Announcement

Collapse
No announcement yet.

Carbon Airbox on S50 engine

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    The low end torque loss only occurs under heavy load, upto 70% throttle there is huge torque.

    This is a characteristic of the 284 cams unfortunately and no amount of mapping is going to get rid of this.

    Funnily enough you don't get this with the 296's.

    Mapping was not easy to say the least!

    A Map sensor can be used for load :)
    Sal
    Last edited by M5Pilot; 24-04-2008, 05:17 PM.
    E34 M5 3.8
    6 speed
    345mm Discs & 4 Pot calipers
    was 347.9 BHP....dunno now but it is faster.

    Why didn't BMW use my engine in the ZM instead!

    Comment


    • #32
      Originally posted by M5Pilot View Post
      The low end torque loss only occurs under heavy load, upto 70% throttle there is huge torque.

      This is a characteristic of the 284 cams unfortunately and no amount of mapping is going to get rid of this.

      Funnily enough you don't get this with the 296's.

      Mapping was not easy to say the least!

      A Map sensor can be used for load :)
      Sal
      296's here i come!

      Comment


      • #33
        Originally posted by M5Pilot View Post

        A Map sensor can be used for load :)
        Sal
        Sal/Maahny,

        I don't wish to come across as critical or a smart arse, but manifold pressure is not equal to "load".

        The term engine load refers to the MASS (e.g grams) of air (or more specifically oxygen) ingested into the combustion chamber prior to ignition.

        To deliver the chemically-correct amount of fuel prior to combustion, the ECU has to receive (or calulate) an air MASS signal, and then divide the air mass by the desired air-fuel mass ratio.

        The relationship between the pressure (P) and mass (m) of a gas is defined by the Ideal Gas Law, that states:

        P.V = m.R.T

        I.E. The true gas mass is a function of the gas pressure, volume (V), and temperature (T).

        This is easy to visualise if you consider a sealed jar full of gas. I.e. increase the gas temperature and the gas pressure will rise, increase the mass (amount) of the gas in the jar and the pressure will rise.

        NB: R is simply the universal gas constant and can be ignored.

        For an engine equipped with a manifold pressure sensor (rather than a manifold air mass flow sensor), the ECU contains a high resolution engine 'air charge' model that continually calculates combustion chamber air mass as a function of:
        - intake manifold absolute pressure
        - intake manifold absolute temperature
        - engine speed
        - throttle / cam position
        The air charge model is characterised throughout the engine speed and torque envelope.

        This is what BMW had to do for the M3 CSL (CSL does not feature a restrictive air mass sensor due to it's mental carbon intake, BMW switched to a pressure sensor).

        If the effects of air temperature, altitude, and high speed engine tuning harmonics are ignored, it is possible to use a manifold pressure signal to crudely calibrate wide-open-throttle fuelling.

        When the throttle plate is fully open at sea level, manifold pressure is approximately equal to one atmosphere throughout the engine speed range. With constant gas pressure AND constant gas temperature you can directly infer a constant fuel MASS across the engine speed range at full load.

        At part load, manifold pressure is not constant throughout the speed range, and hence air mas has to be inferred from the aforementioned air charge model (ECU software based on the aforementioned perfect gas law).

        Basically, you can't mess with the laws of physics, in this case the ideal gas law.

        Sorry if any of that sounded like a lecture -- thought some forum members would appreciate the technical insight.

        Regards, Will

        Comment


        • #34
          Good post Will.

          Airbox looks great, power looks good.

          I had a dip in low down torque/power as soon as I de catted my MC but I soon got used to it and the benefits outweiged the negatives.

          Ragerover you need to do this!

          call me mate.
          Ex 'V3RY M - MCoupe track monster'
          New toys

          Porsche widebody project

          Cayenne Diesel

          Comment


          • #35
            I must say one of the aspects I love about the S50 is the low down grunt and smooth curve. Depends on what you want out of your car at the end of the day really.

            Comment


            • #36
              This car is significantly faster than a standard S50 and even leaves a mildly tuned (my old one) behind. With the shorter diff the car doesn't go near the flat spot caused by the cams. There are a lot of cars that have had this conversion in Germany yet I have not seen a single dyno graph.

              When we get a chance we will use our Pbox to do some timing. We will be pricing the conversion up today once we have worked out how much time it will actually take us.

              Comment


              • #37
                Well now done about 500 miles with airbox and racelogic!

                Please excuse the less than technical explanation, this is from a drivers (my) perspective of my latest mod the Airbox.

                I am very surprised that driveability has not suffered in so much that the cams were already fitted so any flat spot was there before the airbox was fitted. I have a lightweight flywheel and a 3.64 diff, whilst the graph shows a dip in power/torque between 2000rpm and 3500rpm in practice unless you use 100% throttle loading in 3/4/5 gear below 3000rpm the car pulls very hard. Infact low rpm running is better than it was before, perhaps directly related to how much time was spent setting it up.
                I have just spent the weekend in London city doing first gear stop start driving for hours on end and it performed faultlessly pulling smoothly from idle to any rpm you care to mention. Having just got home I have got about 185miles to the tank of Tesco 99, certainly no worse than pre airbox. So all in all very good news!!! Was concerned it may end up a bit of a low rpm nightmare but not at all.

                The fact that low end driveability is at least as good as before just goes to make what happens over 3000rpm all the better. The noise as you can hear from the videos is just superb and the power just builds and builds. As you pass 5000rpm it absolutley flies. Not keen on comparisons but to give some idea of acceleration I picked up a 2006 (I think)Audi RS4 and a Lotus 2 Eleven (Lotus's Radical lookalike track car) the other night, the RS4 was left behind and it was neck and neck with the little Lotus upto about 100mph then I pulled ahead Given the Lotus is quoted at 0-60 in circa 3.8 seonds I was well pleased. So it is fecking fast if you gun it hard.

                For clarities sake it IS quite considerably faster than before. The noise is fantastic. Whilst the Airbox is impressive I am also blown away by how GOOD the Digital Racelogic is, the traction it finds in the wet is unbeliveable! With so much power on tap without good control it is an accident waiting to happen on a wet road. Cannot wait to get on Track next month and will try and get some in car footage!

                Anyway if anyone is local your welcome to a test drive! And if not but you want to know anymore you can PM me.
                Cheers and I hope this may have been useful.
                Jason :)

                Comment


                • #38
                  Originally posted by z3m jason View Post
                  Well now done about 500 miles with airbox and racelogic!

                  Please excuse the less than technical explanation, this is from a drivers (my) perspective of my latest mod the Airbox.

                  I am very surprised that driveability has not suffered in so much that the cams were already fitted so any flat spot was there before the airbox was fitted. I have a lightweight flywheel and a 3.64 diff, whilst the graph shows a dip in power/torque between 2000rpm and 3500rpm in practice unless you use 100% throttle loading in 3/4/5 gear below 3000rpm the car pulls very hard. Infact low rpm running is better than it was before, perhaps directly related to how much time was spent setting it up.
                  I have just spent the weekend in London city doing first gear stop start driving for hours on end and it performed faultlessly pulling smoothly from idle to any rpm you care to mention. Having just got home I have got about 185miles to the tank of Tesco 99, certainly no worse than pre airbox. So all in all very good news!!! Was concerned it may end up a bit of a low rpm nightmare but not at all.

                  The fact that low end driveability is at least as good as before just goes to make what happens over 3000rpm all the better. The noise as you can hear from the videos is just superb and the power just builds and builds. As you pass 5000rpm it absolutley flies. Not keen on comparisons but to give some idea of acceleration I picked up a 2006 (I think)Audi RS4 and a Lotus 2 Eleven (Lotus's Radical lookalike track car) the other night, the RS4 was left behind and it was neck and neck with the little Lotus upto about 100mph then I pulled ahead Given the Lotus is quoted at 0-60 in circa 3.8 seonds I was well pleased. So it is fecking fast if you gun it hard.

                  For clarities sake it IS quite considerably faster than before. The noise is fantastic. Whilst the Airbox is impressive I am also blown away by how GOOD the Digital Racelogic is, the traction it finds in the wet is unbeliveable! With so much power on tap without good control it is an accident waiting to happen on a wet road. Cannot wait to get on Track next month and will try and get some in car footage!

                  Anyway if anyone is local your welcome to a test drive! And if not but you want to know anymore you can PM me.
                  Cheers and I hope this may have been useful.
                  Jason :)

                  buy a roof next!

                  nice one.
                  Ex 'V3RY M - MCoupe track monster'
                  New toys

                  Porsche widebody project

                  Cayenne Diesel

                  Comment


                  • #39
                    Nice to hear what you say about Racelogic. IMO, if you are an S50 owner, it's a very desirable mod, to say the least. If I bought an S50, it would be the first mod that I would do.
                    Strongstrut CL front brace-Yellowstuff pads/Castrol SRF race brake fluid-Rogue top mounts/Rear support bushes-H&R ARBs-Whiteline droplinks-Bilstein Sport shockers-H&R Springs-Black Halo Angel Eye headlight units-Sachs lightweight flywheel/matching clutch-Supersprint exhaust/race catalysers-BBS RSGTs with Falkens-K&N High Flow Air Filter-Recaro Pole Position seats - Exdos mod - ACS flippers

                    Comment


                    • #40
                      I guess it depends how you drive. I haven't really had any moments with the S50 yet, but I'm acutely aware that the safety net of DSC is not there, so I'm not jumping on the throttle mid corner as perhaps I might if I had the TC/DSC.

                      I guess I'll have a better feel for it after my first track day on the 16th. After that I may be ordering Racelogic TC :) I'm intrigued by this airbox. Apart from removing a restiction to airflow, what other purpose does the MAF-less design serve?

                      DC

                      Comment


                      • #41
                        Hi Jason & maahny,

                        I'm very interested in buying a Mac Motoren airbox for the S54. Do they offer a version that does not require Alpha N, rather retaining the MAF sensor? If not, do you think I could just tap into the plenum opening and attach the MAF? I've e-mailed them twice and never got a response.

                        That airbox is gorgeous, the carbon fiber weave looks to be of very high quality. Perhaps it is dry carbon fiber?

                        Thanks!
                        -Andrew
                        Last edited by CaliAgents1688; 03-05-2008, 05:29 PM.

                        Comment


                        • #42
                          Originally posted by DavidC View Post
                          I'm intrigued by this airbox. Apart from removing a restiction to airflow, what other purpose does the MAF-less design serve?

                          DC
                          If you get the opportunity to go in a car with an airbox and the MAF removed you will notice the difference immediately.....Throttle response is hugely improved, car pulls stronger, You will want one from there on in.
                          http://www.bmsport.com

                          Comment


                          • #43
                            Hi Jason/Maahny,

                            nevermind. I contacted HCT, a distributor for Mac Motoren perhaps and they have the option of retaining the MAF sensor!

                            Time to start saving the pennies!

                            -Andrew

                            Comment


                            • #44
                              Andrew,

                              I tried to buy from HCT for a few weeks and they just couldn't get themselves sorted out!! So I bought from MAC instead, it is not easy buying from Germany so be prepared to be patient ;-).....
                              However I think the guy from MAC is a forum member on here, Maahny knows his name I think?

                              As far as the MAF is concerned yes you can retro fit it into the intake of the new Airbox with no problem.
                              My car as previously mentioned has no MAF but runs very very smoothly, there is some growliness caused by the cams. Either way MAF or no MAF its all in the setup.......

                              Good luck with the shopping!! Jason
                              Last edited by z3m jason; 07-05-2008, 04:37 PM.

                              Comment


                              • #45
                                amazing gains.

                                The SHRICK camshafts in 284' is stage 1 or 3?

                                Also Mac Motoren airbox is easy at setup?

                                Regards,
                                Andreas
                                Greece.

                                Racing for the fearless

                                Comment

                                Working...
                                X