my parents out so I didnt say hi.

            QuA

            Originally posted by Kor
            Didn't you make a post just like this a few months ago?
            2008 BMW 135i | M Package | JB3 | DCI | BMW Performance Exhaust

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            • #7
              Re: boosts on auto/tiptronics

              didn't get a chance to try.. people were driving like friggin pussys all the way home didnt' even break 70 on crowchild.. sheesh.. ESP never even kicked in once today in the slush..

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              • #8
                Re: boosts on auto/tiptronics

                Originally posted by QuA
                Yup but I wasnt maying much attention to how long I was holding the boost throughout my higher rpm's ... my 4500-6000 is PATHETIC. Kor help me... please! I saw you at the u of c today but I was helping my parents out so I didnt say hi.

                QuA
                You shoulda screamed hi anyhow

                Now I will use my powers of science for the cause of all that is good.

                Holding boost higher in the RPM range is really the turbo's fault. Thats why lots of people buy a small T3 turbo for the 1.8T and run chipped boost levels, 15psi. You can hold it longer by flowing more air. A turbo inlet pipe is the only mod that I think might theoretically flow more air at higher RPMs. I haven't tested this yet, but it makes sense.

                By 6000 rpms you should probably be down around 10-12 psi. This is just the way the cookie crumbles. However, at 4000 rpms you should still be holding 14-16 psi depending on ambient conditions. Ambient conditions include air pressure and temperature. It is quite possible that you will only run 14 down to 10 psi from 4000 to 6000 rpms.

                No matter what chip you have, there are several interesting characteristics of the factory ECU system that remain unchanged:


                1. On hot days it increases boost (yes, I said 'increases'), while on cold days it reduces boost. This is to keep performance consistent, irrespective of the weather.

                2. The boost control logic takes a signal from the mass airflow meter, dropping boost if mass airflow increases, so as to retain the same performance level. This is probably also the mechanism by which the boost varies with the temperature of the day. This means that adding a TIP or CAI may actually flow MORE air but DECREASE boost.

                Remember that when they designed this system they designed it to be totally consistant and reliable NOT for performance.

                As far as I know, a Manual Boost Control system (bypassing the N75) is the only way to eliminate these variations.
                Last edited by Kor; 12-03-2003, 07:17 PM.
                KR
                Porsche 991 Carrera S

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                • #9
                  Re: boosts on auto/tiptronics

                  qua dude here is the ultimate tip link for you on vortex

                  http://forums.vwvortex.com/zerothread?id=657807

                  Comment


                  • #10
                    Re: boosts on auto/tiptronics

                    Thanks bro!

                    Originally posted by lsc2g
                    qua dude here is the ultimate tip link for you on vortex

                    http://forums.vwvortex.com/zerothread?id=657807
                    2008 BMW 135i | M Package | JB3 | DCI | BMW Performance Exhaust

                    Comment

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