Subaru Tuning
Topics
- .Boxer engine
- .Center of gravity is lower
- ..EJ251 00-04 Subaru 2.5H4
- .Gasket failure at 100,000 miles
- .Upgrade guide
.Boxer engine
http://www.importtuner.com/tech/impp_1103_subaru_ej_series_engine_tech/viewall.html
The Truth Behind The Subaru EJ-Series Engines - Tech-Knowledge
Are they as weak as tuners claim?
Read more: http://www.importtuner.com/tech/impp_1103_subaru_ej_series_engine_tech/viewall.html#ixzz2WsFBZWpJ
Once known simply as the automotive company that built modest commuter cars like the Brat ('78 to '87), Subaru (a division of Fuji Heavy Industries) became internationally known for their boxer engines. Beginning in 1989 and continuing through to the present day, Subaru's horizontally opposed EJ-series motors are the mainstay engines of their model lineup, with all EJ-series engines sharing a 16-valve, flat-four horizontal configuration with displacements ranging from 1.5 to 2.5 liters. So why has Subaru continued their love affair with the boxer engine?
Utilizing a boxer engine configuration similar to what was once used in older-model Volkswagens, Subaru has continued use of the boxer engine with good reason. The Subaru boxer engine is a unique engine that's anything but typical. Engineer Karl Benz patented the flat-four engine in 1896. In 1971, inspired by airplane engine design, Fuji Heavy Industries, through the Subaru brand, released their interpretation of the flat-four. Because the engine was configured to be inline with the transmission it had a lower center of gravity to help minimize body roll in comparison to inline-four and V-type engines, which have a higher center of gravity and are prone to side-to-side vibration. This design provided a lighter weight and compact, economic design for Subaru. In all, there have been 23 engine variations of the EJ motors, including the '11 WRX STi model that develops 305 hp and 290 lb-ft of torque.
Subaru engines have always been known to be well engineered that are both powerful and torquey, but Subaru engineers left a lot to be desired when it came to the EJ205 ('02 to'05 USDM WRX), EJ255 (USDM WRX '06 to present) and EJ257 ('04 to'07 USDM WRX STi) turbocharged models. This month, we get in-depth with three of the top Subaru tuners in the world, as they help dispel myths and speak their minds about the infamous EJ-series engine.
Read more:
http://www.importtuner.com/tech/impp_1103_subaru_ej_series_engine_tech/viewall.html#ixzz2WsFGJbeG
Subaru Tuning Notes Auto
.EJ251 00-04 Subaru 2.5H4
EJ251[edit]
The EJ251 has demonstrated externally leaking head gasket issues on occasion as the engine accumulates mileage over 100,000 miles (160,000 km). SOHC Intake volume is calculated by the use of a MAP sensor, unlike the EJ253 which uses a MAF sensor. Compression ratio is 10.0:1.
Power ISO: 123 kW (165 hp) @ 5600 RPM
226 N·m (167 ft·lbf) @ 4000 rpm
226 N·m (167 ft·lbf) @ 4000 rpm
Usage:
- Impreza 2.5RS, 2.5TS 00-04 (US)
- Impreza Outback Sport 02-04 (US)
- Forester 00-04 (US)
- Legacy 00-04 (US)
- Outback 00-04 (US)
- Baja 03-05 (US)
.Upgrade guide
MRT:
... waste of money options...
TURBO
OK if you have big bucks a turbo upgrade will add power, but really, why not just buy a WRX!
To turbo the NA engine you need a minimum $7000 to do a half decent job and still its not where near like a WRX
Internal engine mods are then needed for reliability.
OK if you have big bucks a turbo upgrade will add power, but really, why not just buy a WRX!
To turbo the NA engine you need a minimum $7000 to do a half decent job and still its not where near like a WRX
Internal engine mods are then needed for reliability.
ENGINE INTERNAL
OK like above if you have wads of cash, thena rebuild will give some benefits, but a rebuild will cost over $5k and then you need to choose carefully.
OK like above if you have wads of cash, thena rebuild will give some benefits, but a rebuild will cost over $5k and then you need to choose carefully.
OTHER OPTIONS
Is the car serviced correctly because often a service by a workshop who really knows subarus will be your best place for power.
Is the car serviced correctly because often a service by a workshop who really knows subarus will be your best place for power.
IE:
- Upper engine cleaner and in tank fuel additive. (when was this last done, its a subaru suggested option).
- Good quality low friction engine oil such as Mobil 5 w 30 will give around 5 kw and better fuel economy over a non synthetic oil.
- Fuel system service, MRT offer this and often get good results, cleans the EGR "gunk" out of the intake and combustion area. Also injectors as well as inlet manf and exhaust as well as fuel pump, lines and sensors.
- Synthetic trans and diff oil, again like engine oil this adds up in benefits.
- Timing belt, fuel filter are again areas that should be checked and renewed.
SUSPENSION
check out the performance / suspension section for REAL gains and benefits.
If I owned a NA suby, I would invest my budget in brakes and suspension as this is guaranteed BEST VALUE!
more here http://mrtperformance.com.au/performance/suspension
* http://forums.nasioc.com/forums/showthread.php?t=2481278
You have options, but engine gets expensive.
I'll try to answer based on budget, as often this is the biggest limiting factor.
$100
Open source tune, doesn't do much without other mods, but cables cheap, software is free. I use Cobb Ap, with a good 91 or 93 octane map, can get better throttle response and a bit more power.
$100-$1500
Intake, cat back exhaust, high flow cat, and headers are the easiest power adders. I did a full custom exhaust with a local shop.
+20 to 30 crank hp
$500-$1000
You can look at cams, delta might do a grind for 09/ impreza, but its a little more complicated to install, personally don't think it's worth it.
+15 crank hp
$3000-$4000
Avo Turbo or Raptor super charger. This will actually add quite a bit of power... More than any above mods.
+50-80 crank hp
Ok, at this point, your getting into swap price range. I'm only guessing at the dollar numbers, and normally this would be a complete swap with engine, tranny and drive train.
$7000
Wrx swap, for 09, is +95 crank hp
$10,000
Sti swap +130 crank hp
Also note, with a swap, your car will be open to all wrx or Sti mods out there.
Full n/a engine builds are possible, but way more expensive than above options, and will never achieve the same performance and reliability of an OEM block, like that of an STI. Unlike Hondas, 300 hp n/a is very hard to achieve.
Personally, I did intake, full exhaust/headers, and Cobb Tune, it's faster and lots of fun to drive, I rarely keep it pinned even in auto x, mainly due to suspension, it's plenty of power for a daily driver.
check out the performance / suspension section for REAL gains and benefits.
If I owned a NA suby, I would invest my budget in brakes and suspension as this is guaranteed BEST VALUE!
more here http://mrtperformance.com.au/performance/suspension
* http://forums.nasioc.com/forums/showthread.php?t=2481278
You have options, but engine gets expensive.
I'll try to answer based on budget, as often this is the biggest limiting factor.
$100
Open source tune, doesn't do much without other mods, but cables cheap, software is free. I use Cobb Ap, with a good 91 or 93 octane map, can get better throttle response and a bit more power.
$100-$1500
Intake, cat back exhaust, high flow cat, and headers are the easiest power adders. I did a full custom exhaust with a local shop.
+20 to 30 crank hp
$500-$1000
You can look at cams, delta might do a grind for 09/ impreza, but its a little more complicated to install, personally don't think it's worth it.
+15 crank hp
$3000-$4000
Avo Turbo or Raptor super charger. This will actually add quite a bit of power... More than any above mods.
+50-80 crank hp
Ok, at this point, your getting into swap price range. I'm only guessing at the dollar numbers, and normally this would be a complete swap with engine, tranny and drive train.
$7000
Wrx swap, for 09, is +95 crank hp
$10,000
Sti swap +130 crank hp
Also note, with a swap, your car will be open to all wrx or Sti mods out there.
Full n/a engine builds are possible, but way more expensive than above options, and will never achieve the same performance and reliability of an OEM block, like that of an STI. Unlike Hondas, 300 hp n/a is very hard to achieve.
Personally, I did intake, full exhaust/headers, and Cobb Tune, it's faster and lots of fun to drive, I rarely keep it pinned even in auto x, mainly due to suspension, it's plenty of power for a daily driver.
