Hi, all. I just recently picked up an 03 5AT sedan with 158k miles on it. As I'm sure you all know, you just can't leave this thing stock, despite the high miles. I've been doing lots of research, but I don't know anything about cars, and I could really use some help.

For an intake, I think I'm set on a stillen + ztube. But I also wanna get a motordyne spacer. I'm pretty sure I'll go with one of the iso thermals, but I'm not sure if I should do the 5/16" or the 1/2". What kind of difference does that make? Also, what the hell is an aramid gasket? Should I get a iso thermal aramid gasket? (about half way down the page) And what about that MREV manifold? Is all of this worth it? And what about that 1/4" manifold spacer?

Now we come to exhaust. Why is M2 stuff so cheap? $100 for headers? Really? Is that stuff just a waste of time,or will it hold up? And how's the performance compared to higher quality stuff?

I'd like a dual cat back system. I've seen the stillen system, but that's way too much. What are my other options? Or should I not go with a full system? I've seen that some people have y pipes and test pipes and down pipes and all sorts of pipes. Is there some benefit to this? I don't even know what a test pipe is. Or a down pipe for that matter. The y pipe is pretty obvious. Do I need hi-flow cats? I'm not too worried about sound, but the M2 cat back system claims to be kinda quiet. Louder is always better, but if that's a good system, I couldn't care less for that price. Is it even worth it to start if I'm not gonna go all out and get a system from the headers back? Is it even worth it to do all of this to an engine with so many miles on it?

I think that's all the questions I have right now as far as air flow goes. Any and all help would be greatly appreciated. I wanna make this thing as awesome as some of the rides I've seen on this site. Well, minus FI. I'm not trying to kill myself. Thanks a bunch, guys.

 

^ send me your # via PM and I will help you with this stuff too.

 

I actually just sent you my number in the payment I sent you for the grounding kit. Thanks, dude!

 

To start off first from the intake to the exhaust...

Our cars haven't really been known to make any power from intakes. Basically you want to just get yourself a drop in filter (k&n) with a z-tube and a revup box.

But if you insist on getting an intake, its mainly going to be for sound. But I have a stillen shield with a JWT pop charger intake paired with my ztube.

In addition, you can have a spacer paired up with an intake. The spacer is just a spacer for the intake mainifold. I suggest you go with the Motordyne 5/16 spacer for that it yeilds the best gains overall throughout the power band. The 1/2 just gives a little more up top but someone can correct me if I am wrong but it does not yeild better gains overall throughout the power band as the 5/16th does.

Isothermal is only depended on where you are located. If you are in TX where it snows sometimes then it would prob be a good idea to get this. Look up at the Motordyne site to confirm.

The armid gasket is just a gasket that is thicker than OEM that sits under the lower manifold collector. If you get the ISO thermal one spacer 5/16th or 1/2 it should come with one.

Headers aren't going to do anything for our motors either.. unless you get some serious cam work done to the engine. OR purchase one of those long tube headers from PPE or whatever that company is thats on this intake/exhaust section. BUT mind you, if money is a factor, headers cost a butt load to install.

As for test pipes/highflow cats. <-- these replace the stock cats which I suggest you go with Motordyne ART pipes. A lot of memebers used these and would agree that this would be the best solution to replace stock cats bc unlike normal test pipes or high flow cats. ART pipes give lots of TQ and HP.

As for an exhaust system. If you want to go cheap. Just buy a true dual system, like those knock off HKS systems. I would not recommend it but thats only bc I like the name brand stuff.

 

I think I'm gonna have to stay away from headers and cats. Headers are just too much money, and cats... well, I need to pass emissions here in Californa. What a shame.

 

That doesn't eliminate HFC's(high flow cats), but if you put on test pipes you could always throw a catback on... Allowing you to pass emissions.

 

Hi-flow cats will pass the sniffer test in cali.

 

Also, my .02.

Before dumping money in aftermarket parts, I'd recommend taking the car in for a thorough tune-up. A little preventative maintenance will go a long way on such a high mileage car.

 

Im just curious but how does putting on a catback with test pipes help you pass emissions???


For all I know, a catback is just an exhaust system with no filters.

 

Please don't give out false information like this.

 

I think he means that I can throw the cats back on. Then after my smog test, I just put my test pipes on again.

 

lol, yeah i think he meant 'cat, back on' not ' catback on'

Pretty much all been said, if you want to keep emissions, go HFC if they pass down there.

5/16th iso thermal kit will give you a nice upgrade with set and forget being the order of the day. If you can save for the Motordyne stuff, i'd highly advise it, i did and now i have it, i'd totally do it again, very, very happy with it all


Tune should also be on your list, no one has complained about one yet.

 

I haven't seen any motordyne stuff that would fit on a sedan besides test pipes and a Y pipe. Is it possible to modify the shockwave to fit on my car? Maybe flip the pipe on the right over so that it follows the other pipe and comes out on the left side? But then I'd have to cut a huge hole out of my bumper to have enough room for the mufflers back there. Hmph.

 

I'll be honest, i can't recall if it will fit the sedan, but if you want an honest answer, call Motordyne and speak to Tony, he will tell you exactly what can and can't be done.