ECUtune Stage 2v4

[SVXRide]

Originally Posted by longassname

We didn't get afr plots at the dyno. The pipe they have for their wideband now doesn't fit in our tailpipe and the plug for their wideband is different than our wideband plug. The afr is easy enough to picture without a plot. It goes from 12.9 at low rpms to 12.4 at high rpms.

Michael,
Looks like I'll have something to contribute (AFR curves) to the community when I get around to doing some more dyno runs later this year
-Bill (z32 in transit....)

[Chiketkd]

Originally Posted by SVXRide

Michael,
Looks like I'll have something to contribute (AFR curves) to the community when I get around to doing some more dyno runs later this year
-Bill (z32 in transit....)

Nice! I can't wait to feel how your car pulls afterwards Bill!

-Chike

[longassname]

my appologies, the power at our corporate office has been out since katrina ran through Miami so I haven't been able to post any new material. The website has been revised to show the stage 2v4 material now and allow it's purchase.

[SVXRide]

long live 2v4 (at least until 2v5 comes out! )

"Since the v4 revision solves the fuel injector cap problem no matter which fuel supply scenario you have I'm personally done with fuel supply discussions." - LAN


Michael,

Does your quote mean that if we want to run the stock injectors and bump the fuel pressure up to where the flow rate of the injectors flattens off that the 2v4 chip will be able to keep the engine from going rich to the point of power actually dropping off? Or is there a fuel pressure point where we'd have to add forced induction to keep this from happening?
Thanks!
-Bill

[longassname]

I don't understand your question Bill. I don't know what you mean by "where the flow rate of the injectors flattens off." Can you come up with a way to make the fuel pressure so high that your afr becomes too rich and you loose power? I suppose it's possible. Will that happen with an impreza fpr? No way.

I've done my best to describe the changes I've made and the effect of them. I think maybe people should read the relatively detailed explanation I gave in the write up more carefully maybe even a few times over until they understand. I'm getting the feeling some people have gotten set in a mindset during pushing for the impreza fpr and haven't taken the time to understand how the software works. Because of the change in the shape of the translation curve the afr will no longer get exceedingly rich as airflow increases. In fact it is leaned out at the higher rpms from where it is with the factory software. If you raise the fuel pressure with an impreza regulator or walboro fuel pump you will not go too rich. The dyno testing was done with a walboro fuel pump after all....I haven't looked in a while but I believe the fuel pressure on our car is 42 psi at wot. We are maintaining power at shortened injector pulse widths at high flow rates thus increasing the airflow that the injectors are capable of supporting. Beyond that the injectors can be driven to highest possible pulse widths since they will be calculated by propperly measured airflows. That's two ways that the software increases the power levels that the factory injectors can support before even raising the fuel pressure. It also allows you to raise the fuel pressure further increasing the power levels the factory injectors can support. This is all the same stuff I've explained in the write up. I'm not sure how else to put it.

I can appreciate wanting to understand how things work. I'm that way myself. I'm going to have to put the burden back on you though and say reread until you understand. I have supercharger manifolds to weld, pulleys to machine, circuit boards to design, software to write, orders to fill, orders to place, paperwork to do. These long posts all take time away from those activities which other customers are waiting on the results of.

Originally Posted by SVXRide

long live 2v4 (at least until 2v5 comes out! )

"Since the v4 revision solves the fuel injector cap problem no matter which fuel supply scenario you have I'm personally done with fuel supply discussions." - LAN


Michael,

Does your quote mean that if we want to run the stock injectors and bump the fuel pressure up to where the flow rate of the injectors flattens off that the 2v4 chip will be able to keep the engine from going rich to the point of power actually dropping off? Or is there a fuel pressure point where we'd have to add forced induction to keep this from happening?
Thanks!
-Bill

[mbtoloczko]

Just want to post this picture of a generic fpr and point out that an fpr can be overdriven by raising the flow rate through the fpr. As the flow rate increases, the orfice opening increases to maintain the fuel pressure at the preset value for that regulator. If the flow rate is continually raised, at some point the spring that operates on the orfice will bottom out. If the spring is operated in this "bottomed out" mode, then the fpr cannot control the fuel pressure.

[longassname]

Originally Posted by mbtoloczko

Just want to post this picture of a generic fpr and point out that an fpr can be overdriven by raising the flow rate through the fpr. As the flow rate increases, the orfice opening increases to maintain the fuel pressure at the preset value for that regulator. If the flow rate is continually raised, at some point the spring that operates on the orfice will bottom out. If the spring is operated in this "bottomed out" mode, then the fpr cannot control the fuel pressure.

I asked you not to bring your fuel pressure regulator discussion in here. If you want to discuss fuel pressure regulator design somewhere else please do. This thread is about stage 2v4 not fuel pressure regulators. If you feel i must be involved in your fuel pressure regulator discussion feel free to give me a link to your thread when you start it.

ps i would appreciate it if you would remove it from here.

[SVXRide]

Originally Posted by longassname

I don't understand your question Bill. I don't know what you mean by "where the flow rate of the injectors flattens off." Can you come up with a way to make the fuel pressure so high that your afr becomes too rich and you loose power? I suppose it's possible. Will that happen with an impreza fpr? No way.

I've done my best to describe the changes I've made and the effect of them. I think maybe people should read the relatively detailed explanation I gave in the write up more carefully maybe even a few times over until they understand. I'm getting the feeling some people have gotten set in a mindset during pushing for the impreza fpr and haven't taken the time to understand how the software works. Because of the change in the shape of the translation curve the afr will no longer get exceedingly rich as airflow increases. In fact it is leaned out at the higher rpms from where it is with the factory software. If you raise the fuel pressure with an impreza regulator or walboro fuel pump you will not go too rich. The dyno testing was done with a walboro fuel pump after all....I haven't looked in a while but I believe the fuel pressure on our car is 42 psi at wot. We are maintaining power at shortened injector pulse widths at high flow rates thus increasing the airflow that the injectors are capable of supporting. Beyond that the injectors can be driven to highest possible pulse widths since they will be calculated by propperly measured airflows. That's two ways that the software increases the power levels that the factory injectors can support before even raising the fuel pressure. It also allows you to raise the fuel pressure further increasing the power levels the factory injectors can support. This is all the same stuff I've explained in the write up. I'm not sure how else to put it.

I can appreciate wanting to understand how things work. I'm that way myself. I'm going to have to put the burden back on you though and say reread until you understand. I have supercharger manifolds to weld, pulleys to machine, circuit boards to design, software to write, orders to fill, orders to place, paperwork to do. These long posts all take time away from those activities which other customers are waiting on the results of.

Michael,
Thanks for the response. I've sent you a PM.
-Bill

[mbtoloczko]

Originally Posted by longassname

...

ps i would appreciate it if you would remove it from here.

I think its pertinent to the thread, so I'm not going to remove it. I've made my point though, so I'm not going to post any more on fprs here.

[longassname]

Originally Posted by mbtoloczko

I think its pertinent to the thread, so I'm not going to remove it. I've made my point though, so I'm not going to post any more on fprs here.

I don't think you made any point except you are trying to push a point. If the spring was "bottomed out" then the fuel pressure wouldn't change with manifold pressure. The fact is the fuel pressure is raised and it is still effected by manifold pressure appropriately. Your picture and the discussion you are forcing has nothing to do with the stage 2v4 software.

[longassname]

Originally Posted by SVXRide

Michael,
Thanks for the response. I've sent you a PM.
-Bill

No problem Bill,

The point of your pm I think IS good material for this thread. You want to make more power after you have stage2v4 installed. Well that's exactly what you should want to do and that is what you should be talking about. I know you got your fuel injectors flow tested and saw that above 60psi you reach a point of dimenishing returns. The thing is you aren't short on fuel so why worry about it yet? The stage 2v4 software takes care of improving accuracy of the engine management and optimizing the timing to get more power out of the air your engine ingests. If you want to make more power what you need is more air. That's what you need to be talking about.

How can you get more air? Well your ram air certainly isn't going to do it on the dyno. I know there has been some discussion in the past about improving high rpm performance by changing your cam timing. I believe Harvey said one notch on your timing belt is a 4 degree change. I would start a thread to start that discussion back up. It could work and it's free. What more could you ask?

That's the kind of stuff we should be talking about. Though not at great length in here. Would love to see links in here to other threads saying hey look how I figured out how to make more power out of this engine now that engine management will let me. Or even just saying hey i think this might work I've started a thread about it here.