Has anyone polished the *inside* of the Greddy elbow? I just finished installing a nipple to accomodate the AWS hose and while I was grinding the interior of the fitting to make it flush with the interior of the elbow, I also polished the interior surface from the cast surface, with all the little bumps and pockets, to a smooth finish. All of the other polished aluminum pipes are smooth inside, so it seems that this one should be also, especially since it make such a sharp bend. I would hope it flows just a little better. Who knows- maybe an extra one or two horse power?

 

Air conforms to shapes not surfaces really. There is a thin layer of air on the surface of things that moves very slow. Think of it as rain on your car driving down the road at 70mph. The rain on the surface of the car moves very slow => the air on the surface of the car moves very slow => if there were little bumps on the surface of the paint (as in the bumps on the surface of your elbow) the air/water on the surface of the paint would still move slow. So, sorry dude but the only thing that your polishing probably did was waste your time.

 

Billyrhom- My last expoxure to three dimensional flow dynamics was in a graduate school physics class in 1971, before you were born, so I do not have the equations to calculate the flow-thru-pipe data at my immediate memory. Given the effort to highly polish intake runners and valves by top piston engine race engine builders, there has to be some merit to polishing intakes. My question was if any of the serious rotary builders had information on improved output by polishing. Anyway, it was not really a waste of time, cause it sure is purty!

 

Most intake plenums and manifolds are not polished smooth inside the runners to assist in creating turbulent airflow. Compressed or turbulent air moves faster than free-flow.

 

A little turbulence is good!

 

So what is the reason that the "port and polish" is used so frequently for intakes and cylinder heads on piston engines? I have done this myself on several small block Chevy engines and most high performance heads and intakes for circle track and quarter mile are shiny enough you can check your teeth in them. I don't think that the major high-priced engine builders do this just for fun. Honda, for example, explains the extra 5-10 HP on some of their V-Tech R engines by claiming extra polishing on the intakes. Any explanation? It may be that a turbocharged intake is less affected by this, but now my interest has been piqued.

 

you just spelled piqued the correct way so I'm with you. I think thats a good idea. I was actually thinking the same thing. the inside surface looked really abrassive. When I drill to connect the aws hose I'm going to do the same thing.

 

Widebody2- I finally found someone who had the correct size thread tap to put the nipple on the elbow. There must have been some kind of run on 5/8 inch pipe thread taps in NC- I had to go to six different hardware stores to find one in stock. It's installed, works fine, looks a lot better than the plastic stock elbow. Don't know if it's any faster but at this point, who cares. Besides being able to correctly spell piqued is an accomplishment in itself. peeked, peaked, piqued, etc.

 

People dont waste your time putting a nipple on the elbow. Just buy a $15 K&N filter and put it on the hose.

 

Which K&N filter do you use for the hose? Is it on eof the ones used as a breather filter on piston engines and does it come in the right size?
As far as the polishing issue goes I'd like to see some dyno data that it does add 5-10 HP. I don't buy it but can be proven wrong if there is data to support that claim. If anyone reads import tuner they do tests on 3 cars every month and get the actual dyno data and then you can compare them to what the company says it does. Its like that Tornado thing they sell for 60 bucks that says it gives up to 30 HP since it addds some turbulance when all it really does is restrict air flow.