Full Version: Subie VS SBC
Going to do a V8 conversion seems more HP for the buck and about the same amount of work.What are the reasons to consider a subie conversion instead?I have a friend with a subie Impreza L 1995 engine anybody know the HP?
seveal members have or are building a Subaru conversion, and many have V8's The Subaru is the newest trend in conversion motors. I have a Buick V6 conversion. Try a search of the forms, with key word Sudaru (or Subie) that should get you some info. V8 conversin have been going on since teh 914 was new, so there are plenty of them out there, lots of folks can tell you about them
From what i have read, and my experiences with the V6:
The V6 / V8 engines do wiegh more than the Subaru (cast iron verse aluminum) of course there are aluminum V8s out there too, still probably more wieght than a Subaru. The V8's have a lot of weight up high, ecspecial with iron heads. this can adversly effect the fine handling of the 914, but still the mid engine design and small car design puts it ahead of the the big American donor car.
i believe the Subaru oil pan needs be shortened to get ground clearance, I know that is a common mod on VW vanagon / Subaru conversions. The V8 pan is just fine as is.
The V8's have a huge potential for torque and horsepower, even in stock form many out perfrom the Subaru, and perfomrance parts for the Big American engines are cheap and abundant.
One potential advantage of the Subaru is the ability to possibly make the water cooling system work inside the engine bay, thus you will not have to cut up the front trunk. i have yet to work out an engine bay cooling system for the V6 / V8 engine do to the hieght of the Vee engines, and proximity of the hot exhaust system up high in the engine bay (thought being that the cololing system in the engine bay would have the radiators/fans on the engine lid with the outlet air flowing up around the engine, and out thru the radiators on top.) The vee engines appear too tall for this.
I cannot believe the grunt torque i get out of my V6, it is awesome, I do not have the figures on the engine, but i do not think a Subaru can make that kind of torque (ie like a rocket) without expensives modifications.. The American Vee engines are cheap to hotrod, and can easily be made powerful enough to break the 914!
The Subaru is a more refined engine. Probably a better daily driver, and they are still fast with the right engine. stock Subarus are near double the HP of the stock 914 4 cylinder, the stock american V8s can be triple or more
I say that if you really want the most raw power for the dollor, go with a big ole American V8, if you have the the money to spend, an all aluminum, or even aluminum head Vee engine will reduce the wieght some. you will have to cut up the front trunk for cooling with the Vee enigne.
if you want to be able to retain your front trunk as stock, the Subaru might be the way to go, (folks are still working this issue out, a engine bay mounted radiator, I think it can be done.)
the Subaru might cost you a little more money per HP than the Vee engines (especailly if you want high HP,you cannot beat the large displacement), but the Subaru will allow you to keep the wieght down, and the center of gravity lower than a Vee engine. read some of the forums, and then ask questions. most all the folks building conversion cars are more than happy to share info, pro/cons if you have specific questions. No particluar set up is "best' for everyone, you just need to determine what is best for your needs, and money.
I happen to have a modified 914 for sale in the classifieds ads it is a rolling project and it is set up for the radiator up front. If that car floats your boat, I'd be happy to sell it, it needs a complete drivetrain, but the body is good looking if you are into a slope nose conversion. i was told it once had a V8, and then a hot rod rotory in it. I got too many projects so its for sale (i am keeping my V6 car)
Now if you have the money, you could put a Porsche water cooled six in the 914, but few folks have done that, probably the cost of a late model Porsche engine is the main factor, and heck the Subaru is not that much different in layout
Both are good choices, just depends on what you want, and can afford. Take your time for reaserch that way you have the best chance of being satisifed with the end result. Also consider the Mazda rotary engine, folks do that, they are aluminum, and fit nicely.
From what i have read, and my experiences with the V6:
The V6 / V8 engines do wiegh more than the Subaru (cast iron verse aluminum) of course there are aluminum V8s out there too, still probably more wieght than a Subaru. The V8's have a lot of weight up high, ecspecial with iron heads. this can adversly effect the fine handling of the 914, but still the mid engine design and small car design puts it ahead of the the big American donor car.
i believe the Subaru oil pan needs be shortened to get ground clearance, I know that is a common mod on VW vanagon / Subaru conversions. The V8 pan is just fine as is.
The V8's have a huge potential for torque and horsepower, even in stock form many out perfrom the Subaru, and perfomrance parts for the Big American engines are cheap and abundant.
One potential advantage of the Subaru is the ability to possibly make the water cooling system work inside the engine bay, thus you will not have to cut up the front trunk. i have yet to work out an engine bay cooling system for the V6 / V8 engine do to the hieght of the Vee engines, and proximity of the hot exhaust system up high in the engine bay (thought being that the cololing system in the engine bay would have the radiators/fans on the engine lid with the outlet air flowing up around the engine, and out thru the radiators on top.) The vee engines appear too tall for this.
I cannot believe the grunt torque i get out of my V6, it is awesome, I do not have the figures on the engine, but i do not think a Subaru can make that kind of torque (ie like a rocket) without expensives modifications.. The American Vee engines are cheap to hotrod, and can easily be made powerful enough to break the 914!
The Subaru is a more refined engine. Probably a better daily driver, and they are still fast with the right engine. stock Subarus are near double the HP of the stock 914 4 cylinder, the stock american V8s can be triple or more
I say that if you really want the most raw power for the dollor, go with a big ole American V8, if you have the the money to spend, an all aluminum, or even aluminum head Vee engine will reduce the wieght some. you will have to cut up the front trunk for cooling with the Vee enigne.
if you want to be able to retain your front trunk as stock, the Subaru might be the way to go, (folks are still working this issue out, a engine bay mounted radiator, I think it can be done.)
the Subaru might cost you a little more money per HP than the Vee engines (especailly if you want high HP,you cannot beat the large displacement), but the Subaru will allow you to keep the wieght down, and the center of gravity lower than a Vee engine. read some of the forums, and then ask questions. most all the folks building conversion cars are more than happy to share info, pro/cons if you have specific questions. No particluar set up is "best' for everyone, you just need to determine what is best for your needs, and money.
I happen to have a modified 914 for sale in the classifieds ads it is a rolling project and it is set up for the radiator up front. If that car floats your boat, I'd be happy to sell it, it needs a complete drivetrain, but the body is good looking if you are into a slope nose conversion. i was told it once had a V8, and then a hot rod rotory in it. I got too many projects so its for sale (i am keeping my V6 car)
Now if you have the money, you could put a Porsche water cooled six in the 914, but few folks have done that, probably the cost of a late model Porsche engine is the main factor, and heck the Subaru is not that much different in layout
Both are good choices, just depends on what you want, and can afford. Take your time for reaserch that way you have the best chance of being satisifed with the end result. Also consider the Mazda rotary engine, folks do that, they are aluminum, and fit nicely.
To add to that:
A subie engine seems better matched to a 901 transmission.
A V8 motor ideally needs a 930 transmission.
A WRX turbo motor can make 300HP+.
I think a WRX motor is actually cheaper than an equivalent hp V8.
A subie engine is an aluminum boxer engine.
Lesbians will love you if you go with Suburu. :-)
A subie engine seems better matched to a 901 transmission.
A V8 motor ideally needs a 930 transmission.
A WRX turbo motor can make 300HP+.
I think a WRX motor is actually cheaper than an equivalent hp V8.
A subie engine is an aluminum boxer engine.
Lesbians will love you if you go with Suburu. :-)
Doing a proper V8 installation is probably a lot more work than a Suabru conversion. As has been said before, cooling can be done in the engine bay. Unless you go with a a really high horsepower Subaru engine, you don't need to go with a stronger transmission or better axles, CV joints, etc. You also don't need to stengthen the chassis as you aren't getting a ton of torque.
Other benefits...
Subaru engine weighs less than a type IV, whereas a V8 weighs considerably more.
Subaru engine is horizontally opposed, V8 is obviously not. Makes for lower center of mass.
Gas mileage with a Subaru EJ25 (166 HP) is typically 35-40 mpg. V8 914s don't do nearly as well. 1/4 of that roughly. WRX engines will get you something like 25 mpg, maybe more.
The V8 is probably very competitive with the Subaru engine only in terms of the engine itself. A well done V8 conversion will require many more upgrades and high power parts than a reasonable Subaru conversion.
-Tony
Other benefits...
Subaru engine weighs less than a type IV, whereas a V8 weighs considerably more.
Subaru engine is horizontally opposed, V8 is obviously not. Makes for lower center of mass.
Gas mileage with a Subaru EJ25 (166 HP) is typically 35-40 mpg. V8 914s don't do nearly as well. 1/4 of that roughly. WRX engines will get you something like 25 mpg, maybe more.
The V8 is probably very competitive with the Subaru engine only in terms of the engine itself. A well done V8 conversion will require many more upgrades and high power parts than a reasonable Subaru conversion.
-Tony
QUOTE(TonyAKAVW @ Oct 16 2006, 09:41 AM) 
Doing a proper V8 installation is probably a lot more work than a Suabru conversion. As has been said before, cooling can be done in the engine bay. Unless you go with a a really high horsepower Subaru engine, you don't need to go with a stronger transmission or better axles, CV joints, etc. You also don't need to stengthen the chassis as you aren't getting a ton of torque.
Other benefits...
Subaru engine weighs less than a type IV, whereas a V8 weighs considerably more.
Subaru engine is horizontally opposed, V8 is obviously not. Makes for lower center of mass.
Gas mileage with a Subaru EJ25 (166 HP) is typically 35-40 mpg. V8 914s don't do nearly as well. 1/4 of that roughly. WRX engines will get you something like 25 mpg, maybe more.
The V8 is probably very competitive with the Subaru engine only in terms of the engine itself. A well done V8 conversion will require many more upgrades and high power parts than a reasonable Subaru conversion.
-Tony
How does the engine bay radiator work? Is there a kit or do you just fabricate it yourself?I have looked at Renegade's website they have the same radiator kit as the V8.Anybody have pics of an engine bay radiator installed?
There is currently no kit available for the engine bay cooling setup.
I have pictures of my engine bay radiator setup in my conversion thread....
http://www.914world.com/bbs2/index.php?show...1579&st=280
http://www.914world.com/bbs2/index.php?show...1579&st=300
here, with the engine in place...
http://www.914world.com/bbs2/index.php?show...1579&st=320
I currently ahve a scoop under the car that picks up air for the radiator. No pictures of it yet though as it isn't realy in a presentable condition.
-Tony
I have pictures of my engine bay radiator setup in my conversion thread....
http://www.914world.com/bbs2/index.php?show...1579&st=280
http://www.914world.com/bbs2/index.php?show...1579&st=300
here, with the engine in place...
http://www.914world.com/bbs2/index.php?show...1579&st=320
I currently ahve a scoop under the car that picks up air for the radiator. No pictures of it yet though as it isn't realy in a presentable condition.
-Tony
QUOTE(TonyAKAVW @ Oct 16 2006, 10:41 AM)
Gas mileage with a Subaru EJ25 (166 HP) is typically 35-40 mpg.
-Tony
Wow ! Hadn't realized that. No wonder the lesbians love 'em.
Having done both (multiple SBC's and now a turbo Subbie) the SBC is half the work.
A carbed SBC putting out 300 hp and 300lb ft of TQ can (i've done it) be done in a weekend. The kit is completely bolt on, very little fabrication work is needed (exhaust)
My subbie required LOTS of fab work. All the intercooler mounting and tubing, the complete wiring harness, exhaust, larger fuel system, etc. were all done by me. I believe Renegade offers most of this stuff, but it will not have the 30 years of refinement as of yet. I used the same radiator for my subbie as for the SBC's (Renegade's in the front trunk) and i will never waste the time trying to do it any other way. It works. (Huge props to tony for being stuborn enough to do things on his own. I wouldn't have been able to)
AS far as HP, 170hp in a light (no huge stereo, powere windows, etc) 914 will be as quick as a new Vette. 250+ HP will be as fast as a new Z06. And beyond that you are severly traction limited (not to mention transaxle strength).
Mileage wise i get low 30's. Had SBC's in the mid 20's, but if you are worried about mileage... this might not be the right choice, by a Geo.
BJH
A carbed SBC putting out 300 hp and 300lb ft of TQ can (i've done it) be done in a weekend. The kit is completely bolt on, very little fabrication work is needed (exhaust)
My subbie required LOTS of fab work. All the intercooler mounting and tubing, the complete wiring harness, exhaust, larger fuel system, etc. were all done by me. I believe Renegade offers most of this stuff, but it will not have the 30 years of refinement as of yet. I used the same radiator for my subbie as for the SBC's (Renegade's in the front trunk) and i will never waste the time trying to do it any other way. It works. (Huge props to tony for being stuborn enough to do things on his own. I wouldn't have been able to)
AS far as HP, 170hp in a light (no huge stereo, powere windows, etc) 914 will be as quick as a new Vette. 250+ HP will be as fast as a new Z06. And beyond that you are severly traction limited (not to mention transaxle strength).
Mileage wise i get low 30's. Had SBC's in the mid 20's, but if you are worried about mileage... this might not be the right choice, by a Geo.
BJH
I'll have to agree with BJ here... In terms of work, it seems pretty clear a small block chevy is the way to go. The wiring for the Subaru engine kept this electrical engineer busy for many many hours. Not to mention fab work....
-Tony
-Tony
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