Header restriction?
Thread Starter
Racer
Joined: May 2008
Posts: 318
Likes: 0
From: Wheaton, Illinois
Header restriction?
The headers in question are a set of Hooker super comps 1 5/8 primaries. On the AFR website I can build a 450 horsepower 355 using those headers. However, their 383 460 hp combo requires a 1 3/4 primaries header. My question is, how big of a 383 can I build using my 1 5/8 headers? thanks
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
My Hooker Super Comps are 1 3/4 in primaries, you must have the Competition ones. Just be careful if you order the Super Comps I had to cut and extend the number 8 primary tube to fit my heads 
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Headers are a restriction when they are smaller than the head exhaust port. You need to look up the port and pipe dimension and figure it out. You always want a slightly larger header than exhaust port
HP level and total exhaust output kind of go hand in hand.
Header science tells you that the larger volume pipe the slower the gas speed. So larger shorter primary pipes can be tuned to the same rpm as longer smaller dia.
For a street motor the reality is to not worry so much about tuned lengths, but worry about making a very free flowing system after the collector.
HP level and total exhaust output kind of go hand in hand.
Header science tells you that the larger volume pipe the slower the gas speed. So larger shorter primary pipes can be tuned to the same rpm as longer smaller dia.
For a street motor the reality is to not worry so much about tuned lengths, but worry about making a very free flowing system after the collector.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Motorhead did bring up a good point. Hooker S/c are 1 3/4 inch. it is easy to tell 1 3/4 inch. The center two pipes on either side touch together.
Thread Starter
Racer
Joined: May 2008
Posts: 318
Likes: 0
From: Wheaton, Illinois
Headers
gskull & Motorhead, I went down to the garage and checked the headers more closely. The headers have a molded Hooker SUPER Competition emblem on them, and the center pipes are very close together! I am very happy to have the larger primaries, now I can build a 383!. Thanks for all your help. Al
Last edited by Al Davis; Dec 16, 2008 at 05:45 PM.
