n00b D17A2 engineering
Thread Starter
Junior Member
Joined: Dec 2006
Posts: 5
Likes: 0
n00b D17A2 engineering
Hello everyone!
I have a few n00b questions for the community, if anyone can help me out.
The basic overall question is, where are the power losses in my stock D17A2 taking place, and how to I minimize power losses while minimizing cost?
1) As the motor is currently NA, I understand volumetric efficiency of both the intake and exhaust systems is paramount. I assume I should replace the most restrictive components first. So concerning intake/exhaust aspiration, how to the various components rank? I assume the way to see less restriction to flow would be a lower differential pressure across the system or part in question. Anyone have any empirical experience with this sort of thing?
3) To make more NA power, I understand I will have to raise compression. Before I do anything, what parameters of engine operation should I actively monitor in order to see problems before they destroy my motor? Here's the list of what I think I should monitor, feel free to add to the list:
Telemetry ill be viewing thru laptop:
a) Air / Fuel ratio
b) Knock events per cylinder over time
c) Current spark timing
(need an ECU piggyback, any good brands?)
Gauge-based telemetry:
a) Cylinder head temp - contact pyrometer
b) Engine coolant temperature - stock sensor
c) EGT - contact pyrometer
d) Differential pressure b/w intake manifold and atmospheric press.
e) Discharge pressure of engine oil pump
f) Engine oil temperature
g) Fuel pressure (at rail)
I like the phantom II series from www.autometer.com. Any other good brands?
Once ive got my instrumentation installed, I'll feel a whole lot better about doing any tuning. Now, for compression...
I see three possible scenarios here...
1) Shorter height head gasket (If this is even possible)
2) Mill the head/block interface.
3) Mill the valves and valve seats? (this is the stock head, 30k miles...should still be sealing pretty well)
3) Change piston geometry? (Is this possible, or just a bad idea?)
Once I know its possible, then the question is, how much can I raise the ratio and still be able to find fuel for the car?
Lots of questions and ideas, absolutely no experience. This should be interesting.
I have a few n00b questions for the community, if anyone can help me out.
The basic overall question is, where are the power losses in my stock D17A2 taking place, and how to I minimize power losses while minimizing cost?
1) As the motor is currently NA, I understand volumetric efficiency of both the intake and exhaust systems is paramount. I assume I should replace the most restrictive components first. So concerning intake/exhaust aspiration, how to the various components rank? I assume the way to see less restriction to flow would be a lower differential pressure across the system or part in question. Anyone have any empirical experience with this sort of thing?
3) To make more NA power, I understand I will have to raise compression. Before I do anything, what parameters of engine operation should I actively monitor in order to see problems before they destroy my motor? Here's the list of what I think I should monitor, feel free to add to the list:
Telemetry ill be viewing thru laptop:
a) Air / Fuel ratio
b) Knock events per cylinder over time
c) Current spark timing
(need an ECU piggyback, any good brands?)
Gauge-based telemetry:
a) Cylinder head temp - contact pyrometer
b) Engine coolant temperature - stock sensor
c) EGT - contact pyrometer
d) Differential pressure b/w intake manifold and atmospheric press.
e) Discharge pressure of engine oil pump
f) Engine oil temperature
g) Fuel pressure (at rail)
I like the phantom II series from www.autometer.com. Any other good brands?
Once ive got my instrumentation installed, I'll feel a whole lot better about doing any tuning. Now, for compression...
I see three possible scenarios here...
1) Shorter height head gasket (If this is even possible)
2) Mill the head/block interface.
3) Mill the valves and valve seats? (this is the stock head, 30k miles...should still be sealing pretty well)
3) Change piston geometry? (Is this possible, or just a bad idea?)
Once I know its possible, then the question is, how much can I raise the ratio and still be able to find fuel for the car?
Lots of questions and ideas, absolutely no experience. This should be interesting.
been there done that
Joined: Jun 2002
Posts: 30,637
Likes: 0
From: 916
the d17a isnt the best engine to stay NA with and make power. it's limited by it's displacement and sohc configuration. either boost it or do a k20a if you're looking to make some good power.
Senior Member
Joined: Jun 2005
Posts: 672
Likes: 0
From: Allentown PA, - Phila, PA
If you understand VE (Volumetric Efficiency) then you should know that the D17 is not known for it's VE...
VE depends upon the ability of the motor to breathe at high engine speeds... With a SOHC you are already at a disadvantage compared to DOHC motors, cause the cam controls both Intake and Exhaust, leaving little room to "optimize" the operation of the intake and exhaust valves at the same time...
That is why DOHC motors ALWAYS have a flatter torque curve... Actually the B16 has one of the flattest torque curves of any engine ever made... Why? Cause VTEC enables the valves to open both more and for a longer duration when needed, increasing the VE and making power up to a very high redline of ~8k rpms...
Like Snoopy said, a k-series is a much better base to start with, and I concur...
VE depends upon the ability of the motor to breathe at high engine speeds... With a SOHC you are already at a disadvantage compared to DOHC motors, cause the cam controls both Intake and Exhaust, leaving little room to "optimize" the operation of the intake and exhaust valves at the same time...
That is why DOHC motors ALWAYS have a flatter torque curve... Actually the B16 has one of the flattest torque curves of any engine ever made... Why? Cause VTEC enables the valves to open both more and for a longer duration when needed, increasing the VE and making power up to a very high redline of ~8k rpms...
Like Snoopy said, a k-series is a much better base to start with, and I concur...
