EJ22T mod discussions for hardcores - you know who you are
Posted: Sun May 09, 2004 10:52 pm
BC-BF Legacy list members said I should post this here.
Seems like it revisits some of the stuff from just about exactly
one year ago
I Have a long term project to upgrade a spare EJ22T engine,
and I think you guys might like to bounce some engine design
opinions around
Plus there are QUESTIONS #1 AND #2
Even with the introduction of the STi, I still believe the EJ22T is
the strongest production block Subaru has ever made,
and would like to stay with it, although my modest desire to
double the 160 factory horsepower of the production engine
can be easily accommodated by the new age blocks out there now.
A while back I spent big bucks to have heads and valves from a
new Phase II 2001 RS 2.5 engine reworked and upgraded by
Dan Paramore
http://www.dprracing.com/ and ttp://www.dprracing2.com/home.html
Those heads are for sale, and anybody that wants pictures,
and what I call the full late nite TV infomercial about them,
send me email
ssspoon@aol.com
I decided against using them, mainly because of the lack of
some features not present on the 2.5 heads as on the stock
EJ22T heads.
Specifically, the EJ22T head coolant passages match the design
of the EJ22T block, and there are 3 holes in the right cylinder head
for the turbo oil supply, oil return, and coolant return
QUESTION #1
Anybody out there know if those features are present on the 2.0T or 2.5T turbo heads ?
Another concern I had about using the 2.5 heads on the 2.2T block
was the resulting compression ratio (C/R).
Increasing the 2.2 displacement is one of the considerations
for my project.
Have to go back and look at the references, but looks like some,
but not all 2.5 cranks will work nicely if I want to persue that option
QUESTION #2
What is the resulting C/R when a 2.5 crank is used in a 2.2T block,
and are new pistons necessary to prevent the EJ22T engine from
going from a non-interference to an interference condition ?
Also the 2.5 heads have larger intake valves, which may be desirable
for higher overall peak power and rpm potential, but my target
is low end street torque, and the smaller EJ22T valves may result
in higher intake flow at low RPM, and actually be more conducive
to the higher low end torque I seek, especially with the proper cam,
which might be the stock cam.
The factory REDUCED the size of the intake valves on the
2.2 turbo engine vs the 2.2 normally aspirated (N/A) engine.
Was that because the automotive engineers designing the EJ22T
engine to accommodate forced induction are stupid ?
I don't think so. The increase in torque produced by the turbo
version of the 2.2 engine over that of the 2.2 N/A version,
is significantly greater than the horsepower increase over that
of the 2.2 N/A version.
Although closely related, low speed performance,
AKA acceleration, is spelled TORQUE, not POWER.
To put things into perspective consider the following with special attention
to engine speeds
The 3.3 liter SVX was rated at
230 HP @ 5400 RPM and 228 Lbs-Ft of torque at 4400 RPM
The new 3.0 liter H-6 engines are rated at
212 HP @ 6000 RPM and 210 Lbs-Ft @ 4400 RPM
The 2.5 RS engine that my reworked heads are from, spec'd out at
165 HP @ 5600 RPM and 166 Lbs-Ft @ 4000 RPM
The North American WRX 2.0 engine is rated at 13.5 PSI max boost
227 HP @ 6000 RPM and 217 Lbs-Ft @ 4000 RPM
The impressive 2.5 STi factory numbers are given with 14.5 PSI max boost as
300 HP @ 6000 RPM and 300 Lbs-Ft @ 4000 RPM max boost 14.5 PSI
The original stock EJ22 engine provided
130 HP @ 5600 RPM and 137 Lbs-Ft at 4400 RPM
The figures for the lowly factory turbo EJ22T engine at 8.7 PSI max boost come in at
160 HP @ 5600 RPM, but check the torque...181 Lbs-Ft at only 2800 RPM
That's a 23% power increase and a 32% torque increase,
but the 32% torque increase is at a 36% lower engine speed.
The max torque comes at an engine speed that's less than two thirds
that of the normally aspirated engine. None of the other engines
have a torque band shifted to the left in the RPM range like the EJ22T.
And none of the other engines, turbo or N/A, produce torque figures greater than power figures
My desire is to expand the power and torque curves,
without shifting them, with engine balancing, increased boost,
enhanced ignition and induction controls, and perhaps
some lighter components.
Power and torque values with respect to boost are not exactly linear,
but if we just look for some ballpark ratio approximations for
reference points, and provide the EJ22T engine with as much boost
as the STi engine we get 267 HP and 302 Lbs-Ft.
That's without all the other improvements.
And there is something just plain appealing to me about working with
the type engine that originally came in the car without changing too
much unnecessarily. Especially if the gains achieved are at the
expense of headaches to get there, and more importantly,
if those changes bring a higher level of risk to reliability and durability
in the final result.
Somebody that want's fancy upgraded 2.5 Phase II heads,
please buy mine so I can have more money for hot rod work,
and you can save money on fancy upgraded 2.5 Phase II heads.
Seems like it revisits some of the stuff from just about exactly
one year ago
I Have a long term project to upgrade a spare EJ22T engine,
and I think you guys might like to bounce some engine design
opinions around
Plus there are QUESTIONS #1 AND #2
Even with the introduction of the STi, I still believe the EJ22T is
the strongest production block Subaru has ever made,
and would like to stay with it, although my modest desire to
double the 160 factory horsepower of the production engine
can be easily accommodated by the new age blocks out there now.
A while back I spent big bucks to have heads and valves from a
new Phase II 2001 RS 2.5 engine reworked and upgraded by
Dan Paramore
http://www.dprracing.com/ and ttp://www.dprracing2.com/home.html
Those heads are for sale, and anybody that wants pictures,
and what I call the full late nite TV infomercial about them,
send me email
ssspoon@aol.com
I decided against using them, mainly because of the lack of
some features not present on the 2.5 heads as on the stock
EJ22T heads.
Specifically, the EJ22T head coolant passages match the design
of the EJ22T block, and there are 3 holes in the right cylinder head
for the turbo oil supply, oil return, and coolant return
QUESTION #1
Anybody out there know if those features are present on the 2.0T or 2.5T turbo heads ?
Another concern I had about using the 2.5 heads on the 2.2T block
was the resulting compression ratio (C/R).
Increasing the 2.2 displacement is one of the considerations
for my project.
Have to go back and look at the references, but looks like some,
but not all 2.5 cranks will work nicely if I want to persue that option
QUESTION #2
What is the resulting C/R when a 2.5 crank is used in a 2.2T block,
and are new pistons necessary to prevent the EJ22T engine from
going from a non-interference to an interference condition ?
Also the 2.5 heads have larger intake valves, which may be desirable
for higher overall peak power and rpm potential, but my target
is low end street torque, and the smaller EJ22T valves may result
in higher intake flow at low RPM, and actually be more conducive
to the higher low end torque I seek, especially with the proper cam,
which might be the stock cam.
The factory REDUCED the size of the intake valves on the
2.2 turbo engine vs the 2.2 normally aspirated (N/A) engine.
Was that because the automotive engineers designing the EJ22T
engine to accommodate forced induction are stupid ?
I don't think so. The increase in torque produced by the turbo
version of the 2.2 engine over that of the 2.2 N/A version,
is significantly greater than the horsepower increase over that
of the 2.2 N/A version.
Although closely related, low speed performance,
AKA acceleration, is spelled TORQUE, not POWER.
To put things into perspective consider the following with special attention
to engine speeds
The 3.3 liter SVX was rated at
230 HP @ 5400 RPM and 228 Lbs-Ft of torque at 4400 RPM
The new 3.0 liter H-6 engines are rated at
212 HP @ 6000 RPM and 210 Lbs-Ft @ 4400 RPM
The 2.5 RS engine that my reworked heads are from, spec'd out at
165 HP @ 5600 RPM and 166 Lbs-Ft @ 4000 RPM
The North American WRX 2.0 engine is rated at 13.5 PSI max boost
227 HP @ 6000 RPM and 217 Lbs-Ft @ 4000 RPM
The impressive 2.5 STi factory numbers are given with 14.5 PSI max boost as
300 HP @ 6000 RPM and 300 Lbs-Ft @ 4000 RPM max boost 14.5 PSI
The original stock EJ22 engine provided
130 HP @ 5600 RPM and 137 Lbs-Ft at 4400 RPM
The figures for the lowly factory turbo EJ22T engine at 8.7 PSI max boost come in at
160 HP @ 5600 RPM, but check the torque...181 Lbs-Ft at only 2800 RPM
That's a 23% power increase and a 32% torque increase,
but the 32% torque increase is at a 36% lower engine speed.
The max torque comes at an engine speed that's less than two thirds
that of the normally aspirated engine. None of the other engines
have a torque band shifted to the left in the RPM range like the EJ22T.
And none of the other engines, turbo or N/A, produce torque figures greater than power figures
My desire is to expand the power and torque curves,
without shifting them, with engine balancing, increased boost,
enhanced ignition and induction controls, and perhaps
some lighter components.
Power and torque values with respect to boost are not exactly linear,
but if we just look for some ballpark ratio approximations for
reference points, and provide the EJ22T engine with as much boost
as the STi engine we get 267 HP and 302 Lbs-Ft.
That's without all the other improvements.
And there is something just plain appealing to me about working with
the type engine that originally came in the car without changing too
much unnecessarily. Especially if the gains achieved are at the
expense of headaches to get there, and more importantly,
if those changes bring a higher level of risk to reliability and durability
in the final result.
Somebody that want's fancy upgraded 2.5 Phase II heads,
please buy mine so I can have more money for hot rod work,
and you can save money on fancy upgraded 2.5 Phase II heads.