Only street port is reliable?
I idle my HBP's around 1300-1400. It idles great. The AFR's bounce around at that RPM, of course, but I target for mid-high 12's:1 if I can get away with it. The negative effects of overlap are pretty apparent down at that RPM.
I don't go into the land where the rotor housing rests. When I cut the ports, I try my best to use it as an edge. I've cut into the rotor housings some when I'd made larger bridgeport cuts (closer to 5/32" - 3/16" wide) but I rarely do it.
How do I get the finish? Carefully and painstakingly.
Seriously, I don't polish the intake ports even though sometimes the pictures suggest it. They're only sanded to 120 grit with the exception of the centre ports which I leave rougher. If you look closely, you'll see fine scratch marks still.
B
I don't go into the land where the rotor housing rests. When I cut the ports, I try my best to use it as an edge. I've cut into the rotor housings some when I'd made larger bridgeport cuts (closer to 5/32" - 3/16" wide) but I rarely do it.
How do I get the finish? Carefully and painstakingly.
Seriously, I don't polish the intake ports even though sometimes the pictures suggest it. They're only sanded to 120 grit with the exception of the centre ports which I leave rougher. If you look closely, you'll see fine scratch marks still.B
I would have swore you polished the ports, your porting is impressive to say the least. Thanks for the honest info.
David
he does have impressive work. he does it by paying attention to detail. i love looking at his work.
i used to drive a carb'd FBP before wasnt too bad to drive, just the fuel mileage was bad. but FI has come long ways....
i used to drive a carb'd FBP before wasnt too bad to drive, just the fuel mileage was bad. but FI has come long ways....
the only problem that concerns me, is that while BDC's HBP's work great on the street, it leaves us NA supporters out in the cold, since without boost, reduced boost lag and spool doesn't really mean much to us. Combine that with an already shaky reputation for low rpm driving and cruising, as well as gas mileage, and I'm wondering, how would you make an HBP work, NA style?
i think the answer to that question is simply determination and high tolerance. if you look up the user trochoid, he's running a HBP 12A, and while i can't remember if that's his daily driver, it is a car driven on the street fairly regularly. you can get his thoughts on it.
based on the bridgey i drove (which was the daily driver of a friend of mine) it needed large stretches of open road in order not to be annoying - not something you found very often in the Bronx and Mount Vernon outside the hours of 2300 to 0530. it wasn't something i wanted - even back in my "crazy" days if it was going to be my only car. use a turbo.
based on the bridgey i drove (which was the daily driver of a friend of mine) it needed large stretches of open road in order not to be annoying - not something you found very often in the Bronx and Mount Vernon outside the hours of 2300 to 0530. it wasn't something i wanted - even back in my "crazy" days if it was going to be my only car. use a turbo.
Thread
Thread Starter
Forum
Replies
Last Post
datfast1
West RX-7 Forum
3
Sep 14, 2015 06:58 PM
mulcryant
2nd Generation Specific (1986-1992)
10
Sep 9, 2015 05:24 PM
13b, affect, bridgeport, life, port, reliability, reliabiltiy, reliable, rotarys, rx7club, single, span, street, streetport, turbo
