Need help with V-AFC tune..
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Need help with V-AFC tune..
Alright, so I bought the car in Georgia not too long ago. Drove it back up to here in PA. At that time, GA and some other southern states didnt have premium gas so regular is what I came up here with. The closer I got to PA I threw some premium in it and it ran better.
Here is the catch. When I bought it, it was on stock injectors. Thats not a problem normally, however, the car is boosted with a "custom" Procharger supercharger.
I bought the car, took it to the place that built the car and as it turned out, the fuel pump was bad making it run very lean. So we replaced the fuel pump and things came close to where they were to be.
Now before I left, they adjusted the V-AFC to the richest it can do. This being on stock injectors maxed them out and I of course would lean out every so often.
So today we put in some 550cc RC injectors. Started it up and it cant keep idle as expected since its running pig rich.
So, my question is, how do I lean out the mixture so that it runs better...
I'm sorry if I posted this in the wrong forum...
BTW, engine mods are as follows:
-Invidia Header
-Invidia Test Pipe
-Invidia Catback
-Procharger supercharger (intercooled)(8psi)
-Bored TB
-RC 550cc Injectors
I believe everything else is stock
Let me know what you think and what I should do.
Art
Here is the catch. When I bought it, it was on stock injectors. Thats not a problem normally, however, the car is boosted with a "custom" Procharger supercharger.
I bought the car, took it to the place that built the car and as it turned out, the fuel pump was bad making it run very lean. So we replaced the fuel pump and things came close to where they were to be.
Now before I left, they adjusted the V-AFC to the richest it can do. This being on stock injectors maxed them out and I of course would lean out every so often.
So today we put in some 550cc RC injectors. Started it up and it cant keep idle as expected since its running pig rich.
So, my question is, how do I lean out the mixture so that it runs better...
I'm sorry if I posted this in the wrong forum...
BTW, engine mods are as follows:
-Invidia Header
-Invidia Test Pipe
-Invidia Catback
-Procharger supercharger (intercooled)(8psi)
-Bored TB
-RC 550cc Injectors
I believe everything else is stock
Let me know what you think and what I should do.
Art
Joined: May 2005
Posts: 4,331
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From: Tallahassee, FL
Get a real EMS solution. VAFC is crap, especially for FI. IMO, its a ticking time-bomb.
If you do not have the $ to get an all-out EMS (AEM, Hondata, FCON, etc.), at least get the Greddy Emanage (blue vs. ultimate can be debated... sounds like you are mildly FI, so blue will probably work).
VAFC will NOT correct anything when the car is in closed loop operation (under 75% throttle input, I think).
My VAFCII used to get over-ruled by the ECU after about 2 weeks, and that was when I was NA.
Its pig rich probably, because you installed 550cc injectors, and the ECU is spraying at the duty cycle of 330cc (stock) injectors. You will need to pull a LOT of fuel, but I think there is only so much you can do with the VAFC before the ECU freaks out... Not sure how to pull the fuel, Mase tuned mine for me...
John
If you do not have the $ to get an all-out EMS (AEM, Hondata, FCON, etc.), at least get the Greddy Emanage (blue vs. ultimate can be debated... sounds like you are mildly FI, so blue will probably work).
VAFC will NOT correct anything when the car is in closed loop operation (under 75% throttle input, I think).
My VAFCII used to get over-ruled by the ECU after about 2 weeks, and that was when I was NA.
Its pig rich probably, because you installed 550cc injectors, and the ECU is spraying at the duty cycle of 330cc (stock) injectors. You will need to pull a LOT of fuel, but I think there is only so much you can do with the VAFC before the ECU freaks out... Not sure how to pull the fuel, Mase tuned mine for me...
John
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John, thats what I was thinking when I bought the car, however when it was at the dyno and they were messing with it, he would adjust it on the vafc and the laptop he had connected would show the readings as he corrected them..
Either way, is there any way to get this done so that I can drive it 1 hour away from my house to get it tuned with those injectors?
Either way, is there any way to get this done so that I can drive it 1 hour away from my house to get it tuned with those injectors?
Joined: May 2005
Posts: 4,331
Likes: 0
From: Tallahassee, FL
I do not know how to tune the VAFC personally... I recall Mase somehow selecting the fuel adjustment area, and turned the knob into the negative numbers to lean it out...
Why not just toss the OEM injectors back in, drive to the dyno, and throw the new injectors in right before it gets tuned (when its already at the tuner)?
Sorry, I am not much help when it comes to physically tuning the various systems...
John
Why not just toss the OEM injectors back in, drive to the dyno, and throw the new injectors in right before it gets tuned (when its already at the tuner)?
Sorry, I am not much help when it comes to physically tuning the various systems...
John
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Joined: Nov 2006
Posts: 1,284
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From: tampa florida
get that vafc out of there, you need to control timing along with fule on a boosted car. like said b4 - full aem or an aem fic or greedy system, you will have better control and get more power out of the car.
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Ahh the infamous vafc. Ok lets see if I can clarify some things for you here since I am also running 8psi with a CTAC with a vafc and factory (360cc) injectors.
8psi you do not need to worry about timing if using a centrifugal style SC like the Comptech, Vortech etc. Is the Pro charger a roots or centrifugal type? i'm not familiar with this one. If its a Roots then I would be concerned about detonation and needing to retard timing due to the much higher level of boost at a lower rpm, if your a centrifugal type at 8 psi level you have no worry's.
Ok the vafc on an s2000 has really only 3 good working functions that can be used and adjusted successfully. They are vtec control and "wide throttle" otherwise known as open loop, and throttle position sensor which determines at what percentage of throttle it takes to engage that open loop "wide throttle" fuel map. Wide throttle can only be used for leaning or removing fuel, increasing fuel will do nothing but freak out the stock ecu causing misfires etc.
"Narrow throttle" works temperately which explains why you were seeing results with your tuner on the lap top, but within a half a dozen or so shut down and start ups yur stock ecu goes back to centering itself deleting any effects of your changes there, this narrow throttle includes idle and the portion of the throttle that is not set on your throttle positioning sensor to utilize the wide throttle kick in point. You can set your throttle position to be 10% if you want which means that is when your adjustable wide throttle range kicks in and have 90% of your gas pedal to be yours to adjust. No matter how far you set to even 100% you will still have the stock narrow throttle and idle transition points to work around.
You will need to experiment to see where your car/set up works best with the throttle position % and I hope you have a wide band afr gauge so you can see where you need to tune, very helpful with the easy to use vafc interface for on the fly street tuning, I will be sorry to see that aspect of this unit go when I replace it for something more suitable for higher boost. I considered trying 440cc injectors but after hearing your idle problem with your 550cc I don't think its going to work much better. Sorry to say your not going to have any luck with the 550 injectors and a good idle and narrow throttle running. You will be able to have the majority of your throttle from about 1/4 to full work well however but at a sacrifice which you are now starting to understand.
I have done a bit more research on my own set up possibilities and speaking with my local tuner, basically what it comes down to is being able to override and adjust your narrow throttle settings and have them stick and work properly with your ecu. The best piggy back on the market with the fastest processing to do this is the AEM FIC. This unit also effectively adjust timing if you need it. This unit is also 1/4 the price at just $400 compared to a full AEM stand alone which I think is overkill for about 75% of peoples set ups I see on this board do to their own fears and misunderstandings of what they need to have a properly functioning system. Some may disagree with that but that's the conclusion I have come up to at this point. Most people are not running anymore then 10 psi and that level dictates allot.
8psi you do not need to worry about timing if using a centrifugal style SC like the Comptech, Vortech etc. Is the Pro charger a roots or centrifugal type? i'm not familiar with this one. If its a Roots then I would be concerned about detonation and needing to retard timing due to the much higher level of boost at a lower rpm, if your a centrifugal type at 8 psi level you have no worry's.
Ok the vafc on an s2000 has really only 3 good working functions that can be used and adjusted successfully. They are vtec control and "wide throttle" otherwise known as open loop, and throttle position sensor which determines at what percentage of throttle it takes to engage that open loop "wide throttle" fuel map. Wide throttle can only be used for leaning or removing fuel, increasing fuel will do nothing but freak out the stock ecu causing misfires etc.
"Narrow throttle" works temperately which explains why you were seeing results with your tuner on the lap top, but within a half a dozen or so shut down and start ups yur stock ecu goes back to centering itself deleting any effects of your changes there, this narrow throttle includes idle and the portion of the throttle that is not set on your throttle positioning sensor to utilize the wide throttle kick in point. You can set your throttle position to be 10% if you want which means that is when your adjustable wide throttle range kicks in and have 90% of your gas pedal to be yours to adjust. No matter how far you set to even 100% you will still have the stock narrow throttle and idle transition points to work around.
You will need to experiment to see where your car/set up works best with the throttle position % and I hope you have a wide band afr gauge so you can see where you need to tune, very helpful with the easy to use vafc interface for on the fly street tuning, I will be sorry to see that aspect of this unit go when I replace it for something more suitable for higher boost. I considered trying 440cc injectors but after hearing your idle problem with your 550cc I don't think its going to work much better. Sorry to say your not going to have any luck with the 550 injectors and a good idle and narrow throttle running. You will be able to have the majority of your throttle from about 1/4 to full work well however but at a sacrifice which you are now starting to understand.
I have done a bit more research on my own set up possibilities and speaking with my local tuner, basically what it comes down to is being able to override and adjust your narrow throttle settings and have them stick and work properly with your ecu. The best piggy back on the market with the fastest processing to do this is the AEM FIC. This unit also effectively adjust timing if you need it. This unit is also 1/4 the price at just $400 compared to a full AEM stand alone which I think is overkill for about 75% of peoples set ups I see on this board do to their own fears and misunderstandings of what they need to have a properly functioning system. Some may disagree with that but that's the conclusion I have come up to at this point. Most people are not running anymore then 10 psi and that level dictates allot.
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