818R "Glynman Style"

[Scargo]

I think it's interesting that the data from the NASIOC manifold flow tests (which I'm familiar with) showed that the worst flow was the plastic "thing" that they put down.

Plastic Thing with TB
Runner 1 293 CFM
Runner 2 283 CFM
Runner 3 283 CFM
Runner 4 291 CFM
Average 287.5 CFM
Runner to runner max variation 10 CFM or 3.5%

What is interesting to me about these numbers is that I ported a set of W25 heads and had Supertech +1mm valves installed. With my Kelford 200-C cams (272/268 Degree, 11.30/10.50mm High Lift) I was able to get 284 CFM out of the intakes. That's pretty decent.
So, why do I need a bigger/better manifold for an essentially stock DAVCS head and destroked motor? Micah McMahan (3MI Racing) and Dominic Acia ("get a Dom tune"- now at Turn-in Concepts) both like this manifold for my destroker motor. I believe it has something to do with the size/flow and some to do with the runner lengths and a small bit to do with it being plastic and not sucking up heat.
I dug out my NA long runner manifold and measured all three. The STi has the shortest runners at 43CM. The TGV-less NA measures abut 59CM and the plastic one is 62CM!

longislandwrx (sorry, I can't remember your name),
Seems I need a set of phenolic spacers if I am going to run an aftermarket, O-ringed TGV and the plastic manifold. Can't do O-ring on O-ring.
I think I will get standard 2mm phenolic spacers (and use ported stock TGVs) unless there is a double O-ringed spacer out there. I haven't run across one. I also wonder about wrapping the manifold or at least putting gold foil on the underside. I don't believe I've seen anyone doing that.