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    Re: 1.2 bar boost pressure - proof picture

    I recently found a quiet stip of straight dry road, and had a play with the boost figures. I only ever use 99 octane Shell vPower fuel.

    Normal Mode
    If I put the car in 6th gear, then I can get 0.9 bar for about 1 sec, then it drops to 0.8 bar and stays there.

    Sport Mode
    Again, in 6th gear, I can get to 1.1 bar for a split-sec with the overboost arrow showing, then it drops to a constant 1.0 bar.

    I am wondering if the reasons a lot of you guys with manual cars are seeing 1.2 bar is because you have reduced the exhaust back-pressure from switching to an aftermarket exhaust?!

    Re: 1.2 bar boost pressure - proof picture

    No, I recall seeing 1.2 bars several times on the way home from my "break-in" trip to California as well as several times after that.

    Re: 1.2 bar boost pressure - proof picture

    Hmmm

    How long do you see 1.2 for Jason? As long as you have your foot fully down on the gas pedal?

    And do you see this in 6th gear or are other gears easier to replicate with?

    I am just wondering if Porsche have deliberately restricted MY08 Turbos for some reason?!

    The 'Drivers Guide' clearly shows a pic of 1.2bar displayed

    Re: 1.2 bar boost pressure - proof picture

    I never, ever saw 1.2bar until I chipped the car

    Re: 1.2 bar boost pressure - proof picture

    I see it every time I press down hard on the gas not necessarily all the way. Doesn't matter what gear I'm in too.

    Seems strange that some of you folks don't see 1.2 bars most times. Maybe you're not looking down quick enough since it does accelerate pretty strongly when hitting 1.2. Maybe you're thinking WHOA, while hanging on and somehow missing that crucial moment.

    I did see it stay on for a couple of seconds once when I had my foot down fully on a long straightway.

    Re: 1.2 bar boost pressure - proof picture

    i get 1.2 bars woth the overboost arrow all the time as well.....no problems there...

    Re: 1.2 bar boost pressure - proof picture

    Max boost pressure increases with air temperature (the electronics try to compensate hp loss due to unfavourable environmental conditions...). Thus, in hot weather conditions the boost pressure is higher than in colder climate. Maybe this helps explaining the observed differences.

    Re: 1.2 bar boost pressure - proof picture

    I have MY 2008 Turbo & see the overboost arrow all the times. Usually appearing for a brief second, but only because I so fear for my life that I have to let go of the gas pedal.

    It appears to be a function not of how fast the current RPM is, but how fast the RATE OF CHANGE is. So yes, smashing on the gas pedal does it for me every time. One example: 75 MPH in 5th gear, rpm probably around 3k or so (not in car now corrects me if I am wrong); if I smash on the gas, the arrow will come on.

    Current temp in California is around 15 degrees Celsius.

    Quote:
    Alex_ said:
    Hmmm

    How long do you see 1.2 for Jason? As long as you have your foot fully down on the gas pedal?

    And do you see this in 6th gear or are other gears easier to replicate with?

    I am just wondering if Porsche have deliberately restricted MY08 Turbos for some reason?!

    The 'Drivers Guide' clearly shows a pic of 1.2bar displayed


    Re: 1.2 bar boost pressure - proof picture

    Quote:
    cannga said:
    I have MY 2008 Turbo & see the overboost arrow all the times. Usually appearing for a brief second, but only because I so fear for my life that I have to let go of the gas pedal.



    Over-boost arrow doesn't necessarily mean 1.2bar though cannga. For me the little arrow can only get me up to 1.1 bar briefly.

    Try dropping down to 60mph in 6th gear on a quiet motorway, put on Sport Mode, and then mash your gas pedal to the floor for a couple of seconds.

    This is the 'least' psychotic way of testing over-boost I have found.

    ...although you will be doing 100mph pretty quickly so watch for traffic cops!

    Re: 1.2 bar boost pressure - proof picture

    Quote:
    MKSGR said:
    Max boost pressure increases with air temperature (the electronics try to compensate hp loss due to unfavourable environmental conditions...). Thus, in hot weather conditions the boost pressure is higher than in colder climate. Maybe this helps explaining the observed differences.



    Intelligent observation; that may well be it

    When I was testing it was only a few degrees above freezing.

    Re: 1.2 bar boost pressure - proof picture

    I see what you mean. I have not looked specifically for the 18 psi number but will next time. For the full 18 psi/1.2 bar, I think we might have to wait for the end of the break in period. My test so far is only done under 4200 rpm.

    Since already I fear for my safety at 4200, at 6000 plus rpm, someone might have to pry my fingers off the steering wheel afterwards. What a rocket this is going to be. YUMMY!!!

    Quote:
    Alex_ said:
    Quote:
    cannga said:
    I have MY 2008 Turbo & see the overboost arrow all the times. Usually appearing for a brief second, but only because I so fear for my life that I have to let go of the gas pedal.



    Over-boost arrow doesn't necessarily mean 1.2bar though cannga. For me the little arrow can only get me up to 1.1 bar briefly.

    Try dropping down to 60mph in 6th gear on a quiet motorway, put on Sport Mode, and then mash your gas pedal to the floor for a couple of seconds.

    This is the 'least' psychotic way of testing over-boost I have found.

    ...although you will be doing 100mph pretty quickly so watch for traffic cops!


    Re: 1.2 bar boost pressure - proof picture

    actually you can experience this rather easily and not violate the 4200 thing...just floor it in say 4th at 3k and let er rip to 4.2k ...it wont be blindingly fast as 1st or 2nd would be but you will actually see it achieve 1.2 bar...or at least i did

    Re: 1.2 bar boost pressure - proof picture

    My car is a 08 TT Cab tip with a little over 2000 mi,,,,
    the most i see in sport mode is A quick flash 1.0 ??

    Hoping it will increase with more miles??


    Any info??

    Re: 1.2 bar boost pressure - proof picture

    Quote:
    Alex_ said:
    Quote:
    MKSGR said:
    Max boost pressure increases with air temperature (the electronics try to compensate hp loss due to unfavorable environmental conditions...). Thus, in hot weather conditions the boost pressure is higher than in colder climate. Maybe this helps explaining the observed differences.



    Intelligent observation; that may well be it

    When I was testing it was only a few degrees above freezing.



    I have just spotted a flaw with that theory. Take a look at the pic in RC's first post. The display clearly shows 2 degrees C. So colder than in my tests

    Re: 1.2 bar boost pressure - proof picture

    Quote:
    dsunnym1 said:
    My car is a 08 TT Cab tip with a little over 2000 mi,,,,
    the most i see in sport mode is A quick flash 1.0 ??

    Hoping it will increase with more miles??


    Any info??



    I am thinking the factory are now setting boost to 0.8 bar for Normal mode and 1.0 bar for Sport Mode for all MY08 cars. I doubt MY08 cars will be slower than older models so maybe Porsche have made small improvements in other areas and then dialed down the Turbos to balance it out?!

    Perhaps though it will get better after the car is more run in. This is more wishful thinking than anything else though .

    What we need is someone with a MY08 Turbo to say whether thay can get 1.2 bar or not.

    Re: 1.2 bar boost pressure - proof picture

    The last couple of days I tried to reach the 1.2 bar in different situations. The best numbers are:
    Normal mode 0.8 bar
    Sport mode 0.9 bar.
    The ouside temperature was approx. 12 celsius.
    On monday I will contact my PZ.

    Re: 1.2 bar boost pressure - proof picture

    Ok guys, I went to 100 mph for the "team" today (a big deal in Los Angeles, I've been told a cop on a bad donut could put you in jail for this).

    Starting in 5th or 6th gear at around low/mid 2000 rpm in Sport mode, I went pedal to the metal (and held on for dear life). I saw 17 psi (1.17 bar) several times, each lasting no more than 1 second. Current temp is 4 degrees Celsius.

    Re: 1.2 bar boost pressure - proof picture

    Quote:
    cannga said:
    Ok guys, I went to 100 mph for the "team" today (a big deal in Los Angeles, I've been told a cop on a bad donut could put you in jail for this).

    Starting in 5th or 6th gear at around low/mid 2000 rpm in Sport mode, I went pedal to the metal (and held on for dear life). I saw 17 psi (1.17 bar) several times, each lasting no more than 1 second. Current temp is 4 degrees Celsius.



    So pretty much what I saw. 1.1 bar for a split-second then levels at 1.0 bar.

    One of the guys over on Rennlist suggested this:

    Quote:

    the boost you see is not an accurate reflection of how fast your car is (or anything else). The ECU is reading the air mass in kg/hr and adjusting boost to suit. The factory are NOT "setting" any levels of boost, it doesn't work like that - unless as you (paranoidly...) imply they may be depriving you of your full 480PS DIN.....

    Boost on Motronically controlled Porsches is not necessarily proportional to hp (when comparing one set of running conditions to another). There are Rlers running 1.2bar (on 993tts -older but same principal ECU) at peak power, managing about 470hp and others running high 500 hp at less than 1bar.....

    If you are concerned that Porsche may be giving you less hp, get a GPS device and do some acceleration runs, missing hp is easily spotted, as you say it is possible (but unlikely) they can still make the 480PS power curve with less boost at DIN



    Re: 1.2 bar boost pressure - proof picture

    I have a very early build 2008 (completed 7/3, I think), and I managed a few tests today. Ambient temp was 37F, with approx 95% humidity. Car is manual with sport mode on. Runs were started in 3rd at approx 2500 rpm, on either flat or uphill highway.

    First run was on a flat, and I saw 1.1 bar.
    Second run was uphill, and I saw 1.2 bar.
    Third run was a repeat of the 2nd -- 1.2 bar.

    Re: 1.2 bar boost pressure - proof picture

    Quote:
    davems said:
    First run was on a flat, and I saw 1.1 bar.
    Second run was uphill, and I saw 1.2 bar.
    Third run was a repeat of the 2nd -- 1.2 bar.



    Very interesting, thanks for sharing

    I will try some uphill runs and see if that makes any difference.

    Re: 1.2 bar boost pressure - proof picture

    This morning I reached the 1.2 bar.
    I fixed the 5 gear (Tip-tronic) and then full throttle. With kick down or lower gears it was not possible.

    Re: 1.2 bar boost pressure - proof picture

    Quote:
    turbosteff said:
    This morning I reached the 1.2 bar.
    I fixed the 5 gear (Tip-tronic) and then full throttle. With kick down or lower gears it was not possible.




    What do you mean when you say you fixed 5th gear??

    I too have a tip and have yet to see 1.2 as of yet!!
    the highest I have seen is 1.0 ....

    Any info would be greatlly appreciated...

    Re: 1.2 bar boost pressure - proof picture

    Quote:
    dsunnym1 said:
    Quote:
    turbosteff said:
    This morning I reached the 1.2 bar.
    I fixed the 5 gear (Tip-tronic) and then full throttle. With kick down or lower gears it was not possible.




    What do you mean when you say you fixed 5th gear??

    I too have a tip and have yet to see 1.2 as of yet!!
    the highest I have seen is 1.0 ....

    Any info would be greatlly appreciated...

    I switch to "manual" mode and 5th gear. In automatic mode the tip made a kick down or switch to 4th or 3rd gear. Then I saw only 0.9 bar max.

    Re: 1.2 bar boost pressure - proof picture

    some 997tt come with overboost but the instrunment cluster programe is the normal (same what happened to my friend) .. go to the dealer and reprograme it ..you can know if you need to be reprograme or not by checking your horizental boost bar shows max 1.0 bar instead of 1.2 bar

    Re: 1.2 bar boost pressure - proof picture

    I was not sure if the 17 psi I saw was not 17.4 (1.2 bar) rounding down. So today I re-measured in bar instead of psi. I was able to achieve reliably/reproducibly 1.2 bar this morning coming to work and again in the afternoon coming back, without any special trick.

    My "procedure": 2200 rpm, 6th gear, stepped on gas pedal all the way and held it there, by 2900-3000 rpm, the car hit 1.2 bar.

    Car is MY 2008, September 2007 built, 6 speed with LSD. Ambient temp was 13 Celsius this morning, 14 in the afternoon.

    Quote:
    Alex_ said:
    Quote:
    cannga said:
    Ok guys, I went to 100 mph for the "team" today (a big deal in Los Angeles, I've been told a cop on a bad donut could put you in jail for this).

    Starting in 5th or 6th gear at around low/mid 2000 rpm in Sport mode, I went pedal to the metal (and held on for dear life). I saw 17 psi (1.17 bar) several times, each lasting no more than 1 second. Current temp is 4 degrees Celsius.



    So pretty much what I saw. 1.1 bar for a split-second then levels at 1.0 bar.





    Re: 1.2 bar boost pressure - proof picture

    Good explanation. But I'd still have questions though:

    1. *Other* cars in similar conditions (at least when it comes to temp and elevation?) have hit 1.2 bar, and Porsche says this car should hit 1.2 bar. So what makes your car different?

    2. Assuming your car makes 505 hp at 1.1 bar already, how do we know that 1.1 bar is optimal and it will make less hp at 1.2 bar?

    3. To exaggerate, let's say your car could only achieve .8 bar in Sport mode, could we say "don't worry, this is optimal"?

    OTOH, if this is the same company that makes the TPMS measurement device, then I'd agree: Never mind!

    Quote:
    Alex_ said:

    One of the guys over on Rennlist suggested this:

    Quote:

    the boost you see is not an accurate reflection of how fast your car is (or anything else). The ECU is reading the air mass in kg/hr and adjusting boost to suit. The factory are NOT "setting" any levels of boost, it doesn't work like that - unless as you (paranoidly...) imply they may be depriving you of your full 480PS DIN.....

    Boost on Motronically controlled Porsches is not necessarily proportional to hp (when comparing one set of running conditions to another). There are Rlers running 1.2bar (on 993tts -older but same principal ECU) at peak power, managing about 470hp and others running high 500 hp at less than 1bar.....

    If you are concerned that Porsche may be giving you less hp, get a GPS device and do some acceleration runs, missing hp is easily spotted, as you say it is possible (but unlikely) they can still make the 480PS power curve with less boost at DIN





    Re: 1.2 bar boost pressure - proof picture

    Quote:
    turbosteff said:
    This morning I reached the 1.2 bar.
    I fixed the 5 gear (Tip-tronic) and then full throttle. With kick down or lower gears it was not possible.




    Tried your method this evening and I am glad to report
    that I finally seen 1.2 boost!!!

    Thanks alot,,,,,, Now if we can only see this in auto mode!!

    Re: 1.2 bar boost pressure - proof picture

    Did a bit more playing today. Managed to spot the ellusive 1.2 bar at last - albeit only for 1 second or so.

    Strange it doesn't stay for longer even if I kept the gas pedal flat on the floor.

    Re: 1.2 bar boost pressure - proof picture

    Great! Welcome to "Club 1.2"!
    Re. why 1.2 for only a second, my speculation: The 1.2, MAX over boost, is achieved only at certain rpm or rate of change in rpm, so it is brief. However, just because we only see 1.2 for a second does not mean OVER BOOST lasts for only a second. The increase from over boost is **across the range**.

    For example without over boost, during our runs, values are, say, .3 bar then .6 then 1.

    With over boost, at the equivalent moments in time, values are .5 then .8 then 1.2.

    I hope I make *some* sense.

    In other words, although we see MAX over boost for only a brief second, we experience over boost for a longer time.

    Quote:
    Alex_ said:
    Did a bit more playing today. Managed to spot the ellusive 1.2 bar at last - albeit only for 1 second or so.

    Strange it doesn't stay for longer even if I kept the gas pedal flat on the floor.


     
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