anybody know about STI engine swap

[SILINC3R]

i want to try and get 200 hp out of my car with out going turbo. i have figured that maybe i will try and do a Sti engine swap with the cluster swap. do i have to go AWD or can i stay FWD. this way the engine would be newer and it would be a 2.5. i couldnt find topics on this even though i know they are there.

[Arctic Assassian]

i want to try and get 200 hp out of my car with out going turbo.

Not happening.

[SILINC3R]

lol. ah come on why not. enev if i go with a 2.5 liter sti engine, biger exhaust from headers all the way back, full CAI, lighter pulleys, and of course afterburners .

[kimokalihi]

I don't think it's worth it. If you're going to go to all that trouble with a FWD just sell the car and buy a honda civic and throw in a turbo swap motor.

[93forestpearl]

You want 200 hp out of a turbo motor without the turbo? Forced induction engined are designed for just that, forced induction. Without a turbo, the motor makes jack shit for power.



If you really want to, you could get a single cam N/A 2.5. Matt Monson was making a bit over 150whp on one with cams, headers, and some mild porting.


To make power naturally aspirated, you need compression, displacement, and revability, and flow. Compression and revability being the big two. And Subaru engines do not lend themselves to high rpms like a Honda.

[GeneralDisorder]

The only replacement for displacement is forced induction..... in fact that's not even technically a replacement because forced induction increases displacement by increasing atmospheric pressure and allowing a larger volume of air (if it were at atmospheric pressure) to occupy the same cylinder space. It's like running your engine on Jupiter and driving on Earth.... if you can grasp the analogy.

High RPM's are a gimick to get power from an engine that's destined to fail in short order. And you lose your torque down low so you burn up clutches and tires trying to get moving when the guy with low-RPM torque or AWD is already gone. This is why Honda's suck at pretty much everything. They have no torque down low, no grip, and they aren't symmetrical so their weight distribution stinks. Plus they are ugly. Why so many people tune them is beyond me.

GD

[93forestpearl]

I dunno. A friend of mine makes about 680 whp in his EK hatch and owns a lot of big dogs. And he can drive it.


builtnotbought

[555BCTurbo]

High RPM's are a gimick to get power from an engine that's destined to fail in short order.

Incorrect statement...


I'm not even going to go into the reasons why...all I can say is get a book on how engines work

[BAC5.2]

The only replacement for displacement is forced induction..... in fact that's not even technically a replacement because forced induction increases displacement by increasing atmospheric pressure and allowing a larger volume of air (if it were at atmospheric pressure) to occupy the same cylinder space. It's like running your engine on Jupiter and driving on Earth.... if you can grasp the analogy.

High RPM's are a gimick to get power from an engine that's destined to fail in short order. And you lose your torque down low so you burn up clutches and tires trying to get moving when the guy with low-RPM torque or AWD is already gone. This is why Honda's suck at pretty much everything. They have no torque down low, no grip, and they aren't symmetrical so their weight distribution stinks. Plus they are ugly. Why so many people tune them is beyond me.

GD

Kind of new to the automotive world, are ya?

[BXSS]

The only replacement for displacement is forced induction..... in fact that's not even technically a replacement because forced induction increases displacement by increasing atmospheric pressure and allowing a larger volume of air (if it were at atmospheric pressure) to occupy the same cylinder space. It's like running your engine on Jupiter and driving on Earth.... if you can grasp the analogy.

High RPM's are a gimick to get power from an engine that's destined to fail in short order. And you lose your torque down low so you burn up clutches and tires trying to get moving when the guy with low-RPM torque or AWD is already gone. This is why Honda's suck at pretty much everything. They have no torque down low, no grip, and they aren't symmetrical so their weight distribution stinks. Plus they are ugly. Why so many people tune them is beyond me.

GD

+1 with what 93forestpearl said.

I have personally seen a EG Civic drive to the 1/4 mile track bolt on a pair of slicks - run 10.0-9.99's multiple times with a full interior, & drive back home afterwards.
I bet the 60' times were not great but the car still ran 9.9's.

Not many Subarus are doing this.

Some Co claimed to hit 300HP N/A - the detail are on RS25, but I'm sure the cost was insane.

[SILINC3R]

I don't think it's worth it. If you're going to go to all that trouble with a FWD just sell the car and buy a honda civic and throw in a turbo swap motor.

sorry but i dont do civics, S2000 yes but not a Civic
ok so maybe 150 or 160 maybe ok for me, but i dont know if i want turbo on this motor. maybe i will stop complaining once i get a 2.5 rs.

[GeneralDisorder]

As RPM increases, mechanical wear increases. That's a basic principle of reciprocating piston design's. Why do you suppose there's almost nothing on the consumer market that will rev past 7500?

You can build tiny little engines to do high-RPM but you will shorten their lifespan.

And as for the 10 second civic - big deal - I never said they couldn't do it - just that it's a stupid format to tune. I've seen 5.0 mustangs pull 8's. There are plenty of Impreza's among those that can pull as well as any civic.

GD

[SILINC3R]

so should i just be happy and try and get 150 or should i get a turbo and go for that 200 mark

[555BCTurbo]

You can build tiny little engines to do high-RPM but you will shorten their lifespan.

Ah...so if those pesky Honda engines didn't rev so high they would last 500k miles instead of only250k...




I'm sorry, but something that makes 175hp out of 1.6 liters, gets 35+ miles per gallon, and lasts for 200k+ miles seems like a pretty damn big deal to me

[BAC5.2]

Why do you suppose there's almost nothing on the consumer market that will rev past 7500?

There is a TON of stuff on the market that crests 7500RPM. Hell, BMW even passed that by 750RPM on a big honkin 5.0L V10!

[kimokalihi]

so should i just be happy and try and get 150 or should i get a turbo and go for that 200 mark

Yes, turbo it! Otherwise you'll end up dissappointed in the end after dumping lots of money into it.

[GeneralDisorder]

Ah...so if those pesky Honda engines didn't rev so high they would last 500k miles instead of only250k...

Yes. But I was referring to the modified Honda engines. Show me one that will last 250k *after* modification, running 10,000 RPM and pulling 10 second 1/4's.....

I'm sorry, but something that makes 175hp out of 1.6 liters, gets 35+ miles per gallon, and lasts for 200k+ miles seems like a pretty damn big deal to me

They have their qualities for sure, but their drawbacks are far greater. The transverse FWD layout is limited in what it can do effectively.

GD

[93forestpearl]

Every engine design has it's drawbacks. Cripes, Subaru engines tend to eat rod bearings like candy due to their inherent design. Thats why this community goes for displacement.


Honda engines due extremely well for what they are. I'm amazed at the 8k redline with being a fairly undersquare motor. I was really surprised at how small the bore is on those things.








Show me any engine that can pull 10's and run for 250k. In this game, nobody leaves their setup alone for that long, or goofs something up and pops it. It's the nature of the mod bug. Don't come here preaching that one mark is soooooo much better than the other, blah blah blah. True enthusiasts respect any and all types cars that have heart and soul into them. I'll even give the low rider guys props sometimes. Have you ever cleaned 5 gallons of hydraulic fluid out of a car?

[drewriviera]

Well, the only thing I can say is that pretty much the same concepts that matter on an American made 1970's V8 could work....IF you had the cash You could put together some kind of hybrid 2.5, and make some custom pistons to get about 10 or 11 to 1 compression ratio, headers, some kind of custom grind cams, stuff like that. Of course this would cost out the ass, but how cool would that be to hear a Subaru engine with 11 to 1 compression? That would sound MEAN!! The problem with all this is that even building your engine like this, if you wanted to run it with the computer, it would be a pain. Ultimately you would probably only get it to run maybe a little better than a stock turbo motor with a lot of custom work to do on it. Compression is your biggest priority when not using a turbo.

[skid542]

^^^

EJ25 shortblock, $800?
EJ22E heads, $100
Delta cams, $200
Equal Length headers, $300
Head Porting, $300

Total - $1700, minus gaskets

Result, ~200 whp

This is a relatively common setup. A member here sold his car with a similar setup and is claimed to own at Auto-X. It's a has a lot of torque.

A search for Frankenstien Motor will probably dig up a bit of info from the work that Doug or Matt did on this setup.

[GeneralDisorder]

Every engine design has it's drawbacks. Cripes, Subaru engines tend to eat rod bearings like candy due to their inherent design. Thats why this community goes for displacement.

Almost all piston engines eat rod bearings first. It's just the nature of reciprocating designs. The loads on rod bearing surfaces are highly uneven and they oval out. The rest of the bearing surfaces in the engine don't have nearly the same loading problems - even the wrist pins usually last a long time as they only oscillate.

My point was only that without a turbo, you are severely limited in what a small displacement engine can do effectively and safely. Forced induction allows you to change the displacement by changing the cylinder pressures, and thus effectively making the engine larger and more powerful. This comes at the price of higher cylinder pressures. A properly built engine though can last a long, long time with forced induction. The EJ22T has been known to last 300k in stock configuration.

Modification here and elsewhere of Subaru turbo engines are rarely done properly and thus most of them result in a reduced lifespan. For example - if you raise cylinder pressure's then you increase bearing loads. Oil pressure should be raised and potentially the bearing clearances should be changed to compensate. The proper engineering is generally not done as most of these modifications are done by non-engineer's without the background or experience necessary to fully understand what they are doing.

GD

[93forestpearl]

I guess we are getting after different points here, so touche.




You are correct in how people modify their cars and engines. The proper homework is rarely done and/or understood by people wanting to dive in and start changing things. Even with my engineering background, I've still had my occasional "oops." Nobody can think of everything, especially when relatively new to the game. There are always new things to learn too. Whenever I have a chance to grill a local Subaru engine builder, I do, because he has 15 years of hotrodding these things and has seen and made many many expensive mistakes, and knows what works vs. what doesn't. I wish I had talked to him before getting my pistons from Wiseco, but such is the game. Now I cross my fingers and hope none of my pins break or pin bosses crack.