Sam, did you order yours with an extra bung and plug to connect the wideband for tuning?

 

Thank you for all the positive feedback Where I am actually going with this is going to be a webpage detailing all the mods I did to my car, and HOW I did them. I've learned a lot from the Internet and I always like to give a little something back. It will go on my personal webpage, but I'll make sure to put a link to the actual page when it gets done.

In response to some questions:

I drove the car LA-Las Vegas and back. It worked out to just under 600 miles. To date I have not seen any check engine light. The one people usually get with headers (universally; I've seen them on anything from Hondas to BMWs) is for "catalytic converter inefficiency", and you are guaranteed to see it with no cats, but since this car is catted I haven't seen it yet.

A few more comments:
I was really impressed by how much weight I removed from the car by removing the cast iron headers and large factory cats. Weight reduction is one of my favorite mods as long as it doesn't amount to "gutting" the car
I chose to run a catted X-pipe first and foremost for noise reasons; I've ran catless exhausts before and they are just too loud. The low restriction of the cat causes virtually un-noticeable power loss (1-5hp on a bolt ons car) but does quiet the system down some. My second reason for running cats is that they would allow the car to pass a sniffer test, should I ever have to get one. Realistically though, passing emissions in California with a long tube header car will require a $200 bribe to my local smog guy. No big deal

If you've ever wondered WHY you can't have long tube headers: It is illegal to relocate the factory cat converter. The reason for that is the same reason why the factory puts it so close to the engine in the first place; the platinum honeycomb element does not begin to work until it reaches high temperatures. Moving it away from the engine heads increases the cat's light up time and thus drastically increases cold start emissions. Oh well...

BTW did I mention that with headers + CAI, even pre-tune, this car HAULS? I had a 2003 Z06 before and now with the bolt ons the C6 would absolutely walk it in a straight line

Getting tuned THIS SATURDAY, NOON by Charlie at RPM Motors

 

No, I did not, which is strange because I have daily driven two cars that had wideband AFR gauges in them and it is one of the best tuning tools out there. I also have a very nice PLX Devices Wideband O2 setup just sitting in a box right now.
The main reason I didn't do that is because I wanted the headers here as soon as possible and didn't want to add any more cost time and complication to the order, but I also had two other good reasons:

1- I can have the car professionally tuned for a lot less money than it will cost for me to purchase the tuning software, and as of now I don't intend to tune it too many times.
2- Professional tuners typically mount their O2 sensors at the end of the tail pipe. If that works, then I can simply remove one of the two post-cat O2 sensors and run my wideband there. Most tunes disable the post cat sensors since they are only there for emissions reasons, so this would work well.
Also, my PLX Devices O2 sensor has a 0-1 volt setup that can be used to perform the duties of a regular narrowband O2 sensor. This means that I can actually mount it in place of any O2 sensor in the car and feed the ECU the signal it needs to run the engine in closed loop.

 

Sam, you do not want to use the sniffer for tuning, becasue after the exhaust gases go through the CATS, the reading will not be accurate at the exhaust tips. I spoke to Charlie about this. If you did not get a bung welded in, prior to the CATS, Charlie will probably put one in for you, in order to get a good reading and a proper tune. I am ordering Kooks, and will have them weld one in for me. The only issue is that you cannot weld it in a location that will read the exhaust gases from both banks, because the X pipe is BEHIND the cats, so I will have them weld the bung on the driver's side primary.

 

I don't see much of an issue with only monitoring the Air/Fuel ratio of one of the engine banks; the air for all cylinders is monitored as one unit and the fuel injector duty cycle is the same for all cylinders. The only thing that could cause a variation in AFR would be if some of your injectors were flowing partially, or if you had unequal mass airflow distribution through your manifold. Either issue would be very hard to diagnose without individual cylinder EGT or AFR monitoring, and if you had such an issue you would have a much bigger problem than just trying to get the car tuned right.

I am aware that some of the O2 available post combustion is consumed during the catalytic converter processes but I have seen enough tuners use tailpipe O2 readings that I am not too concerned with it. If Charlie wants to weld up another O2 bung that's cool too, as long as he doesn't ruin my beautiful JetHot coating in the process

 

It might be a little harder to install the bung now with the headers in the car, but it might be doable. Yes, it will somewhat ruin the Jet-Hot coating for that specific area. I had my car tuned both at Synergy and LAPD, and they both used the additional bung to connect to the wideband sensor, and through my correspondence with Charlie, he does the same as well.

 

Nice writeup. I got the PO420 and PO430 Cat System Low Effiency error codes on my Kooks 1 3/4" with Kooks Hi Flo Cats about at the 1000 mile mark after installing them. You can tune the error code them out, (which I did) but am wondering if Charlie can actually tune them out via other means. Ask for me.

Kooks sadly does not provide them, but that is what I also used to secure my sensor wires.

 

FYI unless you have wires touching the header primaries you will have no issues burning or melting plug wires. My Kooks headers on my C5 Z06 don't come close to any plug wires. I ran 4-6 HPDEs a year w/o any ceramic coating or cool sox type protectors on the wires. Zero issues. I now have my entire exhuast ceramic coated with a turbo black coating, but I did it more to keep heat out of the clutch hydraulics than for anything else.

As for your wires... they make small rubber clamps that come together and can be bolted... it's hard to describe but another header install I saw on here had them and they removed one of the tunnel plate bolts and then re-installled to hold the wires out of the way. Very clean and professional way to do it.

On my C5 I used black zip ties to keep everything out of the way and have had no issues with melting anything over the past 4 years I've had the headers in.

I agree about the sound... Kooks headers are the closest to equal length primaries of any of the designs out there and make for a very blended exotic tone.

 

Thanks man, I apreceate it!

 

Cool! Great write up!

 

Excellent write up, now all we need is a video clip....

 

makes me want to do headers!!

 

My headers will be going in this month, at least I will assist with the install, nice write-up.

 

So, if you haven't seen my tuning thread yet, the header / intake combo was good for 364hp / 361.6tq , which Charlie at RPM motors tuned into 395hp / 387.4tq.

But what you really want to see is what it sounds like:
http://www.youtube.com/watch?v=-0Z6hprbIvk

 

vette baby

 

 

Congrats they look great! Headers make a huge difference if only by improving the sound. Here is how I did mine. You can see the clamps on the third picture down. I found them at the local hardware store I also didn't have a neighbor around so I had to use tie straps as a 3rd arm.

http://forums.corvetteforum.com/show....php?t=1943176

 

Great writeup. I installed my AR headers a couple weeks ago...

You mentioned that all of the bolts from the manifold to cats will shear... I had a tough time breaking mine loose, but with a little bit of high performance penetrant, they all came out with little problems...

Also, you should go to your hardware store and pick up some clips to clip your O2 wires to the tunnel plate. You don't know how long that tape will hold.

 

Nice job, Gotta luv the Kooks no leak collectors.
And perfect fit. Plus They are on Dennis's fastest c-6 bolt-on car.
enough said

 

http://corvetteactioncenter.com/spec...l#.UWcBfb4o5qM


just so you see how "rare" z51 mn6 cars are. Obviously they are out there but just harder to find than most!