Just have to be carefull with ebay stuff.. I got a cold air intake from it a while back, and the inside of the tubing was crap... It had little pieces that came off and went into the turbo.. It ate the blades up on a t25 real fast.. After that I ditched it and put a 14b turbo on.. But when you get it, just make sure to check the inside of it to make sure its smooth.. If its not, that crap will be falling off over time and going into your motor.

 

A cold air intake will only give you like a 5HP boost. Id say to start, buy some headers, dwonpipe, and new CAT exaust.

 

All that combined might give you about a 10 hp gain. That motor just does not take well to bolt on parts. But at least it would sound really good.

 

depends on the exhaust you get, i had a thermal cat back and it was loud as sin and i hated it. you can take DunDun's advice (btw there is no downpipe on a N/A car) and get ur cat-BACK exhaust, high flow cat or test pipe, header and intake but you will see..... oh, mabey 5wp out of all of that. here's a write up on the 420a that i just did, read it, learn from it lol.
__________________________________________________ ______________________________

This is being made for those hundreds of people out there that just bought their 95-99 Eclipse non turbo but had the stereotype label in your head that all eclipses are fast, or can be fast relatively easy. This information, sadly, is not true.
The second generation Eclipse came with the 420aengine, 2.0 liter, Dual OverHead Cam (DOHC), In-Line 4 cylinder engine N/A (naturally asperated = non turbo'd/non supercharged). This engine comes with a base horsepower rating of 140hp from the factory. This puts the engine between 105 and 120whp depending on the type of dynograph used. This is also the engine used in certain years of the Dodge Neon and Dodge Avenger.
In a nutshell, this engine was built for reliability and long term use, not street performance and modifications.
I'll start by listing the mods that i had done to my Eclipse (performance wise) just to give you a good idea of how poorly these engines take performance mods:
99 Eclipse GS OZ Special Edition
-Thermal Research and Devopment Cat Back Exhaust
-OBX Racing high flow cat
-OBX Racing Header
-OBX Racing Intermediate Pipe
-AEM Cold Air Intake
-Port and Polished Throttle Body
-Greddy Grounding Kit
-EGR Blockoff Valve
-Cometic Head Gasket
-Venom 400 Performance Chip
-Stripped interior including Stereo system (nothing but driver seat)
Yellow Top Battery (relocated to trunk)
On a mustang Dynometer (the heartbreaker of all dyno's its called) i put down 111whp. 111WHP!!! how rediculous is that?
I added it up before i sold my car and found out that i had spent over $1500 on this car's performance to only gain... mabey 5whp. To give you an idea of how fast/slow this car is on the street i would barely pull on 6 cyl Mustangs, keep right up with 6 cyl Cameros, walk Grand Ams, and a few hondas around here but other than that... that's just about it.

HERE ARE YOUR CHOICES:
1.) Intake, Exhaust, and a few other nick nacks to make it go a little faster and leave it at that.

2.) Nitrous - i've only met one person that ran nitrous but he had a 50 shot set on it and said he put it on a Dynojet (very forgiving and very generous dyno) 162whp. You can pick up a decent nitrous kit for $400-$1000 depending on how detailed you would want to get with the kit. You will also need a wideband, tune, probably a new clutch, exhaust and intake to run the system safely and realize the full potential of the nitrous.

3.) Turbo - They make turbo kits for this engine but i will never recomend it. Here is why: a good turbo kit for this car will run you between 2800 and 3800 bucks. There are NO kits on the market that come with everything that you need. In every kit you will need at least 1 or 2 more things. Not to mention if you do add a turbo kit to your car you will only be able to run 8-10psi before the bottm end gives out. Another thing that most people don't think about when buying a turbo kit for their car is all of the things that they will have to upgrade to make it reliable such as a clutch, wideband o2 sensor, tune etc.
You can piece together your own turbo kit for less than the cost of a turbo kit from a company but you will stil end up spending at least 2000 in the process to, yet again, only run between 8 and 10 psi.
Here's a list of the absolute minimum to turbo this engine:
-exhaust/turbo manifold
-turbo
-wastegate
-o2 housing
-downpipe
-intercooler piping
-front mount intercooler
-blow off valve
This is the absolute minimum, to run the car safely you will need:
-wideband o2 sensor
-boost gauge
-boost controller
-tuning device
-tune
At this point you will be reaching the maximum limits of your bottom end of your engine and you cluch is toast so you now have to have a new clutch and if you want to run anything over 8-10 psi you'll need:
-forged pistons
-forged rods
-piston rings
-new main bearings
-new rod bearings
-head studs
-main studs
Now you are ready to run up to 18-20psi. This is the maximum limits of your head so you won't be able to run over this. Also, i have never spoken to anybody who had taken the time to build this far so i have no idea what the max PSI or HP the transmission can hold.
At this point we are at apx 4500-6000 depending on if you got the parts new, used, refab'd, from a friend, whatever.
At 20PSI on a rebuild bottom end with forged-turbo happy pistons with a good compression ratio you will be realizing between 280-350whp depending on the size turbo you have, compression ratio, street tune, dyno tune, tuning device... there are many fators.

HERE IS THE POINT OF EVERYTHING:
To get your 420a to realize 300-350whp you will have spent over 5000 dollars ON TOP of the cost of the car... lets say... 2000 dollars, so we are at apx 7000 dollars on the build.
You can get a 2nd generation GS-T eclipse between 3000-5000 these days. If you find the right deal you can find these cars already with mods and a 6 bolt swap. So lets say for simplicity reasons that you get a decent GS-T with an intake, exhaust, and manual boost controller for 5000. You can put 1500-2000 dollars into this car and have a comfortable 350whp with the option to put a larger turbo on there and run betwen 400 and 500 whp on the stock bottom end.

So, lets look at the facts. You can have a maxed out head on top of a rebuilt bottom end with a turbo at 350whp and nowhere else to go IF you haven't blown your transmission yet. OOOORRRRRR a comfortable 350whp with room to add much more hp on the stock engine. Both for the same price.

__________________________________________________ __________

there you go, all set