if you want info and number etc relating to secondary PP's it may pay to e-mail RICE RACING

he has toyed with alot of that stuff and has had good results

 

Thanks, I just fired off a message.

 

Yeah, I've only seen pictures two secondary pports before. One is scoots and another is one that Greg showed me.
Since my other computer is running right now I'll go check on the info on Scoots car.


40mm PPorts + Street Ported Primaries and Secondaries
Cut down 20b thru bolts
Needle Roller Main Bearings

711ps
327.3km/h

6 speed Holinger transmission
Brembo F50 Brakes
NB Apex Seals
T51R

http://www.geocities.com/fdkai2000/tsukuba.htm

 

Just remembered another thing to think about concerning plenum location. Remember how I said it doesn't matter if the tb is far away from the plenum since the intake pipe is not a part of the plenum volume? You can put the plenum in front of the tb with no ill effects. Many people have done this. Everything still works the same since the plenum size is what dictates certain things and not its location. Strange what I think about at 4:45 am.

 

Yet many people still haphazardly throw away the carefully crafted OE intake systems in favor of a simple tube with a cone filter stuck on the end. Not everyone is gullible, though... Miata types have found that removing the resonators from the intake tract causes a big hole in the torque curve (around 3500rpm IIRC).

- PJ ("Make a change and test it. If there is no improvement, undo the change, no matter how pretty the new parts are")

 

So on an n/a, if it's stock port or street port and you make an adapter like Yaw's, how do you blend it into the header? Do you gradually open up the shape from the sleeve adapter? Do you keep that shape constant for the 3" from the manifold surface? I'm confused as to how and when to blend it into the header tubing size without causing the turbulence.

 

If you saw the picture of the Yaw inserts then you noticed that the shape is not round but has a flat top side. You would have to look at the pictures of his headers on his website very carefully to answer your question. Since we can't see the actual pipe inlets we assume that they ae round. His pipes are actually the same shape as the port inserts. Over the next 3" they taper to round. Notice that his do go straight for those 3" before they turn. The reason there isn't any turbulence even though the shape changes slightly is because there is no appreciable area increase of the runner. This is unlike the stock sleeve/header combo. The problem of the stock sleeves isn't so much the shape change but the fact that the ports are increases a couple of times over an extremely short distance.

I am starting a new thread devoted to the sleeves alone. Hopefully I can answer everyones questions better on there since I am posting new pictures.

 

Oh cool... heh heh heh... sorry we're all so demanding.