The only number I have seen for lost HP was less than three with the splitters. Exhaust design will be much easier with them.
The tubes for your Pport should be thick walled and a light press fit, in the inner wall in order to support the edges of the housing when the stack is torqued up. Keeps the chrome from cracking. Fill in the water void between inner and outer housing with an aluminum filled mechanical epoxy. If there is no water, it can't leak. Devcon Plastic Aluminum if you can find it.
http://www.freemansupply.com/DevconEpoxyPlastic.htm
The putty. Not the liquid.
Use a milling machine. Practice on a junk housing or two. Paul Yaw did up a nice Pport and had the pictures on his web page.
www.yawpower.com. I'm on dial up until the 6th, so I didn't look through his stuff to see if any of that was still there. Leave at least 1/2" of chrome on each side to support the apex seal.
I built one for a guy who ran it through two passes at an autocross and never developed oil pressure.
Said it ran real good. It was in a Mini Cooper woody wagon. The engine had set in his shop for two years before he ran it. (10 inch tires were not enough)
Keep runner (tube) ID about the same as the combined area of both stock runners. High velocity is what you want. Bigger is not better until you get closer to 10,000 RPM.
Cover all of the chrome you don't want ruined with three layers of duct tape.
Look for 200+ HP
Lynn E. Hanover
In a message dated 5/2/2008 7:15:02 PM Pacific Daylight Time, eanderson@carolina.rr.com writes:
Does anyone have a set of new rotor housings for 89 to 92 13B? Where should one look? What is a good price for them? I want to build a P Port but I wonder if the non turbo variety would help for noise suppression? Thanks for any help.
Joe Berki
Limo EZ