Swapping your 2.5i/rs to a wrx/sti; is it worth it?

radd269 · 06-13-2011, 05:53 PM

Hello All,

This thread is designed to put thoughts into proper prospective. Last week, I recently successfully swapped a 2006 2.5i to a 2006 wrx. A FULL complete swap, so that I can get it to pass smog. It cost a lot of money, a lot more than I originally thought. Am I happy? Yes, I see what I was missing, and the grass really is greener on the other side, but I am writing this so that other people won't make the same mistakes I did.

While a 2.5i body and wrx (even the STI) body are almost exactly the same, they are COMPLETELY DIFFERENT CARS. It's not just about changing the engine. You need to register this in your mind. Electronically, very few components can be reused here. Even the fuel system is different. As long as you're cool with that and are willing to take a trip to the dark side like I did, then keep reading.

My first mistake: I didn't do enough research. SO MANY PEOPLE WARNED ME AGAINST IT, saying "You'd be better off selling your impreza and buying a wrx." While this is true from a financial standpoint, I didn't care. I felt a swap like that would be ten times more fun and rewarding. So I saved 8 thousand dollars and started looking at engines and parts I would need. Also make sure you have ALL THE PARTS YOU NEED BEFORE YOU START, to save yourself time and money later.

Mistake 2: If you decided to say "F%$k what everyone is telling you and do it anyway" like I did, unless you are physically doing it yourself, take it to a mechanic THAT HAS DONE THESE BEFORE.

And I'm not talking about one swap or two. Take it to someone who has done more than 20 swaps if you can. (If you live on the east coast, there are a few places that do it (eg ECS) but where I live in the tri-valley bay area, there isn't many swappers in town.)

The reason is simple. It's easy for a mechanic to quote you a price to do a swap and say, "Oh that shouldn't cost more than 4k in labor." But unless he has done tons of these swaps on our cars, It will ALWAYS BE MORE THAN WHAT THEY QUOTE YOU, sometimes double.

For Example, One thing that needs to be changed obviously is the ECU. This doesn't mean just taking out one box, and replacing it with the turbo one. THE ENTIRE WIRING HARNESS NEEDS TO BE SWAPPED including the fuel harness. If your mechanic is not familiar with how to do this efficiently, it could be as much as 15 hours labor extra charged to you, that you weren't expecting.

Mistake 3: The Immobilizer key is something else that's extremely important.

If you are going to do this kind of a swap, When you purchase your ECU, Try to buy the ECU, wiring harness, and immobilizer key FROM THE SAME CAR!!! I didn't know this, so when I bought my ECU, and after finishing everything, when my mechanic went to start the car, it wouldn't start. In imprezas, there is no chip in the car keys. but in a WRX/STI, there is. Thus the Immobilizer unit and key has to be changed and possibly reprogrammed if you want to be able to start the car.

If the wrx/sti ECU and Immobilizer came from the same car, you don't have to worry about anything because the codes in the key will match the ones in the ECU. If they didn't, the only way your car will start when everything is finished, is taking it to a subie dealer and have them to reprogram the ECU/Key. THIS CAN BE AVOIDED WITH RESEARCH!!! If you or your mechanic doesn't know this, they can potentially charge you with extra labor just trying to troubleshoot "where they potentially wired something wrong" LOL

Let's get down to business. The swap I did was designed so I could pass smog. Here are all the parts you need (If I remember correctly):

1. Engine (obviously. and AVOID BUYING ONLINE IF YOU CAN. (e.g. gotengines.com) Try to buy from a place where you can physically see the motor yourself and have someone you trust WHO KNOWS THESE ENGINES go with you. If all the accessories are on there in good working order (eg intercooler, intake manifold, header/downpipe, turbo, water pump) then you scored major points. if not, then you need to be ready to buy those components, including a new radiator, as your impreza one will no longer work.

Also, if you use the TMIC (Top mount intercooler,) you'll also need to obviously change the hood of the car, unless your willing to invest time and money into a FMIC (Front mount).

You CAN retain your original AC, ABS, and power steering systems. The power steering line will appear to be unmountable, but it can be made to fit and mount up perfectly.

2. Fuel System. To be safe, try to find the entire fuel system including entire fuel lines and wiring. Most complete ECU harnesses will have all of the fuel wiring you need, but be ready for NOT having everything you need, always. The fuel system will require new fuel lines (the impreza has only 2 lines (return vs returnless) (at least they do in the 06), the WRX has 3), tank (not sure if you need this, but I changed it just to be safe), and the fuel pump controller. Also, a new fuel pump will be required for sure; the impreza fuel pump is too weak. I found a brand new Walbro for 80 Bucks online or a stock wrx pump will work too.

3. If you didn't score these parts earlier, You'll also need a new stock airbox/intake (NOT INJEN!!!) intercooler and piping and mounting, a new exhaust (stock or aftermarket), turbo manifold, downpipe, radiator, and engine cradle. Make sure you have all the little things too, like the stock BPV for the turbo. The new engine cradle is VERY IMPORTANT. You can't skip this one. The impreza cradle is has different mounting holes and points than that of the WRX. When you go to put the new motor in, you you don't have the right cradle and crossmember, the new motor won't mount to the car. (the new crossmember takes away a lot of sway on the car too

)

Don't worry about getting any aftermarket parts that require tuning right now, unless you have a tuner you can tow your car to once the swap is complete. Putting something like a CAI (cold air intake), TBE (turbo-back exhaust), downpipe or other parts on your car without tuning it could be fatal for your motor and make all the hard work blood sweat and tears meaningless. If you are gonna go TBE later, just get a used cheap stock exhaust for now or an ebay catback, and upgrade later once you find a good tuner. Intakes are meaningless unless you have a FMIC, or 400whp and at that point you need to tune for it anyway. Worry about those parts later.

4. Transmission. This is up to you. If you want, you can choose to leave this part alone. I did; the motor will mount up to your current tranny all the same. Virtually the WRX tranny and the impreza tranny are literally Identical, except for slightly different gearing. one is not weaker than the other, even though many people have a misconception that the WRX tranny is stronger. If you are doing something crazy like swapping to a 6 spd, you'll need to change the clutch, flywheel, driveshaft,axles, lsd and other STI components, as well as appropriate wiring. If you leave your original tranny alone, note that a wrx clutch will not work with your CURRENT FLYWHEEL. You will need to use a impreza clutch and flywheel (perfect time to upgrade this component if you can). If you want to use a WRX clutch, the flywheel has to MATCH. Also the tranny wiring used to tell the car when your in gear and in reverse is different and will need to be modified.

5. (optional) Instrument Cluster and other things (speedometer) I changed mine, but you don't need to if you don't want to, or you can do it later.
if you want your interior to look flush, STI seats can be used on your original brackets

Those are all of the components that come to my mind
Here are some links to some pictures of the finished product.

I hope that gives you a little insight on what's involved. If you are willing to put in the blood sweat and tears to get a result like this then I welcome you to do this

"DO or DO NOT. There IS not try." haha. Enjoy your new found beauty.

http://i1201.photobucket.com/albums/...Picture053.jpg
http://i1201.photobucket.com/albums/...Picture052.jpg
http://i1201.photobucket.com/albums/...Picture051.jpg
http://i1201.photobucket.com/albums/...Picture054.jpg

* Registered users of the site do not see these ads.

Osgood30 · 06-14-2011, 09:43 AM

Just for a discussion purposes, I think its kind of odd to do a swap of RS to STI of the same year and body, because you can just sell RS and buy STI. You can get the same color, put the same body work (e.g Wing) and many of the people won't even realize you got the different car.

Another thing is when people put WRX/STI drivetrains in to older bodies such as GC8 RSs. I think that in that case there is a factor of uniqueness, something that you can't buy.

But other than that, all of the lessons and mistakes apply to pretty much every swap.

Alex

subieguy87 · 06-14-2011, 09:56 AM

RSTi's that aren't available here

radd269 · 06-14-2011, 12:10 PM

Quote:

Originally Posted by Osgood30

Just for a discussion purposes, I think its kind of odd to do a swap of RS to STI of the same year and body, because you can just sell RS and buy STI. You can get the same color, put the same body work (e.g Wing) and many of the people won't even realize you got the different car.

Another thing is when people put WRX/STI drivetrains in to older bodies such as GC8 RSs. I think that in that case there is a factor of uniqueness, something that you can't buy.

But other than that, all of the lessons and mistakes apply to pretty much every swap.

Alex

I totally agree with you, and I'm not tryin to rain on anyone's parade here.

Basically the goal of the thread is this: If you are gonna do something major to your car like a swap, do a little research before you start, be properly prepared, and unless ur doing it yourself, take it to someone who knows what they're doing to save yourself a fat migraine and money down the drain.

Other than that, I think it's a great Idea. I love my freshly swapped subie! it runs and feels like a completely different car.

stiv_5 · 06-16-2011, 09:00 AM

Both I agreed with both of you guys. Even in an older Rs you still have to do a lot of research before you dive in. That's what I did when I swapped my GC. I was lucky enough to find a donor wrx locally that still runs.

It definitely takes a lot of time and some extra monies especially if you are doing it yourself. I did the mechanical part with some help from my brothers but the harness was merged by one of the best IWire.

Good write up to inform those who want to swap their newer imprezas.

radd269 · 06-16-2011, 01:33 PM

Quote:

Originally Posted by Osgood30

Just for a discussion purposes, I think its kind of odd to do a swap of RS to STI of the same year and body, because you can just sell RS and buy STI. You can get the same color, put the same body work (e.g Wing) and many of the people won't even realize you got the different car.

Another thing is when people put WRX/STI drivetrains in to older bodies such as GC8 RSs. I think that in that case there is a factor of uniqueness, something that you can't buy.

But other than that, all of the lessons and mistakes apply to pretty much every swap.

Alex

True. And the STI tranny is gonna give you stronger axles, something you wont get with a 5 spd.

olsen726 · 06-16-2011, 10:30 PM

You do realize that you didn't need to swap all of the wiring and ecu and all of the fuel lines over correct? Also the wrx/ sti motor will bolt into the stock crossmember, but the up-pipe won't fit unless you either cut or swap the crossmember, or run a custom up-pipe.... not trying to ruin your thread or anything, just clearing up some misinformation... congrats on the swap man

n0rcal2wheeler · 06-17-2011, 06:51 PM

nice build.

radd269 · 06-17-2011, 08:45 PM

Quote:

Originally Posted by olsen726

You do realize that you didn't need to swap all of the wiring and ecu and all of the fuel lines over correct? Also the wrx/ sti motor will bolt into the stock crossmember, but the up-pipe won't fit unless you either cut or swap the crossmember, or run a custom up-pipe.... not trying to ruin your thread or anything, just clearing up some misinformation... congrats on the swap man

I know. I wanted it to pass smog. I don't know about the fuel lines tho; in the 06/07 imprezas there are only 2 fuel lines; the wrx has 3. I don't know how you would make that work without changing or adding what's needed there maybe it was different with the older models.

radd269 · 06-18-2011, 01:21 AM

Quote:

Originally Posted by n0rcal2wheeler

nice build.

thanks

UK-Wagon · 06-23-2011, 02:38 PM

Quote:

Originally Posted by Osgood30

Just for a discussion purposes, I think its kind of odd to do a swap of RS to STI of the same year and body, because you can just sell RS and buy STI. You can get the same color, put the same body work (e.g Wing) and many of the people won't even realize you got the different car.

Another thing is when people put WRX/STI drivetrains in to older bodies such as GC8 RSs. I think that in that case there is a factor of uniqueness, something that you can't buy.

But other than that, all of the lessons and mistakes apply to pretty much every swap.

Alex

Here is where you are wrong.....

No 02-07 (GD) STi body came in any Red color body in the US market untill 2008. If you are like me who has a 06 2.5i in red...... well now im the only one with a red 06 STi!

Second..... and most obvious reason for the swap vs. buying a WRX/STi is the price of INSURANCE!! its way cheaper for a 2.5i than a Turbo car, About half the price, I know this because I had a 05 STi and 03 WRX at one time. My insurance company uses your Vin# to base the vehicle make & model off of, yes they are aware of the swap and said if its factory Subaru parts then they dont care, any body shop will just get the price of repairs and parts for what they see.

skrach77 · 08-01-2011, 08:40 PM

Just a thought coming from someone considering this swap- selling and repurchase is not a valid option for me, I bought a rebuilt car for about half of what kbb value on an identical/ nonrebuilt car was. I've already saved more in gas over the past year than what I paid (I drive A LOT).

Now that it's no longer a daily driver, I want to make mine more fun... So I'm considering this swap, and not selling/ repurchasing...

ghimpreza · 08-06-2011, 03:34 PM

nice write-up man, i have a blown head gasket, thought about the swap to an STI though, i was searching for crashed sti (auction) and transferring all the parts to my wagon, but it's gonna cost around 8000 for a crashed sti, and 4000 min for labor. the mechanic that i will take it to has done around 45 swaps. but no money to do that

IckyLove · 08-06-2011, 04:46 PM

I have an RS that I was thinking about doing this to. It sounds like this is one of those things that has to happen all at once. I want this, but at the same time it almost seems like money might be better spent making it a nice DD while working on a cheaper car, like a Miata or some older car. Also, would it be better to get an STi motor or WRX motor to build towards my end goal of ~350 whp (if I do it)?

smo0ve · 08-22-2011, 12:35 AM

beautiful write up, def. helped alot, one question though... i hear the 06 wrx an the 06 2.5i clutches are the same.. and will work..?

CanadianScooby · 09-05-2011, 03:59 AM

Just a question. when all said and done what was the time frame from when you parked it and when you first drove it again? What was the final cost (I know you said you saved $8000 but I figured maybe it cost you more due to forgetting something or less because of a good deal on parts)? and did you have any help like a mechanically inclined friend or someone to hold the flashlight for you and whatnot? Or maybe you had a mechanic finish certain things.

I'm just curious as I have a choice to at the moment to replace the existing engine with a rebuilt one of the same year and model or swap to an sti.

I have complete faith in my abilities to swap as I have replaced a few engines and transmissions in previous vehicles I just never had to put one from a different year or car in and had to screw with electronics for the most part.

Thanks in advance i would just like to get an idea of what it took the average guy also great write up.

radd269 · 09-13-2011, 01:11 AM

Quote:

Originally Posted by IckyLove

I have an RS that I was thinking about doing this to. It sounds like this is one of those things that has to happen all at once. I want this, but at the same time it almost seems like money might be better spent making it a nice DD while working on a cheaper car, like a Miata or some older car. Also, would it be better to get an STi motor or WRX motor to build towards my end goal of ~350 whp (if I do it)?

If your goal is 350whp, you can pretty much get that from an wrx motor. All you would need would be sti tmic, sti turbo, walbro fuel pump, tbe and a good tune. the WRX motor already has enough injectors (550CC) but any more power than that would be unreliable. Using ethanol also would be a good idea here

radd269 · 09-13-2011, 01:18 AM

Quote:

Originally Posted by smo0ve

beautiful write up, def. helped alot, one question though... i hear the 06 wrx an the 06 2.5i clutches are the same.. and will work..?

Hey man,

The clutches are not the same; I know this because i tried it. The wrx Flywheel is different than the RS (the bolts dont match up, same with the STI. none of the clutches on ANY of the cars are interchangeable between models)

That being said, a RS tranny WILL work with a WRX motor. (my tranny is from the original rs). and the trannys THEMSELVES are interchangeable. But you have to match clutch with the flywheel. THEN a WRX clutch will work.

What I did is while the tranny was disconnected from the motor I upgraded the clutch to a exedy stage one.

radd269 · 09-13-2011, 01:25 AM

already posted

radd269 · 09-13-2011, 01:39 AM

Quote:

Originally Posted by CanadianScooby

Just a question. when all said and done what was the time frame from when you parked it and when you first drove it again? What was the final cost (I know you said you saved $8000 but I figured maybe it cost you more due to forgetting something or less because of a good deal on parts)? and did you have any help like a mechanically inclined friend or someone to hold the flashlight for you and whatnot? Or maybe you had a mechanic finish certain things.

I'm just curious as I have a choice to at the moment to replace the existing engine with a rebuilt one of the same year and model or swap to an sti.

I have complete faith in my abilities to swap as I have replaced a few engines and transmissions in previous vehicles I just never had to put one from a different year or car in and had to screw with electronics for the most part.

Thanks in advance i would just like to get an idea of what it took the average guy also great write up.

I made the mistake of taking the car to someone who didnt specialize in subarus. the motor i also bought was from online (I DO NOT RECOMMEND THIS) and came with all of the accessories broken which cost me more money. in a perfect world, the total cost would have cost me around 8k. Nothing against the mechanic, but in honesty we wasted a lot of time and money trying to figure things out that he should have already known.

It took about three months to do, between the mechanic's load of customers and my car. If I took it to someone who specialized in the car it probably would have been done in less than half of the time.

even tho motorswaps are all pretty much methodically the same, If you are doing this yourself, I highly recommend working on the car with someone who knows performance vehicles (obviously preferably subarus). the STI swap is also much more complicated, as a lot of the other systems have to be swapped over (LSD, tranny, axles, driveshaft, ect).

If the STI route is the way you are going, I would try to find a source for parts (e.g. a guy who sells em cheap, or a salvaged sti with a lot of the systems still intact) what year is the car, and what year is the STI motor?

02RS25 · 09-29-2011, 01:30 PM

Quote:

Originally Posted by radd269

I totally agree with you, and I'm not tryin to rain on anyone's parade here.

Basically the goal of the thread is this: If you are gonna do something major to your car like a swap, do a little research before you start, be properly prepared, and unless ur doing it yourself, take it to someone who knows what they're doing to save yourself a fat migraine and money down the drain.

Other than that, I think it's a great Idea. I love my freshly swapped subie! it runs and feels like a completely different car.

Agreed. I have an 02 RS. and that is the only year i would do a full STI swap. I just have a thing for those bodies

but ya, other than that, id sell and upgrade

gliba · 10-10-2011, 02:01 AM

I recently picked up a 2010 WRX engine with the manual tranny, and willl be working on getting it swapped into an 08 2.5i A/T. The engine comes with the TMIC, up-pipe, turbo, DP, and all the front mount equipment such as the A/C, and Power Streering. I did not get the radiator, and the front right knuckle assembly is slightly damaged. I also got a 2010 WRX ECU from a different source. The bulk wiring harness was damaged on the source car, so I am looking for one if the original can't be salvaged. Do you think I can go to a dealer with the ECU, and have them source me an immobilizer key to match? The crossmember was also damaged, so I'm looking to pick one up before I start on this, but the other cradle parts are more or less intact. The fuel pump was also included, but I don't have the harness for it since I assume it's different from the 2.5i. I got the pedal assemblies for the clutch, gas, and break, as well as the shifter assembly with the solenoid. Anything I'm forgetting before I start this swap? I already put the WRX seats in, and no way I can back out now haha.

radd269 · 10-10-2011, 07:19 PM

Quote:

Originally Posted by gliba

I recently picked up a 2010 WRX engine with the manual tranny, and willl be working on getting it swapped into an 08 2.5i A/T. The engine comes with the TMIC, up-pipe, turbo, DP, and all the front mount equipment such as the A/C, and Power Streering. I did not get the radiator, and the front right knuckle assembly is slightly damaged. I also got a 2010 WRX ECU from a different source. The bulk wiring harness was damaged on the source car, so I am looking for one if the original can't be salvaged. Do you think I can go to a dealer with the ECU, and have them source me an immobilizer key to match? The crossmember was also damaged, so I'm looking to pick one up before I start on this, but the other cradle parts are more or less intact. The fuel pump was also included, but I don't have the harness for it since I assume it's different from the 2.5i. I got the pedal assemblies for the clutch, gas, and break, as well as the shifter assembly with the solenoid. Anything I'm forgetting before I start this swap? I already put the WRX seats in, and no way I can back out now haha.

Auto to manual is normally not too hard to do, but I honestly have no Idea on how hard it'll be with an '08/10 body. I used to own a 1995 Infinity G20, that I converted to a SR20DET/Manual from the Automatic and it was relatively simple. BUT DO RESEARCH ON THE AUTO TO MANUAL CONVERSION BEFORE YOU BLOW YOUR MONEY on the swap and feel violated.

In regards to your ECU, I towed my car to the dealer and they did it for me. Does your harness also include a immobilizer key? If not, you will need to buy a brand new one from the dealer, as you can only program either the key or the immobilizer unit, not the ECU.

I bought the ECU, halfway thru the swap realized I needed an immobilizer unit/key and bought that seperately. it ended up being useless as it was unable to program and the car wouldnt start. You need the key codes stored in the ECU to match the immobilizer unit and key for the car to start.

To clarify, a brand new immobilizer can be programmed by the dealer to read and copy the codes in your USED WRX/STI ECU to the unit itself. the only other way is if the ECU harness included the immobilizer key. Hope that makes sense.

radd269 · 10-10-2011, 07:25 PM

Quote:

Originally Posted by gliba

The fuel pump was also included, but I don't have the harness for it since I assume it's different from the 2.5i.

Yes the fuel pump in a WRX is bigger than the 2.5i you will need the harness for this as it is completely different for a wrx. To be safe, I swapped it out completely, also putting a Walbro in it's place.

I also dont know about the '08 2.5i, but the 06 2.5i only has 2 fuel lines, and the WRX has 3. I would look into that as well if I were you. Also make sure you have the fuel controller as well.

gliba · 10-10-2011, 08:06 PM

Thanks for the help! I will go back to the seller and see if he still has the immobilizer unit. If he does, I will go to the dealer with both the ECU and immobilizer and have them mate the two before I start, as well as source me a couple of keys.

And when I finally get my hands on a WRX harness, I will make sure it includes the fuel pump harness.

06-13-2011, 05:53 PM	#1
radd269 Scooby Newbie Member#: 261241 Join Date: Oct 2010 Chapter/Region: BAIC Location: Dublin, CA Vehicle: 2014 C63 AMG Black	Swapping your 2.5i/rs to a wrx/sti; is it worth it? Hello All, This thread is designed to put thoughts into proper prospective. Last week, I recently successfully swapped a 2006 2.5i to a 2006 wrx. A FULL complete swap, so that I can get it to pass smog. It cost a lot of money, a lot more than I originally thought. Am I happy? Yes, I see what I was missing, and the grass really is greener on the other side, but I am writing this so that other people won't make the same mistakes I did. While a 2.5i body and wrx (even the STI) body are almost exactly the same, they are COMPLETELY DIFFERENT CARS. It's not just about changing the engine. You need to register this in your mind. Electronically, very few components can be reused here. Even the fuel system is different. As long as you're cool with that and are willing to take a trip to the dark side like I did, then keep reading. My first mistake: I didn't do enough research. SO MANY PEOPLE WARNED ME AGAINST IT, saying "You'd be better off selling your impreza and buying a wrx." While this is true from a financial standpoint, I didn't care. I felt a swap like that would be ten times more fun and rewarding. So I saved 8 thousand dollars and started looking at engines and parts I would need. Also make sure you have ALL THE PARTS YOU NEED BEFORE YOU START, to save yourself time and money later. Mistake 2: If you decided to say "F%$k what everyone is telling you and do it anyway" like I did, unless you are physically doing it yourself, take it to a mechanic THAT HAS DONE THESE BEFORE. And I'm not talking about one swap or two. Take it to someone who has done more than 20 swaps if you can. (If you live on the east coast, there are a few places that do it (eg ECS) but where I live in the tri-valley bay area, there isn't many swappers in town.) The reason is simple. It's easy for a mechanic to quote you a price to do a swap and say, "Oh that shouldn't cost more than 4k in labor." But unless he has done tons of these swaps on our cars, It will ALWAYS BE MORE THAN WHAT THEY QUOTE YOU, sometimes double. For Example, One thing that needs to be changed obviously is the ECU. This doesn't mean just taking out one box, and replacing it with the turbo one. THE ENTIRE WIRING HARNESS NEEDS TO BE SWAPPED including the fuel harness. If your mechanic is not familiar with how to do this efficiently, it could be as much as 15 hours labor extra charged to you, that you weren't expecting. Mistake 3: The Immobilizer key is something else that's extremely important. If you are going to do this kind of a swap, When you purchase your ECU, Try to buy the ECU, wiring harness, and immobilizer key FROM THE SAME CAR!!! I didn't know this, so when I bought my ECU, and after finishing everything, when my mechanic went to start the car, it wouldn't start. In imprezas, there is no chip in the car keys. but in a WRX/STI, there is. Thus the Immobilizer unit and key has to be changed and possibly reprogrammed if you want to be able to start the car. If the wrx/sti ECU and Immobilizer came from the same car, you don't have to worry about anything because the codes in the key will match the ones in the ECU. If they didn't, the only way your car will start when everything is finished, is taking it to a subie dealer and have them to reprogram the ECU/Key. THIS CAN BE AVOIDED WITH RESEARCH!!! If you or your mechanic doesn't know this, they can potentially charge you with extra labor just trying to troubleshoot "where they potentially wired something wrong" LOL Let's get down to business. The swap I did was designed so I could pass smog. Here are all the parts you need (If I remember correctly): 1. Engine (obviously. and AVOID BUYING ONLINE IF YOU CAN. (e.g. gotengines.com) Try to buy from a place where you can physically see the motor yourself and have someone you trust WHO KNOWS THESE ENGINES go with you. If all the accessories are on there in good working order (eg intercooler, intake manifold, header/downpipe, turbo, water pump) then you scored major points. if not, then you need to be ready to buy those components, including a new radiator, as your impreza one will no longer work. Also, if you use the TMIC (Top mount intercooler,) you'll also need to obviously change the hood of the car, unless your willing to invest time and money into a FMIC (Front mount). You CAN retain your original AC, ABS, and power steering systems. The power steering line will appear to be unmountable, but it can be made to fit and mount up perfectly. 2. Fuel System. To be safe, try to find the entire fuel system including entire fuel lines and wiring. Most complete ECU harnesses will have all of the fuel wiring you need, but be ready for NOT having everything you need, always. The fuel system will require new fuel lines (the impreza has only 2 lines (return vs returnless) (at least they do in the 06), the WRX has 3), tank (not sure if you need this, but I changed it just to be safe), and the fuel pump controller. Also, a new fuel pump will be required for sure; the impreza fuel pump is too weak. I found a brand new Walbro for 80 Bucks online or a stock wrx pump will work too. 3. If you didn't score these parts earlier, You'll also need a new stock airbox/intake (NOT INJEN!!!) intercooler and piping and mounting, a new exhaust (stock or aftermarket), turbo manifold, downpipe, radiator, and engine cradle. Make sure you have all the little things too, like the stock BPV for the turbo. The new engine cradle is VERY IMPORTANT. You can't skip this one. The impreza cradle is has different mounting holes and points than that of the WRX. When you go to put the new motor in, you you don't have the right cradle and crossmember, the new motor won't mount to the car. (the new crossmember takes away a lot of sway on the car too ) Don't worry about getting any aftermarket parts that require tuning right now, unless you have a tuner you can tow your car to once the swap is complete. Putting something like a CAI (cold air intake), TBE (turbo-back exhaust), downpipe or other parts on your car without tuning it could be fatal for your motor and make all the hard work blood sweat and tears meaningless. If you are gonna go TBE later, just get a used cheap stock exhaust for now or an ebay catback, and upgrade later once you find a good tuner. Intakes are meaningless unless you have a FMIC, or 400whp and at that point you need to tune for it anyway. Worry about those parts later. 4. Transmission. This is up to you. If you want, you can choose to leave this part alone. I did; the motor will mount up to your current tranny all the same. Virtually the WRX tranny and the impreza tranny are literally Identical, except for slightly different gearing. one is not weaker than the other, even though many people have a misconception that the WRX tranny is stronger. If you are doing something crazy like swapping to a 6 spd, you'll need to change the clutch, flywheel, driveshaft,axles, lsd and other STI components, as well as appropriate wiring. If you leave your original tranny alone, note that a wrx clutch will not work with your CURRENT FLYWHEEL. You will need to use a impreza clutch and flywheel (perfect time to upgrade this component if you can). If you want to use a WRX clutch, the flywheel has to MATCH. Also the tranny wiring used to tell the car when your in gear and in reverse is different and will need to be modified. 5. (optional) Instrument Cluster and other things (speedometer) I changed mine, but you don't need to if you don't want to, or you can do it later. if you want your interior to look flush, STI seats can be used on your original brackets Those are all of the components that come to my mind Here are some links to some pictures of the finished product. I hope that gives you a little insight on what's involved. If you are willing to put in the blood sweat and tears to get a result like this then I welcome you to do this "DO or DO NOT. There IS not try." haha. Enjoy your new found beauty. http://i1201.photobucket.com/albums/...Picture053.jpg http://i1201.photobucket.com/albums/...Picture052.jpg http://i1201.photobucket.com/albums/...Picture051.jpg http://i1201.photobucket.com/albums/...Picture054.jpg * Registered users of the site do not see these ads. Last edited by radd269; 11-27-2012 at 03:22 PM. Reason: .

09-13-2011, 01:25 AM	#19
radd269 Scooby Newbie Member#: 261241 Join Date: Oct 2010 Chapter/Region: BAIC Location: Dublin, CA Vehicle: 2014 C63 AMG Black	already posted Last edited by radd269; 09-13-2011 at 02:20 AM.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Is It Worth It?	STI_Hatchy11	AccessPort	5	06-16-2011 09:37 PM
Swapping your 2.5i/rs to a wrx/sti; is it worth it?	radd269	Newbies & FAQs	8	06-14-2011 03:04 PM
wtt my 94 impreza wrx swap for youre 2.5 rs or 2002 wrx	94 wrx mike	Private 'Wanted' Classifieds	2	03-05-2009 08:27 PM
So i traded my 2.5i up to a wrx	geeb	General Community	37	09-08-2006 10:35 PM
Custom Short Shifter design help, it is worth it :) 2000 RS to 02 WRX.....	joostin420	Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo)	3	05-14-2001 10:41 AM

06-14-2011, 09:43 AM	#2
Osgood30 Scooby Specialist Member#: 20437 Join Date: Jun 2002 Chapter/Region: Tri-State Location: Downingtown, PA Vehicle: 1999 Impreza RS STI Ver7	Just for a discussion purposes, I think its kind of odd to do a swap of RS to STI of the same year and body, because you can just sell RS and buy STI. You can get the same color, put the same body work (e.g Wing) and many of the people won't even realize you got the different car. Another thing is when people put WRX/STI drivetrains in to older bodies such as GC8 RSs. I think that in that case there is a factor of uniqueness, something that you can't buy. But other than that, all of the lessons and mistakes apply to pretty much every swap. Alex

06-14-2011, 09:56 AM	#3
subieguy87 Scooby Specialist Member#: 153412 Join Date: Jul 2007 Chapter/Region: MWSOC Location: Springfield,il Vehicle: 1998 Impreza wrxRS Black	RSTi's that aren't available here

06-16-2011, 09:00 AM	#5
stiv_5 Scooby Newbie Member#: 150327 Join Date: Jun 2007 Chapter/Region: MWSOC Location: MN Vehicle: 2001 Impreza Wrx Aspen White	Both I agreed with both of you guys. Even in an older Rs you still have to do a lot of research before you dive in. That's what I did when I swapped my GC. I was lucky enough to find a donor wrx locally that still runs. It definitely takes a lot of time and some extra monies especially if you are doing it yourself. I did the mechanical part with some help from my brothers but the harness was merged by one of the best IWire. Good write up to inform those who want to swap their newer imprezas.

06-16-2011, 10:30 PM	#7
olsen726 Scooby Specialist Member#: 154175 Join Date: Jul 2007 Chapter/Region: NWIC Location: PDX Vehicle: 07 Impreza Wagon 2.5i???	You do realize that you didn't need to swap all of the wiring and ecu and all of the fuel lines over correct? Also the wrx/ sti motor will bolt into the stock crossmember, but the up-pipe won't fit unless you either cut or swap the crossmember, or run a custom up-pipe.... not trying to ruin your thread or anything, just clearing up some misinformation... congrats on the swap man

06-17-2011, 06:51 PM	#8
n0rcal2wheeler Scooby Newbie Member#: 270095 Join Date: Jan 2011	nice build.

08-01-2011, 08:40 PM	#12
skrach77 Scooby Newbie Member#: 255944 Join Date: Aug 2010	Just a thought coming from someone considering this swap- selling and repurchase is not a valid option for me, I bought a rebuilt car for about half of what kbb value on an identical/ nonrebuilt car was. I've already saved more in gas over the past year than what I paid (I drive A LOT). Now that it's no longer a daily driver, I want to make mine more fun... So I'm considering this swap, and not selling/ repurchasing...

08-06-2011, 03:34 PM	#13
ghimpreza Scooby Newbie Member#: 177615 Join Date: Apr 2008 Chapter/Region: SCIC Location: San Diego Vehicle: 2005 sti aw	nice write-up man, i have a blown head gasket, thought about the swap to an STI though, i was searching for crashed sti (auction) and transferring all the parts to my wagon, but it's gonna cost around 8000 for a crashed sti, and 4000 min for labor. the mechanic that i will take it to has done around 45 swaps. but no money to do that

08-06-2011, 04:46 PM	#14
IckyLove Scooby Newbie Member#: 263862 Join Date: Nov 2010 Location: Hampton, VA Vehicle: 2002 2.5 RS Deep Blue	I have an RS that I was thinking about doing this to. It sounds like this is one of those things that has to happen all at once. I want this, but at the same time it almost seems like money might be better spent making it a nice DD while working on a cheaper car, like a Miata or some older car. Also, would it be better to get an STi motor or WRX motor to build towards my end goal of ~350 whp (if I do it)?

08-22-2011, 12:35 AM	#15
smo0ve Scooby Newbie Member#: 253950 Join Date: Aug 2010 Chapter/Region: South East Location: Orlando, FL Vehicle: 2006 2.5i	beautiful write up, def. helped alot, one question though... i hear the 06 wrx an the 06 2.5i clutches are the same.. and will work..?

09-05-2011, 03:59 AM	#16
CanadianScooby Scooby Newbie Member#: 264153 Join Date: Nov 2010 Location: The great white north Vehicle: 1999 impreza 2.5 RS rally pearl blue	Just a question. when all said and done what was the time frame from when you parked it and when you first drove it again? What was the final cost (I know you said you saved $8000 but I figured maybe it cost you more due to forgetting something or less because of a good deal on parts)? and did you have any help like a mechanically inclined friend or someone to hold the flashlight for you and whatnot? Or maybe you had a mechanic finish certain things. I'm just curious as I have a choice to at the moment to replace the existing engine with a rebuilt one of the same year and model or swap to an sti. I have complete faith in my abilities to swap as I have replaced a few engines and transmissions in previous vehicles I just never had to put one from a different year or car in and had to screw with electronics for the most part. Thanks in advance i would just like to get an idea of what it took the average guy also great write up.

10-10-2011, 02:01 AM	#22
gliba Scooby Newbie Member#: 293490 Join Date: Sep 2011 Location: SF Bay Area, CA	I recently picked up a 2010 WRX engine with the manual tranny, and willl be working on getting it swapped into an 08 2.5i A/T. The engine comes with the TMIC, up-pipe, turbo, DP, and all the front mount equipment such as the A/C, and Power Streering. I did not get the radiator, and the front right knuckle assembly is slightly damaged. I also got a 2010 WRX ECU from a different source. The bulk wiring harness was damaged on the source car, so I am looking for one if the original can't be salvaged. Do you think I can go to a dealer with the ECU, and have them source me an immobilizer key to match? The crossmember was also damaged, so I'm looking to pick one up before I start on this, but the other cradle parts are more or less intact. The fuel pump was also included, but I don't have the harness for it since I assume it's different from the 2.5i. I got the pedal assemblies for the clutch, gas, and break, as well as the shifter assembly with the solenoid. Anything I'm forgetting before I start this swap? I already put the WRX seats in, and no way I can back out now haha.

10-10-2011, 08:06 PM	#25
gliba Scooby Newbie Member#: 293490 Join Date: Sep 2011 Location: SF Bay Area, CA	Thanks for the help! I will go back to the seller and see if he still has the immobilizer unit. If he does, I will go to the dealer with both the ECU and immobilizer and have them mate the two before I start, as well as source me a couple of keys. And when I finally get my hands on a WRX harness, I will make sure it includes the fuel pump harness.