NGC Tuning w/ SAFC - For Low Boost Applications
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Joined: Oct 2005
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From: Honolulu
NGC Tuning w/ SAFC - For Low Boost Applications
I wrote this as a reply to a PM... This is basic tuning for a NGC controlled car using a adjustable rrfpr, stock injectors, 5th injector, and a SAFC.
As mentioned this is for low boost applications. I was able to run 10psi on this set-up and made 219whp and 244 wtq on stock internals. (i did not use stock injectors though) This may or may not be the set-up for you. I am not here to tune your car, but I hope this will give a better understanding on what I did and what worked for me.
PS, if you blow up your car, don’t come to me unless you want to get laughed at.
----------------------------------------------------------------------
Basic SAFC usage: This may be repetitive, bare with me…
The MAP connection is what is controlling fuel. (0v-5v) By altering the fuel on the AFC, it alters the signal the ECU sees from the MAP. The ECU takes the voltage and adjusts fuel. Low Pressure/Low Voltage = less fuel needed High Pressure/High Voltage = more fuel needed. The fuel is adjusted by the fuel tables on the AFC. You have your low fuel tables and your high fuel tables.
The TPS connection is what tells the AFC which table to use. (0v-5v) So now you set your TPS percentages to tell when to go into low table and high table. So let us say you set low at 30% and high at 70%. 30% and lower throttle position the AFC will use low settings. 70% and higher the AFC will use high settings. Anywhere in between the AFC will use a mix of both low and high settings.
Now you ready for the curve ball… lol I explained the above so you have a general knowledge of how it works.
NGC SAFC Application:
MAP:
The above MAP information stays the same. The MAP sensor connection is critical because this is what is controlling your fuel. For our cars a SAFC is only used to pull fuel out. You can not add fuel with a SAFC! As mentioned, the MAP signal is a 0v-5v signal. Most say 4.6v is WOT on naturally aspirated neon. 5v on our MAP sensor is positive pressure (boost). If the ECU sees 4.6v or above than there will be an issue.
Now the SAFC takes percentages of signal away. You high fuel table settings will cover your tuning while in boost. (I’ll speak more of this in the TPS section below.) In order for your ECU not to see boost in the high fuel setting you would need to take 8% of fuel out across the RPM range. Simple math tells you that 8% of 5v is 4.6v (WOT as mentioned before). Fine tuning of fuel will continue below the -8%.
TPS:
I mentioned that the MAP connection is critical for fuel. In my basic usage section it tells how the TPS connection only tells the AFC when to switch fuel tables from high to low.
Rather than hooking up the TPS connection to the car’s TPS sensor, you want to hook it up to the MAP wire. This connection must be hooked up closest to the MAP center in order to get an accurate reading. The TPS connection just reads and does not alter.
ECU------SAFC MAP CONNECTION------SAFC TPS CONNECTION------MAP SENSOR
The TPS also reads 0v-5v… The MAP signal is now going to tell the SAFC when to switch from low settings to high settings. The TPS setting on the AFC read by percentage from 0% - 100%.
0% = 0v
100% = 5v (MAP sensor max)
Now the NGC is real good at making 14.7 A/F. You want to use this to your advantage. Out of boost the car will run just fine under the stock ECU control as long as your fuel pressures are close to stock. Low fuel table will be used only for when you are not in boost. If your fuel pressures are correct then you can usually set the low fuel table flat across the RPM range. In order to use the low fuel settings for when you out of boost you want to set the low throttle percentage at 85%. 85% will = 4.25v on the MAP sensor.
As pressure builds within the manifold the voltage of you MAP will increase. At about 4.6v you will be reaching positive pressure or 0psi on the boost gauge. You would ultimately want to be in your high fuel table before positive pressure hits. Set the high fuel table percentage to 90%. 90% will = 4.5v on the MAP sensor. Right before your MAP signal crosses over into positive pressure your SAFC will already be switched to your high fuel settings.
If you remember how I mentioned in the basic info.
0%-85% will be low fuel settings (0v – 4.25v MAP)
85% - 90% will be a mix (will be happening so fast there is no need to worry about it)
90% - 100% will be high fuel settings (4.5v – 5.0v MAP)
Because you’ve set your high fuel table at -8% fuel you ECU will never see boost. This is where you take over controlling fuel.
Your stock injectors pulse… open, close. Using the adjustable RRFPR you will be increasing the pressure in the system. The injectors will open as they would stock, but with the higher pressure in the system you will be forcing more fuel through them. You will have to play with the rate of gain and pressure to compensate for the larger volume of air you will be pushing with a turbo.
5th Injector:
The fifth injector idea is another way to add fuel. It’s uncontrollable. You can set it on a boost switch and tell it when to come on. A cold start injector doesn’t pulse. Once it’s on, it’s on… although it won’t flow as much as a normal injector. You will have to find a happy medium between your over pressured stock injectors and the 5th injector spraying fuel into the intake tube.
Tuning:
Tuning will consist mainly of your RRFPR and 5th injector. The AFC will be used to fine tune and pull un-needed fuel out. It will also prevent your ECU from seeing boost. The adjustable RRFPR also has a onset of gain setting to get fuel in faster. This part you are on your own. Every motor will be different and many variables can determine the amount of pressure needed to get a good A/F.
If you’re using your stock injectors then you want to set the base pressure to the stock fuel pressure. The RRFPR will not raise pressure until boost hits so all out of boost cruising and reliability will be easy controlled by the NGC.
k3v
As mentioned this is for low boost applications. I was able to run 10psi on this set-up and made 219whp and 244 wtq on stock internals. (i did not use stock injectors though) This may or may not be the set-up for you. I am not here to tune your car, but I hope this will give a better understanding on what I did and what worked for me.
PS, if you blow up your car, don’t come to me unless you want to get laughed at.
----------------------------------------------------------------------
Basic SAFC usage: This may be repetitive, bare with me…
The MAP connection is what is controlling fuel. (0v-5v) By altering the fuel on the AFC, it alters the signal the ECU sees from the MAP. The ECU takes the voltage and adjusts fuel. Low Pressure/Low Voltage = less fuel needed High Pressure/High Voltage = more fuel needed. The fuel is adjusted by the fuel tables on the AFC. You have your low fuel tables and your high fuel tables.
The TPS connection is what tells the AFC which table to use. (0v-5v) So now you set your TPS percentages to tell when to go into low table and high table. So let us say you set low at 30% and high at 70%. 30% and lower throttle position the AFC will use low settings. 70% and higher the AFC will use high settings. Anywhere in between the AFC will use a mix of both low and high settings.
Now you ready for the curve ball… lol I explained the above so you have a general knowledge of how it works.
NGC SAFC Application:
MAP:
The above MAP information stays the same. The MAP sensor connection is critical because this is what is controlling your fuel. For our cars a SAFC is only used to pull fuel out. You can not add fuel with a SAFC! As mentioned, the MAP signal is a 0v-5v signal. Most say 4.6v is WOT on naturally aspirated neon. 5v on our MAP sensor is positive pressure (boost). If the ECU sees 4.6v or above than there will be an issue.
Now the SAFC takes percentages of signal away. You high fuel table settings will cover your tuning while in boost. (I’ll speak more of this in the TPS section below.) In order for your ECU not to see boost in the high fuel setting you would need to take 8% of fuel out across the RPM range. Simple math tells you that 8% of 5v is 4.6v (WOT as mentioned before). Fine tuning of fuel will continue below the -8%.
TPS:
I mentioned that the MAP connection is critical for fuel. In my basic usage section it tells how the TPS connection only tells the AFC when to switch fuel tables from high to low.
Rather than hooking up the TPS connection to the car’s TPS sensor, you want to hook it up to the MAP wire. This connection must be hooked up closest to the MAP center in order to get an accurate reading. The TPS connection just reads and does not alter.
ECU------SAFC MAP CONNECTION------SAFC TPS CONNECTION------MAP SENSOR
The TPS also reads 0v-5v… The MAP signal is now going to tell the SAFC when to switch from low settings to high settings. The TPS setting on the AFC read by percentage from 0% - 100%.
0% = 0v
100% = 5v (MAP sensor max)
Now the NGC is real good at making 14.7 A/F. You want to use this to your advantage. Out of boost the car will run just fine under the stock ECU control as long as your fuel pressures are close to stock. Low fuel table will be used only for when you are not in boost. If your fuel pressures are correct then you can usually set the low fuel table flat across the RPM range. In order to use the low fuel settings for when you out of boost you want to set the low throttle percentage at 85%. 85% will = 4.25v on the MAP sensor.
As pressure builds within the manifold the voltage of you MAP will increase. At about 4.6v you will be reaching positive pressure or 0psi on the boost gauge. You would ultimately want to be in your high fuel table before positive pressure hits. Set the high fuel table percentage to 90%. 90% will = 4.5v on the MAP sensor. Right before your MAP signal crosses over into positive pressure your SAFC will already be switched to your high fuel settings.
If you remember how I mentioned in the basic info.
0%-85% will be low fuel settings (0v – 4.25v MAP)
85% - 90% will be a mix (will be happening so fast there is no need to worry about it)
90% - 100% will be high fuel settings (4.5v – 5.0v MAP)
Because you’ve set your high fuel table at -8% fuel you ECU will never see boost. This is where you take over controlling fuel.
Your stock injectors pulse… open, close. Using the adjustable RRFPR you will be increasing the pressure in the system. The injectors will open as they would stock, but with the higher pressure in the system you will be forcing more fuel through them. You will have to play with the rate of gain and pressure to compensate for the larger volume of air you will be pushing with a turbo.
5th Injector:
The fifth injector idea is another way to add fuel. It’s uncontrollable. You can set it on a boost switch and tell it when to come on. A cold start injector doesn’t pulse. Once it’s on, it’s on… although it won’t flow as much as a normal injector. You will have to find a happy medium between your over pressured stock injectors and the 5th injector spraying fuel into the intake tube.
Tuning:
Tuning will consist mainly of your RRFPR and 5th injector. The AFC will be used to fine tune and pull un-needed fuel out. It will also prevent your ECU from seeing boost. The adjustable RRFPR also has a onset of gain setting to get fuel in faster. This part you are on your own. Every motor will be different and many variables can determine the amount of pressure needed to get a good A/F.
If you’re using your stock injectors then you want to set the base pressure to the stock fuel pressure. The RRFPR will not raise pressure until boost hits so all out of boost cruising and reliability will be easy controlled by the NGC.
k3v
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RE: NGC Tuning w/ SAFC - For Low Boost Applications
You stated that u can't add fuel to your car by using the Apexi Safc Neo. U said u can only take fuel out. If someone wanted to add fuel, would they need to get a high flow fuel pump and increase the amount of fuel with a regulator then take whatever amount of fuel out of the car by using the Apexi?
Thread Starter
Joined: Oct 2005
Posts: 2,019
Likes: 0
From: Honolulu
RE: NGC Tuning w/ SAFC - For Low Boost Applications
ORIGINAL: lblackneon
You stated that u can't add fuel to your car by using the Apexi Safc Neo. U said u can only take fuel out. If someone wanted to add fuel, would they need to get a high flow fuel pump and increase the amount of fuel with a regulator then take whatever amount of fuel out of the car by using the Apexi?
You stated that u can't add fuel to your car by using the Apexi Safc Neo. U said u can only take fuel out. If someone wanted to add fuel, would they need to get a high flow fuel pump and increase the amount of fuel with a regulator then take whatever amount of fuel out of the car by using the Apexi?
k3v
Thread Starter
Joined: Oct 2005
Posts: 2,019
Likes: 0
From: Honolulu
RE: NGC Tuning w/ SAFC - For Low Boost Applications
Rising rate fuel pressure regulator... no, it'll bump the pressure a bit but not enough to compinsate for boost. You need the regulator and a return line for the regulator to work.
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Thread Starter
Joined: Oct 2005
Posts: 2,019
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From: Honolulu
RE: NGC Tuning w/ SAFC - For Low Boost Applications
I think i said this before to you... It's probably not needed for an N/A car.
If you have an 03+ the NGC will correct your attempts to add more fuel. The computer is programmed to cruise and idle at 14.7:1 A/F and WOT @ 13.5:1. Those are perfect and would need no adjusting on an N/A car.
Other second gen models run rich from the factory anyway. My suggestion, still, is to get a wide band o2 sensor and see what you are running. I'm 98% sure you will need no adjusting.
k3v
If you have an 03+ the NGC will correct your attempts to add more fuel. The computer is programmed to cruise and idle at 14.7:1 A/F and WOT @ 13.5:1. Those are perfect and would need no adjusting on an N/A car.
Other second gen models run rich from the factory anyway. My suggestion, still, is to get a wide band o2 sensor and see what you are running. I'm 98% sure you will need no adjusting.
k3v