Headers

Well, I never thought I'd do headers, but I had to do some major engine work and I decided to make things altogether as simple as possible. The old exhaust stuff is rather bulky and annoying. It has very heavy manifolds, an obstructive crossover pipe, tons of heat shields, and in very prone to rattling in it's old years. Though effective, there is always room for improvement.

Please see this page and this page fore some explanations of problems I had/am having with the headers

Unfortuneately, like many of the mods I have done, I cannot accurately tell you how much the headers have helped HP wise. Reason being is as I rebuilt the engine, I added an upgraded CAM to my engine as well. The car feels plenty more powerful, but how much is due to the headers I do not know. I can say they look great, they stay clean, and they are much easier to install/remove than the stock application (if necessary). Headers are just another step to creating a high performance engine. Some mods don't do you much good unless you improve upon other systems on the car. Headers are a good step for an NA as they maximize air flow beyond the engine, allowing cams, intake, etc to maximize their input. Headers improve exhaust flow by channeling each exhaust port independently until their flow is combined into a larger tube at a distant place at a much lower angle. The stock exhaust manifolds jam all the exhaust at a right angle right into the same chamber...though they do flow well where the two manifolds meet down to the catalytic converter, much can be done to get the exhaust away from the heads with freer flow. The stock manifolds also get really really hot and stay really really hot for a long time.

I got my headers from Motorsport Auto. I understand that MSDS actually makes the headers. I paid a bit extra to have them JetHot coated ($50 cheaper if you do it when you buy the headers rather than later), which is the wise way to purchase the headers...honestly, minutes after stopping the car the header pipes are already cool to the touch. Jet hots look more like this (negative image of pic above...I should've taken pictures before) :

I would recommend MSDS after researching the alternatives. Pacesetter (Monza) only claim a 5 HP gain and I have heard they are difficult to install. The worst part of the MSDS install was the EGR tube. The connector stick up to far, so you have to cut out about a 1/2-3/4" section and reweld it. By the way, if you order from Motorsport Auto, don't forget to tell them you are part of a ZClub so you can get 10% off your order. Quite a good discount if you're buying JetHot coated headers.

The MSDS were fairly easy to install. Once you have the old exhaust off, you can slip the collector tubes up through the bottom of the engine and bolt them on. I had a little trouble fitting them onto the studs, which required a little bit of filing around the stud holes on the headers; but all in all, not too bad. I replaced all my studs, washers, and nuts, and used some of the old washers for the collector to Y-Pipe Bolts. Installation is simple enough that I do not have to detail it. I will say that some of the bolts on the manifold were difficult to get to. One or two I had to give 1/12 turns, flip the open-end wrench (12mm) and give it another 1/12 turn until I had them down all the way.

If you have the engine out of your car, put the headers on before you put the engine back in...wish I had known that. I will say, you've gotta pic yourself up one of these 12mm/13mm offset Craftsman socketed wrenches (as seen below)...it'll save you a headache if you install the headers with the engine in. The oil filter, by the way, will be tough from now on, but get K&N oil filters with the built-in nut on the end and it'll be no problem. 4 of the 6 collector to Y-Pipe bolts are pretty tough to get to if you don't have a car lift :), but you'll manage.

The OEM Nissan gaskets have worked fine for some people, but I would suggest aftermarket Composite gaskets...the OEM Manifold gaskets are fine, but the collector to Y-Pipe gaskets (in my case) don't do the trick...I had plenty of leaks at first there. The Y-Pipe to Catalytic converter gasket was worse. The OEM is a thin steel gasket...didn't seal at all. I used a doubled-up aftermarket composite gasket there. MSDS should send you the Collector to Y-Pipe gaskets and the manifold gaskets, just as you'll need them. But you'll have to pic up the caty gasket yourself. Napa carries it...don't try elsewhere (at least not Checker, Autozone, or PepBoys). Motorsport Auto says they'll send all the right gaskets, yet I know they don't send you the caty gasket (they told me). They also said NOT to use OEM gaskets for headers...they specifically mention you should use aftermarket gaskets intended for use on the headers.

(From left to right: Y-Pipe to Cat, Driver's Side Collector to Y-Pipe, SlipPipe on PassSide of Y-Pipe)