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2000 2.5RS BRP
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Discussion Starter #23
So I guess the question I have is....

1993 Impreza L (1.8L SOHC Dual Port) SWAPPED to a 2.2L SOHC Dual Port from a 1990 Legacy...just used the 1.8 I/M and plugged the EGR line.

M90, mounted in place of the airbox.

TMIC from a WRX(stock TB location)

Now, will my 1.8 ecu handle a M90 on 5-6psi?

What wiring is involved?

More importantly...will my 200k 2.2L bottom end hold up to 6psi?

If so, will it make it 50k miles or 3k miles?

Lastly, how do I adjust timing on a car that doesn't have a knock sensor and has a coil pack?

I understand low charge temps/ cold plugs/ oil cooler...But what about running a Meth/Water injection kit on that TMIC? Will I increase my motors odds of longevity?(assuming the meth/water doesn't crap out at 6k rpm under 6psi)

any help would be greatly appreciated...

:projectsti.com:
Signs of life, but is it intelligent? :p ;)

I'm not promising you anything with a 200k bottom end :p. You have something that likes the next gear as opposed to liking redline. They do go 300k+, though. Get it plenty of fuel like the rest of the others. Yours shouldn't need the timing adjustment as a precaution or even water meth. Add fuel with that intercooling and you're good at 5-6psi. Enjoy. 02+ ECU behavior, fuel quality, AND piston machining are what does them in. It's a combination of things preventing them from being boosted as easily.

I like 1.8 ecus for being dumb with lots of timing advance. Well built stuff can still go under these ECU combinations. You can run up to 18psi of boost on all of them just like the factory stuff. It's just more time consuming to get it right.

The 1.8L ECU has an aggressive timing curve. Water/meth in theory does fine on any combo. I've always hated their required and untimely upkeep. BTW, you can't run water/meth through an intercooler. Place the nozzle downstream of the intercooler. THIS IS ALSO NO SUBSTITUTE FOR A LEAN AFR! Detonation is more often caused by a lean AFR than bad fuel quality. Quality and excess heat are tied for second in what is a 3-way battle to kill your engine! Keep all of them from winning that battle!

I've pushed for more focus on available ECU timing and fuel quality because it helps so much. They are SO happy they break transmissions, diffs, axles, clutches, etc. 250hp on 8psi is a snap with good fuel...a snap of something ELSE vital ;). The only reason you need to retard the timing at all is available fuel quality, not necessarily a "fault" of too much timing or even the pistons. 5-6psi you don't really need timing retard. The mix of defensive measures and appropriate tuning change per year range and with how much power you want. I tried to highlight those differences.

Plan it right and you can take advantage of aggressive timing. Stop the pinging anyway you can. I prefer prevention. The settings are aggressive enough in these combinations to see gains from good fuel. Water/meth works in favor of more timing but only to a point. It will always be a band-aid, IMO. Heat is the straw that breaks the camel's back. Intercooling is more reliable than water/meth, even though you could run water/meth with no intercooler.

BTW, these combinations are still thirsty like any other boosted subie. If you go from a catted downpipe to a catless or from a stock airbox to a hi-flow unit, you're going to need more fuel. The most gains to be had with a scoob are really from airflow, not boost. Better airflow also restrains detonation from better temperature control. With that improved airflow comes the demand for more fuel, though. So, again, never forget the fuel...

Trivia: A 600hp/tq Subie on E85 going around the track at full blast gets approximately 2mpg. Yes, 2mpg.


etc..

A turbo and supercharger? You're on your own, like everyone else who has tried it. These are best as "geeky" combinations. One or the other. 5psi from either will hopefully keep you entertained. 5psi won't take all of your money and demand alimony. It can also be reliable and enjoyable for the life of the car. Keep the boost low and learn how to tune the engine. I get creative because I can and know how. Everything you're reading here is what was first shown to me boosting the older cars. The ones still on the road all still follow these same basic rules. You can just get in and go. It's boost without the babysitting.
 

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1993 Impreza L WAGON!!!
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Signs of life, but is it intelligent? :p ;)

I'm not promising you anything with a 200k bottom end :p. You have something that likes the next gear as opposed to liking redline. They do go 300k+, though. Get it plenty of fuel like the rest of the others. Yours shouldn't need the timing adjustment as a precaution or even water meth. Add fuel with that intercooling and you're good at 5-6psi. Enjoy. 02+ ECU behavior, fuel quality, AND piston machining are what does them in. It's a combination of things preventing them from being boosted as easily.

I like 1.8 ecus for being dumb with lots of timing advance. Well built stuff can still go under these ECU combinations. You can run up to 18psi of boost on all of them just like the factory stuff. It's just more time consuming to get it right.

The 1.8L ECU has an aggressive timing curve. Water/meth in theory does fine on any combo. I've always hated their required and untimely upkeep. BTW, you can't run water/meth through an intercooler. Place the nozzle downstream of the intercooler. THIS IS ALSO NO SUBSTITUTE FOR A LEAN AFR! Detonation is more often caused by a lean AFR than bad fuel quality. Quality and excess heat are tied for second in what is a 3-way battle to kill your engine! Keep all of them from winning that battle!

I've pushed for more focus on available ECU timing and fuel quality because it helps so much. They are SO happy they break transmissions, diffs, axles, clutches, etc. 250hp on 8psi is a snap with good fuel...a snap of something ELSE vital ;). The only reason you need to retard the timing at all is available fuel quality, not necessarily a "fault" of too much timing or even the pistons. 5-6psi you don't really need timing retard. The mix of defensive measures and appropriate tuning change per year range and with how much power you want. I tried to highlight those differences.

Plan it right and you can take advantage of aggressive timing. Stop the pinging anyway you can. I prefer prevention. The settings are aggressive enough in these combinations to see gains from good fuel. Water/meth works in favor of more timing but only to a point. It will always be a band-aid, IMO. Heat is the straw that breaks the camel's back. Intercooling is more reliable than water/meth, even though you could run water/meth with no intercooler.

BTW, these combinations are still thirsty like any other boosted subie. If you go from a catted downpipe to a catless or from a stock airbox to a hi-flow unit, you're going to need more fuel. The most gains to be had with a scoob are really from airflow, not boost. Better airflow also restrains detonation from better temperature control. With that improved airflow comes the demand for more fuel, though. So, again, never forget the fuel...

Trivia: A 600hp/tq Subie on E85 going around the track at full blast gets approximately 2mpg. Yes, 2mpg.


etc..

A turbo and supercharger? You're on your own, like everyone else who has tried it. These are best as "geeky" combinations. One or the other. 5psi from either will hopefully keep you entertained. 5psi won't take all of your money and demand alimony. It can also be reliable and enjoyable for the life of the car. Keep the boost low and learn how to tune the engine. I get creative because I can and know how. Everything you're reading here is what was first shown to me boosting the older cars. The ones still on the road all still follow these same basic rules. You can just get in and go. It's boost without the babysitting.

Thank you. Thats what i needed to hear, im not looking for crazy boost, just some extra low end grunt with throttle response, thats why i want a blower. I only asked about meth inj because i know it can greatly reduce charge air temps which youre saying is very important. I have seen the aftermath of a failed meth kit and it was expensive lol. So more fuel, GOOD fuel, cool intake temps and cold plugs. Not much boost and dont rev the piss out of it, sounds like common sense to me. Chances are, ill be running a cone filter just bc of fitment issues and my stock manifold along with a mild exhaust. I want a nice little power increase that can still be a nice reliable DD. Im very grateful for the advice, when I get around to this in the summer months, ill post my work as best i can in a step by step tutorial. since there isnt one for exactly what i want.
 

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01 STM RS EJ257, 6MT, Brembos
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Good writeup. I agree with it based on my turbo'ed EJ25. I however have a low compression build and have been running 12 psi for a few years (up from 8 psi for a few years previous) and it is still very healthy. So healthy it destroyed 3rd gear in my transmission last month. I'm using an EJ22T ECU to control the motor, so there has been very little tricking of the ECU to make it run, the ECU knows what boost is and how to tune for it. I am making the switch to standalone EMS soon and am planning to run nearly 15psi, I am confident the motor can handle it.
 

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2000 2.5RS BRP
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Discussion Starter #27
Also, when you say good fuel, do you mean 93/94 or head to the racetrack? Could i get away with 93/94 with a octane boost?
Everything I have referenced is for premium pump. Upwards from there are more gains from good fuel. E85, 100, or 104 is what I had in mind for better fuel. E85 is everywhere around here but not so in other parts of the country. Good fuel lets you take advantage of the aggressive timing presets by making more torque.

8psi on high compression would be the comfortable limit of pump gas. Lowering compression lets you run more boost. That rule doesn't change. For those looking for more, you indeed can run up to 18psi just like any other boosted factory scoob. Controlling injectors larger than 440s is the problem. 565s don't idle well on the stock ECUS. It's also easier to graft secondary injector controllers onto older ECUs. The right equipment under these older ECUs can make 350-400hp still on the stock ECU. Boosting the older cars teaches you all about the mechanical side that the WRX n00bs sorely miss. It's not all about who you paid to "tune your map". It's about the parts you use.

Thank you ALL for being genuinely interested and not a bunch of spoiled trustifarians. You will gain more confidence and knowledge to work on, repair, and modify your own vehicle while said trustifarian runs up his cellphone bill with his "tuner".
 

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In your experience, with a solid tune, what are the first parts to fail in a hybrid turbo motor? As I said a couple posts back, I'll be going for 15psi with a solid tune on my low-comp motor build using EJ22T/EJ25 internals. I have heard the EJ22T rods are the weakest link. Of course my block is open deck, but I don't usually see people cracking their piston sleeves very often.
 

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Discussion Starter #29 (Edited)
Further ramblings...

You could cruise around on wastegate with a happy commuter and save 15psi for when you really mean it. Think about the sources of heat and how often you really need to use them. Cruising around town, you don't need scramble boost. Even 15psi all the time kills them quicker. If you want 100k from it, then go for it. If you want 300k from it, learn to use wastegate boost.

You also really can tickle 500ft/lbs on vf turbos at 18-21psi but the transmission and engine don't last. The top end also sucks. A 6spd or built auto is required for that. The ones on 5spds that live are smart about it, honestly. The mountain of torque is in the midrange where a rally car needs it. It's a very solid midrange punch that is eager to get to the next gear. Even with good fuel the engine still takes a beating. That's also the hairy edge even with good fuel. It's not possible on pump gas, IMO. 0-150mph on a REALLY well tuned combination happens in about 20 seconds. Low boost on pump gas takes about 30 seconds.

Any intercooler or fuel really HATES 400F discharge temps. Overworked compressors are the #1 source of intake heat. 14-18psi on stock turbos is where it performs optimally when pushed hard. They are quite happy on lower boost levels, too. When you ease restrictions of stock top mount intercoolers, use a bigger downpipe, or port the stock header, then every boost level performs better. Two things piss off a WRX owner that just lost to you: the fact that you are on less boost--or worse--no boost at all...

Easing airflow restrictions reads as less boost when done on the intake side. The air is going in easier. On the exhaust it can raise or lower boost levels depending if there was a restriction before or after the turbo. You guys with bolt on kits to USDM n/a wishbones should heavily consider header port work at the exhaust flange. That pressed fit pipe is horrible for exhaust flow. Headers with this mod have no carbon deposits in that area other than a film of soot. Where carbon builds up in chunks is where soot and fuel have been collecting, like every stock header has :unamused:. When fixed, the exhaust pushes more efficiently against the turbine. It improves scavenging of the cylinders and lowers operating temperatures. Little detailed stuff like this is almost more like "grooming" the combination than "tuning" it.

When you work on all of these little inefficiencies, power goes up without really stressing the motor or turbo. More boost means squat next to more airflow. Newer stress levels goes to the driveline instead. The target boost levels you used to see now perform more efficiently and lag virtually disappears. There are lots of gains to still be had in part throttle, mileage, and turbo response. If anything increases on a dyno, its torque. What comes easier is drivability and the next gear you need :).

Consider yourselves on notified, too. We're about to unveil our complete modular water intercooler systems. A few heat exchanger frames went out the door quickly for custom projects already. SEMA in November was wonderful. We are about to be able to ship the same day for most of our newer completed systems. Announcements were to wait upon reaching that point and we are there this week. People are very capable of assembling their own water intercooler sytems. Making a quality heat exchanger was always the most challenging part of the job. We took care of that while still addressing a tinkerer's needs :). No more welding up a box that can't do the job efficiently in the first place. You subie heads won't be forced to cut your firewalls for iced intercoolers anymore. There's tabs and bosses incorporated into the designs. The inlet/discharge castings are universal and can be rotated different ways on the assembly. Our 600hp capable heat exchanger is still only 1.25in. tall! At this point a subie is still my faster toy of choice. Decisions decisions...

Booyah! ;)
 

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GF OBS-T, GM RS EJ20, SF EJ20
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SubieNate--The lower the compression the more you can get away with. A 205 at 14psi is no comparison. Those are much quicker. Boosting an older Subie nowadays involves a swap or working with what you've got on the cheap. The nice thing is that you could put just a 2.0L short block under old school heads and keep everything you just built.

You always end up doing some kind of maintenance anyway. It's best to do what you know you're going to need to do first. Turbo pipes can make the passenger rear cam seal a real pain. I have to do a kitchen sink very shortly at 105k. Maintenance bites everyone eventually.
I Never Noticed this Nice write-up.

Not sure what a ej205 with a td04 @ 14psi runs in the 1/4 mile in a GF OBS wagon but my 1999 single port ej222 OBS ran 13.31 in the 1/4 @ 10psi of boost with a running weight of 3050lbs with me in the car.

I've been boosting this wagon since 2004 using a HKS EVC to switch between my 4.5psi base boost level & my high boost setting.
 

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I'm very new at this guys.I would like to know if I can do a low compression build with my stock 2000 RS block and just swaping sti pistons and rods.will the rods and piston from an STI fit in my RS block?
 

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1993 Impreza L WAGON!!!
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Discussion Starter #35
Excellent read. What do you think of the EJ22E and EJ25 DOHC combination for turboing OP?
Not sure about that one. My nose tells me you'll have a low compression combination good for up to 18psi. EJ25 heads on anything smaller displacement usually drops the compression A LOT and messes up the quench area a bit. The lowest compression ratio I've heard of on stock parts is 7.8:1 for EJ25 SOHC heads.

I honestly don't keep up with every engine code and combination. Most of what I put here was recalled from memory. A project for you guys might be listing the different combinations and their compression ratios.
 

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Makes me sad I bought an 04 RS, I came so close to getting a Black 01 RS coupe. For starters I need a new intake manifold and pistons.

Also for the 1.8L sohc, are those single port exhaust? or do you use different heads? Do they even make a single port turbo manifold?
 
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