ported air horn - ZR-1 Net Registry Forums

LGAFF · 12-12-2011

Did a plenum for someone.....they went to 63mm TB so they asked me to open up the Plenum to TB and Air Horn.......

Besides moving to 63MM I went in and smoothed out the all the trasitions some ported and unported pics:

Unported

Ported

Unported

Ported

Blue Flame Restorations · 12-12-2011

LOTS OF WORK!

pantera1683 · 12-12-2011

Nice work Lee. How much does that run?

LGAFF · 12-12-2011

I threw it in with the port job....

tomtom72 · 12-13-2011

uoooooh smooooooth !

nice flow ya got there mister!

Jim Nolan · 12-13-2011

Was that increase to 63mm just for the porting. I know Aaron Scott stopped putting 63m throttle bodies on his portings because the HP gain was near zero. Did I miss something here?

LGAFF · 12-13-2011

This person needed a rebuild due to an issue so he upgraded through someone......I just followed up on the request...its worth a few HP...smoothing should help...I was a skeptic, but a Mercury smoothing the airhorn actually showed a modst increase. They apparently had an engine on the dyno and did step by step mods for HP

mike100 · 12-13-2011

I kind of wonder at what hp level the 63mm throttle body is beneficial. I guess you might get a couple of hp from smoothing the sharp edges on a stocker- maybe, but I'd have to think you might benefit on a 500 hp engine more.

Has anybody done much testing on different combos?

Kevin · 12-13-2011

i remember reading, maybe incorrectly, that the pirate car didn't have any gains from a 63mm tb

Paul Workman · 12-14-2011

Transitioning the edges won't hurt, for sure. But, it seems to be quite abrupt still.

A topic for an FBI pizza night: I've been pondering something with a smoother and less abrupt transition; more in keeping with the 4% guideline (some use) for port transitioning. What I envision is more along the lines of a pair of internal funnel-like tubes. They would extend from the "big" ports and merge along a knife edge and morph to fill the shape of the horn at the inlet oval. Borrowing a term from another discipline, "impedance matching" is the goal: The less abrupt the change, the better for flow.

OK, it isn't an original idea. If you get a chance to look into the rectangle inlet of a supersonic fighter e.g., an F-15 or the like, and you'll see what I'm talking about. My point is, "bumps" in the air stream, like rocks on the bottom of a shallow stream of water, cause pressure waves that extend way beyond the shape of the intrusion.

Concept:

I have no idea if it would be worth the trouble to build, but it might be something to experiment with. Just a thought.

P.

12-12-2011	#1
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	ported air horn Did a plenum for someone.....they went to 63mm TB so they asked me to open up the Plenum to TB and Air Horn....... Besides moving to 63MM I went in and smoothed out the all the trasitions some ported and unported pics: Unported Ported Unported Ported __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359 Last edited by LGAFF; 12-12-2011 at 09:54 PM.

12-12-2011	#2
Blue Flame Restorations Join Date: Feb 2010 Location: Pendleton, IN Posts: 3,904	Re: ported air horn LOTS OF WORK! __________________ 1988 KOH Prototype EX5023 sold 1990 ZR-1 #444 Convertible 1990 ZR-1 Black #966 1991 ZR-1 Quazar Blue #296 1957 Duntov SS Project

12-12-2011	#3
pantera1683 Join Date: Mar 2010 Location: Fort Worth, TX Posts: 396	Re: ported air horn Nice work Lee. How much does that run?

12-12-2011	#4
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: ported air horn I threw it in with the port job.... __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

12-13-2011	#5
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: ported air horn uoooooh smooooooth ! nice flow ya got there mister! __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

12-13-2011	#6
Jim Nolan Join Date: Jan 2007 Location: Florida Posts: 241	Re: ported air horn Was that increase to 63mm just for the porting. I know Aaron Scott stopped putting 63m throttle bodies on his portings because the HP gain was near zero. Did I miss something here?

12-13-2011	#7
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: ported air horn This person needed a rebuild due to an issue so he upgraded through someone......I just followed up on the request...its worth a few HP...smoothing should help...I was a skeptic, but a Mercury smoothing the airhorn actually showed a modst increase. They apparently had an engine on the dyno and did step by step mods for HP __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

12-13-2011	#8
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,802	Re: ported air horn I kind of wonder at what hp level the 63mm throttle body is beneficial. I guess you might get a couple of hp from smoothing the sharp edges on a stocker- maybe, but I'd have to think you might benefit on a 500 hp engine more. Has anybody done much testing on different combos?

12-13-2011	#9
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,633	Re: ported air horn i remember reading, maybe incorrectly, that the pirate car didn't have any gains from a 63mm tb __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

12-14-2011	#10
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: ported air horn Transitioning the edges won't hurt, for sure. But, it seems to be quite abrupt still. A topic for an FBI pizza night: I've been pondering something with a smoother and less abrupt transition; more in keeping with the 4% guideline (some use) for port transitioning. What I envision is more along the lines of a pair of internal funnel-like tubes. They would extend from the "big" ports and merge along a knife edge and morph to fill the shape of the horn at the inlet oval. Borrowing a term from another discipline, "impedance matching" is the goal: The less abrupt the change, the better for flow. OK, it isn't an original idea. If you get a chance to look into the rectangle inlet of a supersonic fighter e.g., an F-15 or the like, and you'll see what I'm talking about. My point is, "bumps" in the air stream, like rocks on the bottom of a shallow stream of water, cause pressure waves that extend way beyond the shape of the intrusion. Concept: I have no idea if it would be worth the trouble to build, but it might be something to experiment with. Just a thought. P. __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry Last edited by Paul Workman; 12-14-2011 at 06:37 AM.