[BB_cuda]

I'm finally getting around to cleaning the intake i got from Bodacious. I removed all attached hardware (swirl flaps, intake runner screws, rubber gaskets, manifold pressure sensor, and 7 grommet looking things (close to square ports).

I took it to the car wash and blasted it out. I next used oven cleaner and let it soak for 20 minutes and then water hosed that out. I next used a jug of Super clean (bug time grease cutter). I got a long bristle brush from Walmart (24" long) and scrubbed the runners. I was able to curve it and scrub from cylinders 1 through 4 from EGR valve side too. I tooked in with flash light after wards and it looks very clean now.

I am wondering if there is a negative impact to fitting the swirl flap blanks the Europeans use. I found a set for decent price. The swirl flaps on this intake are 33 mm.

I went ahead and cleaned the OEM swirl flaps in case i go back together with them. The long rod that actuates all of them wasn't too hard to disassemble along with the actuator that pushes the rod.

My reading tells me the flaps produce swirl flow at idle condition for better combustion. I don't know how far off of idle they are of benefit. I have read here that our US built cars have the improved flaps and aren't supposed to be a danger to our cars. Euro flaps have had issues with the little itty bitty screws coming loose and being injested by engine. I will take picks of the cleaned intake and the super long bristle brush. I was surprised to find one that long.

[Yozh]

What is a performance benefit in removing the flaps?

[BB_cuda]

I don't know of any benefit. Only getting rid of screws coming loose.

Is the large square port where flaps reside the main flow path into head? If yes then perhaps a smudge better air flow without the wafer thin plate in the runner. I'm quite sure the engineers did proper fluid dynamics work to minimize disturbance.

[Yozh]

I doubt engineers did much proper fluid dynamics at all. Wishful thinking. Look at the EGR in these engines, and the intake manifold mismatch to the EGR, and all the interruptions in the intecooler connections.

[BB_cuda]

Good point on the EGR's throat. Perhaps the bean counters and EPA teamed up to win argument against performance minded engineers. I've been put in that box before as a designer.

Maybe I'll put the swirl flaps back then. Thanks