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Discussion Starter #1 (Edited)
Here is the information from the manufacturers that make this header for the MKIV Supra...

"XERD Stainless Steel headers are designed to achieve maximum horsepower and torque gains by providing the correct sized primary runners and placement of the collectors to even out the exhaust pulses. For best results we always recommend adding our exhaust systems to complete the headers and use an air/fuel controller for further tuning. All XERD headers are for off road use only and not to be used on public roads and highways. As of 10/01/03 all headers come with a lifetime limited warranty."


Here are some pictures of the XERD headers… ( These were coated first with WOTM new coating service!! )





A pic of the stock manifold




Most supra owners would agree that these are the best bang for the buck!! These headers give the typical NA motor 17+whp and can push even more when tuned with an AFC and an intake. These headers weigh in at 15lbs, where the stockers are roughly 25-30lbs depending on how much crap is in the cat that this header replaces.




Removal:

Disconnect the battery!

You must remove most of your intake piping to allow room to get the old headers out. You will not need to pull the distributor or the throttle body!!

Disconnect the (2) O2 sensors that are bolted on to the stock manifolds.

The stock manifolds are bolted to a cat, which is then bolted to the mid-pipe. I found it best to leave the cat and manifolds bolted together and remove it all as 1 piece.

There are (8) 14mm nuts that hold the manifold onto the engine head and (2) 14mm bolts that join the stock cat to the mid-pipe. Remove the (2) bolts first, making sure the rest of the exhaust line is supported so it doesn’t hit you in the head when you remove the bolts (yes, I did that!). These will be the hardest bolts to remove. Make sure to use a 6-point socket and a good wrench and lots of PB Blaster, or other type of solvent to help the bolts / nuts come loose. Using a large breaker bar is also a good thing too. Worst case, you will need to cut the bolts out, but be sure not to damage the stock mid-pipe.

Once those are removed, remove the (8) nuts for the manifolds. Now you can remove the manifold straight up out of the engine bay area. This will take a little effort, and you may need to bend the two manifold flanged towards each other.




Installation:


Replace the stock O2 gaskets. I used new Toyota gaskets, but I believe that XERD supplies you with gaskets as well.

Drop the XERD headers into the engine bay area. You will need to start one end of the headers, preferably the front side closest to the distributor, and thread the nut that is all the way in the front, under the distributor, on just a few threads. You may will then need to use a long pry bar and pry the (2) flanges away from each other to fit the other flange on the studs. Once the flanges are on the studs, push the headers in just a little bit, thread all the nuts on the studs, and then push the header all the way in. If you are having issues gettin the headers all the way to the head, try tightening all of the top bolts on the 2 flanges a little at a time. This will pull the header all the way in as well. Torque the header nuts to 29ft/lbs. Replace the (2) bolts and nuts that connect the collector on the headers to the mid-pipe. Do not re-use the stock bolts. You could, but why? It’s a miracle if you got them off without breaking or stripping them. Go pick up some grade 8 bolts about 1.5” long. I used some 9/16” flange bolts from Napa.

Now for the O2 sensors. If your stock O2 sensors have been replaced, then you can simply remove the flange and re-install the old O2 sensors into the XERD headers and be done. If you’re like me and still have the stock O2 sensors, the flanges are welded on and can not be removed. This means you must purchase (2) new O2 sensors. Here is what I did…

Since the stock O2 sensors are $130+ each, I chose a less expensive route. I picked up (2) new universal BOSCH O2 sensors, part # 12051 from Napa for $39.66 each. These do not have to proper connectors on the ends to snap into the stock wiring harness, and are a little short. I cut off the wiring and connectors off of the stock O2 sensors, and soldered them onto the new O2 sensors. This added more length to the wire, and allowed the new O2 sensors to plug into the vehicle harness and work properly. Put a little bit of “anti-seize” compound onto the O2 sensor threads, and screw them into the manifold. These should be torque down to 20-25ft/lbs.

Reconnect the battery

Now you can replace the intake tubing and anything else you removed and reconnect the battery.


Now, start your engine and let it idle for 20mins. This will allow the ECU to relearn the fuel curve since you have removed the primary cat.


Here is a sound clip of the XERD headers on my supra, with the TRD cat-back exhaust and stock mid-pipe.

Outside of the car 4.2mb
Inside of the car 5mb


I am trying to find an audio clip of before the XERD headers. I will update this post when I find it.


Any questions…send me an email. If you have more information of if my info is not accurate, let me know and I will update this main post.
 

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Did you get your car dynoed? Im planning a NA setup similar to yours and was wondering what whp im shooting at.
 

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Discussion Starter #3
I am trying to get my car in for alignment and a base-line dyno with the above mods. I don't have a stock base to compare to, but it will give some people a good idea what to expect.

My S-AFC II is installed, just not tuned or active right now. Hopefully if I can get some dyno time cheap, I can tune that as well to show what can be gained from adding the AFC and the headers.
 

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Discussion Starter #4
Updated the pics for you guys.

Also, MVP is now selling these headers too!!! XERD seems to be totally shutdown.
 

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Hardtopper
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Great post, mind if I add this to the archives on club na-t? Trying to save as many tutorials as possible for you guys :)
 

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Discussion Starter #6
no prob
 
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