RKSport 3.8 Headers Review/Install Guide

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This review was originally posted by Mike Wenski.



To do before the install:

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1. Have thicker flanges welded onto the flanges of the headers and the Y-pipe where they come together. The reason the headers leak at these flanges is because they are so thin that they warp when tightened. Having an exhaust shop do this will strengthen them and prevent warpage.</font>
2. If you don't like paper gaskets, buy a set of stock manifold gaskets (they are a very strong looking metal type consisting of 3 thin metal sheets and a larger metal piece with some sort of a lip on it (real descriptive, isn't it?). For the header to Y-pipe connection, take the paper gaskets that come with the kit to an exhaust shop and ask them if they have any metal gaskets of the same dimensions.</font>
3. Set aside a weekend, as this whole job takes time.</font>
4. Soak all the bolts that will be removed with a penatrating oil of some sort (WD-40, etc.) the night before (please let it cool first so that you don't start a fire).</font>
5. Make sure you have the right tools. You'll need a 3/8" drive ratchet, various extensions, 10 mm, 8 mm, and 13 mm sockets, an offset closed end 13 mm wrench (makes getting at the manifold bolts much easier), U-joints, a torque wrench, a hack saw (or a sawzall or cutting torch) a small screw driver (useful for pushing those tabs in on the O2 sensor connectors) and some drop lights or flashlights.</font>
6. Get a 13 mm bolt and a nut for the EGR adapter tube. The header port isn't threaded, so you will need a bolt that is longer than the original one and a nut to keep the EGR adapter tube sealed.</font>

Removal of old exhaust manifolds:

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1. Disconnect the negative battery terminal.</font>
2. Driver's side: remove the EGR adapter from the manifold (do NOT bend it out of the way, as this can cause a crack in the tube (see cons section) and don't grip it too tightly when you pull it out).</font>
3. Driver's side: remove the bolt holding the oil dipstick tube, then remove the oil dipstick and tube.</font>
4. Unfasten the nuts holding the heat shields on, then remove the heat shields. I had trouble doing this, as it took lots of wiggling and I even had to grind the big one on the passanger side in half to get it off.</font>
5. Safely raise the car (jack stands or a lift).</font>
6. If you aren't upgrading the cat, cut the y-pipe off about a half to one inch from the cat inlet. If you are upgrading the cat, cut off the pipe somewhere after the cat, and have the new cat welded onto the RKSport Y-pipe.</font>
7. Loosen and remove the bolts holding the Y-pipe to the manifold. I broke one during my install, but it didn't matter much to me because I wasn't planning on reusing the stock exhaust anytime soon.</font>
8. Unclip the O2 sensor connectors. Some may be easier to reach from above, good luck, this was another PITA part.</font>
9. Disconnect the plug wires and label them.</font>
10. Remove the exhaust manifold retaining bolts/nuts. A ratcheting wrench is really handy, as the sockets and ratchets are a tight fit. (For the driver's side, you may find it much easier to reach them if you remove the heat shield for the starter. Some bolts are easier to reach from above, some from below.)</font>
11. Once all the bolts are off, remove the manifolds (careful about the O2 sensors!) and manifold gaskets, clean the mating surfaces.</font>

Install of new headers:

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1. Switch the O2 sensors from the manifolds to the headers. I used a regular old open wrench to get them out, but you can use an O2 socket, I won't mind [img]smile.gif[/img] . When you put them in the headers, use some electrically conducting antisieze lube (GM p/n 5613695) on the threads. Tighten to 30 ft-lbs. (according to Chilton's repair manual).</font>
2. If using the paper gaskets that come with the headers, soak them in some water to make them expand. This helps them fill in the irregularities (heard about this in September's issue of Car Craft in the "Stop header leaks for good" article).</font>
3. The driver's side header will not fit into the car right now. It won't clear the steering. You can either disconnect the motor mounts and jack the engine up a few inches (right way to do it) or shave about an inch or so off the front stud (the way I did it). If you chose to shorten the front stud, put a nut on it before you begin cutting, so if any threads are damaged the nut being removed will "fix" them.</font>
4. Put the headers on with the gaskets. If you are using any sealants apply them first according to the instructions on the package. (Note: there is a right way and a wrong way for the gaskets to go on; i.e. the bolt holes will not line up and have the ports line up with the headers if you put the gaskets on wrong, you have to flip/rotate the gaskets until they do match up.)</font>
5. Torque the nuts and bolts to 22 ft-lbs. (Good luck with the passenger side ones!)</font>
6. Connect the electrical connectors for the O2 sensors. (Another PITA!)</font>
7. Reinstall the starter heat shield.</font>
8. Reconnect the plug wires.</font>
9. Install the Y-pipe and the gaskets. Again, if you are using any sealants, now is the time to apply them.</font>
10. Reinstall the dipstick tube. To find the hole to the crank case the easiest, have a buddy hold the dipstick tube in place by holding the mounting bracket to where it is supposed to bolt to (sorry for the lack of clarity here) and get underneath and feel for a small hole in the block near where the tube is.</font>
11. Reconnect the EGR adapter tube to the headers. Remember, the adapter in the headers doesn't have threads, so either tap them yourself, or use a nut and bolt.</font>
12. Reconnect the battery cables.</font>
13. To prevent exhaust leaks, start the car and let it warm up the exhaust system. Tighten all the bolts, then turn it off and let the vehicle cool. Retighten the bolts, then repeat this step another 4 times.</font>
14. Enjoy your drive to the muffler shop with open headers. [img]smile.gif[/img]</font>
15. Once at the muffler shop, tell them to weld the Y-pipe to the cat (if you upgraded the cat, you'll have to tell them something slightly different). NOTE: if you have a 98+ F-body, you will only have three sensors, one in each manifold and one after the cat. 96-97s have an "extra" O2 sensor in the Y-pipe before the cat. If you have a 98+ you will need to get a pipe plug and put it in the O2 fitting, or you can put a spark plug in there too.</font>
16. Come home, retighten all the bolts.</font>
17. Check the bolts every so often: after the first week, after the first 100 miles, then again at 250, then 500, then 1000, then every oil change (or not, depends on how much you want to avoid leaks). If they don't need to be tightened anymore after the 1000 mile mark, chances are that the gaskets aren't going to shrink anymore.</font>

Pros for this modification:

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• Gotta love that sound!</font>
• More horsepower (about the same gains as a catback exhaust).</font>
• A vital step if you plan on adding a major power adder (blower, N2O, etc.).</font>
• Cleaner engine bay and easy access to plugs and wires.</font>
• Bragging rights! [img]smile.gif[/img]</font>
• One dyno sheet (taken right after the install was performed (not my car) without letting the computer readjust the fuel trim) showed gains of 5-7 hp and 5-7 ft-lbs. at all points in the rpm range. That means a LOT more area under the torque curve for quicker 1/4 mile times.</font>

Cons for this modification:

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• Expensive if you break something, like an EGR tube ($60 part and I paid another $100 in labor to have the whole assembly replaced--opps!).</font>
• Pain in the butt install (but worth it, especially now that there is a how-to floating about the net).</font>
• Not much bang for the buck (5-7 hp at peak) if you only look at peak numbers.</font>
• Leaks if you aren't lucky.</font>

Comments:
My headers blew those paper gaskets out within 15 minutes of driving because the header to Y-pipe flanges warped so badly. The Y-pipe also rattled against the Tranny crossmember because of the way it was shaped. I had my local exhaust shop weld thicker flanges onto the Y-pipe and the header flanges and they reshaped the Y-pipe so it wouldn't hit the frame or the tranny for $100. They also used some metal gaskets and I have had no leaks since then (about 6 months). Also, the sound was best when the headers were open, and when they were leaking at the Y-pipe flanges (it sounded like it was snarling). It would sound much better with a "real" cat back as my Meanstreak muffler sounds similiar to stock and the custom bent pipe probably isn't much better than stock.

[ March 06, 2004, 01:09 PM: Message edited by: Stefan ]