i was supposed to have mine extrude honed but i ran out of money https://www.nopistons.com/forums/pub...DIR#>/wink.png

$250.

Thats cheaper than buying the cosmo intake componets.

How much bigger are you making the runners?

How much does that run if you don't do it your self?

yep, but still not as big. https://www.nopistons.com/forums/pub...R#>/tongue.png

Bigger isn't always better, but in your application Jspec it probably is.

If you lay the gasket on top of the runners, you can see there is a decent amount of space to open it up. I ported it till the gasket was flush with the edges of the runners. I don't think extrude honing works that well by itself on the fd. Don't hear of anyone doing it. Like I said, If you port them and also get them polished or cerasmic coated, the tumbler they run through to prepare for the process smooths out the inside as well. Poting it can only increase the benefits.

I was always under the impression that intake passages that are really smooth will have a negative effect on performance. It's best to have a somewhat rough surface, because it will churn up the air/fuel mixture slightly, helping it to better atomize the mixture. Like everything else dealing with tuning cars, there's that magical happy medium. Not too rough that it slows down the air/fuel charge considerably, but not smooth as glass that it just slips on through without being properly atomized.



*Shrug* That's basically how I always understood it.

Nope, polished is the way to go. Less turbulance knocking the fuel out.