DIY header install

[gabezilla275]

I just recently got a set of performance headers for my 2004 350Z touring 6speed. The thing is I've looked online for directions on how to install them. I found some crazy thing about pulling the engine and removing 300 seperate parts from the car. It's also very time consuming. I decided to do even more research and downloaded the Nissan service and repair manual for my car. It says I don't have to do any of that crazy stuff to replace my headers. The only major thing it says to do is drain the coolant so you can disconnect some of the hoses. I was thinking if the Nissan manual seems easy what about a Haynes repair manual. It pretty much says the same thing. I was wondering has anyone removed their headers with out pulling their engine? If they have could they give me some advice.

[aris_unlimited]

Wait a couple of months and I will probably have a writeup for it. I am planning on installing mine but I have to wait til the guy I have helping is available (he keeps delaying).

[gabezilla275]

I plan on doing the install in a few days I just need some quick tips and I will probably do a write up and pictures also

[bmike818]

sounds like a write up battle

....Who's literacy skills will reign supreme?

[spitalul2bad]

I did a full exhaust install, including headers, cats and cat-back exhaust.

The headers took a full day, the rest of it, only 60 minutes.

The mounts (screws) that hold the headers in place are SO hard to reach (from underneath and from above), even with elongated torque wrenches, that the best way to do it is to remove the engine. I didn't want to do that, and spent a whole day in the shop doing just the headers.

And this was with the gearbox OFF the car ! (I was changing the flywheel assembly too).

So, what I'm saying is: it's a b**** to change headers.

But goodluck... I don't think there's a need for a DIY since it's a fairly easy thing to do, it's just that it's SO UNACCESSIBLE.

You can find pictures of my build here: zer...urnal

P.S. Since then, I've ordered a big brake kit, uprated cams, Volk CE28N wheels and have done the "mandatory" HKS true-dual bumper-tuck.

[gabezilla275]

Wow that photo journal was extremely helpful thank you very much. I have a much better idea now on how I'm going to attack this thing. Just one more question do you happen to know what size the bolts are that are holding the stock headers in place and were the heat sheilds the easy part.

Modified by gabezilla275 at 9:22 AM 7/29/2009
Modified by gabezilla275 at 9:35 AM 7/29/2009

[MisteenoMike]

I second the difficulty of this install. Though I did a pair of DC Headers on a G35, almost everything still applies.

Yes, you will have to drain the coolant (at least half of it) so that you can remove the coolant hard pipe that blocks access to the passenger side header bolts. Intake has to come off for the Driver's side.

NUMBER ONE TIP: have the largest assortment of sockets, extensions, wrenchs, penetrating lubricant etc. A 50-piece Wal-Mart tool kit will NOT cut it. For example, I believe the header bolts to be 14mm (can't remember) but I ended up using 3 different kinds of 14mm sockets for access: regular, thin-walled deep socket, and wobble sockets. All with varying extension combinations on them.

The bolts for the cats have some tricks as well. Two of the bolts that join the cat to the header can be accessed from underneath, but one bolt is actually easier from under the hood with an 18-24" extension (and flashlight).

Honestly, 40-50% of your time is going to be spent on just 4 bolts: The top one closest to the radiator on the Driver's side, the bottom one closest to the radiator on the passenger side, and a couple of the bolts closest to the firewall on the passenger side. If by some miracle these give you no problems, you should IMMEDIATELY go out and play the lotto.

The only reason people suggest pulling the engine is because if you are the type of person that likes to bolt everything to spec you should know that there is NO WAY you will fit a torque wrench anywhere NEAR most (if not all) of the bolts with the engine in the car.

If you aren't the type that gives up easily, AND you have access to a decent assortment of tools, AND you can handle 6-16 hours without your car, you'll be alright!

GOOD LUCK!

[orangeNblue]

spitalul2bad

I was thinking about doin a couple of the mods you did.....did you get good results from the spacer and mrev2?I was looking into getting the Cosworth but its so expensive for what it does.but i have been looking into a lot of the same pieces DC headers, HKS exhaust and a plenum of some sort....

[spitalul2bad]

@orangeNblue I'm sorry to not be able to help. I installed all the current mods at once. I spent the money on a shop to help me do all the installs in one day (and thanks to the headers being a b**** to install, it took two days), so when I got the car out of the shop, it had all my mods on.

So I can't say the MREV and the spacer are great or bad. Because thanks to a reflash ECU, flywheel, full exhaust and Injen intake the whole car changed the way it delivered its power, so I can't pinpoint the EXACT difference the MREV and spacer did. If I had done the mods one by one, then I could've felt the difference from the exact mods I've put on.

If you want to do a FULL N/A build and keep on doing it, get the Cosworth. It will be better in the long run. If you want to do a FULL forced induction build (turbo/twin turbo/supercharger..maybe), get the Kinetix plenum. Users on other forums (which I'm not allowed by moderators to link to) proved that with a good ECU dyno tune, it's way better than any other. However, if you plan on doing small mods, here and there (intake/exhaust), the spacer & mrev are fine choices, and good price/performance.

@gabezilla275I'm sorry, but I don't remember the size of the headers' bolts. They weren't anything ususual though, so you shouldn't have a problem. But remember that MisteenoMike said something I forgot: you need a GOOD and STOCKED toolbox! Extensions, wrenches, the lot! Changing the headers without the engine out is a time-consuming, cursing Nissan builders, wife killing, awful ordeal that will make you want to abandon the build. Just remember you were warned.

Also, the heat shield comes off fine. If you're doing cats and exhaust as well (you only mentioned headers), taking the gearbox off will prove a good move, giving you much needed access below the car. Just remember you need a friend to help you get it down safely. All of this can be seen in my build, in the photos.

Hope this all helps.

[gabezilla275]

yes this all helps a lot. I need to go tool shopping. I have only one set of metric sockets and 4 sets of standards I don;t feel like rounding any bolts