OBX Headers have arrived and ........
Instructor
Joined: Jun 2008
Posts: 211
Likes: 0
From: Lapeer Michigan
I'll try and find the link again since nobody here seems to want to help others do the legwork... 
I'll post the link when I find it, but I think the guy had something like 332hp/336tq and went to 365hp/3xxtq. He had supporting bolt ons and already had a previous tune. So, all things being equal the gains were from the headers alone and just a modified tune when adding the headers.
I'll post the link when I find it, but I think the guy had something like 332hp/336tq and went to 365hp/3xxtq. He had supporting bolt ons and already had a previous tune. So, all things being equal the gains were from the headers alone and just a modified tune when adding the headers.
http://forums.corvetteforum.com/c5-t...headers-5.html
Post #96:
"
Ok, so the HP increase rate is similar between the two graphs, that's good!
So you went from 325.79 hp & 336.68 Tq to 356 hp & 365.4 Tq, so you gained 30.21 Hp & 28.72 Tq from headers and a fresh tune, not bad considering it had already been tuned before! With the mods you have I would have expected more if it had never had a tune before, or less if it didnt have a tune and you didnt get one this time.
So that's not bad.
You have 350 torque from 2500 -5250 RPM with it peaking at 365.4, & still over 310 Tq down at 2000 RPM, that's pretty darn good I think!
So you went from 325.79 hp & 336.68 Tq to 356 hp & 365.4 Tq, so you gained 30.21 Hp & 28.72 Tq from headers and a fresh tune, not bad considering it had already been tuned before! With the mods you have I would have expected more if it had never had a tune before, or less if it didnt have a tune and you didnt get one this time.
So that's not bad.
You have 350 torque from 2500 -5250 RPM with it peaking at 365.4, & still over 310 Tq down at 2000 RPM, that's pretty darn good I think!
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
Here is a link regarding installation and dyno results from this OBX header system. The dyno results are in post #91. The pictures of the dyno sheet are no longer available.
http://forums.corvetteforum.com/c5-t...headers-5.html
EDIT: Thanks Black Out...you beat me to it!!!
http://forums.corvetteforum.com/c5-t...headers-5.html
Just got it dyno tuned by Charlie at RPM. Before the headers I had the Vararam, Borla Cat Backs, 3.42's and a dyno tune with RWHP 326. Now with the OBX headers and great tune by Charlie I got 356 rwhp and 365 ft-lb of torque! I asked Charlie how these headers compared with others and he said they were slightly above average in the hp gain and that the torque was the really impressive thing. I will look for my old dyno sheet and let you know the peak torque back then. If i remember right the peak torque was less than 320 ft-lb. As for now here is a few pics of the dyno sheet. Hope this answers any ?'s if not let me know
EDIT: Thanks Black Out...you beat me to it!!!
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
Resonators are simply hollow tubes with maybe some sound baffling material inside. Cats are catalytic converters used for emissions control. Resonators have no emissions regulation, they will not pass inspection.
This is my understanding, someone correct me if wrong.
This is my understanding, someone correct me if wrong.
Instructor
Joined: Oct 2008
Posts: 129
Likes: 0
From: bellefonte pa
here in PA if resonators look like cats they should pass, its a visual check only. They seem to look the same to me. But would resonaters pass an emissions check if they actually start taking exaust readings? Are resonaters designed to filter unburnt fuel?
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
If they sniff the tailpipes, you're screwed.
Here is a photo of the inside of the "resonators" on the OBX setup:
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Race Director
Joined: Jul 2007
Posts: 11,467
Likes: 8
From: 972 and 405
Yeah I have the bullets too and the resonators have NO emmissions control. They are not deigned for it. But back on topic, the horsepower gains are spot on. Plus the ease of installation for the other guys seems to be just as easy as the big brands
-Alex
-Alex
Team Owner
Joined: May 2003
Posts: 23,480
Likes: 9
From: East Meadow NY
St. Jude Donor '12
The missing 02 sensors may tip off the inspector.
Team Owner
Joined: May 2003
Posts: 23,480
Likes: 9
From: East Meadow NY
St. Jude Donor '12
There are universal or car specific. The universal will generally just have a size for the tubing. You would need to get a pair of catalytic converters that match the size of the exhaust tubing you are feeding in and out.
2", 2.5", 3", etc
2", 2.5", 3", etc
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
There are different sizes. For example, Random Tech sells them in 2.75" or 3" depending on stock/modified exhaust.
Random Tech
http://www.westcoastcorvette.com/p-2...et-c5-z06.aspx
Random Tech
http://www.westcoastcorvette.com/p-2...et-c5-z06.aspx
Pro
Joined: Nov 2001
Posts: 689
Likes: 4
From: Long Island NY
Team Owner
Joined: May 2003
Posts: 23,480
Likes: 9
From: East Meadow NY
St. Jude Donor '12
Random technologies lists their flow numbers and they claim they flow as well as, if not better than, a performance muffler. Random Technologies also uses stainless steel for the cats. Are the cheapies above stainless or are they going to rust out? How do the cheapies above connect into the exhaust system. Do you have to weld them in, clamp them in or do they bolt in?
Last edited by chaase; Apr 9, 2009 at 02:28 PM.
Team Owner
Joined: May 2003
Posts: 23,480
Likes: 9
From: East Meadow NY
St. Jude Donor '12
Once you start talking headers, it is a different ball game. It depends on how the header manufacturer designed the headers. A lot of the bigger name designers seem to use Random technologies converters, so the headers are designed to mount up with either those or a mid-pipe and still connect to the factory cat back system. Think about the parts to the system. There is the header itself, the x-pipe + cats or some x-pipe + off-road pipe, then the factory cat back.
Other brands of converters may work if they are the same size. I would say you are SOL if its a universal catalytic converter.
Last edited by chaase; Apr 9, 2009 at 02:42 PM.
Le Mans Master
Joined: May 2008
Posts: 5,892
Likes: 47
From: Helotes TEXAS
And 03vettemaniac is the member with nothing but great things to say about these headers. Not to mention all the proof that they are just as good as the HIGHER priced brands,
Last edited by Sinister-one; Apr 9, 2009 at 04:42 PM.
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
Once I get my cam installed, I'll have some dyno numbers for all you worry warts out there !
And 03vettemaniac is the member with nothing but great things to say about these headers. Not to mention all the proof that they are just as good as the HIGHER priced brands,
And 03vettemaniac is the member with nothing but great things to say about these headers. Not to mention all the proof that they are just as good as the HIGHER priced brands,
