• The effect of heat soak on BMW M's turbo motors (S63TU), large power loss - F10 M5 back to back dyno pull testing by Evolve Automotive

      BMW marketing has practically managed to convince people that their turbo motors are the greatest thing ever invented and a necessary evolution which will result in peace on earth and prosperity for all mankind. Fortunately, there are people out there who actually do real work and testing with these motors and what you are about to see is one of the downsides of the turbo generation. That would be the tremendous heat generated and power loss.


      The new BMW M cars are not exactly light. The F10 M5 is heavy and it takes a good amount of turbo torque to get it moving. But that generates heat, a lot of it. Several wide open throttle pulls will result in what you see below which is horsepower going from 498.2 at the wheels to 443.2 for a loss of 50 wheel horsepower after seven WOT (wide open throttle) pulls.

      On a hot day not only will one lose a lot of power after a few blasts but this is not a motor designed with the racetrack in mind. Yes, all motors suffer from heat soak, but the classic naturally aspirated motors do have an advantage in power retention and avoiding limp mode to the heat generated overwhelming the cooling system as they do not put out as much heat and do not requite as much cooling.

      The odd thing about this is that the motors are supposed to be Motorsport derived. This is BMW M after all, isn't it? Well it's supposed to be but what this graph shows you is that the new M cars are more suited to quick wide open throttle blasts than sustained runs. That used to be AMG's game. Now it's BMW M's.

      All dyno runs WHP vs WTQ



      Highest/Average/Lowest dyno runs WHP vs AFR



      Highest/Average/Lowest dyno runs WHP vs IAT (measured after MAF)



      This article was originally published in forum thread: BMW F10 M5 Dyno Testing Stock Car For Consistency started by Imran@Evolve View original post
      Comments 35 Comments
      1. Sticky's Avatar
        Sticky -
        BMW marketing has practically managed to convince people that their turbo motors are the greatest thing ever invented and a necessary evolution which will result in peace on earth and prosperity for all mankind. Fortunately, there are people out there who actually do real work and testing with these motors and what you are about to see is one of the downsides of the turbo generation. That would be the tremendous heat generated and power loss.

        Click here to enlarge

        The new BMW M cars are not exactly light. The F10 M5 is heavy and it takes a good amount of turbo torque to get it moving. But that generates heat, a lot of it. Several wide open throttle pulls will result in what you see below which is horsepower going from 498.2 at the wheels to 443.2 for a loss of 50 wheel horsepower after seven WOT (wide open throttle) pulls.

        On a hot day not only will one lose a lot of power after a few blasts but this is not a motor designed with the racetrack in mind. Yes, all motors suffer from heat soak, but the classic naturally aspirated motors do have an advantage in power retention and avoiding limp mode to the heat generated overwhelming the cooling system as they do not put out as much heat and do not requite as much cooling.

        The odd thing about this is that the motors are supposed to be Motorsport derived. This is BMW M after all, isn't it? Well it's supposed to be but what this graph shows you is that the new M cars are more suited to quick wide open throttle blasts than sustained runs. That used to be AMG's game. Now it's BMW M's.

        All dyno runs WHP vs WTQ

        Click here to enlarge


        Highest/Average/Lowest dyno runs WHP vs AFR

        Click here to enlarge


        Highest/Average/Lowest dyno runs WHP vs IAT (measured after MAF)

        Click here to enlarge

      1. inlineS54B32's Avatar
        inlineS54B32 -
        The WHP vs AFR graph is very interesting to me... You can definitely infer a lot about that information - looks like the DME is being a nanny to keep things (hopefully overly?) safe.

        It really is an incredible amount of power loss for a car of this caliber (as you said, it's an M car). I am curious how badly this would happen at the track with more airflow - regardless, it's not a good thing for those that take their car to the track. Consistency is key.

        I really hope BMW shapes up - at least the motorsport division. It's shameful.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by inlineS54B32 Click here to enlarge
        The WHP vs AFR graph is very interesting to me... You can definitely infer a lot about that information - looks like the DME is being a nanny to keep things (hopefully overly?) safe.

        It really is an incredible amount of power loss for a car of this caliber (as you said, it's an M car). I am curious how badly this would happen at the track with more airflow - regardless, it's not a good thing for those that take their car to the track. Consistency is key.

        I really hope BMW shapes up - at least the motorsport division. It's shameful.
        If they want to give people torque monster for a straightline that's fine. But where's the balance? Porsche - 911 Turbo / GT3. Mercedes - E63/CLS 63 then the C63 and SLS Black Series for the track.

        The other companies have serious track options. BMW doesn't once the E92 M3 is gone and even then the other two guys offer far higher track performance thresholds.

        But a few seconds of fun is the new market. The N54 started it.
      1. KB's Avatar
        KB -
        I wonder if this is how BMW get the HP figures for their new turbo motors. Maybe they measure the HP after some heat soak and this is why we think they underate the engines but in reality they are what they say they are. We always see dynos with cool engines and try to make the conditions so we get the highest reading. What do you guys think?
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by KB Click here to enlarge
        Maybe they measure the HP after some heat soak and this is why we think they underate the engines
        No they're definitely overrating them not compensating for heat soak.
      1. Legionofboom's Avatar
        Legionofboom -
        Meth
      1. DFM's Avatar
        DFM -
        Click here to enlarge Originally Posted by E90SoFlo Click here to enlarge
        Meth
        A stock M5 should not need meth to maintain its level of performance.
      1. Legionofboom's Avatar
        Legionofboom -
        Click here to enlarge Originally Posted by DFM Click here to enlarge
        A stock M5 should not need meth to maintain its level of performance.
        It also isn't ment to be run without proper airflow, and that picture is hood down with only a single fan.

        And I obviously wasn't talking about stock car's, Im not sure the point in all of that tomfoolery.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by E90SoFlo Click here to enlarge
        It also isn't ment to be run without proper airflow, and that picture is hood down with only a single fan.
        It will go into limp mode even with 'proper' airflow.
      1. BlackJetE90OC's Avatar
        BlackJetE90OC -
        M5 you can almost deal with heat soak. Owners aren't buying them as track cars.

        But when you consider what BMW is doing with the next M3/M4, then I get worried. Will it be able to even handle one 20-30 min track session? Before engine management starts reducing power, or all together goes into limp mode. BMW better perform magic, there is a reason why FI cars have reps for being headaches on hot track days.

        Wouldn't it be funny to go to a future BMWCCA track event and everyone is in the garages cooling their cars down. While guys in their E46/E92 M3's are ripping laps off.
      1. BlackJetE90OC's Avatar
        BlackJetE90OC -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        It will go into limp mode even with 'proper' airflow.
        I went to BMWCCA event not too long ago. They were giving rides in the new M5 around COTA. It took only 1.5 laps before in went into limp mode. The driver said it had been happening all weekend.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by BlackJetE90OC Click here to enlarge
        I went to BMWCCA event not too long ago. They were giving rides in the new M5 around COTA. It took only 1.5 laps before in went into limp mode. The driver said it had been happening all weekend.
        I'm shocked.
      1. mm28's Avatar
        mm28 -
        one thing to keep in mind is that the fan being use on the dyno is nowhere near powerful enough to simulate the force of wind being ram into the radiator in a real life 4th gear (or 5th gear?) 130+mph pull. if one stand in front of one of these fans, in most cases it would feel like sticking your hand out the window while travelling at 70mph.

        edit: the point had been mentioned in the posts above, guess I should read the entire thread before responding next time...Click here to enlarge
      1. Imran@Evolve's Avatar
        Imran@Evolve -
        Regarding the fan. It had enough airflow to let the car produce 498 WHP on a conservative Dyno Dynamics once. The airlfow didn't change after that. As you can see from the graphs the IAT did. Granted until we do the same test on the road we will not know how much faster the IAT will recover.

        Here is a video of the fan we use. Yes its one fan but its so much more powerful than the multiple "leaf blowers" and "carpet dryers" I see most places using.



        I will post the calculated flywheel graph when I get the chance. I think there is something in the notion that they have quoted the BHP that it makes consistently and not the one off higher figure.

        You will see much more from us in terms of testing and development on this platform in the coming months.
      1. Puerto Rican 335d's Avatar
        Puerto Rican 335d -
        Ok amigos having a 335d I had the same issues I have pics of the OEM IC compared to the WAGNER IC, its just a simple plug and play and that my friends has made huge differance in how the car handles the hooter temps as we do here in Puerto Rico
      1. Puerto Rican 335d's Avatar
        Puerto Rican 335d -
        oops here it is
      1. Puerto Rican 335d's Avatar
        Puerto Rican 335d -
        Sticky cant upload it
      1. Puerto Rican 335d's Avatar
        Puerto Rican 335d -
        Sent you a PM and txt msg ok
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Puerto Rican 335d Click here to enlarge
        Sticky cant upload it
        Looks fine to me...
      1. andrew20195's Avatar
        andrew20195 -
        Click here to enlarge Originally Posted by Imran@Evolve Click here to enlarge
        It had enough airflow to let the car produce 498 WHP on a conservative Dyno Dynamics once.
        Out of curiosity, how conservative do you think it is? BMW rates the engine at 560 crank horsepower. 498 would be only a 12% drivetrain loss, which seems low. 443.2 from 560 would be a 20% drivetrain loss, which could be within reason for a conservative dyno. Maybe BMW does measure power output in a partial heat soak situation?

        Shame about the M5's limping at the track, but that's what happens when you try and cram so much equipment into such a tight area. It's one of the reasons I'm not a fan of mounting turbos in the valley.