Okay, this is mostly for the guys that have a VI already, because I'm sure they will know what I'm talking about, but if others have info, please chime in. When your looking at the top of the VI without the cover over the butterflies, you can see all the casting. One thing I noticed is that nissan didn't do a very good job (IMO) of cleaning up the casting, it still seems pretty rough, and some areas like the mold wasn't the greatest. I was going to clean up the rough casting with some sandpaper and polish it up when I got another idea: The ports around the butterflies are all square edges, wouldn't it flow a little better if the edges were rounded? It wouldn't affect the butterlies, because they sit below the edge. My thoughts against this however: What if the square edges help with the extra turbulance that boost HP and tq over 5k rpm? If I smooth out all the edges I can't go back and make them square again. Any thoughts or ideas on this anyone?

 

I'd assume cleaning up the squareness of the upper port lip might make things a little better. It won't be significant at all, but it might make you feel better


Dave

 

Your probably right dave, I just like to mess with things...

 

hmmm I have mine off my car and it wont be going on for a long time...

 

for those that don't know what I'm talking about:



The areas in red...

 

Since it's already off, I'd send it out to be P&P, but that's just me.

Like Dave said, it probably won't make much if any difference, but why not if it isn't too expensive.

 

Well for airflow, air doesn't like going around sharp edges. That's why you see ported heads with very smooth transitions around edges. I can't really see exactly what you are referring to(maybe you can just show me sometime as I live pretty close). But as long as you don't really mess with where the butterflys meet to engage the 2ndaries, I would think you could go to town. But if you are just using some sandpaper and hand action( ), I doubt you could do anything but just take off some rough edges. Any of you guys have a decent sized compressor? I have an air-powered hand grinder w/ metal working attachments I've been wanting to try out. I don't have a compressor at home yet(I haven't picked it up from my dad). I do have a Dremel though

 

If I did it, it would be with a dremel and/or some precision metal files, with final polishing being done by sandpaper and metal polish. Their are other areas of the casting that are pretty rough as well, and I want to try and smooth all those out as much as possible before I install this... I can show ya sometime jeff, I'm not gonna install it for another month or so.