maybe this is a dumb question

but has anyone had their mrev or lower plenum ported/polished, would any gain be seen by this on a NA application or is it pointless?

 

well, you would think motordyne would make the mrev the best they possibly could make it, no?

 

yes I agree but would also add to the cost so maybe not?

 

Well theres only one way to find out, dyno, polish, and dyno again........

 

they did, tony did it and for the time and effort he yielded another 1-2 hp at best...

 

check out the DIY plenum thread...lots of talk about polishinng the plenum - general consesus was that it would hurt flow (other applications and books say that a polished surface changes the flow characteristic of the boundary layer and actually causes more resistance)...it's supposed to have a certain amount of roughness. Porting it would help ~ but this take a long time! I've been working on my own, and it's a huge pain...I can't really see a way to automate this process, so the cost would be fairly high.

Here's 2 pics of me trying to port match the lower plenum to the collector:



I also milled off the top of my runners similar to MD's lower plenum - I spent another ~3-4 hrs smoothing out the transistion of the milled out area so that it didn't look like a 'flat top'. After doing all of this, I'd say buying the MD lower plenum is well worth the $.

Here's a pic of my lower plenum (I painted it w/ a high temp ceramic paint - I did that to lower heat transfer and hopefully give the surface a more uniform texture so that air flow wouldn't be weird:


-Peter

 

thanks peter!