Quote:
Originally Posted by Max Well
I'm not sure what to make of published HP and torque values anymore. It's long been felt that the F97/98's values are, for various potential reasons, understated in the official publications.
The objective basis to support that contention lies in the numerous independent dynos (granted those vary based on Mnfr, etc...), as well as the actual quarter mile and top-end Autobahn data which, when plugged into the sim, don't match BMW's claims.
In a post back in 2019 in the Qtr mile thread [ https://x3.xbimmers.com/forums/showp...7&postcount=49 ] I shared the acceleration curve using BMW's numbers and it fell way short of capturing Nate's 1/4 mile times. Only when I plugged in his dyno numbers (roughly 550HP and 500lb-ft torque) did it almost superimpose. Although just a rough construct, it has performed well on a number of different vehicles over the years. Also, the rated top speed of 177 mph could only be obtained with Nate's numbers, otherwise it maxed out at 172mph (and Autobahn videos confirm that isn't correct).
Finally, if you look at the graph of Wt/HP vs 0-60mph times I put together back in 2017 [ https://x3.xbimmers.com/forums/showp...6&postcount=15 ], it also doesn't make sense using BMW's numbers, which yields more in the 9.1lb/HP ratio which should give around 3.9-4.0sec 0-60mph times. If you use 550HP instead, that ratio becomes 8.4lbs/HP, which falls nicely into the 3.6-3.7sec range, a value we are seeing routinely. Personally I have formal 1/4mile documentation of that 3.6s during a verified drag strip run.
So personally I wouldn't place too much stock in the published data. We just need to wait for some to get these in the real world and run them as we all are with our F97/98 models.  |
I think that on the engine dyno BMW use the engine will rate at their quoted HP and torque, they can't and don't just make the numbers up they adhere to DIN standards as an example.