Quote:
Originally Posted by BimmerEngineer
In testing, the N55 has a much more linear powerband then the N54. The N54 is like a supercharger, making great low and mid range power but falling flat after 5500rpm... The N55 just keeps on going and going, good pwr till 300-400rpm under redline... Also, the 135 N54 and N55 have been raced by BMW in private and each time, the N55 would pull ahead by half a car at 70mph and by 100 1.5 cars, and to 140, the N55 had a commanding 3.5 car length lead... That's that linear powerband and top end steam the N54 lacked.
FYI: 1 car length is rear bumper of lead car even with front bumper of competing car...
There are good turbo upgrade options for the N55 too. Not to mention single turbo conversions making 500-700hp in N54 cars for $7000-8500. I've owned both N54 & 55 and would take a N55 car in a heart beat....
|
I would really like a source for all this. I know this is an open forum, but statements like these need some form of validation because you are missing some factors in comparing the two cars. 1st why would BMW "race" an N54 and N55? 2nd you say "each time" which indicates that this happened many times. 3rd A proper test of the engine would be seeing what it is capable of producing where the engine is still kept stable(within engineering design spec) rather than a drag race(why would they be competing by car lengths).
Which leads me to believe that your experience with these cars might be at a dealership in which you drag old vs new models and get away with it.
The only situation where you'd be able to keep all the external variables constant is to have these tests done side be side. This of course means that the N54 would suffer from a loss in power as all engines do simply because of the passage of time because you can't get a new n54 powered 35i and then make the same spec of n55 powered 35i to be in the same chassis.
Now if you are familiar with design spec(your handle is BimmerEngineer), you would know that there is also a tolerable loss between the exact same item and that tests would need to be replicated to exhaustion to prove the point you are trying to make. I can't see a feasible reason that BMW would waste R&D money dragging out of date engines against the newer version to see which is faster by car lengths. There is only one situation in which this *might* happen and this is if they are planning to race the car. But here is what confuses me even more because the purpose of the car is not to drag it. Even if they were competitively racing their i6twin powered engine, then they could simply modify the software for the driver of the car rather than waste R&D money dragging the car.
I know there are other engineers on this forum, why have none of them chimed in? Some of these statement made are just silly.
I am not pro or anti the new twin power setup. I will admit I do bias towards the N54 simply because it caught my eye first, but I can't see a credible reason why your statements would be true.