ECUtune Stage 2 version 3 ( 2v3 )

[mbtoloczko]

Originally Posted by shotgunslade

So, does just substituting the Impreza FPR improve power without other mods on an NA engine? I am running the Green Filter and a Magnaflow exhaust, but no other mods.

The Impreza RS fpr operates at 43 psi at WOT vs the SVX fpr which operates at 36 psi at WOT. The increase in fuel pressure results in a little over a 1 point richening of the afr when the ecu is operating in open-loop (aggressive driving). With the SVX fpr, the afr is a little lean for max power at moderate rpms and right on the money near redline. With the Impreza RS fpr, the afr right in the optimum range at moderate rpms, but near redline, it starts getting a bit too rich. Have a look in my locker to see what the Impreza fpr does to the afr. This will happen regardless of whether or not you have done any intake or exhaust mods.

[longassname]

Originally Posted by shotgunslade

So, does just substituting the Impreza FPR improve power without other mods on an NA engine? I am running the Green Filter and a Magnaflow exhaust, but no other mods.

An impreza fpr probably costs a little bit of power and worsens fuel efficiency on a car with our software. It might improve things a bit on a car with a stock ecu since the cars run way too lean at low rpms from the factory but we've already taken care of that in our software.

[SVXRide]

Originally Posted by longassname

An impreza fpr probably costs a little bit of power and worsens fuel efficiency on a car with our software. It might improve things a bit on a car with a stock ecu since the cars run way too lean at low rpms from the factory but we've already taken care of that in our software.

Michael,
Thus my question about the 2V3 chip for those of us runing the Impreza FPR and upgrading to the 2V3 w/z32 in a NA mode Definitely don't want to be doing anything that's going to reduce the amount of Hp/Torque being created (and I really don't want to have to go back in and swap out the Impreza FPR, since my stock FPR was on its last legs when I replaced it with the Impreza FPR...)
-Bill
p.s. Long term, I think the Impreza FPR is the right way to go, as it pumps up the output of the stock injectors so they'll be capable of supporting the higher Hp/Torque we're all working towards

[longassname]

Originally Posted by SVXRide

Michael,
Thus my question about the 2V3 chip for those of us runing the Impreza FPR and upgrading to the 2V3 w/z32 in a NA mode Definitely don't want to be doing anything that's going to reduce the amount of Hp/Torque being created (and I really don't want to have to go back in and swap out the Impreza FPR, since my stock FPR was on its last legs when I replaced it with the Impreza FPR...)
-Bill
p.s. Long term, I think the Impreza FPR is the right way to go, as it pumps up the output of the stock injectors so they'll be capable of supporting the higher Hp/Torque we're all working towards

But if I tuned for the impreza fpr then everyone who doesn't have one would need to get one when they wouldn't otherwise need it. I feel your pain but I don't think the majority of people would want to buy a new fpr that they don't need.

[SVXRide]

Originally Posted by longassname

But if I tuned for the impreza fpr then everyone who doesn't have one would need to get one when they wouldn't otherwise need it. I feel your pain but I don't think the majority of people would want to buy a new fpr that they don't need.

Michael,
I fully understand your thinking, from a business standpoint (must be that minor in Economics that came with the Mechanical Engineering degree )...I just keep coming back to the following:

Stock FPR with Stock Injectors = 36psi with 240 cc/min = 230 HP @ crank

Impreza FPR with Stock Injectors = 43 psi with 270 cc/min = 260 HP@crank (Based on BSFC=.45 and Max Duty Cycle = 75%)


Granted this is a "theoretical" calculation...it just gets me to thinking that, just as the stock MAF has become a "bottleneck" for further HP gains (2v3 w/z32 MAF to the rescue!!), the stock injectors with the stock FPR are the next "bottleneck" we're faced with and the Impreza FPR does help us in this regard.

-Bill

[mbtoloczko]

Originally Posted by longassname

But if I tuned for the impreza fpr then everyone who doesn't have one would need to get one when they wouldn't otherwise need it. I feel your pain but I don't think the majority of people would want to buy a new fpr that they don't need.

Bill kinda does have a good point. Your stage 2v3 will provide the capability to measure much more air flowrate into the motor, but how do you intend to deal with the limitations in fuel flow for the stock engine? If you tune for stock fuel injectors and the stock fpr, then what are people going to do when they hit the fuel flowrate limit? The stock fuel injectors and fuel pressure regulator are only good to maybe 250 HP. I guess you could just presume that people will add auxillary injectors and control those with an auxillary injector control unit. Was that the plan?

[longassname]

If you are running lean because you have reached the limit of the fuel injectors and then add the fpr to increase your fuel flow then you won't be running too rich and loosing power will you? At that point you are correcting your afr to get back to the sweet spot; however, using the fpr to raise your fuel pressure if you have not increased your airflow is a bad idea and asking that I take out extra fuel to undo a few people's bad idea to the detriment of everyone else is kind of well..you know.

If you start running lean by all means raise your fuel pressure.

You are worrying over nothing anyway. By now you should realize I always tune in a way to allow the largest margins of variablity between cars. Not like I went and pulled the walboro out of the demo car I did the fuel tuning on. In the demo car it runs 12.9 to 12.4 at wot accross all rpms on the street.

[shotgunslade]

It seems like the Stage 2 chip is designed to handle increased air flow, which, if it were available might tax the stock FPR. So, for those of us who are not yet ready to put $5-6K into a forced draft system, what might be the options for increasing airflow, so that we could get to this lovely dilemma of being too lean?

[SVXRide]

Originally Posted by longassname

If you are running lean because you have reached the limit of the fuel injectors and then add the fpr to increase your fuel flow then you won't be running too rich and loosing power will you? At that point you are correcting your afr to get back to the sweet spot; however, using the fpr to raise your fuel pressure if you have not increased your airflow is a bad idea and asking that I take out extra fuel to undo a few people's bad idea to the detriment of everyone else is kind of well..you know.

If you start running lean by all means raise your fuel pressure.

You are worrying over nothing anyway. By now you should realize I always tune in a way to allow the largest margins of variablity between cars. Not like I went and pulled the walboro out of the demo car I did the fuel tuning on. In the demo car it runs 12.9 to 12.4 at wot accross all rpms on the street.

Michael,
Great! Given the dyno results I got when I put the 1v4 in my car - AFR curve indicating a little richer than I'd like in the upper rpm range (backed up by very black head pipes) - I've been axiously waiting for your next "stage" Looks like the 2v4 w/z32 might just get those of us looking for even more Hp/Torque into the "sweet spot"
Can't wait to get everything together and get back to the dyno (yes, I've addressed the issues we discussed with my last runs )
-Bill
p.s. the 12.9 to 12.4 you refered to is with the 2v4 w/z32 MAF?

[mbtoloczko]

Originally Posted by longassname

If you are running lean because you have reached the limit of the fuel injectors and then add the fpr to increase your fuel flow then you won't be running too rich and loosing power will you? ....

I've been thinking about this a bit, and I think that adding the Impreza RS fpr to a stage 2v3 tuned for 36 psi fuel pressure will not *properly* fix fuel flow limitations. My thought is that adding the Impreza RS fpr will richen the afr about 1.3 points, but the car will still reach the limit of fuel flow at the same air flow rate. This is because the injectors are still going to reach 100% duty cycle (or whatever it is the the SVX ecu will run them to) at the same point as with the 36 psi fpr whether or not the SVX fpr or the Impreza RS fpr is used. On the other hand, if you tune for a 43 psi fpr, then the fuel injectors will not reach their duty cycle limit until higher air flow rates. I've posted a little picture of what I'm thinking:

[longassname]

I have it in hand. The z32 maf allows the ecu to drive the injectors harder if need be and the changes i made to the vq table in order to effect the afr has the injectors not being driven as hard as they were before at high levels of output while at the same time increasing power output--or so I believe we will find out tomorrow.

This is running a walboro fuel pump the effect of which is somewhere between stock fuel pressure and if you had an impreza fpr, a good happy medium.


The effect of this is to make the software work for everyone, to improve accuracy of the engine management at high ouput, reducing fluctuations in afr and combustion temps between cyllinders and revolutions while increasing acuracy of timing control, allowing us to increase ignition advance for further power gains, while lowering injector duty cycle at high output thus increasing possible output and rpms.

[shotgunslade]

Just got my Stage 2 V. 4 kit. For some reason, the Ecutune website wouldn't come up. Instructions not absolutely precise on one point. The switch is only for changing to lower octane rating gas, is that not correct. If we want to continue to pay through the nose for high test, we don't need to install the switch.

[SVXRide]

Originally Posted by longassname

I have it in hand. The z32 maf allows the ecu to drive the injectors harder if need be and the changes i made to the vq table in order to effect the afr has the injectors not being driven as hard as they were before at high levels of output while at the same time increasing power output--or so I believe we will find out tomorrow.

This is running a walboro fuel pump the effect of which is somewhere between stock fuel pressure and if you had an impreza fpr, a good happy medium.


The effect of this is to make the software work for everyone, to improve accuracy of the engine management at high ouput, reducing fluctuations in afr and combustion temps between cyllinders and revolutions while increasing acuracy of timing control, allowing us to increase ignition advance for further power gains, while lowering injector duty cycle at high output thus increasing possible output and rpms.

Michael,
Why would running a walbro pump have an effect between the stock fpr and the impreza fpr? Isn't the walbro pump just increasing the maximum flow rate? Ultimately the fpr is still controlling the fuel pressure that the injectors are seeing. Maybe I'm just missing something here
Thanks again for all your hard work in support of the EG33/SVX!!
-Bill
p.s. can you provide a little more detail as to what you mean by "The z32 maf allows the ecu to drive the injectors harder if need be..." Do you mean a higher duty cycle?

[svxfiles]

When I installed my Walbro 255, it did nothing to my fuel pressure at all...

But I have had a fuel pressure dropoff when I shut off the engine, for a long time, most easily explaned by a leaking fuel injetor.

[SVXRide]

Originally Posted by svxfiles

When I installed my Walbro 255, it did nothing to my fuel pressure at all...

But I have had a fuel pressure dropoff when I shut off the engine, for a long time, most easily explaned by a leaking fuel injetor.

Thus confirming my thinking...again, unless I'm missing something here buried deep in the entrails of the ECU
-Bill