nikn

Hello everyone, now that im actually getting a "saabaru" after debating over a used is300 and 240sx i guess i can start fantasizing about turboing my new NA car. Oh yea, im new here :-p... hope this turns out ok for a first thread...

The title says wagon rs... but its actually a saab linear... same engine. I am really interested in turboing this car, although i realize i wont be doing it anytime soon. I was just wondering about the new 2.5rs impreza engine management system.

Im guessing the engine uses a MAF to measure airflow? If it does, what hp does it max out at?

How big are the injectors [lb/cc] or how much hp can they handle. Is the stock fuel pump any good?

On a side note, will wrx/sti exhaust parts fit onto a 2.5rs, particularly the headers and up-pipe?

If i were to turbo the car i prolly wudnt push it past 6 psi. Sorry if i missed anything or everything using the search button. Thanks in advance!

GotBoost?

iTrader: (3)

first off, why dont you just by the 9-2x that is already turbo'ed? save yourself a headache or 2 and probably some money as well.

Secondly, dont forget, there IS a difference between a n/a block and a turbo block, as well as the heads and pistons. A turbo block is re-inforced more to be able to handle the boost pressures, and they are inherently a lower compression block than an n/a block.

Next, I'm not sure if the 2.5rs ECU has parameters to control boost, its a different ECU than the WRX one.

the stock MAF can handle HP numbers up to around 320 at the wheels depending on the setup of the car. So thats close to 400 bhp.

Stock injectors on a WRX are around 440cc/min, and are good up to around 215-230whp, same with the fuel pump. The most common fuel system upgrade is the STi Pink injectors (565cc/min) with the walbro 255 fuel pump. This system is probably good up to around 280whp, too much more than that and you need bigger injectors, but the fuel pump will still be ok.

The headers and uppipe....not really sure about fitment on the 2.5rs....never tried it, but I dont see why it wouldnt work...the engine layout is the same as the WRX/STi.

So if you were to turbo the car why only go to 6psi? That is hardly even worth the amount of work that it will take to convert your car over, only to gain about 30-40hp if that......for comparison sake....on a bone stock WRX you can gain about 30-45whp by doing nothing more than reflashing the ECU.

My opinion, and recommendation to you would be to just pay a little more and get the 9-2x that already has the turbo setup....I think you'll be much happier in the long run.

-Ted

nikn

thanx for the info. There arent any manual aero's left. The only manuals i cud find are linears. Trust me i searched wide and far, the dealer i got my car from is 2 hours away from me, in a different state.

any info on 2.5rs injector sizes?

Dynapar

alright heres what i knowon the subject.

ej25 NA injectors flow about 280cc/min, which is adequate. the AVO turbo kit uses teh stock injectors but keeps them open longer tog et more fuel into the engine. the stock fuel pump should be fine

as for exhuast it all depends on if you have dual or single port heads. (ie 2 holes on teh bottom of each head or one?) WRXs are dual port i believe. so if youa re single port you are SOL. not to mention that in order to use the WRX up pipe you will either need to swap in a crossmember from either a WRX/STi or a Legacy Turbo, or you can take the cutting torch to yours (i dont recommend this).

at 6 PSi you can get up to a 50% power gain from stock. wich should be about 200WHP which is more than a a stock WRX. not to mention the low end torque that you have to start with.

you might want to do alittle reasearch into premade kits, since they are far easier to work with then designing your own. however it will cost a lot more to get one of these pre-made kits. around 4k for a premade one, while if you are good at finding part you can put together a kit for less than 1k. granted it is way cheaper to make your own but the amount of time involved and the drop in reliability (1k is far to cheap to include engine management).

either way if you get one or make your own if you get a good EM system and a reliable tune you should have over 200 crank hp, and be reliable enough to drive it daily.

as for the blocks. the NA ej25 is an open deck engine (IIRC), which means there is very little reinforcemnt for boosting, but it wieghs less. this engine also runs at abot 10:1 compression ratio which gives it its NA power. turbo motors are reinforced and heaveir, and also run at lower compression to prevent detenation from boost.

by keeping your high compression and adding a small amoint of boost (6 or less) you will see dramatically greater HP gains then you will on a turbo motor, however since you are runign higher compression you also increase your chances of knocking/detonating. so you will need to get some timing/ignition control if you want to go over 6psi.

i have heard of people (cant rember names ight off the top of my head) that are runnign 6 psi with just an new fuel pressure regulator.

good luck and start doing some research

nikn

Thanks a lot Dynapar, that info you gave me answers a lot of questions and will keep me thinking for a while!