Those running SD, do you still have the MAF on the car? and does the ribbed bellow really create that much turblance, was going to leave my maf and ribbed bellow on car (I like how neet it looks and it keeps it looking stock) or will you really get that much better air flow with something else?
thanks for any responses!

 

I don't have an SD tune but I don't think it would make enough of a difference where you would notice. A smooth bellow won't change anything and I doubt you would even gain any hp either way. From what I've seen a lot keep the maf and stock bellow with an SD tune. Just unplug the maf

 

the bellow does help, its just a question of how much... maybe like 1/4 of a horsepower but it does look better in the engine compartment and most people just make their own with tubing from home depot or lowes

 

I would leave it in there. You might be able to get away with de-screening it now and not having complications with Speed Density.

 

Personally I doubt you'll see any difference in HP or ET's by removing the MAF and going smooth bellows. If you have a full 90mm setup with a 85mm lid then it may be of benefit.

As for the bellows, well IMO it's the biggest rip off there is (worse than the bloody Tornado!!!!). The SLP smooth bellows isn't even smooth, its a humped length of silicon hose with SLP stamped on it. And they charge $50 for a $10 3x3" section of silicon tubing which you can buy from 100's of other places.

So most smooth bellows are not in fact smooth.

Also there is some evidence that suggest the stock bellows possibly flows better than a smooth one, this is due to the boundary layer. Golf ***** imploy the same idea, they have an uneven surface by means of lots of dimples. This creates an unstable boundary layer and reduces friction which allows it to travel further.