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Discussion Starter #1
AH!!! i figured out something really odd this week...

I use to have equal length headers on my Tahoe, and i couldnt get the tune right at all...EVEN AFTER 12 hours on the dyno...I kept burnin out the #7 and #8 cylinder spark plugs...

I changed it to shorty Headers, and two things happened...I gained SO much more milage, from 15L / 100km (16MPG) to 11.9L / 100km (20.3MPG)...That is at 80mph to boot and AVG Economy....And the burnin of cylinders #7 and #8 stopped...Well my power really increased but no braggin till i slap her on the dyno...

So i am on the search for a pair of shorty Headers for the CTS-V...This is better for the following reasons:

1. Stock appearance remains the same
2. The stock O2 sensors read the expelled gases quickly rather than down the line...
3. I could still use a 3" exhaust and retain good ground clearance...
4. Price is a factor which will be saved for other options..

I look forward to all your replies to this thread...

FYI this is not a comparison between shorty and full length headers, this is a pure search and purchase enquiry...Everything has a give and take, I am just going against the flow a bit and see what i come up with...

Again thank you for your time

Naf
 

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05 Redline CTS-V
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having just installed kooks longtubes on my V... i'd hate to have to try and cram any more pipe between the shock tower and the block, its already a cramped fit trying to bolt LT's in there, i can't imagine cramming a ball of spaghetti set of headers in there, i had shorties on a mustang, and those were a pain and i had NOTHING in that engine bay except the engine
 

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'05 CTS-V, '12 CTS-V Manny Vagon
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I'm not aware of any shorties specifically made for our cars. B&B makes some mid's. Perhaps if this is what you really want, go with some hooker block huggers, and fab up some connecting pipes.

Another option might be to extrude hone your current OEM manifolds, and swap out to some Randowm Tech OEM replacement cats. I had the RT cats, and they were very high quaility (they make the ones which come with the Kooks look like turds.) You end up with more flow, and OEM-like reliablilty, and a very stock appearance (the onlything more stock looking you could do would be to gut your OEM cat's). This solution MIGHT net 1/2 the hp (and less TQ) of some quality LT's.

I know you aren't looking for advice on this, but I think you're looking in the wrong direction here with the shorties.

Good luck,

Chris
 

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2007 CTS-V Thunder Gray; 2004 Cowboy Cadillac (SRT10)
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17,712 Posts
AH!!! i figured out something really odd this week...

I use to have equal length headers on my Tahoe, and i couldnt get the tune right at all...EVEN AFTER 12 hours on the dyno...I kept burnin out the #7 and #8 cylinder spark plugs...

I changed it to shorty Headers, and two things happened...I gained SO much more milage, from 15L / 100km (16MPG) to 11.9L / 100km (20.3MPG)...That is at 80mph to boot and AVG Economy....And the burnin of cylinders #7 and #8 stopped...Well my power really increased but no braggin till i slap her on the dyno...

So i am on the search for a pair of shorty Headers for the CTS-V...This is better for the following reasons:

1. Stock appearance remains the same
2. The stock O2 sensors read the expelled gases quickly rather than down the line...
3. I could still use a 3" exhaust and retain good ground clearance...
4. Price is a factor which will be saved for other options..

I look forward to all your replies to this thread...

FYI this is not a comparison between shorty and full length headers, this is a pure search and purchase enquiry...Everything has a give and take, I am just going against the flow a bit and see what i come up with...

Again thank you for your time

Naf
If your serious about your request and for a test I would recommend Heavy's B&B's. The cats are about were the stock cats are located and the O2 sensor is up about were the original one was located.

I know you aren't looking for advice but I think the LT's are good for a couple of reasons.
#1 better flow
#2 Relocate the cats to underneath the car and drop the engine bay temps.

I have been running the LT's without a tune and the car is running well. At first the car wasn't too happy about the headers but after a little while it has settled down and the mileage is about the same as it was.

Sorry for giving you the info but I couldn't resist!
 

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2005 CTS-V
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There are shorty headers for LS6 Corvettes, JBA for example, that could be adaptable to a CTS-V.
 

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Discussion Starter #8
Thank you all for your inputs...

I found the part # for the stock manifolds, which are also found on the STS series...So useful, GM always finds a way to impress me to their enginuity in keepin the customer at their mercy...

I also found that the 2004 LS6 Corvette headers are a bit longer, but they are tight and need a small bit of work done to the exhaust...You were right about that Darkman

In regards to engine bay temp, as long as the exhaust gases flow and there is no excessive back pressure, the heat will be kept to a min...Plus a set of Stainless steel headers goes a long way in retainin the heat...

I will keep you all posted to my progress and we can all compare mpg and final numbers with certain setups...
 

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Discussion Starter #10 (Edited)
If you are only goin to slap on the LT headers with no tune, you will lose milage. It is a given that once you install LT headers your mixture goes rich...I have seen it with Kooks SW and others...

So slap on a pair, head down to the local tune shop and refine the mixture, then watch that milage go up and then mash it and watch that gas needle go down...
 

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2005 CTS-V
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It is a given that once you install LT headers your mixture goes rich...I have seen it with Kooks SW and others...
I do not question this but I do wonder why that is. My only recent experience has been with motorcycles engines, both carburreted and fuel injected, that consistently go lean with addition of lower restriction exhaust systems.
 

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2015 BMUU 335i MSport, 2006 STS-V--2005 CTS-V ( traded in)
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It didn't help my mileage but that may be because I really like to mash the throttle with the Headers!
:yeah:


I can make it return to "normal" (15-15.5 in the city) But blowing a WOT exhaust note, especially next to some a hole trying to cut you off, makes the slight loss worth it. :D
 

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2007 CTS-V Thunder Gray; 2004 Cowboy Cadillac (SRT10)
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I do not question this but I do wonder why that is. My only recent experience has been with motorcycles engines, both carburreted and fuel injected, that consistently go lean with addition of lower restriction exhaust systems.
I am not sure either so if someone has an answer to this I would like to know.

This is what I know from mod's I had done on other motors - When it breathes better it needs more gas to maintain the same ratio. For exmaple when I put a tuned pipe on the jetski (2 stroker but air flow is air flow) I had to put larger jets in the carb.

Now with the O2 sensors and the computer to compensate for the additional requirement of fuel why doesn't the computer compensate? I realize a tune will take care of this but can someone shed a little light on the details?
 

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:yeah:


I can make it return to "normal" (15-15.5 in the city) But blowing a WOT exhaust note, especially next to some a hole trying to cut you off, makes the slight loss worth it. :D
:yeah:
Usually the ricer in the Honda with the fart pipe and that over the top wing!:rant2:
 

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05 maggied CTS-V, 2017 NSX Whoo Hoo!
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Go ask Ric.

There are fuel tables and the like that the computer uses.

The 02 sensors provide feedback so that "trim" can be adjusted to maintain an even mixture/burn, but the 02 sensors do not "rule" the system so they can only adjust for so much.

Kind of like thinking that the computer will readjust to compensate for a larger throttle body swap or a maggie addition.

Not gonna happen.
 

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2007 CTS-V Thunder Gray; 2004 Cowboy Cadillac (SRT10)
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Thanks Heavy but I think I will just do a search and do some reading.

I'm sure Rick would be able to answer my questions but I'm sure he's busy and has better thing's to do then answer my silly questions.

I am thinking about getting the HP tuner or the software to put on a laptop for a couple of reasons. The first is to clear the codes when I make changes and the second is to tune the car but the last thing I want to do is screw up the tune on the V, lean it out, then blow it up! Maybe I should leave it to the pro's.

There are some out there that have tried this and I was just trying to get a feel of how difficult it was.
 

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I will leave the tuning to the EFI guys.

I really like the support Ric gives for his work.

Guess I am lucky in that regards because I can get data when I get Reed to plug in the laptop and go for a ride.

Anyway, the 02 sensors are small gears in the big picture.

If they were big gears your car wouldn't run without em.
 

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I didn't know the O2 sensor was a gear, learned something new... (j/k) :D

I trust Rick and I am getting a Tune from him next week.

Reed seems like a good guy and I'm sure he is very sharp, your lucky to be that close to him.

I realize there are more sensors then the O2, like the MAF, CAM Position Sensor, Crank Position Sensor, Temp Sensors...... These cars are loaded with sensors but I was just using the O2 sensor as an example.

I was not thinking about doing the tune because I thought I could do it better but because I like to tinker and I like to see how things work. Been my experience that the more you know about what your modifying the better decisions you can make about modifications.

Also, I was one of those kids that would tear stuff apart to see how it works. The only difference for me now is I have figured out how to put it back together or can pay someone to do it! :)

Fun stuff.
 
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