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Blanked swirl flaps - less power

22K views 13 replies 9 participants last post by  Maj12345  
#1 ·
Hi,

Has anyone found their car to be down on power, particularly at low end revs (<2500 rmp), after they got the swirl flaps blanked off?

I have a 2007 535d and have noticed a difference and it really annoys me! I am thinking of buying a new inlet manifold from the dealers for €600 just to get this back the way it was.

But I was wondering what other peoples experiences were?

Thanks
 
#2 ·
I didn't notice any difference after doing mine on 2005 e46 330cd.
It maybe worth checking the manifold has sealed correctly, none of the seals are damaged etc, and no vacuum pipes are leaking, all my vacuum pipes were starting to perish, they were snapping very easily when removing them so mine will all need replacing soon.
Did you remove the swirl flap actuator and if so did you seal that vacuum pipe off.
If it were mine I'd make a fresh brew and then revisit the job and just double check everything, there's no need to buy a new inlet manifold. I'm sure it'll be fine.
 
#3 ·
I suffered the same issue. I got mine removed in the hope that it would sort out the rpm jerk im suffering between revs along side side the failure of the flaps.
Same issue still, plus poerr loss at low revs.
now im goig to get the dpf removed and egr deleted, so hopefully this should sort out the rmp jerk and also gain some low down power...
 
#14 ·
I suffered the same issue. I got mine removed in the hope that it would sort out the rpm jerk im suffering between revs along side side the failure of the flaps.
Same issue still, plus poerr loss at low revs.
now im goig to get the dpf removed and egr deleted, so hopefully this should sort out the rmp jerk and also gain some low down power...
Did you fix the problem mate??
 
#10 ·
Helpful response :confused

I do agree somewhat that it is comical when forum members bleat off about blanking swirl flaps as a 'performance' upgrade when it is more a preventative measure and in theory is the exact opposite.

From what i read the issue is less prevalent on LCI cars, so I never bothered blanking them off.. Though the 530d isn't noticeably laggy, I didn't want to exacerbate what small amount of lag you will inevitably get from a single turbo setup :)

To be fair, an indy I used highly recommended I do the same as he had done a lot of work on x30d engines after they had failed. However, whos to say he wasn't just trying to draw in trade off the back of the hype like a lot of 'blanking plate' firms :) But I prefer to keep the car to as close to stock as possible (bar the remap). I would even have kept the DPF as is, if it hadn't clogged itself up.
 
#11 ·
agreed! i only did the plates because on inspection they looked like they were about to die.

as for the dpf and egr, its blocked and the car aint been the same, so im taking it tomorrow for a full delete and remap. otherwise i would leave it as stock becuae the more you mess with it, the more issues crrep up
 
#12 ·
I checked the flaps on my 2004 530d at 130k and they were fine so I left them in. now done 185k and its still fine. There's far too much hysteria over swirl flaps. Yes the early ones did lose there screws and wreck motors, in my opinion because they were never assembled correctly in the first place. if you check them and the screws are tight they will stay tight. If I found a suspect flap now I would repair or replace it with another flap, not blanking plates. it works better with them in. also anyone taking off a DPF is only hiding from the problems that caused it to not regen and block up in the first place. if its maintained it works.