If you REALLY want to go all-out on the engine!

[DOHC46]

I just found out you can buy a full built Cosworth 2.5L EJ25. Probably costs twice as much as the 818 kit though. :p

http://americas.cosworth.com/products/performance-parts/block-assemblies/long-block-assemblies/

However, if you have the money, and are going to be doing a LOT of track days, I think it'd be worth it.

[longislandwrx]

A fully built cosworth longblock can cost upwards of $15k. Add an appropriate intake/turbo/injectors/manifold etc etc and you are easily over $20k

[Mechie3]

I'm of the opinion that some of their stuff is worth it, some of it you're paying for name brand.

[JRach]

With the following that the WRX has, there are MANY very reputable engine builders throughout the U.S. (and beyond) that are happy to use parts of equal quality at half the price. JE, Weisco, CP, Carillo and many other manufacturers make excellent pistons, rods, cams, valves/valve springs for these cars.
There's no need to shell out the $15k for a motor build when a reputable engine builder can make one just as good if not better to YOUR specifications for about half the price :)

[shim2]

You can buy a CW EJ25 longblock on ebay for 16 grand.

[Etos]

I just found out you can buy a full built Cosworth 2.5L EJ25. Probably costs twice as much as the 818 kit though. :p

http://americas.cosworth.com/products/performance-parts/block-assemblies/long-block-assemblies/

However, if you have the money, and are going to be doing a LOT of track days, I think it'd be worth it.

IMO not worth it. You can go to many good engine builders who will make a better engine for cheaper. You are paying more for a name then for quality parts.

Also not worth it for the sake of having a controllabe car. Big engine with big numbers means big turbo. I have a 570HP s2k that is pretty much untrackable. It's just too light for its power that comes out of nowhere. That's even with 265 tires in the rear, there's just no way to keep it under control in the turns under power. At least if it was more linear power delivery it could be manageble but it doesn't have it.

Also must bring up the other factors of price. So you got a big beefy 15k long block. Now you're gonna need an exhaust manifold that can use a big enough turbo. Then there's the turbo and intercooler. Now you're fuel system needs a massive upgrade from rails, lines, injectors, fuel pumps. Alright now you got that bad boy purring, but there's no way a factory 5 speed or factory clutch is gonna handle 600hp, so now you gatta either pony up for a very expensive mulitdisc clutch to have smooth engagements or go cheap and have a nightmare driving it. Also the big money it would cost to put new big beefy gears/diff. Let's not forget that now you're gonna need massive wheels/tires cause the car weighs so little yet makes so much power that there's literally no way to keep the rears from spinning.

Point being, once you make the engine big and beefy- you now have to make everything else big and beefy. It gets expensive FAST. Trust me, been there done that.

[metalmaker12]

Agreed, I know of many builders locally that have used all the above mentioned companies and they all work very well without going the Cosworth route. The thing with the 818 is you don't have to build it beyond factory specs. 300-400 whp is plenty of power for the track, and insane for the street in a 818kg ride. With proper traction and a good Lsd 300-400whp will get you low 11's with a top speed of 140-170 mph depending of transmission and motor used. It is a good pipe dream, but I thought this car was supposed to be affordable. A built engine is cool, but not needed, even if you got the money.

[AMW1011]

Agreed, I know of many builders locally that have used all the above mentioned companies and they all work very well without going the Cosworth route. The thing with the 818 is you don't have to build it beyond factory specs. 300-400 whp is plenty of power for the track, and insane for the street in a 818kg ride. With proper traction and a good Lsd 300-400whp will get you low 11's with a top speed of 140-170 mph depending of transmission and motor used. It is a good pipe dream, but I thought this car was supposed to be affordable. A built engine is cool, but not needed, even if you got the money.

Yeah, at that point a GTM build might make more sense. Hard to say, they should be very different cars in the end, if the 818 is done right.

[Evan78]

I thought this car was supposed to be affordableWhat's affordable varies with each person. Just because the kit is on the low end of the price spectrum doesn't mean every build has to be bare bones. If anything, the fact that the kit is cheap means there is more money to spend on other stuff.

[Evan78]

Yeah, at that point a GTM build might make more sense. Hard to say, they should be very different cars in the end, if the 818 is done right.As you said, they're very different cars, even putting price aside. 2500 pounds vs 1800 to start with.

[flynntuna]

Agreed, I know of many builders locally that have used all the above mentioned companies and they all work very well without going the Cosworth route. The thing with the 818 is you don't have to build it beyond factory specs. 300-400 whp is plenty of power for the track, and insane for the street in a 818kg ride. With proper traction and a good Lsd 300-400whp will get you low 11's with a top speed of 140-170 mph depending of transmission and motor used. It is a good pipe dream, but I thought this car was supposed to be affordable. A built engine is cool, but not needed, even if you got the money.

Isn't it true the street version of the corvette zr1 has less horsepower than than the track version?

[NonProfit]

It gets expensive FAST. Trust me, been there done that.

This is a great reminder, thanks Etos!

[metalmaker12]

Isn't it true the street version of the corvette zr1 has less horsepower than than the track version?
Yeah but of coarse the street version has less power.... My point was why would you want anymore than 400whp in this very light car. Also if you build a motor, you don't have to spend more than 7k to get a awesome combo. Example a ej207 version 8 spec c heads with jun 264 cams and a stock bottom end and stock vf37 turbo with a good tune can get you over 400whp for like 5,500 and last you a long time. Why I say bottom end "stock" you wonder. Forged pistons are great for 400 plus hp, but they wear the rings out at about 60k or sooner. They are great for an engine you take apart a lot and build over and over, but not good for a car you drive daily and want to last. If your out to make insane power and like taking the engine apart, get a legacy 2.2 closed deck block and build it to the hills. Most tunes can get 500-700 reliable whp with a gt30 turbo kit and good fuel system etc etc. Shops have gotten over 1,000hp with them.

[Etos]

Yeah but of coarse the street version has less power.... My point was why would you want anymore than 400whp in this very light car. Also if you build a motor, you don't have to spend more than 7k to get a awesome combo. Example a ej207 version 8 spec c heads with jun 264 cams and a stock bottom end and stock vf37 turbo with a good tune can get you over 400whp for like 5,500 and last you a long time. Why I say bottom end "stock" you wonder. Forged pistons are great for 400 plus hp, but they wear the rings out at about 60k or sooner. They are great for an engine you take apart a lot and build over and over, but not good for a car you drive daily and want to last. If your out to make insane power and like taking the engine apart, get a legacy 2.2 closed deck block and build it to the hills. Most tunes can get 500-700 reliable whp with a gt30 turbo kit and good fuel system etc etc. Shops have gotten over 1,000hp with them.

Lots of misinformation there. There has never been a VF37 to ever come close to 400WHP. And even if that was the case, you'd still need a much better fueling system from injectors to fuel pumps. You would still need to beef up the trans to handle 400WHP as well. Forged pistons don't wear out rings, dropping in a set of pistons without measuring anything wears things out. Also never heard of a GT30 ever getting to 500WHP in a subaru, yet alone even 700. Very few shops have EVER gotten to 1000hp with a subaru block and those that do are so outright built it's not even funny the money that went into the engine yet the rest of the car to be able to support 1000hp.

Just take a look around this forum to get an idea of what it takes to even get 500whp: http://forums.nasioc.com/forums/forumdisplay.php?f=79

And an example of the parts needed to get 535WHP: http://forums.nasioc.com/forums/showthread.php?t=2415860 That's with a 35r, 272 cams, 1mm oversized valves, built block, exhaust, intake, meth injection and a $2600 ECU. It's not even funny how many people I spoke with who think it takes very little money to hit 500whp in a subaru cause some EVO was able to do it. EVOs are easy to make big power, subarus are not.

[el_jefe]

Isn't it true the street version of the corvette zr1 has less horsepower than than the track version?

Actually, the ZR1 has more hp than any of the road racing Corvettes that I know of.

[flynntuna]

Thats what I thought, got the question backwards.

[jimgood]

Actually, the ZR1 has more hp than any of the road racing Corvettes that I know of.
I thought I remembered reading that the ALMS Corvettes had to dial back power to allow others to be competitive or something like that.

All this talk about big power makes me wonder if anyone thinks about the safety ramifications. This car will not have the aerodynamic limitations that are present in the FFR Challenge cars. 350 horsepower might mean a car that's capable of hitting 160 at the end of a straight vs. 140. I don't know how significant a difference 20 mph makes when you run out of talent. But I think you have to take that into consideration with respect to the safety structure.

[metalmaker12]

Your mistaken , but i am not hear to point fingers blah blah Dsm blah.my info comes only from facts. I will be loading dyno sheets from wicked innovations in ri. Not only have they gotten 375 whp out of a stock ej207 but 565whp out of a 2.2 legacy built block, complete fuel system and built heads mated to a built Tranny for some coin but not even 20k. And it is not completely true that it cost more to get serious power, there have been numerous current comparisons that it is cheaper to get moderate power out of a subaru than a Dsm. It is true to get to 1000hp in any motor cost retarded money. And it is true that forged pistons wear out rings faster than hyperkinetic pistons no matter how good the engine build is. There are countless articles on this , and honestly not even worth taking about. Here we go another Dsm junky, jk I have owned one once. You can get very similar power out of both with around the same amount of coin put in. I also never said how long the engine would stay together on a tune to get around 400whp out of a stock ej207 with a vf37, just saying it has been done. My original point was to say that you don't need crazy power in the 818. Also I could care less about a zr1's track vs street power, I am a Subaru,Ford and Honda guy, not into vettes.

[metalmaker12]

Anyway,no hard feelings, but this is a Subaru based kit car

[langsbr]

I don't see a vf37 making 400 rwhp on anything, lol. I had a V7 STI motor in my WRX, and the turbo was similarly sized, just not a twin scroll. You need a 20G at a minimum to hit a true 400 RWHP. I've seen some guys make 350ish on E85 with the vf37.

I think that would probably be one of the best routes to take - JDM STI (I like the V7 since it has forged pistons vs cast in the V8), 16 or 20G on E85 - that would be LOADs of fun and have gobs of torque (relatively speaking - the 207 motor doesn't make torque like the 2.5 at all, lol).

[Etos]

Your mistaken , but i am not hear to point fingers blah blah Dsm blah.my info comes only from facts. I will be loading dyno sheets from wicked innovations in ri. Not only have they gotten 375 whp out of a stock ej207 but 565whp out of a 2.2 legacy built block, complete fuel system and built heads mated to a built Tranny for some coin but not even 20k. And it is not completely true that it cost more to get serious power, there have been numerous current comparisons that it is cheaper to get moderate power out of a subaru than a Dsm. It is true to get to 1000hp in any motor cost retarded money. And it is true that forged pistons wear out rings faster than hyperkinetic pistons no matter how good the engine build is. There are countless articles on this , and honestly not even worth taking about. Here we go another Dsm junky, jk I have owned one once. You can get very similar power out of both with around the same amount of coin put in. I also never said how long the engine would stay together on a tune to get around 400whp out of a stock ej207 with a vf37, just saying it has been done. My original point was to say that you don't need crazy power in the 818. Also I could care less about a zr1's track vs street power, I am a Subaru,Ford and Honda guy, not into vettes.

Ok, I'll agree that a razor edge tune can make the dyno sing high numbers. But I assumed we weren't comparing completely balls to the walls I don't care if I break my thousands of dollars worth of stuff tunes to safe and reliable tunes that will keep everything lasting very well. You sure as hell never made that distinction that you were not talking about safe tunes. Honestly that is IMO a horrible thing to do. It's leading people on to believe they can attain something they clearly can't without major risks.

For instance a completely from the factory 257 long block can make 600HP, it's been done. No one should ever expect it to hold that kind of power for even 100 boosted miles. That is essentially what you told people. Go ahead and take some risks it's ok, don't worry about spending money on something that will not break, you'll have a blast before that happens!

[metalmaker12]

Ok, I'll agree that a razor edge tune can make the dyno sing high numbers. But I assumed we weren't comparing completely balls to the walls I don't care if I break my thousands of dollars worth of stuff tunes to safe and reliable tunes that will keep everything lasting very well. You sure as hell never made that distinction that you were not talking about safe tunes. Honestly that is IMO a horrible thing to do. It's leading people on to believe they can attain something they clearly can't without major risks.

For instance a completely from the factory 257 long block can make 600HP, it's been done. No one should ever expect it to hold that kind of power for even 100 boosted miles. That is essentially what you told people. Go ahead and take some risks it's ok, don't worry about spending money on something that will not break, you'll have a blast before that happens!

Your right, my mistake for being misleading everyone, i was just getting suby excited.
But you can all get 300whp with a stock sti with a good safe tune that will last and last for like 4k-6k. My major point is a stock engine with a safe tune is all you need in the 818. I have own ej257's and ej207, if I were to choose one for the 818 It would be the ej207 due to the higher rev capabilities. This is just personal taste, both are great, even a usdm wrx engine is great with a nice tune. I have Avery low mileage ej207 sitting in my garage matted to a 02wrx rebuilt 5spd with a cusco LSD and act clutch kit. The engine will get an open source tune to make 300-325whp with the 818 setup. I will send a pic, going to take it

[metalmaker12]

Ok, I'll agree that a razor edge tune can make the dyno sing high numbers. But I assumed we weren't comparing completely balls to the walls I don't care if I break my thousands of dollars worth of stuff tunes to safe and reliable tunes that will keep everything lasting very well. You sure as hell never made that distinction that you were not talking about safe tunes. Honestly that is IMO a horrible thing to do. It's leading people on to believe they can attain something they clearly can't without major risks.

For instance a completely from the factory 257 long block can make 600HP, it's been done. No one should ever expect it to hold that kind of power for even 100 boosted miles. That is essentially what you told people. Go ahead and take some risks it's ok, don't worry about spending money on something that will not break, you'll have a blast before that happens!

Your right, my mistake for being misleading everyone, i was just getting suby excited.
But you can all get 300whp with a stock sti with a good safe tune that will last and last for like 4k-6k. My major point is a stock engine with a safe tune is all you need in the 818. I have own ej257's and ej207, if I were to choose one for the 818 It would be the ej207 due to the higher rev capabilities. This is just personal taste, both are great, even a usdm wrx engine is great with a nice tune. I have Avery low mileage ej207 sitting in my garage matted to a 02wrx rebuilt 5spd with a cusco LSD and act clutch kit. The engine will get an open source tune to make 300-325whp with the 818 setup. I will send a pic, going to take it

[metalmaker12]

Techancial difficulties, I have to resize, i am too big lol.

[metalmaker12]

Heres two pics of the ej207 and wrx 5speed
1222812229
I got a set of BBS 5x100 wheels with minor curb rash from my donor for 650 plus shipping if anyone is interested. 1,100 plus shipping if I clean them up, blast and repaint them a color of your choice.
12230

[Etos]

I don't believe you can go too small on the engine as far as any well running EJ engine for the 818. There's a very fun feeling about keeping that gas pedal pegged. To even get a p/w ratio of the STi(about 14 pounds per HP) you just need 130hp, much lower then any EJ there is. Even 300hp(which is not hard to get at all) is like having a 550hp STi. At 450hp, that's like having a 850hp STi. This car is going to be the epitome of low cost high performance for a long time.

[metalmaker12]

agree totally, with 300-450hp this car is going to be insane, i am getting build jitters, I hope it happens soon, I need a new project, just finished my shed and fence around my yard, got all my parts almost 100% ready and money to get the kit asap. I can't wait to peg it down and rev it up to speed very quickly.

[longislandwrx]

This thread was good for a Monday morning LOL. ESX built a 1000hp sti with a GT72... now they have a bigger turbo pushing 1400hp with a HUGE nitrous shot.

They have millions invested in their development program.

So yes anything is possible, it just costs a fortune.

[tirod]

Considering the whole point of the kit, and the initial reason Shelby American got started - simple power train in an undersized car = performance.

Cobra - 289 iron block iron head OHV motor.
Loser? Ferrrari with DOHC aluminum motor.

Frankly, if the 818 with Subaru motor can't get it done, spending 3X the kit price for exotic power won't either. The car should be considered as a whole. Look at the history of SA - they didn't need to push engine development much over the years, what changed much more drastically was the chassis and appointments. Coolers, pumps, brakes, wheels, etc etc. It was a transverse leaf front end from the '50s that beat Ferrari's double A arms, in the Coupe, with 289. Not some wild motor.

If you allow perspective to remain focused only on the power plant, then the rest of the car becomes a liability. It's never developed to match, and the exotic, expensive horsepower is wasted with poor handling and horrible traction issues. The fastest 818 will have a fully developed suspension, shock valving, optimized spring rates, great brakes, adjustable sway bar links, etc etc. You can't get that dumping cubic dollars down the throttle body throat trying to gain a few more hp. Use the ones you have, and the car goes faster, sometimes quite a bit cheaper. Compare the cost of a 65 Ferrari to a 65 Cobra, new in the day.

If you can't get the horsepower to the ground and control the vehicle at speed, then the motor has taken up too much of the budget.

[Xusia]

If you can't get the horsepower to the ground and control the vehicle at speed, then the motor has taken up too much of the budget.

Well said. And I totally agree...

[JAubin]

I'd be willing to bet that the highest performing 818s on a track will be well under 400hp. Having a really robust torque curve and useful power for the gearing, with a quick spooling turbo will all help track performance. A drag car might be more interested in just straight power, but it's pretty difficult to have a reliable 500 hp 2.5L that has instant power across the rev range. Plus as was said above when you start getting into those kinds of power levels, the ability to control the car comes into serious question... 300 whp on a car like this will be pretty impressive.

[bugeye_fever]

Im curious/ excited to see how the new subie FA series engines will integrate with the 818 in the future. Obviously we'll have to wait for a new wrx for the proper transaxle, but an updated engine design with DI, should be interesting. The FA20 in the brz/fr-s has been quieting all the naysayers with a few examples putting out over 400 wheel, one over 500 on stock blocks. I also believe that you dont need a huge hp number to have fun, but this is an engine thread after all.

[rjh2pd]

I've read that all of the ej transmissions will billy up to the new FA engines. Not sure if it's true our not, just what i heard

[DOHC46]

Ouch, I post a link to an engine I thought was cool, come back three days later and I've been fried to crisp! Jeez guys, I know it's completely unnecessary and overkill, but I still think Cosworth engines are sweet.

and for what it's worth I never said or implied that I thought you needed 500+ HP in these cars. I was thinking in terms of you could build that engine for 350ish HP and have it last forever with lots of track sessions.

[Silvertop]

Ouch, I post a link to an engine I thought was cool, come back three days later and I've been fried to crisp! Jeez guys, I know it's completely unnecessary and overkill, but I still think Cosworth engines are sweet.

and for what it's worth I never said or implied that I thought you needed 500+ HP in these cars. I was thinking in terms of you could build that engine for 350ish HP and have it last forever with lots of track sessions.

Don't take it too personally. Just some people having a little fun. And some guys WILL opt to build their cars with monster horsepower! :D

[bugeye_fever]

I've read that all of the ej transmissions will billy up to the new FA engines. Not sure if it's true our not, just what i heard

Believe me i wish it did: EJ
http://forums.nasioc.com/forums/showthread.php?t=1324209

FA 10th pic down:
http://www.ft86club.com/forums/showthread.php?t=3981

Its close, but not quite.

[longislandwrx]

Don't take it too personally. Just some people having a little fun. And some guys WILL opt to build their cars with monster horsepower! :D

yeah didn't mean to flame.. was just pointing out the cost of said motor.

[wjfawb0]

This place is turning into NASIOC. Signal/noise ratio is diminishing. ;)

[el_jefe]

This place is turning into NASIOC. Signal/noise ratio is diminishing. ;)

I hope not, I was banned from NASIOC

[shinn497]

If you REALLY REALLY want to go All out I say crawford 2.7 liter stroker (http://store.crawfordperformance.com/store/products/443). It is 18k....for the long block!

On a side note, metal maker I fully agree without on the ej207, it is the engine I really want to use.

Btw if you want a lightweight, expensive, mid-engine, sports car with a cosworth engine. Why not a BAC mono? (http://us.bac-mono.com/index.php) It is 75k, though...but it has cosworth!

[metalmaker12]

If you REALLY REALLY want to go All out I say crawford 2.7 liter stroker (http://store.crawfordperformance.com/store/products/443). It is 18k....for the long block!

On a side note, metal maker I fully agree without on the ej207, it is the engine I really want to use.

Btw if you want a lightweight, expensive, mid-engine, sports car with a cosworth engine. Why not a BAC mono? (http://us.bac-mono.com/index.php) It is 75k, though...but it has cosworth!

The ej207's sing a special tune for sure.

[DOHC46]

That's actually the engine that I've been wanting to use for awhile. Just a little worried about getting it to work from an electrical stand point. I dont know anything about Subie electrics.

[metalmaker12]

It is very easy, they plug and play and there are wire kits to support the differences..If you got questions PM me

[Thorne]

There are allot of under educated people claiming numbers that are off the wall. As a Subaru Pro Tuner I want to clear some of this up.

1st a 30r isn't making 500-700hp unless your spraying it
2nd The highes STi Turbo dyno I've personall done was 360awhp-425awtq on e85
3rd Unless your planning to make more then 450whp a Ej255/257 on e85 can safely do this
4th As a tuner I've driven 1000+hp Corvettes and Camaros on the street and they are a handful (zr1 is pinto by comparison)

400whp through a 818 in theory could run 9's in the 1/4 and will be a handful to drive period.

[MiniVanMan]

Thorne, how feasible is it to get 200 whp out of a EJ25* motor naturally aspirated?

I'm guessing, (and my skill level as a tuner is "pro guesser"), that a high compression, bored and stroked motor converted for E85 would be a really good start.

I've always wanted to do a naturally aspirated performance oriented motor, and I think a nice torquey motor with moderate horsepower would be a blast in a car like this.

[AJW Performance]

Quote Originally Posted by shinn497 View Post
If you REALLY REALLY want to go All out I say crawford 2.7 liter stroker. It is 18k....for the long block!

On a side note, metal maker I fully agree without on the ej207, it is the engine I really want to use.

Btw if you want a lightweight, expensive, mid-engine, sports car with a cosworth engine. Why not a BAC mono? It is 75k, though...but it has cosworth!


We have that motor in our STi, its great but not worth the $ for 95% of users IMO.

[DOHC46]

AJW Perf., do you guys have an idea on pricing for your donor kits yet? (I believe you guys are behind 818donors, if i'm not i'm terribly sorry)

[Thorne]

Thorne, how feasible is it to get 200 whp out of a EJ25* motor naturally aspirated?

I'm guessing, (and my skill level as a tuner is "pro guesser"), that a high compression, bored and stroked motor converted for E85 would be a really good start.

I've always wanted to do a naturally aspirated performance oriented motor, and I think a nice torquey motor with moderate horsepower would be a blast in a car like this.

It's possible to get 200whp out of the 2.5 but not easy. For the amount of money you will have invested in camming it and a tuning solution Id wager you could have just boosted it.

[Silvertop]

It's possible to get 200whp out of the 2.5 but not easy. For the amount of money you will have invested in camming it and a tuning solution Id wager you could have just boosted it.

That is almost certainly true. It would probably be easier and more cost effective to simply start with a WRX donor and leave it stock rather than get involved tweaking the NA engine. However, the benefit of the NA solution is a broader torque curve, simplicity, and no "heat soak" and other potential reliability issues. It's what I'm going for. My NA donor will get cams, some intake bolt-ons, a tune, and exhaust upgrades. And will likely not reach 200 HP at the wheels -- probably more like 200 flywheel HP. And I'll be happy, even though I probably didn't save any money.

[Gary in NJ]

However, the benefit of the NA solution is a broader torque curve, simplicity, and no "heat soak" and other potential reliability issues. It's what I'm going for. My NA donor will get cams, some intake bolt-ons, a tune, and exhaust upgrades. And will likely not reach 200 HP at the wheels -- probably more like 200 flywheel HP. And I'll be happy, even though I probably didn't save any money.

This is my approach as well. Porting and polishing the heads is probably worth the effort as well.

[Silvertop]

This is my approach as well. Porting and polishing the heads is probably worth the effort as well.

Yes, I agree. Porting and polishing will be worthwhile also.

[AJW Performance]

AJW Perf., do you guys have an idea on pricing for your donor kits yet? (I believe you guys are behind 818donors, if I'm not i'm terribly sorry)

Yes sir you are correct!
It is all about what you are looking for, but they have ranged from 5,000.00 (Base donor) to 14,000.00+ (built block, Stg3, + more) thus far, depending on what the customer adds on or wants. You can build these for 15,000.00 completed or 30,000.00+ of course, just depends on your budget or what you are looking for. Shoot us a message if you are looking for a more specific estimate based on your goals for the platform.
info@818donors.com

[MiniVanMan]

That is almost certainly true. It would probably be easier and more cost effective to simply start with a WRX donor and leave it stock rather than get involved tweaking the NA engine. However, the benefit of the NA solution is a broader torque curve, simplicity, and no "heat soak" and other potential reliability issues. It's what I'm going for. My NA donor will get cams, some intake bolt-ons, a tune, and exhaust upgrades. And will likely not reach 200 HP at the wheels -- probably more like 200 flywheel HP. And I'll be happy, even though I probably didn't save any money.

A lot of what I'm thinking. I'm wanting/willing to throw some good coin at it. Yeah, I know a turbo can get there cheaper and easier, but I think "broader torque curve" is very often underappreciated. I see dyno charts where people are drooling over some high HP number that's really only usable within a very small powerband.

There's also a limited amount I actually want to use from the donor. I'd like to upgrade the brakes (necessary or not, it's an aesthetic thing). Different seats, steering wheel, and a lot of aesthetic upgrades that would make getting a standard Impreza, or even Forester, a much better, and cheaper option than finding a WRX donor. I can take that savings and throw it at upgrades.

Either way, I've always wanted to do an overbuilt NA engine, and this car provides an amazing platform with boundless potential.

I was looking at TWE Performance and they do some NA engine packages. Expensive for sure, but you'll get a high compression engine (11.2:1) with ported and polished heads, cams, balancing, etc, etc. I could probably shop around and get the price down, as I'd like to bore and stroke the engine as well. Element Tuning will do a big valve job on the heads, increasing them another 1 mm. They're claiming 20% increase in flow on the exhaust side. That's a $1,700.00 job.

From Element Tuning website


Many may ask why don’t you port the intake ports fully? We don’t do this because almost 100% of the gain is realized by just fitting the larger intake valve and performing a bowl blend. (HP/value/compared to porting) On top of this the head retains 100% of it’s reliability due to how thin the cast walls are. It’s all too common to see highly stressed, high HP, road race engines blow through over ported head walls.

This is one of the few times in my life where I won't be dragged down by analyzing price to performance ratios. This time, going for what I want, and damn the torpedoes.

[JRach]

I've got a built 2.5 DOHC motor for my open light class stage rally car. Havnt got it on the Dyno yet but should have numbers really soon.
The awd mustang Dyno I use is very conservative reading. (Stock STI 220-225 whp, stock ej205 w/ td04 160 whp).
I'm expecting right around 180 whp.

Ej25 DOHC n/a motor
Mods as follows
-custom 10.8:1 wiseco pistons
-stock rods/crank
-ACL race bearings
-modified oil passages, shimmed 10mm oil pump
-port and polished heads
-stock size valves
-delta cams
-ems pro standalone ecu
-equal length header
-ITB intake manifold (in the works)

Got it all together and in the car, just have to wire up the ecu and get it on the Dyno. But other projects have taken over lately :)

[Gary in NJ]

JRach,

If you don't mind me asking, how much coin do you have invested in that engine?

[JRach]

JRach,

If you don't mind me asking, how much coin do you have invested in that engine?


I own/operate a small Subaru shop here in Seattle so I got some deals on a few things :)

Pistons-$520
Bearings- $100
Cams- $500
Header- $75 (used)
ECU- $cheap (got a special discount for documenting the build/results)
Machine shop costs- $600
Gasket set- $250

I did all the labor, port/polish work and assembly, so minus the cost of shop supplies an time... Free.

[Gary in NJ]

I did all the labor, port/polish work and assembly, so minus the cost of shop supplies an time... Free.

Thanks, that's the bogey I was looking for. I plan to do much of the assembly myself (I've built plenty of engines in the past, but no Subaru's) relying on local machine shops and speed shops for the detail work of porting, polishing, cylinder honing and the like.

[metalmaker12]

Don't get me wrong I like a NA powerband, but these ej engines with stock turbos and a safe tune have a very broad powercurve with boat loads more power start to finish than any Na build can get. I guess it is just different strokes for different folks.

[Thorne]

So I've tuned tons of GMs that have been boosted and in general you don't lose your powerband persay you make it bigger. compared to a Stock engines powerband. Also keep in mind Camming a car does move the powerband. I'll see If I can grab some dynos this weekend of NA vs Stage2 wrx

[Xusia]

Don't get me wrong I like a NA powerband, but these ej engines with stock turbos and a safe tune have a very broad powercurve with boat loads more power start to finish than any Na build can get. I guess it is just different strokes for different folks.

Speaking only for myself, it's not a comparison of NA vs. turbo of the same size engine (really, what's the point of that? The turbo adds power no matter how you look at it...). Rather, it's a comparison of NA vs. turbo to make a certain AMOUNT of power. In that scenario, the NA engine would normally need to have more displacement. Generally speaking, a larger displacement NA engine is going to have a broader torque curve compared to a smaller displacement turbo engine making the same power (because "power" typically means peak HP).

Putting it in real world terms, my choice is between a mostly stock H4 with turbo, or a mostly stock NA H6. From a power standpoint, these are comparable. However, for me the H6 is the winner because it has that smooth NA throttle response I really want and a broader torque curve (which will help with the added weight my 818 is sure to have by the time I'm done adding the amenities I'm sure to want). I know I'm giving up some fuel economy (or at least I assume, but my truck gets 13mpg, so really, anything is a huge improvement) and the ability to go wild with mods & tuning (which isn't on my list and not really my cup of tea anyway), and I'm OK with that. :)

[MiniVanMan]

I guess ultimately, it comes down to everything I'm planning on doing to an NA engine is what I'd be doing to a turbo engine as well. With the turbo, there's added cost. This is what I'd like to do, and the way it's forming in my head, an Impreza donor is going to be MUCH cheaper than a WRX donor. Either car is going to have the engine removed and have the bottom end rebuilt and some head work done. Looking at what's practical for this car, by the time I rebuild the engine, go for much higher compression, cams, head work, convert to E85, I'll have plenty of horsepower to scoot it along, and make it fun for a track day or two, if I ever get there (totally planning on it).

That's the way it's playing out in my head. If I manage to find a WRX donor for really cheap, things may change. The WRX stock motor will be plenty for this car, for me to handle. I'm not the Stig. But, that's boring. I want to tinker, and a motor is something I've always wanted to do. That being said, if the price is right, and I don't end up sacrificing power band and end up with a 300 whp turbo application, who would I be to complain.

[Nuul]

NA engine would normally need to have more displacement.

Agreed, that's generally the case. A turbo or supercharger is basically adding displacement by forcing more air/fuel into the cylinder. So for them to be roughly equivalent you need more displacement on the NA engine. Not counting the 818, where space and weight are at a premium, I'll take a NA engine over a turbo every time.

[Darkpiggy's dad]

I'd be very happy with a 255 and driving instruction. I have seen great drivers in some stock socker mom cars beat the times of good drivers in high dollar sports cars. I just want to be a better driver. That said, I love a lightened flywheel and proper suspension tuning/ tires. Are inboard brakes possible?

[Silvertop]

Agreed, that's generally the case. A turbo or supercharger is basically adding displacement by forcing more air/fuel into the cylinder. So for them to be roughly equivalent you need more displacement on the NA engine. Not counting the 818, where space and weight are at a premium, I'll take a NA engine over a turbo every time.

And that's exactly what I just did. A couple of hours ago, I made my "official" selection of an 2004 NA Donor Palette from AJW Performance over a 2002 WRX. While the WRX donor palette was more expensive than the 04 NA Outback Sport, the modifications I will need to make (Cams and Springs, intake mods, Equal Length Headers, ECU tuning) will ultimately make my NA selection at least $1000 more costly than if I had gone with building my 818 with a box-stock WRX donor. And the NA will come up about 30 horsepower short of the stock WRX, even with the mods. But I like the relative simplicity of the NA application, and believe that the end product will be eminently more drivable. And it will still approach being stupid fast......

It might have something to do with my age/generation -- but for some reason making power without the benefit of a turbocharger just has more panache to me. Different strokes for different folks, I guess........

[Xusia]

Agreed, that's generally the case. A turbo or supercharger is basically adding displacement by forcing more air/fuel into the cylinder. So for them to be roughly equivalent you need more displacement on the NA engine. Not counting the 818, where space and weight are at a premium, I'll take a NA engine over a turbo every time.

I would argue that the EZ series H6 takes up less space overall because it's nearly the same external dimensions, but lacks an inter-cooler. If it does add weight, it can't be a net gain of much. Plus I'm skinny and light and already planning to add weight with creature comforts like A/C and leather, so what's a few more pounds? Even if the car winds up being 1900 lbs, that's still far lighter than nearly any comparable car...

[tmpst]

I just found out you can buy a full built Cosworth 2.5L EJ25. Probably costs twice as much as the 818 kit though. :p

http://americas.cosworth.com/products/performance-parts/block-assemblies/long-block-assemblies/

However, if you have the money, and are going to be doing a LOT of track days, I think it'd be worth it.

I had one of those fully built Cosworth 2.6l long blocks. I was actually going to put it into the 818. Sadly it was recently damaged in a fire (the engine didn't catch fire, the garage it was in caught fire).

If you go all out and get the 2.6l kit, billet crank, manifold intake, headers and dry sump, you're looking at spending well over $40,000 on parts, labor and tuning. On top of the engine you'll need a bigger turbo, a new ecu, a new turbo back, and a big FMIC (all included in the $40k). The actual Cosworth supplied block is not very expensive and no different from a standard ej257, what you are paying for when you buy the CS600 shortblock kit are all the forged internals.

HP numbers will vary from dyno to dyno, but you'll be looking at somewhere in the range of 500+ awhp on pump gas (On a conservative Maha dyno I had 630 at the crank on 94 octane pump gas and a "safe" tune). The weak point ends up being the head gasket, you should expect to replace this at least once a year if you push the car regularly (mine was doing laps every week).

I'm not going to rebuild the engine. I'm going to take the insurance money from the engine and build a much tamer ~400hp engine for the 818. An 818 with 600+ hp seems kind of pointless and there are much better places to spend your money if you want to make the car faster (I'm thinking 5-speed sequential gearbox). A 400hp engine will set you back less than $10k, after that it's diminishing returns.