With my most recent acquisition of a 2011 550xi, and my new found interest in the N63's unexplored territory for power improvement. My hands are itching to learn, explore, discover, and confirm any information I hear or find that will further help the development in improvement for the N63 & N63tu.
I officially have access to a Dynojet 224x via a affiliated shop that will help with further testing and development. Since I got the car, I was itching to start doing mods left and right, but as hard as it was, I held out until I got a baseline session of the car in its 100% form.
With that being said...
SHORT NOTES:
- All runs performed in 4th gear, Sport+, DSC off
- Had about 3-4 gallons of fuel left (does it make a difference?)
- Removed charcoal filter for 5th & 6th run (proof that theres no gain?)
Detailed notes:
This is a 2011 M-Sport 550xi, one of the first F10 M-Sports in the country, build date 9/2010 with 44K miles on the clock.
So the car went in fully stock... the shop where I did the dyno specializes in Evo's and STis. The first 2 runs, the car swayed back and forth a little, so on top of the X straps, they added 2 additional straps (1 on each side) to hold it down some more.
Charcoal Filter Fiasco
After the 4th run, I removed the charcoal filters... and did the run, with really weird results. Nearly 25hp loss, and nearly no torque loss, I told them to run it once more right away without shutting down and cooling off. Jumped back up to 383HP/411TQ, still 2HP less.
So.... you be the judge, inconsistent run? or are all your butt dyno's lyin?
My guess is that the 5th run was just a weird run to begin with (I have a video of it if interested). The results woulda been the same had I removed the charcoal filter or not, or was it the fact that I opened the airbox, thus possibly releasing the pressure that was already built up inside the intake box?
Either way, I dont think removing the charcoal filter has any affect on the outcome. The way the filter sits inside the airbox, it leaves about 2" of space right near the inlet for the induced air to bypass and go straight to the air filter, so having that charcoal filter there doesn't restrict the movement of air. One thing I think should be taken into account is that the turbo's don't suck the air from the outside of the car, but rather suck the air that's compressed INSIDE the box into the motor. The air that enters the box will simply hang out in the airbox until the throttle starts sucking it in, and having the charcoal filter placed directly up against the top of the airbox should not be restrictive.
I'm looking forward to comments and opinions, as well as suggestions on what actions I should take on the next dyno runs to follow. I think next time I want to see if theres any difference by having the muffler flaps fully open vs letting them open on their own. The next dyno session will also feature a prototype product
