I have the same but haven't removed the deflector out of the exhaust port yet. Any idea on the difference with or without?

Hi Georges,

This is another one of those eternal debates on the list.  I think the consensus is that they must cost some power, but maybe not even enough to notice.  They are said to make a noticeable difference in exhaust noise though, which is a good thing.  So far, I've only used the turbo housings, which don't have the splitter.

I sure wish I had a big Lottery check, so I could install a dyno, and spend enough time playing with these things to figure it all out.  Short of being able to do that, all we can do is collect any info we can from the sources we have.  Unfortunately, this data rarely compares directly with what we need, and by the time we try to mentally convert the conditions of the test, the results are skeptical at best.  

One example of this is Lynn's numbers for ported and PP engines.  While I really do appreciate the data, it wasn't quite the gold mine of info I was hoping for.  There are just too many variables, such as racing choke limitations, which I can't account for.  I'm afraid I still don't know what the real difference between a side and peripheral port engine would be.     

I have to admit that I'm starting to give some thought to building a test stand, and having some way to measure power.  Perhaps just a good mixture monitor, a big variable pitch IVO prop, and reliable fuel flow measurement.  Short of having a real dyno, I'm not sure what else I could do.

Cheers,

Rusty (buying more lotto tickets)