Megan Racing Headers Install

[r4dr]

cut the EGT wire at the sensor and disconnected it up top. The thing is useless without cats. Put the sensors on before you mount them.

I don't think this is accurate, is it? To my knowledge the pre-cat O2 sensors and EGT sensor all play a part in AFR calibration by the ECU.

[Arith2]

I don't think this is accurate, is it? To my knowledge the pre-cat O2 sensors and EGT sensor all play a part in AFR calibration by the ECU.

POST Cat O2s are what I was talking about. The EGT can't be used for anything but emission because it is only on one bank and it's post cat I believe. Things could get screwed up by only measuring on side. In 1999, when our car was being engineered, it was not on their mind. AFRs and EGT relations need accurate readings from both banks at a minimum. Remember, bank 2 will run leaner than bank 1 causing more heat.

[Circa Surviven]

POST Cat O2s are what I was talking about. The EGT can't be used for anything but emission because it is only on one bank and it's posy cat I believe. Things could get screwed up by only measuring on side. In 1999, when our car was being engineered, it was not on their mind. AFRs and EGT relations need accurate readings from both banks at a minimum. Remember, bank 2 will run leaner than bank 1 causing more heat.

If I remember reading something correctly, don't the post (or pre?) o2s have to be switched around when moving them to the megan headers? If not it runs with misfires? I'm looking for a visual picture, but is the orientation of the pipes coming down to the section 1, different than the stock headers?

[Arith2]

If I remember reading something correctly, don't the post (or pre?) o2s have to be switched around when moving them to the megan headers? If not it runs with misfires? I'm looking for a visual picture, but is the orientation of the pipes coming down to the section 1, different than the stock headers?

One of the post cats won't sit in the top bracket anymore. I have all the connectors in the original locations and just rerouted the wires. I would ditch the post cat O2s but I need it to look somewhat legit visually. It's been a while since I did the install. The EGT slipped under my VCG once. When I stopped at a light, smoke was bellowing out on my car from oil dripping on the headers. It ruined the finish on the headers so that was the final straw. I just cut it off

[Circa Surviven]

Yep, those are the ones I used as well.

So the stock e46 11mm copper nuts work on the n54 torx studs?

[Johnvu]

So the stock e46 11mm copper nuts work on the n54 torx studs?

Yes, they work. The thread is the same diameter and pitch, the stud just sticks out longer and easier to install. Make sure you order new nuts since they are one time use. You can get away with installing old ones but might as well spend the extra few bucks to get new hardware.

[Obioban]

POST Cat O2s are what I was talking about. The EGT can't be used for anything but emission because it is only on one bank and it's posy cat I believe. Things could get screwed up by only measuring on side. In 1999, when our car was being engineered, it was not on their mind. AFRs and EGT relations need accurate readings from both banks at a minimum. Remember, bank 2 will run leaner than bank 1 causing more heat.

EGT is for sure used for engine management with the csl engine management. I don’t know if that’s also true for the non csl engine management.

[Circa Surviven]

Yes, they work. The thread is the same diameter and pitch, the stud just sticks out longer and easier to install. Make sure you order new nuts since they are one time use. You can get away with installing old ones but might as well spend the extra few bucks to get new hardware.

For sure! I have 18 new ones ready to go. The local dealership has the torx studs in stock, so I'm going to use those instead of the stock design. We're they hard to thread for you? I've read a couple comments by those using them on the e46 m3, saying they were hard to install by hand and they stopped trying in fear of stripping the head.

[BlAikenstein]

Are any of you guys wrapping or coating these at all? I was thinking about using a ceramic paint, wrap and silicon paint to keep the under hood temps down. I’ve read wraps deteriorates the headers quicker but I don’t plan to keep these on for more than a few years. Recently Ive been looking at heat shield products header armor, looks interesting and does away with the corrosion problems. Anyone have experience with this product specifically?

[Obioban]

Are any of you guys wrapping or coating these at all? I was thinking about using a ceramic paint, wrap and silicon paint to keep the under hood temps down. I’ve read wraps deteriorates the headers quicker but I don’t plan to keep these on for more than a few years. Recently Ive been looking at heat shield products header armor, looks interesting and does away with the corrosion problems. Anyone have experience with this product specifically?

Since this is a non header brand specific question...

I'm running swaintech white lightning on my V1s. From everything I've read it's the most effective coating, and it doesn't prematurely age the headers.

[BlAikenstein]

Since this is a non header brand specific question...

I'm running swaintech white lightning on my V1s. From everything I've read it's the most effective coating, and it doesn't prematurely age the headers.

Yeah swaintech is top tier from my understanding as well but also more expensive than the Megan headers so I’d only put it on ssv1’s or maybe or euro headers.

[Cubieman]

For sure! I have 18 new ones ready to go. The local dealership has the torx studs in stock, so I'm going to use those instead of the stock design. We're they hard to thread for you? I've read a couple comments by those using them on the e46 m3, saying they were hard to install by hand and they stopped trying in fear of stripping the head.

Be sure to clean the female threads the best you can and definitely use anti-sieze, take your time and you'll be just fine.

[jbfrancis3]

Yeah swaintech is top tier from my understanding as well but also more expensive than the Megan headers so I’d only put it on ssv1’s or maybe or euro headers.

Consider that the benefit of the coating isn't tied to the value of the headers. Also consider the value of the coating isn't retained, so if you're waiting for nice headers and then should you should eventually sell, you won't get that money back. Obviously the same is true for intermediate step of coating the Megan headers.

Point being, why is it worth going a few years without good underhood temp reduction, only then to eventually have it with the nice headers. I know you're trying to use wrap to achieve the short term goal but let's say you leave the cheap headers in 4 years - you very well may be re-wrapping/recoating/etc which takes fussing around with removal and more materials. Would have been better to coat properly at the beginning.

[Circa Surviven]

Be sure to clean the female threads the best you can and definitely use anti-sieze, take your time and you'll be just fine.

Rookie question: copper anti-seize on the threads that go into the block, or only the section that the nut is tightened on?

[Cubieman]

Rookie question: copper anti-seize on the threads that go into the block, or only the section that the nut is tightened on?

Only the threads into the block need anti-sieze, keep the exposed (sticking out of head) stud dry. With anti-sieze you should be able to bottom out the n54 studs on their "shoulder" by hand but some may require the use of a ratchet.
If using a ratchet only grip the head of the ratchet as to apply very little torque until you know you've got it then use ratchet handle to seat the stud fully.

A light coating is sufficient.