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Discussion Starter #1 (Edited)
I've noticed a lot of new people come in here asking the same questions over and over again, either because the questions have never been answered succinctly enough or because the new guy doesn't know how to use the search function. I was guilty of this myself when I was a noob, but I thought it would be nice to write up a good basic overview of things to consider when beginning to mod a car, whether you're a beginner at performance modding in general or just with this specific car, as well as posting some of the most common answers to some of the most common questions.

I AM BY NO MEANS A PROFESSIONAL NOR DO I HAVE TONS OF EXPERIENCE. Anyone who thinks I've omitted something or gotten something egregiously wrong, PLEASE feel free to correct me or add whatever you think would help. Opinions based on personal experience are welcome too!

One of the most basic questions I had when I got here was "what is a good plan?" Where should you start, what are good simple mods that you can do yourself for a reasonable price that will get you the biggest power gain? There is no correct answer to this question, rather it poses another question itself.

The first thing you should think about when modding your car is "what do I want this car to do?" Do you want a fire breathing, four digit horsepower beast that burns ethanol and runs a .2 in the quarter? Do you want a simple daily driver that has a little extra pep? Or like most of us here, do you just want enough of a car to never get bored with it?

I'll cover all of these briefly but I'm going to devote the majority of my attention to the middle ground: building a car that is fast, track ready, and fun to drive, but that will still provide you with a comfortable drive to work and years of reliable driving without breaking the bank.

As with any hobby, or really anything in life/nature/reality, making the car of your dreams is going to involve a lot of compromise. To paraphrase Mark LaRue, (firearms manufacturer,) "You can have it done cheaply, quickly, or correctly. Pick any two." This is no less true in the automotive world. The trade-offs you have to be aware of in this case abound. Everything from easy to grasp ideas like more horsepower = shorter engine life to complicated topics regarding effective RPM ranges for increased performance will affect your decisions. Making a 24,000 dollar sports coupe perform like a 500,000 dollar exotic may in fact be possible, but you're not going to like the cost or even the result if you intend on driving this car every day. This being said, understand what you really want out of your car and how that corresponds to what you're willing to pay for/deal with as the end result. Let's cover some basic things to expect when modding your car.

Modest Daily Driver

If you're looking at the "Eclipse Performance" section of this website, chances are you either are about to get "the bug" or you already have it. "The bug" is a common affliction. It typically affects males between the ages of 2 and 80, but can be contracted by anyone, regardless of age or gender. Basically it's that primal instinct that whatever piece of machinery or neat new toy you have, it's just not good enough in its stock form, or even if it is you just really want to take it apart and see how it works. In this particular case however, I'm assuming you have a good level of self control and are just looking for something fun to occupy your time and make your daily commute a little more exciting.

If this is the case, the kinds of mods you'll be looking into are (for the most part) cheap and modest in their results. Things such as a Cold Air Intake (CAI) or a short throw shifter assembly are good mods to get you started. They are cheap, easy to install, (you should be able to do it yourself or with the help of a mechanically inclined friend in an afternoon provided you have the right tools,) and if done properly should in no way adversely effect the performance of your car. In the case of our particular car, one of the first mods people tend to go with is lowering the car by an inch or two, in the hopes of eliminating that God awful wheel gap that Mitsubishi stuck us with. This is where you're going to run into your first big compromises:

1) Warranty: Generally speaking, performance parts like these should NOT void your warranty. Furthermore if your dealership says they have, the burden of proof that the aftermarket part adversely affected the warranty claim you've brought your car in for is on the dealership. THIS BEING SAID, if your dealership is less than friendly, or (as is often the case,) they are more concerned with making a profit than with stimulating the aftermarket community for our cars, they will tell you your warranty has been voided without providing you with this proof. Yeah, you can take them to court, sure, but rest assured your court costs are going to be a good deal more in most cases than just ponying up for the repair work. This topic has been covered in great detail, and the best place to get quality information regarding warranties and their legal implications is the SEMA website.

I saw someone post a link to more specific information in another thread but couldn't find it when I looked, could someone repost it here?

2) Performance & looks vs. driveability: A short throw shifter will make your shifts faster and more precise. It also means you have to assume a slightly more aggressive posture while driving your car. A cold air intake will increase the amount of airflow to your engine, providing you with a reasonable increase in horsepower and torque, as well as a wonderful sound both when starting the car and at high RPM's. It also involves the relocation of your Mass Air Flow sensor, which could potentially (depending on instillation and the type of CAI) cause your Service Engine Soon light to engage. Additionally, those of us who are tragically uncool might not like the new sound or the fact that in extremely cold weather you might have a rough idle when you first start your engine. The biggest compromise here will be found with lowering springs; they will marginally improve the handling of your car by lowering its center of gravity as well as providing you with a (slightly) firmer suspension. On the down side, since the springs are being placed on your stock suspension, which is designed specifically for your stock springs, the struts are likely to wear that much faster and may need to be replaced long before their original life expectancy.

All this is par for the course when attempting to make your car do things it was never designed for. The question you have to ask yourself is "is this what I really want?" Is it worth the gain in performance? In cases such as these, I would venture to say by all means it is worth the benefits, because the down sides are so small. Most people attempting mods as simple as these will never look back or be disappointed. Even that SES light issue can usually be resolved by disconnecting your battery for a few minutes.

The best part about mods like these is that they are things you can do yourself, even if you've never worked on a car before in your life. Having the right tools IS ESSENTIAL. Having an experienced friend to guide you is no less. However if you are the one who got your hands dirty and did the work, not only will you have learned a lot about the way your car actually works, you'll feel a certain satisfaction that you just wouldn't have if you'd paid someone else to do it. Every time you hear that whine from the CAI at high RPM's, every time you see your car sitting pretty and lower, the way it should have been made, you'll feel proud that you are the one who did that.
 

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Discussion Starter #2
Drag Strip Monster/Dyno Queen

I'm going to glance over this section because the sad reality is that without being filthy rich, you're probably never going to make a 1400 horsepower 7 second car out of our 3700lb FWD 4th Gens. If you've got your heart set on some silly power though, consider the following: This will be expensive in every way. The work itself might be within your budget, if you've got a good chunk of change lying around yeah you can get a custom turbo setup, maybe even get everything toughened up enough to support that kind of power. The real problem begins when you actually try to drive the car. My aunt used to have a Ferrari F355. She raced it at Summit Point Raceway in WV, and after a good solid weekend of racing she would have to replace not only her brake pads, but her disks as well. It was costing her nearly 10,000 dollars a weekend to race that car. She had a friend who raced a Ferrari Enzo. Replacing his brake rotors cost him 10,000 dollars per rotor. These are obviously not cheap cars but with exotic performance comes exotic price tags, regardless of what kind of car you have. A 900whp time attack Evo is not an uncommon sight, they're all over all the tuner magazines these days, but if you tracked one you'd have to be prepared to replace your driveshaft after every race. This from what is considered in the tuner world to be the ultimate poor mans performance car.

The other thing to consider is how practical is this goal? Are you gonna cart this car to the track on a trailer? You sure as hell won't want to drive it on the road. A stage 4 clutch takes time to heat up, and so do carbon-ceramic brakes. They'll be a pain in the ass to drive to work with unless your driveway is a mile long circut you can warm the car up on. Also the engine itself will be a whole new animal. Having a turbo the size of your head looks good and dynos better but how long are you willing to wait for that power when you step on the throttle? Installing really aggressive cams that advance your ignition by a billion degrees will provide you with mad stupid power but only at very specific RPM's. Are you willing to floor it everywhere you go, and hold your RPM's between 5000 and 5500 the whole way? That's fine for a track, but unreasonable and impractical on the road.

If you have your heart set on doing something like this good luck, and by all means don't let me talk you out of it. Take plenty of pictures and show them to me because I'd love to see it, but don't expect to be driving this car long, or anywhere but a track.
 
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Discussion Starter #3
Weekend Warrior

This is what the majority of people seem to be looking for, and what I'm attempting myself. It covers a very broad spectrum but generally speaking this is the case of "the bug" I referred to earlier. You got this great car, and it was fast, but you just had this undefinable itch. Undefinable until you saw that cold air intake, that is. So you put the CAI in and then you saw the cat-back exhaust. And then you saw the coil over suspension. And before long you're just tinkering with your car more and more in the hopes that someday you'll be content with it but you never will because what you're really looking for is one of two things: beat that slightly more expensive car from one stoplight to the next, regardless of what's in it, or (more likely,) you just love tinkering with things and you wouldn't buy a Ferrari if you could because there's just not enough you can do to make it better.

By now I'm going to assume you understand the risks of what you're doing, and I'm just going to give you what I consider to be a reasonable, well structured plan for improving your car that will take enough time to be fun, generate enough power to make you smile, and be cost effective enough to keep you eating and living under a roof.

Your starting point should be suspension. Wanting a lot of power is understandable but that power will mean nothing without a means for getting it to the ground. If you're driving a 4G Eclipse, you are going to have to learn to live with front wheel drive. Especially if you have a GT, you will have noticed that it is very easy to spin the tires. Spinning the tires looks cool but it's a waste of tire and a waste of power. Supercharging your car without any supporting mods is just going to make your tires spin faster, and it won't make you drive any faster.

Sway Bar, Tires and Coil Springs

This should be step one. An Anti-Sway Bar is already installed on your car. Actually two are. The rear one in particular is too thin and not tight enough for my tastes. Replacing this with a stiffer, adjustable sway bar will make your car handle more neutrally. Some say this takes a lot of getting used to, but personally I thought the car felt much more natural after installing this mod. Because it is tightening up the rear end of the car, it corrects the large amount of inherent understeer in our cars and makes the car point where you want it to more accurately.

Tires are probably the most important mod you can do on your car. A good, sticky set of tires will vastly improve your handling and you'll be surprised at how big the difference is. The stock tires are supposed to perform reasonably in all conditions. What this really means is that they perform excellently in none. Get something too performance oriented, and you'll have to change your tires every couple thousand miles, won't be able to drive in the rain or snow, and will basically either need another car or another set of wheels in order for the car to be cost effective and practical. I myself kept the stock tires on stock rims and got much stickier performance oriented tires on aftermarket wheels so I can switch them at will. This is a good compromise I think, but there are plenty of good quality performance all-weather tires too. They won't be as impressive but are still worth the investment.

Coil Springs will lower your center of gravity and stiffen up your suspension. This will help in the handling department and will make your car look much better, BUT like I said before it has an adverse effect on your struts. My advice: if you're serious about suspension, skip this step and get coilovers. If you're okay with replacing your struts five or ten years down the road, (stock you probably would never have to replace them,) the coil springs will do a good intermediate job.

Coil Overs, Bushings, and Braces

Coil Over Suspension, i.e. the whole mcpherson strut including spring, is a much more comprehensive (and expensive) alternative to the coil springs themselves. It is, however, easier to install, and will provide you with MUCH more versatility in your suspension setup. Coil overs are typically adjustable for ride height, damping force, (stiffness,) and even camber. The gains here will be much more pronounced than the coil springs. REMEMBER: If you are getting coil overs, you are signing on for a stiffer ride. Yeah you might be able to adjust them for a stock feeling damping force but then what's the point in spending all that money on suspension parts? Good handling is characterized by the stiffness of the car. A stiffer car handles better. If you don't like that, keep it stock.

Replacing your stock suspension bushings (which are made of soft rubber in order to ensure the smoothest possible ride) with polyurethane will also increase this stiffness. You will feel the bumps more, and if you don't grease them up well enough you'll hear them squeak too. It is still worth it if you ask me. These are not the easiest things in the world to install but Slippercream wrote a great how to in the how to section on installing those bushings.

There are currently two frontal braces that are available for our cars. Both Tanabe and Cusco make a strut tower brace, and Tanabe makes an underbrace as well. These are both geared toward stiffening up the vehicle in a horizontal direction, to reduce chassis flex. This is good for handling as well and won't really translate much to a stiffer ride, at least not nearly so much as some of the other mods. They are also both VERY easy to install, as in 20 minutes tops for the strut tower brace and not much more for the underbrace.

Some people say the strut tower brace is not essential. I rather like it but that's mostly because its pretty and inexpensive. If there's a real difference in performance I'd have to track my car more to notice. All in all though, since you can have it on while the stock one is on as well, I'd say more material = more stiffness and that just makes sense to me. The underbrace hangs a little low, so people who live in areas with really awful roads or unreasonable speed bumps might be weary, especially if your ride is lowered. My car is lowered just a hair under 2 inches and I haven't found a speed bump I can't manage yet, but that doesn't mean it's not possible.

Limited Slip Differential

This is a huge job, and not cheap. However it will absolutely provide an increase in traction in every respect. You'll corner better, you'll launch better, and you'll get out of snowy intersections better. For a good idea of what a differential does for your car, check out HowStuffWorks.com

Differentials in general:
Howstuffworks "How Differentials Work"

Torque Sensing (Torsen) type diffs:
Howstuffworks "Locking and Torsen"

OKAY. Now that you've got a good suspension setup, you can start working on power! The fun stuff!
 
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Discussion Starter #4 (Edited)
More Power!

A common misconception is that more horsepower = better car. As I hope I've already made clear, very little in the automotive world is so simple. You need to know what you want the car to do, and plan your horsepower and torque goals accordingly. Furthermore, you have to balance those goals with reality; i.e. what the car is capable of.

When you're chugging along at 120 miles per hour, that's the horsepower you're feeling. When you're peeling out from a stoplight and you're being pressed back into your seat, that's not horsepower you're feeling, that's torque. Horsepower is the motors ability to do work. Torque is the amount of work being done.

Another concept you must be familiar with is how your engine speed translates to these two variables. For example, a Ferrari 599 GTB makes 620 horsepower at 7600 RPM. That's a lot of power, right? However because it's a very performance oriented car, if you drive it like a pansy and never get your RPM's above 3000, you're going to be very disappointed with your expensive car's performance, or lack thereof. Other, more track-oriented cars, will be even worse in this regard. You may be able to make 800 lb-ft of torque and 900 horsepower but under 5000 rpm you're getting less than half of that! The reason for this comes down mostly to cam timing. I'll explain this further soon, but for those of you who are less than sure how an engine works here's a basic explanation.

Think of your engine as an air pump. Fuel is important, yeah, but it won't burn unless there is enough oxygen in your engine to allow it to. Everything you do to an engine that makes it more powerful probably has something to do with allowing it to process more air, faster. The air is going to go through a number of steps before it even gets to your engine, which I'll outline briefly.

Intake: This is where the air comes in. At this point it is coldest, thus making it most dense. This is good, and your goal should be to keep it cold and dense. Denser air means more of it can fit in your engine.

Throttle Body: This is where your car translates the pressure you're applying to the pedal into how much air is let into the engine. Again, keeping this part as cool as possible, along with increasing its size and efficiency, will increase the amount of air that is processed through your engine.

Intake Plenum: A plenum is defined as a chamber in which a vacuum is contained. In this case, the chamber will only be a vacuum for one fourth of each cycle of your engine. I'll get more into that when we get to the engine itself, but the intake plenum is where air is stored and directed to the intake manifold while the engine prepares to accept it. The same rules about thermal efficiency apply here, however size must be more carefully considered. While the engine is closed and not allowing more air in, and the throttle body is allowing more air in, the air will bounce off the back of the intake plenum and return along the path it followed until it encounters a higher pressure area, i.e. the new air coming in from the throttle body. Under natural aspiration this is rarely an issue but if you have a turbocharged or supercharged car, increasing the volume or size of your intake plenum without planning it properly can cause there to be a vacuum at the wrong time, asphyxiating your engine when it needs air most. If the engine opens its valves to let the air in, and the air has bounced back to the throttle body, there's nothing for it to feed the combustion cycle and you stall out.

Intake Manifold: This is where the air is directed into each cylinder of the engine. The intake manifold can be ported (widened) and polished to make more air travel more quickly. Here also, cooler air = denser air. At this point your air has traveled through a lot of hot piping, and has been compressed a little, so it's going to be much hotter than it was when you first got it. Since this is your last step before the engine accepts the air, it is also your last chance to cool it.

Valve Train: This is where the engine prevents or allows the air to flow into and out of the cylinders. Your valves are controlled by your cam or cams, and will be open at very carefully determined times, for very carefully determined durations, and will open to very carefully determined heights. I'll cover this more when I get into the cams themselves. The primary job of your valves is to ensure that air is kept in/out when it's supposed to be and is allowed in/out when it's supposed to be.

Cylinder Head: This is where the action happens. Your engine is called a four stroke engine, because each cycle consists of two revolutions of the crank, or four directional changes for the piston. The piston will have two primary positions that concern us, those being Top Dead Center (TDC) and Bottom Dead Center (BDC.) As you might imagine, these are the farthest points the piston will travel to in each direction. When the piston is at TDC and moving downwards for the first time, it is beginning the intake stroke. At this point the valves are open, and air is flowing into the cylinder. As the volume of your cylinder is increasing at this time, there is a low pressure area being created up above, in the intake plenum. This is when it becomes a vacuum. Once the piston reaches BDC for the first time the intake stroke ends, the valves close and the compression stroke begins. The piston travels upwards, and the air has no place to go. It is compressed, (increasing its kinetic energy,) and fuel is introduced.

Once the piston reaches TDC for the second time, the ignition or combustion stroke begins. The spark plug ignites the fuel/compressed air mixture, and it burns. It is called combustion and not explosion for a reason: explosions are unpredictable and uncontrolled. You do not want an explosive force to be battering your pistons around. The reason for the movement in this case is the thermal expansion caused by the burning of the air/fuel mixture. As energy is released, it pushes the piston back down to BDC, where the combustion stroke ends and the exhaust stroke begins. Your exhaust valves open at this point, and as the piston rises back up, it pushes all the waste/unburned air back out of the cylinder.

Valve Train (again): As you might imagine, there are separate valves for intake and exhaust, since they're traveling to different places. Your fouled up, mostly burned exhaust air is now going to leave the cylinder through your exhaust valves. At this point it is being pushed out by the piston, but it could always use a little extra help, which is where your...

Exhaust Manifold: comes in. Your exhaust manifold is going to be shaped specifically to create a low pressure area between the exhaust pipes and the exhaust valves. This way, the exhaust air is sucked out more quickly. This is called scavenging. Heat can also be controlled here, because the hotter the air, the more space it takes up. If the air is taking up less space, more of it can get out of the engine, and your scavenging effect is more efficient.

Headers: This is where the exhaust is piped from the top of the engine where it left, to the bottom of the car where it's going. Scavenging occurs here as well, and the same rules apply. More room for the exhaust and cooler exhaust temperatures will both improve the performance of your engine.

Catalytic Converter: This is some hippie bullshit that someone decided they should make a law about. It's basically a section of the exhaust that works like a filter and sucks out all the things that are bad for the atmosphere. This has the adverse effect of slowing your exhaust rate drastically and creating back pressure, which you don't want. Think of it as a collar that is choking the crap out of your car. Unfortunately they are required by law on most modern cars. However, the aftermarket has come to our rescue by providing us with high performance models that restrict your airflow much less and still get the job done to legal standards.

My concept of how these actually work is limited at best. If anyone wants to expand on this please feel free!

Exhaust Pipe/Muffler: This is the last section of your air pump. All the exhaust pipe is is a path for the exhaust to travel so it doesn't come out in your face. The muffler is meant to (you guessed it) muffle all the noise from your engine. Again, more is better for the most part, and adding another half inch in diameter to your exhaust piping, or adding a less restrictive muffler (or no muffler at all) will aid your headers and exhaust manifold in effectively scavenging the exhaust from the engine.
 

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Discussion Starter #5
So what do I do now?

If you're looking for a decent increase in power that will make your car sound cool and bring a smile to your face, this is where you can stop. Improving that process I explained above without going into any of the more complicated aspects is possible and will deliver anywhere from 10-70 horsepower. That can be done with the following, in order from intake to exhaust:

Cold air intake

Reduces the amount of maze-like tubing the air has to go through to get to the throttle body. Also provides the coolest possible air from the front of the car. Very easy install, little to no adverse effect.

Ported throttle body

Allows more air to pass through the throttle body when the throttle is open. Easy install if you got one aftermarket, only adverse effect is currently being theorized about. Safer idea might be to port it yourself but that's going to be a bigger job.

Anyone who wants to expound/shed some more light on this topic, please feel free.

Thermobaric throttle body spacer (gasket)

Helps keep temperature of the throttle body itself lower than stock. No install issues that I'm aware of, shouldn't be any harder than swapping out the throttle body.

Ported and polished intake manifold

Improves airflow from the plenum to the cylinders. The mechanically inclined can do this themselves but I would recommend if you've never done it before, get help whether it's in the form of a trusted mechanic buddy or a good machine shop.

Thermobaric intake manifold spacer (gasket)

Similar to the throttle body spacer, keeps intake manifold temperature down. There have been install issues with one product that may or may not have been hammered out by the time of this writing. I haven't gotten a chance to install mine yet.

Again, anyone want to clarify for me? Thanks!

Performance headers

Increases scavenging effect, provides less restrictive path for exhaust flow. Install ranges from mild to difficult depending on the type of headers. This will be covered in greater detail in another thread.

High-flow catalytic converter

Reduces the amount of crap your exhaust has to fight its way through. If done at the same time as exhaust, the install shouldn't be too bad. Might require welding depending on the type of exhaust.

Cat-back exhaust/performance muffler

Provides more room and smoother path for exhaust to flow, also when combined with all these other things gives your car a wicked sound. Install is typically not too difficult, may require welding depending on the type of exhaust.

The items in bold are the most basic ones. That should be step one for anybody modding their car to make more power. In its stock configuration, your car is being choked by all the factory comfort and emissions oriented components. Replace them with a freer flowing set and everything else becomes easier.

Other important things to consider are items that will improve the transfer of torque from your engine to your wheels. When you open the throttle of a powerful engine, it naturally wants to move before the torque can be transferred to the pavement because your 3700lb car is sitting on top of it. Following the path of least resistance, the engine will move in its mounts, which causes you to lose a small amount of oh-so-desirable torque. This can also cause wheel-hop, which costs you in the traction department. Thankfully there are ways to fix this too, like the following:

Engine Torque Damper

This is a device that braces your engine with a stiff hydrolic arm that connects on one end to the engine itself and on the other to the chassis. It is adjustable for damping force and can provide only a little more stiffness, or a whole lot, depending on your preference. If you apply the tighter settings, you will notice a small amount of engine vibration transferred to your chassis. The install is very simple. Just don't lose any bolts in your engine like I did.

Polyurethane Motor Mounts

Following the same train of thought as the polyurethane suspension bushings, this is using a more ridged material in place of the comfort-minded rubber bushings in your motor mounts. These, like the engine torque damper, can increase the amount of engine vibration felt from inside the car. These are similar to the suspension bushings in difficulty. The hard part is really just getting the old ones out and pressing the new ones in. Again, reference Slippercream's great How To on suspension bushings for more information.

So based on that, here is a...

Reasonable Plan For A Fast, Fun, Reliable Car

Remember with the intake end, start at the front and work your way back, and with the exhaust end, start at the back and work your way forward. This will give you the most bang for your buck. Big headers feeding restrictive exhaust doesn't make much of a difference at all.

(in my recommended chronological order)

Performance Tires, Anti Sway Bar, Coil Over Suspension, Polyurethane Suspension Bushings (if for no other reason than they'll be easier to get to if you're already doing coilovers.)

Cold Air Intake, Headers, Exhaust (if you're doing a high flow cat at all, now is the time since everything's already off.)

Engine Torque Damper, Polyurethane Motor Mounts, additional suspension items as you see fit (strut tower bar, underbrace, etc.)

Ported Throttle Body, Throttle Body Spacer, Intake Manifold Spacer, Ported and Polished Intake Manifold (if you're feeling up to it.)

This should put you in a pretty good place overall, you'll be happy with your car (for a while) and unless you're getting back from a deployment like me and have gobs of cash and free time, it will take you a good while to get all this done.

One thing I haven't touched on much is wheels. Lightweight, sturdy wheels can improve your vehicle's performance too! Every pound of rotating mass translates to something like four pounds when it is in motion. Our stock 17 inch wheels weigh 26 lbs when they're sitting still. Multiply that by 4 and you're adding 78 lbs to each wheel when it starts moving, for a total of 104 lbs per wheel! You have four of them of course, so that's 416 lbs of wheels your car has to lug around! This thing is heavy enough, trust me. A good set of lightweight wheels (15-20lbs max) will free up as much as 11 lbs of rotating mass from each corner, and your engine doesn't have to work as hard to push it all around. This means if your engine is working just as hard, you're going faster! Just another thing to think about before you go putting 22" chrome wheels on your ride.

Stay tuned for a more in-depth discussion involving cams, displacement, and forced induction!

And thanks everyone for responding so well to this thread, I'm glad it's appreciated!
 

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Discussion Starter #6
First of all Very nice write up! I wish I could explain things that easily. My questions is with this quote. Wouldnt peak torque happen at the same time or close to peak horsepower? Again Very nice write up Im looking forward to more. +Rep for you!!
Thanks for the rep! And great question! I was gonna wait to address it until my next post but it was bugging me so I figured I'd do it now.

Basically torque is a measurement of force that has been around for a very long time. Horsepower is a measurement that was created so that those newfangled automobiles would have a good selling point against their primary competitor, (you guessed it!) horses. Unfortunately, at the turn of the century it was very difficult to get a horse's hoofs to spin the wheels of a dyno accurately enough to get a usable reading, so a formula had to be made to ensure that it was a reliable means of measurement.

For those of you who don't shy away from math (as I often do,) horsepower can best be defined by the following equation:

HP = Torque X RPM
````````5252

(ignore the little grave things, I couldn't figure out a better way to make the 5252 show up in the right place.)

For example, say you have a car that makes 200 lb-ft of torque at 6000rpm. To calculate the horsepower this car makes, multiply 200 by 6000 (1200000) and divide the result by 5252. You'll find that the car has 228.5 horsepower. Actually it's 228.48438690022848439 but that doesn't fit on the cover of Import Tuner so I round.

If you remember more highschool algebra than I do, you can flip this equation around to make it say what torque equals and what RPM equals too. If you're really good, you can even plot it out on a graph, in which case you'll notice that your figures for torque and your figures for horsepower will intersect at exactly 5252 RPM, every single time.

So if your peak horsepower for a particular engine is at 5252 RPM, then yes, your peak torque will be exactly the same. If your peak horsepower is reached at 9000 RPM, peak torque will be realized much lower. Consider the terms "torque curve" and "power curve." These refer specifically to the kind of graph I just mentioned, which incidentally is the same graph you get from testing your car on a dyno. The angle of the point at which the torque and power curves intersect is going to determine how closely related your torque and horsepower are.

I just realized how tired I am but next time I get back to this I'll bring some dyno sheets for a better explanation. I hope I at least began to answer your question!
 

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Discussion Starter #7
i have a 99 rs and im planning on turboing the 420a. my goal is to have between 300 and 350hp. what upgrades would you recommend to achieve this power and still be a reliable daily driver?
Unfortunatley I have no experience with the 420a at all and really can't tell you much. Based on what other people are saying though, 350whp and reliable might just not be synonomous. Aftermarket turbos require a LOT of supporting mods to make them work without sacrificing reliability. You're probably talking a bottom end engine rebuild, custom plenum and turbo manifold, new fuel pump, new fuel rails, and depending on the charicteristics of the 420a's ECU (again I don't know anything about it,) you may not even be able to do much in the way of reliable tuning without a stand alone. Getting a factory turbo motor means you can make little tweaks here and there without having to start from scratch, and it won't sacrifice much in the way of daily driver reliability.

SO! It's been like a year or something, but I promised I'd come back and add stuff and after rereading my (newly tacked! Thanks!) thread I realized I neglected one of the most important mods you can do!

Brakes!

If you look at my sig line you can see what I've done to the car. Sadly it hasn't changed in quite some time, but when I got it dyno tuned (before the TB but after everything else) I was making 287whp and 291wtq. This car will beat a stock Evo X from a 40 roll, I've even managed to keep up with a 2010 STi from a dig, although admittedly he made me work my ass off to do it.

So it's a fast car, right? Well I didn't think it was fast enough. Or at least I didn't until I took it to the track for the first time about a year ago. Truth be told, this car has WAY more power than I can handle when it's really being pushed to the limit. I raced around the Shannandoah circut at Summit Point, a very short, technical track with (I think) 22 turns. At the top of the longest straight, I was going about 110 in fourth gear and was barely into the MIVEC range before I had to stand on the brakes for the next turn. This is with Perelli P-Zero tires, StopTech slotted rotors, Mintex race pads, SS braided brake cables, and Wilwood high temp brake fluid. Even with all that, the car gets up to speed a LOT faster than it slows back down. After a day at the track, I talked it over with my brother and dad and came to the conclusion that the only things that could make me faster around the track at this point would be more practice, and bigger brakes.

Unfortunately, like everything else, the top of the line, performance oriended brake kits come at a trade-off with user-friendliness. The first thing you'll notice, strangely enough, will be that the car stops a lot faster. This doesn't seem like a bad thing at all, until you remember that the jackass in the SUV tailgating you doesn't track his vehicle, and thus doesn't have great brakes to keep him from running into you. Forgetting this fact has very nearly gotten me run over several times, and I've still got stock calipers. Also if your girlfriend is doing her makeup in the passenger seat and you decide you really can't make that light, she probably won't be too happy with the resulting war paint. Hopefully it was just makeup, and not a cup of coffee.

Before I get any more specific, I'll briefly cover what each component does, just like last time. Your brake system starts with the brake pedal, obviously, but where does the pressure from your foot go from there?

It starts by pressurizing your brake master cylinder. I'm going to glance over this as (last time I checked) there wasn't anything us 4G owners could do to tinker with it, but think of it as a hydrolic press full of brake fluid. It pressurizes the brake fluid, which is non-compressable, and causes it to flow at high pressure through your brake lines. At the end of the brake lines are the calipers, which contain pistons that are backed on one side by the hydrolic effect of the pressurized brake fluid, and on the other by your brake pads. The brake pads themselves have a high friction surface that will contact with your brake disks, connected to the axle hub, and close around said disks causing them to come to a stop. Once the pressure on the brake pedal is released, the pressure in the master cylinder decreases, the fluid relaxes in the brake lines, and the calipers stop pressing the pads against the disks.

Brake lines are mostly just thin metal pipes, but between the static frame of your car and the mobile wheels themselves which bounce around on your suspention and turn when you turn the wheel, the brake lines must be flexable. The factory answer to this is to make them rubber, like a coolant hose. This is cheap and reasonably effective, but because of the very nature of rubber, the high pressures associated with extreme braking will actually cause the rubber to flex outward and expand. This causes you to lose braking power. The performance answer to this is to cover the outside of the brake lines in a braided stainless steel weave, which still allows the line to be flexable from side to side, but prohibits expansion. The difference in braking from this mod alone is startling. Once you've driven a car with steel braided brake cables, you'll never again feel safe driving one without.

This mod is simple enough, but it can be very tedious. If you're not experienced, ask someone who is to help you. It's definitely something you can do in your own garage, but it's usually a two person job and it's one you really don't want to screw up, for obvious reasons.

Pads are probably the simplest mod to do, simply because you're gonna have to change them at some point anyway, you might as well replace them with something a little more fun. This, however, is where you will find one of the biggest compromises you'll have to make. The better the pads grip, the faster they'll wear out, the more noise they'll make when you stop, and the more brake dust they'll leave on your wheels. The dust can be cleaned, the noise can be dealt with (especially if you have good exhaust or the RF soundsystem, in which case you won't notice, just everyone else will!) but replacing pads every couple months can get really old. I still put up with it because I love having tremendous stopping power on tap, but someone less over the top than me might want to find a middle ground with their pads, and get something that lasts a little longer at the expense of performance.

The disks, or rotors, will be important too. Stock size rotors are probably the answer for most people, because they're a direct drop in job, nearly as easy as changing a tire. They come in multiple varieties; dimpled, drilled, slotted, drilled and slotted, or even stock appearance. The idea behind any kind of finishing like slots is to aid in cooling. You don't want your disks getting too hot, because the abrasive compounds on the pads won't be abrasive anymore once it reaches a certain temprature. This temprature varies from pad to pad, but for typical road usage it's not super high, and you want the brakes as cool as you can get them. DO NOT TRY TO COOL THEM MANUALLY THOUGH, as the disks can crack if you pour water on them while they're hot, or use other such shortcuts.

Drilled rotors have a reputation for breaking as well, since the integrety of the disk is compromised. Unfortunately they look so freaking cool that many people can't resist the temptation. I myself have never actually seen one crack, but I also don't spend nearly as much time at the track as some other more reputable folk who have horror stories about this. If you're going for looks, and don't push your car to the limit every weekend or more, cross drilled rotors will probably serve you just fine. If you're serious about performance though, it might be best to consider slotted rotors.

Slotted rotors aid in cooling just as well as cross drilled rotors, but without sacrificing structural integrity. They also have the added benifit of slightly resurfacing the pads under heavy braking, thus decreasing the possibility of "warping rotors." This term is misleading, as the rotors themselves don't actually warp, but uneven heating on the pads can cause deposits of pad material to slag off onto the rotors and dry, which makes for wobble under braking and a "warped" appearance on the surface of the rotor. The slots in the rotors will actually help to cut down on this a little by shaving off the topmost layer of abrasive, but in that very process they decrease pad life even more. This is another thing to consider when shopping for performance brake parts.

I was about to get into calipers but I'm at work and now I have to actually pretend like I have responsibilites here or something, so I'll finish it next time. I also intend on clearing up some of the issues I made vague references to with the TB spacer and plenum spacer install issues discussed above.
 
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Hey man awesome post, I think its perfect, and bein a noob, good chance im going to follow it like a christian follows the bible! Thanks!

Sent from my DROIDX using Tapatalk
 

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hey thanks for explaining it to us... the noobs lol. This was exactly what i was looking for. Now its time for me to start getting it all together w00t lol.
 

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This helped me a lot on what to do first, and exactly why I should do it. :) + rep.
 

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rifleman
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Well I hope your knowledge will make me happy when I smoke hondas on the 5 everyday after work bc I can't fucking helP but drop gears and get to my womans house so I can beat some guts! Just one question overall is it more cost effective to make all these mods and be just as fast as the gt or is the v6 still a better motor then my gs?
 

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Perfection over power
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Well I hope your knowledge will make me happy when I smoke hondas on the 5 everyday after work bc I can't fucking helP but drop gears and get to my womans house so I can beat some guts! Just one question overall is it more cost effective to make all these mods and be just as fast as the gt or is the v6 still a better motor then my gs?
Check my wall I answered this question for you. in my opinion anyway
 

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i just got a cold air intake for my 4g eclipse gt 3.8 when installing i come across a delema the instructions tell me to install the hose comming from the throttle body to the intake but then i got 2 lines left in the open with no where to go. is there a way i can bypass those other 2 lines with out making my computer freak out. i have a C.A.R.B. E.O. and the 2 lines are running off the same wires to the MAF sensor
 

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new to this site and very very informative for someone just getting there feet wet on modding
 

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Nice artical. I wish they would have als provided the cost of the new parts (wheels, carbon fiber, seats, etc) and some better pics and review of the drivability after all was said ad done.

A 1 second 1/4 mile and 0 to 60 is nice. But no sterio, heater, sunroof, reclining/heated seats and the loss of all sound deadning.

I also question how much of the performance increse was related to the headers alone. But, in one breath they say we left headers out, but then say their 4-2-1 headers shead 15lbs and increased mid-range power. So did they or not?

And guessing $2500 to $3000 for 6mpg or 87 miles per tank. Assuming 1 tank a week at 3.50 a gal that's about $8 savings a week so about 6 1/2 years for break even. All while having no sterio, heater, sunroof and a very loud interior.

Would it not be easier to do the headers, CAI, exhaust and tune. Less money and more power. If you keep your foot out of it, more power relates to better milage (to some extent). Pay back is less time. You have not depricated the value of the car and it is still fun to drive.

But who says us gear heads ever keep our foot out of it or worry about payback. We mod to improve our car in our eyes :)
 

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The first page, without ditching the ac, is a very doable concept for under $600, which you would make back on that extra gas mileage in the first 6 months. Plus aci actually has a great price for a complete carbon fiber hatch. I'd like to look into that plastic glass they were talking about on the 5th or 6th page. That combined with a carbon hatch should drop quite a bit of weight. I'll be looking into that, new rims and tires, or coilovers with my tax return. I like the concept of the plate under the car to reduce drag, but i would still like to keep the engine bay open to let heat escape.
 

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My question is after completing the plan you put fourth what performance might I expect if I was to also have the engine internals rebuilt ?? As far as wHP torque etc.? And would you recommend a reflash with your plan you put on your article ?
 
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