O2 sensor location

[427SSSS]

I've been all over all three forums searching for stock EFI sensor location, and they are all over the place, even in sidepipes. I just received set of GP headers 4 to 4 headers. Is there a definitive " best" location for sensor?

[GWL]

After all four pipes come together as one where all the pipes can be read as one. The sensor should be tilted slightly down so condensation will not collect in it.

That is the 'best' place but there are sometimes compromises when the four pipes don't come together till the side pipes. Some will put it in one single header pipe hoping the reading it gets is consistent with the other three. I think where the transition from 4 to 4 takes place may be the best as they may be able to be read as one there. Maybe, depends on how they come together, as one or does it keep the pipes totally separate down to the side pipe?

George

[427SSSS]

Thanks George. Just spoke with GP Headers, they have a "collector" that I should have asked for in the first place, (live and learn) so I'll be sending headers back so they can weld it in. BTW, these are absolutely a work of art.

[Papa]

You could have ordered your GP Headers with a double collector.

[Papa]

Looks like you realized GP Headers had the double collector option as I was posting my reply. And, yes, they make a very nice product.

[427SSSS]

thanks papa. Well, their website is not clear on double collectors, ( in my opinion) looks like those are only available for coyote engine. I've been wrong before, and will again.

[427SSSS]

Wow! So I talk with gpheaders, (3 times, to be clear about what I want, you guys understood what I was saying on this thread, I doubt I was any less clear when talking to zack)and explain what I want and I get sent two bungs. Good thing I did not listen to his suggestion to send headers back to him and they would do the welds, that would have been a waste of $130.00 . Now he tells me that it's a completely different header. So I ask where they would have welded the bungs had I sent them the headers...answer..on one & two, or 7 & 8. So GP headers does not have a definitive "best" place for the bungs..which was my original question to start this thread.

So I tell him that their website does not show those headers...and get this..he says " maybe we don't sell them"!

[Papa]

Their website for ordering Cobra headers has a set of dropdown selection fields for material, coating, flange style, and header style. You need to specify (select) the collector option in the header style. You can also tell them which header (passenger, driver, or both) that you want the O2 bungs in when they call to confirm your order. Not sure what is causing the confusion on your order, but Zach was very helpful when I placed my order.

Dave

[427SSSS]

Papa, I've been to their website several times, talked with ,zack 5 times, I think I'm reasonably computer savy. And I still say they are not clear on their website and as I posted above Zack said : maybe we don't sell those headers for an efi 302. I've ordered 100s of cobra parts online, and the only other problem I've ever had was ordering hallibrand wheels.I

I really appreciate all the help everyone has posted, maybe Zack and I speak different languages.

For them to not have a definitive " best" place for the bung really confounds me!

[Papa]

Papa, I've been to their website several times, talked with ,zack 5 times, I think I'm reasonably computer savy. And I still say they are not clear on their website and as I posted above Zack said : maybe we don't sell those headers for an efi 302. I've ordered 100s of cobra parts online, and the only other problem I've ever had was ordering hallibrand wheels.I

I really appreciate all the help everyone has posted, maybe Zack and I speak different languages.

For them to not have a definitive " best" place for the bung really confounds me!

I'm not trying to be argumentative and I apologize if I'm coming across that way. I can only offer help from my own experience, and I don't know what your discussions with Zach were. I know when I ordered from them, I made my selections and placed the order. They manufacture each set of headers to order, no mass production. Before they started building my headers, they called to confirm all the specifics with me. If that wasn't how your order was handled, that would be an issue in my mind. I hope you get it worked out.

Dave

[427SSSS]

When I retired and moved to Texas I sold the three cobras I had. Got there and realized it was a mistake, bought a cobra from NY had it inspected, it was a home built dog! Moved back to californina, decided to sell this dog. It was still a fun car to drive, but it was crap. I could not sell it as it was, pulled the body, installed cobra wiring harness, po had not even cut off excess mustang wiring. Trigo wheels, I pulled carpet, installed heat insulation, New carpet, 40 other replacement/improvement/repair parts and decided to install headers instead of j pipes. This is the only other cobra out of the 10 cobras I've had that is efi. All my other cobras, another FF5 two bennet cobras and a GT40 in my shop will be carberated....I think efi in a cobra is sacralige. Just my opinion, im old school.
Zack was a pleasure to deal with, when I don't communicate with someone I accept that it's at least 50% my fault, I'm not blaming Zack or GPheaders it was just miss communication, a mind bolging miss communication, but that's what it was.

[427SSSS]

[QUOTE=427SSSS;376965]When I retired and moved to Texas I sold the three cobras I had. Got there and realized it was a mistake, bought a cobra from NY had it inspected, it was a home built dog! Moved back to californina, decided to sell this dog. It was still a fun car to drive, but it was crap. I could not sell it as it was, pulled the body, installed cobra wiring harness, po had not even cut off excess mustang wiring. Trigo wheels, I pulled carpet, installed heat insulation, New carpet, 40 other replacement/improvement/repair parts and decided to install headers instead of j pipes. This is the only other cobra out of the 10 cobras I've had that is efi. All my other cobras, another FF5 two bennet cobras and a GT40 in my shop will be carberated....I think efi in a cobra is sacralige. Just my opinion, im old school.
Zack was a pleasure to deal with, when I don't communicate with someone I accept that it's at least 50% my fault, I'm not blaming Zack or GPheaders it was just miss communication, a mind bolging miss communication, but that's what it was.

[427SSSS]

Thanks for the post dave, I'm not trying to be argumentive either, I do really appreciate the help on this forum. I've never owned an efi car in my life, like I said,I'm old school. After retiring to texas, on the water, i could walk out my back door into the water and wade fish, or fish off my dock. this " DOG" was the cheapest cobra I could find, that's what I could afford at the time. My partner, has a welding shop, he does everything else with cars also he's had one of two of my cobras down there for last year or so, we work on them ( including this dog) at his shop, or cobras at my shop when he doesn't have other work. I'm a cobra finatic!!!!!!!

[donkeykong]

I don't know how you'll go back to a carburetor after EFI. Perfect air/fuel mixture, no cold starts, beautiful throttle response, no adjusting, no tuning, better gas mileage. There's nothing a carb does better! As far as sacrilege putting EFI on a Cobra...I'd agree on an original, but that's not what we have.

To the original question...place the sensor into the collector. I wasn't able to get a perfectly level or tilted sensor installed, however, there would really have to be an awful lot of moisture in the pipe to damage it in my opinion. The collector is the absolute best spot, it can get a reading of that entire bank of cylinders instead of a reading out of one pipe.

[Papa]

I don't know how you'll go back to a carburetor after EFI. Perfect air/fuel mixture, no cold starts, beautiful throttle response, no adjusting, no tuning, better gas mileage. There's nothing a carb does better! As far as sacrilege putting EFI on a Cobra...I'd agree on an original, but that's not what we have.

To the original question...place the sensor into the bung. I wasn't able to get a perfectly level or tilted bung installed, however, there would really have to be an awful lot of moisture in the pipe to damage it in my opinion. The collector is the absolute best spot, it can get a reading of that entire bank of cylinders instead of a reading out of one pipe.

This thread is heading off topic now, but I certainly understand the appeal of a push rod engine with a nice loping cam. That low RPM lidle is great. For those of us who start our drives at 6,000 feet and crest 12,000 feet an hour later, EFI is a much better way to go. My last toy car was carbuerated and I hated it. Start it in the garage and two-pedal it to keep it running as you moved it outside to keep from choking to death, then keep playing with the throttle until it warmed up enough to idle on its own. Get up to 10,000 feet and hope it can get over the top of the mountain as all the hybrids are passing you and cursing you for killing all the trees....

You get the picture.

[Avalanche325]

I have been catching up on my Engine Masters shows lately.

They were doing single-plane vs dual-plane dyno testing. They had an O2 sensor in every tube. The variance in A/F ratios was around 2.0 between cylinders, which is HUGE. That definitely proved to me that O2 sensors should be in the collector.

donkeykong,
I will agree that EFI is "better" in most ways. I would not have a daily driver with a Carb. I also don't want my Cobra to drive like a daily driver. Warming up, being temperamental and snotty, having to really drive it, is what a Cobra is all about to me. Carb for me.

"no adjusting, no tuning". That is not correct at all. EFI "self learning" is equivalent to installing carb out of the box, and is a way to sell EFI to people that don't know better. Yes it will run, and probably pretty well on most engines, just like an out of the box carb. But it isn't doing what it could do. They both need tuning.

[donkeykong]

donkeykong,
I will agree that EFI is "better" in most ways. I would not have a daily driver with a Carb. I also don't want my Cobra to drive like a daily driver. Warming up, being temperamental and snotty, having to really drive it, is what a Cobra is all about to me. Carb for me.

"no adjusting, no tuning". That is not correct at all. EFI "self learning" is equivalent to installing carb out of the box, and is a way to sell EFI to people that don't know better. Yes it will run, and probably pretty well on most engines, just like an out of the box carb. But it isn't doing what it could do. They both need tuning.

Couldn't disagree more! Warming up and being temperamental isn't enjoyable, for me anyways. Pulling up to a stop sign and the car dying unless I'm constantly feathering the gas, not fun. Having the car buck and sputter until warm, not fun. But hey, that's what's interesting about different people, we all like different things.

As far as no tuning on and EFI being "not correct at all", again, couldn't disagree more! I've had 2 Holley Terminator and now two Holley Sniper units, I currently have a Sniper in my Cobra now. "I" didn't do any tuning to any of the systems. To claim that "no tuning" is a way to sell EFI is a bit intellectually dishonest. "self learning" is not me tuning anything. No, hooking up a Sniper and turning your car on is NOT "doing what it could do", the same as a carb, you're correct on that.

There's two major differences from that point on. 1) With the Sniper I'm going to start driving the car and in an afternoon it's going to have worked any problems out on it's own...and then continue to improve as I drive from that point on. It doesn't "need tuning"..it just does it! Unless there's some way to turn that feature off so it no longer tunes itself, and why would you do that, it just does it! You're not tuning anything, you're not manually doing anything...you're just driving. It's not a "sales gimmick" it's how the system works. A carburetor is NEVER going to get any better out of the box by just driving it. EVER. 2) Once the EFI system has "tuned" itself, unless something has changed on the vehicle, it's done. It doesn't have to be messed with again. There's no adjusting an accelerator pump, floats, idle screws, jets etc. Not so on a carburetor. I'm not saying you have to adjust that stuff on a carb on every drive...but it's typically not set and never touched again, especially if you live somewhere with elevation changes.

[427SSSS]

Yup, efi is easier to deal with, simpler...but, and I certainly know these things are not originals, but to open the hood and see a big Holly carp, or a set of stacks, start it up and head that klakity klack of solid lifters...if I'm going to have a copy of an original cobra body, that's only half the car, a copy of the original 289 or 427 engine, with carb is what I love about these cars. To each his own.

[Avalanche325]

I wasn't going to add anything else, but as luck would have it.....

I watched an Engine Masters last night where they couldn't get a Holley Terminator to even do a dyno pull after spending half a day trying to let it self tune. They had to change the intake manifold. An industry standard Edelbrock Performer RPM Air Gap on a fairly average street engine. The self tuning couldn't figure it out. They called self-tuning as a "misnomer". They said it loads a basic map based on the setup inputs that gets some tweaks. Even after the manifold change, they had to do some manual tuning to get a decent pull.

Self learning EFI gives you a safe, middle of the road tune most of the time. Fine for most street cruisers. There is more to be had in almost all most cases with a custom tune. For some cars, including a friend of mine with FiTech, the self tuning just doesn't do it. Tuning EFI is what most of the tuner shops spend their days doing. EFI and carbs should both be tuned for serious performance.

[427SSSS]

BTW, modified rollbar to make exterior of car look more like originals.

Without cutting new holes in body or modifying or relocating receiving pockets in trunk.

[rich grsc]

GP's site, Cobra kit header; 302&351 2" bolt spacing ...double collectors $350.00
https://www.gpheaders.com/products/cobra-kit-headers/

[427SSSS]

Rich, you are right, there it is, clear as day, add double collector $350.00. I missed it. Part of my problem is i'd never heard of a double collector, never had an efi car. I still don't understand why Zack and I didn't communicate, It was my error not zacks. I didn't know enough to ask for double collector. So I asked for headers with 2" spacing for an efi car in 5 phone conversations. I welded bungs onto #4&#8, as others suggested on this site, installed 4 to 4 headers, car runs perfect!

Corrected typo, from7 to 4, thanks Doc

[Big Blocker]

Sure hope that is a typo . . . "I welded bungs onto #7 & #8". Guess exhaust sensing on one side only is the new way to get it running at the peak of its performance . . . ???

FWIW, FORD engines are numbered 1-2-3-4 on the passenger side, 5-6-7-8 on the drivers side. Hope you thought #4 was #7 and they are in the [sorta] correct spots.

Doc

[427SSSS]

Yup Doc, my typo.