ECUtune Stage 2v7 & Stage 2v7F

[kcpaz]

if you want to unload the other two injectors that you don't use let me know, I'm probably going to buy a set of 4 on ebay this week. From what I understand, you HAVE to run the 370's with the stage 2 chip because that is what it's calibrated for. NO2, boost, or N/A, you still have to run the 370's


Just one more question about the 2v7....

When the engine is under full load, say at full boost, or WOT, what is the target AFR that the ECU looks for. Does it just lean it out until it starts to knock and then pulls timing and adds fuel? or is it more complicated than that?

Originally Posted by immortal_suby

Me too! This was a good discussion, I understand much more about the system now.

Got a quick question

I have finally secured (8) used 370cc injectors now but from 2 different engines. All are the sr20DET purple tops.
Without running NO2, am I safe to just pick the best looking 6 and drop them in along with 2v7 and see how she runs, or should I wait and send them off for matching/blueprinting. I have thursday off and an itchy set of tools that want to see how 2v7 runs......Please, I need a good reason not to drop them in if there is one. I am an excitedly impatient bastard sometimes.

[longassname]

The ones I've gotten have all had brittle/broken pintel caps. If yours look good though, go for it.

Originally Posted by immortal_suby

Me too! This was a good discussion, I understand much more about the system now.

Got a quick question

I have finally secured (8) used 370cc injectors now but from 2 different engines. All are the sr20DET purple tops.
Without running NO2, am I safe to just pick the best looking 6 and drop them in along with 2v7 and see how she runs, or should I wait and send them off for matching/blueprinting. I have thursday off and an itchy set of tools that want to see how 2v7 runs......Please, I need a good reason not to drop them in if there is one. I am an excitedly impatient bastard sometimes.

[longassname]

The afr is different and the timing is different for every combination of rpm and boost. There isn't any single target afr. The higher the boost the lower the afr will be.

Originally Posted by kcpaz

if you want to unload the other two injectors that you don't use let me know, I'm probably going to buy a set of 4 on ebay this week. From what I understand, you HAVE to run the 370's with the stage 2 chip because that is what it's calibrated for. NO2, boost, or N/A, you still have to run the 370's


Just one more question about the 2v7....

When the engine is under full load, say at full boost, or WOT, what is the target AFR that the ECU looks for. Does it just lean it out until it starts to knock and then pulls timing and adds fuel? or is it more complicated than that?

[kcpaz]

That doesn't make sense to me. There has to be a certian point at which you don't want the AFR to go any richer (probably somewhere around 10.0 for turbo). If the AFR is 11.0 at 8psi, are you saying that at 12psi, the AFR will be even lower (richer)? at what point does the ECU sustain any given AFR?

I understand that timing would change with RPM, and the airflow will increase with RPM and and boost, but at some point, doesn't the ECU regulate fuel to maintain a certian AFR?

[longassname]

The ecu will sustain whatever afr the cell for any particular rpm and load combination tells it to sustain. There are 256 cells in a table. For me to give a numerical answer on afr I would have to know specifically what rpm and load combination you want to know the value for and go look it up--which before you even ask I won't do. You wouldn't know what load to tell me anyway since even if you had the equipment to log airflow you wouldn't know the translation table values or load forumla. Again, the optimum timing and afr is a function of load = mass of air ingested per revolution. 8 lbs of boost does not equal 8 pounds of boost which does not equal 8 lbs of boost. The load under 8 lbs of boost can vary pretty widely depending on charge temp, cams, and exhaust flow. I can just tell you that as a general rule the higher the load the lower the afr. The tables are populated with values based on our experience to date; they are what we have thus far found to be the best values.

Originally Posted by kcpaz

That doesn't make sense to me. There has to be a certian point at which you don't want the AFR to go any richer (probably somewhere around 10.0 for turbo). If the AFR is 11.0 at 8psi, are you saying that at 12psi, the AFR will be even lower (richer)? at what point does the ECU sustain any given AFR?

I understand that timing would change with RPM, and the airflow will increase with RPM and and boost, but at some point, doesn't the ECU regulate fuel to maintain a certian AFR?

[kcpaz]

okay, so I'm assuming there was a lot of dyno work done for you to come up with the re-programming for the chip. When you are doing a dyno pull, I'm also assuming you are recording with a wideband right? Isn't it possible to look at the dyno pull and get a reading from the wideband? If you had a line graph of a dyno pull, that would answer my question. Then I could visually track the AFR during a pull.

I'm not trying to be a PITA, I'm just trying to learn about the system because I am probably going to run forced induction and I want to make sure my engine management will be up to the task. I think it's amazing that you have a system that can go from N/A to forced induction with no modification to the engine management.

[longassname]

dude.......

if you're looking for plots instead of undestanding then read the threads.

Anybody want to jump in here and try to bridge the gap between what I'm saying and what he's understanding? I can't think of any other way to explain what I've said and honestly don't understand why you don't understand.

1. your fuel and timing tables have load as one axis and rpm as the other
2. the tables have 16 rows and 16 columns = 256 cells
3. in the timing table each cell specifies the timing for the corresponding combination of load and rpm
4. in the fuel table each cell specifies the afr for the corresponding combination of load and rpm
5. the stage 2 tables cover the load range out to 500ish hp
6. the na operating range is a subset of that load range (the left side of the table)
7. for every combination of load and rpm below 500 hp there is a cell specifying the afr and a cell specifying the ignition timing

Once you understand that, you see that na operation is just a subset of forced induction operation and that an engine management system capable of handling forced induction is automatically capable of handling na operation.

And for you to question the afr being run under any condition less than 500hp means you are just questioning the value I put in some cell. Now I'm not going to say that the values in the current tables are the end all, absolute best values possible; they are the best known values to date and the result of years of experience tuning the SVX. When significantly better values are found you can rest assured they will be used in 2v8.

It sounds like you are focussed on looking for "it runs between 10 to 1 and 11.7 to 1 under boost." Yes it does. But if you are really worried that I'm specifying values like 17 to 1 at 20 lbs of boost you should run, not walk, away from using an engine management system of my design.

Originally Posted by kcpaz

okay, so I'm assuming there was a lot of dyno work done for you to come up with the re-programming for the chip. When you are doing a dyno pull, I'm also assuming you are recording with a wideband right? Isn't it possible to look at the dyno pull and get a reading from the wideband? If you had a line graph of a dyno pull, that would answer my question. Then I could visually track the AFR during a pull.

I'm not trying to be a PITA, I'm just trying to learn about the system because I am probably going to run forced induction and I want to make sure my engine management will be up to the task. I think it's amazing that you have a system that can go from N/A to forced induction with no modification to the engine management.

[immortal_suby]

She's up and running on 2v7. Didn't take long at all to install.

Idle is smooth, no burps or anything while driving. Feels strong! Thanks Michael!

I'll be sending my 2v5 chips back soon - just want to drive her a few more times to make sure nothing goes wrong with the used injectors.

[TomsSVX]

now make a run on the funny stuff!!!

Tom

[immortal_suby]

Originally Posted by TomsSVX

now make a run on the funny stuff!!!

Tom

all in good time....

[longassname]

Thanks,

You're welcome. You don't have to send back the 2v5 ROMs. It's only the 2v6's I'm requiring back.

Originally Posted by immortal_suby

She's up and running on 2v7. Didn't take long at all to install.

Idle is smooth, no burps or anything while driving. Feels strong! Thanks Michael!

I'll be sending my 2v5 chips back soon - just want to drive her a few more times to make sure nothing goes wrong with the used injectors.

[Myxalplyx]

Originally Posted by longassname

I think I may have just figured out what is making you missunderstand. I bet you are thinking the fuel table specifies how much fuel to inject. It doesn't on an SVX. The ECU is able to calculate exactly how much fuel to inject to reach an afr from the mass air readings. The fuel table specifies what afr to run under the operating conditions which match a cell.

The cells in the region of the table which an na car operates is in the left side of the table. The region of the table of the table a forced induction car operates under when under boost is towards the right side of the table. Get it? Load is an axis of the fuel and timing tables. When you talk about having a lower target afr for a turbo car you aren't talking about changing the value of a cell; you are talking about reading the value out of a cell further to the right in the table.

Likewise with timing. When you talk about running less ignition timing under boost you aren't talking about changing the value of a cell; you are talking about reading the value out of a cell further to right in the table.


So long as the engine management system is able to measure the mass of air being ingested, deliver the required quantity of fuel, has tables that cover the entire load range, and has the correct values in those tables it doesn't matter what hardware you use to get the air in.

Perhaps you should consider teaching classes about this. This is the first time 'I feel' I have come to a understanding of this, this way. Thanks! (Chest sticking out).

[kcpaz]

Originally Posted by longassname

dude.......

if you're looking for plots instead of undestanding then read the threads.

Anybody want to jump in here and try to bridge the gap between what I'm saying and what he's understanding? I can't think of any other way to explain what I've said and honestly don't understand why you don't understand.

1. your fuel and timing tables have load as one axis and rpm as the other
2. the tables have 16 rows and 16 columns = 256 cells
3. in the timing table each cell specifies the timing for the corresponding combination of load and rpm
4. in the fuel table each cell specifies the afr for the corresponding combination of load and rpm
5. the stage 2 tables cover the load range out to 500ish hp
6. the na operating range is a subset of that load range (the left side of the table)
7. for every combination of load and rpm below 500 hp there is a cell specifying the afr and a cell specifying the ignition timing

Once you understand that, you see that na operation is just a subset of forced induction operation and that an engine management system capable of handling forced induction is automatically capable of handling na operation.

And for you to question the afr being run under any condition less than 500hp means you are just questioning the value I put in some cell. Now I'm not going to say that the values in the current tables are the end all, absolute best values possible; they are the best known values to date and the result of years of experience tuning the SVX. When significantly better values are found you can rest assured they will be used in 2v8.

It sounds like you are focussed on looking for "it runs between 10 to 1 and 11.7 to 1 under boost." Yes it does. But if you are really worried that I'm specifying values like 17 to 1 at 20 lbs of boost you should run, not walk, away from using an engine management system of my design.

Alright, I went back and re-read everything and I get where you are coming from now. Sorry for being such a pain in your ass. Thanks again for sharing your knowlege about your amazing product.

[Myxalplyx]

Originally Posted by kcpaz

Alright, I went back and re-read everything and I get where you are coming from not. Sorry for being such a pain in your ass. Thanks again for sharing your knowlege about your amazing product.

You did mean 'now' and not 'not' right? If you meant 'not'.......Lol!

[longassname]

Now I understand the problem....it's borat!

Originally Posted by Myxalplyx

You did mean 'now' and not 'not' right? If you meant 'not'.......Lol!