Advanced Engineering Tech For the more hardcore LS1TECH residents

How does altitude change header pipe diameter needs?

Thread Tools
 
Search this Thread
 
Old Mar 29, 2007 | 02:11 PM
  #1  
clubber's Avatar
Thread Starter
Teching In
 
Joined: Jan 2007
Posts: 33
Likes: 0
From: Salt Lake City, Utah
Default How does altitude change header pipe diameter needs?

I'm putting an LS-1 in an RX-7. There are two headers that fit and one has 1 3/4 primaries and the other has 1 7/8 primaries. I know that as altitude increases, it has an effect but is it bigger? Smaller with higher is my guess but I'm far from sure. The particulars for my application follow; Stock 346 with a small cam (TR 224), with headers for starting but later to add better heads and intake. Any help is appreciated. Oh yea, I live at about 5000ft.
Stan

Last edited by clubber; Mar 29, 2007 at 02:19 PM.
Reply
Old Mar 29, 2007 | 10:47 PM
  #2  
Sabre002's Avatar
12 Second Club
iTrader: (7)
 
Joined: May 2004
Posts: 543
Likes: 1
From: Columbia, SC
Default

think about breathing through a straw at sea level, then go up to the mountains and try the same thing its even harder on you. Same goes here you are working with thinner air up there so you need more flow to make the same HP I will make here at sea level.
Reply
Old Mar 29, 2007 | 11:09 PM
  #3  
SScam68's Avatar
11 Second Club
iTrader: (20)
 
Joined: Sep 2002
Posts: 2,684
Likes: 3
From: Albuquerque NM - The Land of 8000ft DA
Default

Go with the 1 3/4"

With less dense air the engine breathes less lb/hr of air.
Reply
Old Mar 29, 2007 | 11:13 PM
  #4  
1997bird's Avatar
TECH Fanatic
iTrader: (2)
 
Joined: Nov 2006
Posts: 1,360
Likes: 0
From: Aztec, NM
Default

At your altitude you are effectively loseing about 20% of your HP. The 1 3/4" primaries are more than enough to support your HP output.
Reply




All times are GMT -5. The time now is 08:00 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE