Shortys vs. Long Tubes
Thread Starter
Intermediate
Joined: Apr 2003
Posts: 25
Likes: 0
From: Morgantown WV
Shortys vs. Long Tubes
I understand from my reading on this forum that shorty headers aren't worth much from a HP gain and that Long Tubes are the only way to go. As the Long Tubes eliminate the Pre Cats, has anyone dynoed a car with and without the pre cats to understand the true gains from the installation of Long Tube headers? The exhaust system on the C5 seems like it ought to flow pretty well and I am amazed at the gains I read about from the LT Header install. I wonder how much restriction the pre cats contribute and if the LT Headers would provide as significant gains if the baseline was established with the pre cats eliminated from the exhaust system.
I would really appreciate hearing from those that have eliminated or gutted their pre cats and then gone to the long tube headers. Are the gains still as significant?
Finally, I am not attempting to cast a stone at the header industry. I am really curious about this and am trying to understand why / how such
significant gains are proven when, in the end, the exhaust is still chocked down to either a 2.5 or 3.0" tube prior to entering the muffler system. :confused:
I would really appreciate hearing from those that have eliminated or gutted their pre cats and then gone to the long tube headers. Are the gains still as significant?
Finally, I am not attempting to cast a stone at the header industry. I am really curious about this and am trying to understand why / how such
significant gains are proven when, in the end, the exhaust is still chocked down to either a 2.5 or 3.0" tube prior to entering the muffler system. :confused:
Pro
Joined: Apr 2002
Posts: 726
Likes: 2
From: Denver CO
Re: Shortys vs. Long Tubes (JayMullen)
I suggest you study more on this forum and look at other websites for header information. It's a very complex subject and has been beaten to death :smash:
Start with this article:
http://www.popularhotrodding.com/tech/0310phr_burns/
then visit www.headerdesign.com and read up on the science. There's no easy answer, but shorties are a waste of money and time, and it ain't the pre-cats, and gutting them will free up flow but hurt velocity and it would be better to just replace them with tubing, rather than gut them, etc., etc., etc..
Good luck and enjoy your learning adventure, also,
Welcome to the Forum!!
:cheers:
Start with this article:
http://www.popularhotrodding.com/tech/0310phr_burns/
then visit www.headerdesign.com and read up on the science. There's no easy answer, but shorties are a waste of money and time, and it ain't the pre-cats, and gutting them will free up flow but hurt velocity and it would be better to just replace them with tubing, rather than gut them, etc., etc., etc..
Good luck and enjoy your learning adventure, also,
Welcome to the Forum!!
:cheers:
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
Re: Shortys vs. Long Tubes (JayMullen)
You need to think beyond just pipe size, flow capacity and restriction to understand.
Long tube headers work on the principle of scavenging. Instead of your engine pushing the exhaust out through the pipes and various restrictions, the header's scavenging effect serves to actually pull the exhaust out of the engine.
This is always why there's a good debate and discussion about ideal header tube dia and length, collector style, etc..these are the factors which need to work together to create the scavenging effect and can determine how well a header performs.
If it were just a matter of "bigger is better" and less restriction, we'd probably all have 8 2" pipes bolted to our heads running clear to the back of the car.
:cheers:
Long tube headers work on the principle of scavenging. Instead of your engine pushing the exhaust out through the pipes and various restrictions, the header's scavenging effect serves to actually pull the exhaust out of the engine.
This is always why there's a good debate and discussion about ideal header tube dia and length, collector style, etc..these are the factors which need to work together to create the scavenging effect and can determine how well a header performs.
If it were just a matter of "bigger is better" and less restriction, we'd probably all have 8 2" pipes bolted to our heads running clear to the back of the car.
:cheers:
Drifting
Joined: Jul 2003
Posts: 1,796
Likes: 1
From: Annandale VA
Re: Shortys vs. Long Tubes (blackjack)
I made 383 HP with Hooker shorties & full cats on my SS, w/ a very mild cam (218/224). The car was nice & quiet, passed emissions w/ ease, no ground clearance problems.
