03-09-2018 | #11 |
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,699
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Re: 1 3/4" vs. 2" Header Size
Paul,
I think Marc may have documented no significant difference between 1 7/8 v the 2” primaries. If there was a difference it could be easily lost somewhere else.
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[SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX |
03-09-2018 | #12 |
Join Date: Jul 2012
Location: Allentown, PA
Posts: 309
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Re: 1 3/4" vs. 2" Header Size
Smaller primaries would likely be the better choice for road course racing where more time is spent in lower and mid-range rpm's and larger would be the better choice for drag racing.
Sent from my HTC U11 using Tapatalk
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'95 ZR-1, aqua/gray, #167 368 LPE/Haibeck, Web cams, Stainless Works headers, B&B Fusion exhaust, 18" Fikse wheels, Alcon brakes, lowered. 491 SAE RWHP. |
03-18-2018 | #13 |
Join Date: Jan 2010
Location: Freedom Pa
Posts: 275
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Re: 1 3/4" vs. 2" Header Size
I have a book by David Vizard, I think the SBC on a budget. It links exhaust flow to the size of the primaries. Also there are "stepped headers" that have a bigger initial size then going down to a smaller, i.e., regular size tube that sounds like it's the cats meow. I bet you could find the article on line.
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03-21-2018 | #14 |
Join Date: Jul 2005
Location: Jupiter, Fl.
Posts: 815
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Re: 1 3/4" vs. 2" Header Size
Don’t “stepped headers” have the opposite, smaller initial tubes, then get bigger down line to the collector?
I have had Watsons with 2” downtubes since 1995, and they’re pretty good, (117mph trap speed on an otherwise stock engine.) Sent from my iPhone using ZR-1 Net Registry
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"It's about the car, not the people." 1991 ZR-1 White/Black #1236 (Owner since 1994). Stock engine with bolt-ons: Hurst shifter,"Forced Air" intake, Coplon duct, Bee Cool Radiator, Demon coils, Jeal prom, Watson headers, X pipe, 3" B&B's, Rippie flywheel, 4:10 gears, A molds, Toyo Proxes-R888's 12.06@117mph. 1.76 60ft. |
03-21-2018 | #15 | |
Join Date: Nov 2007
Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri
Posts: 6,493
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Re: 1 3/4" vs. 2" Header Size
Quote:
Gotta love that sea level DA!
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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 |
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03-21-2018 | #16 | |
Join Date: Jul 2010
Location: Woodstock, Ontario, Canada
Posts: 1,275
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Re: 1 3/4" vs. 2" Header Size
Quote:
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peace Paul ZR-1 Net Registry Member #1494 |
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