Well, isn't it different when you have mods? I have i/e/tp and soon to be headers when i decide which ones. So by the time I tune the vafc I will have i/h/e/test pipe

 

wow, you really think Im gonna take what one car did as the rule. Every car and tuning and dyno numbers are different, come on now...

 

yea exactly... What bass doesnt understand is when you add mods that you need tuning to get the full gains out of those mods.

 

You notice anything with all your cooling mods?

 

I think you were asking about me... I only have the radiator cap and oil cap on right now. The switch and the thermostat will go on soon hopefully. So I can't tell you right now. I think there will be a little difference though which I'm looking forward to. But I think where I will really notice the gains will be in the warm weather/ track days where I wont be adding power but getting back that power back I would loose to heat soak. And it gets real hot here in cali so I think it will be a good little mod.

 

I will back up Steve and tell you the VAFC is a joke . You might have slight gains , but dyno it again in 2 weeks and see what the #s are . The factory ECU will retune itself. The ECU will look at the O2s and other variables and think the MAP its out of adjustment and correct itself.

Here I dont feel like typing things over and over so I Qouted this from Honda-tech

"Tim's Soap Box on Piggback AFCs
Original banter by: Tim "The Stick"

Ok, this topic has been beaten like a dead horse, but I keep seeing the SAME question time and again. So, lets answer the eternal question:

"Where can I put my AFC?"

In a trash can. And that's the final answer folks. Here's why for archival posterity:

An air fuel controller adjusts fuel control, and in some cases VTEC activation. This is GREAT for a DSM (like a 4G63 eclipse/tallon etc...) because that engine uses a MASS AIR FLOW SENSOR. Honda's use MAP sensors (manifold absolute pressure, or intake air pressure sensor). What's the difference between the 2 and why will it work for one and not the other??? Simple.

-A Mass Air Flow system adds fuel based on "How much air did I just suck up". MASS AIR IS A REAL VALUE. Real values have a basis, and no further calculation is needed. "X air needs X fuel." Adjusting any values PAST that point in the ECU's equation is OK!!!!! If you add fuel to that mixture (by increasing the injector duration), then the ECU will acknowledge that input and add fuel.

-A MAP sensor style system only see's what the manifold pressure (and other data) is, and then has to CALCULATE in order to figure out "How much air did I just suck up?" This number is NOT a REAL VALUE, but a derived value, and therefore is a variable. "X manifold pressure-times X throttle position-times X RPM-times X intake air temperature-times......." ".....equals how much air I FIGURED OUT that I sucked up." See the difference?? The ECU NEEDS this data in order to come up with a derived number for "X fuel."

So here's ALL the reasons why NOT to mount up your AFC:

1: ALL Correct Sensor Data is NEEDED.
A Honda needs all it's sensor data, and needs to recieve it CORRECTLY to determine how much air it's getting. It auto adjusts for fuel consumption based on these sensor values. If you're running boost, then you need to TELL THE ECU it's getting it. Unfortuneately, a Honda ECU in stock form doesn't have the programming for any manifold pressure ABOVE normal barometric pressure. So, what happens when a Stock ECU see's boost at the MAP sensor??? The ECU doesn't have enough data to calculate the fuel table, so..... "Check Engine." "Please help me, I'm an ECU and I'm dumb, what does 7 psi mean?? I don't have that number in my tables, so I can't calculate. Wait a minute....if I don't have that number, then the MAP sensor must be broken, because if I don't have the number, then it doesn't exist. Please replace the MAP sensor." An AFC won't cure that. ONLY A NEW ROM CHIP WITH BOOST TABLES WILL CURE THAT.

2: The ECU "auto adjusts" itself.
Lets say you want to tune in 10% more fuel with your AFC. Fine, tell your AFC to add 10% more fuel. No problem right?? Wrong. What happens to the O2 sensor when it's got 10% more fuel?? It tells the ECU that it's running 10% rich. So, the ECU "auto adjusts", and takes 10% out of the mixture. You've added 10% with the AFC, and the ECU has taken 10% back out to get back to stoich. What's the net increase in fuel?? That's right, 0%. NOW...... Lets add fuel untill the ECU can NO LONGER adjust (or, you've added so much additional fuel that the ECU doesn't know what's happening, and can't compensate that far). Simple. You run rich. "Hi, I'm the check engine light again. There must be something wrong with my O2 sensor because I've backed the fuel off as far as I can go, and it keeps telling me that I'm still too rich. Please change the O2 sensor for me, because that must be what's wrong with me. Thank you."

3: VTEC engagement point calibration.
VTEC is a combination of 3 different things. 1: The changeover of the cam lobes. 2: The changeover of the fuel MAP. 3: The changeover of the Timing MAP. If these 3 things don't happen all at the same time, what happens?? Simple again, you have a "hole" in the fuel and timing MAPS. If VTEC engages at 3000 RPMS, and the fuel and timing table follow the ECU's instructions and changeover at 5200, then have you added any more fuel and or timing from 3000 untill 5200?? No. Therefore, what did you gain?? Nothing. So what, the cam changed over, but you didn't add any fuel to it, or change the timing curve. You got more air, but the ECU didn't know that it was going to get it! So it didn't DO ANYTHING ABOUT IT. Yes, adding more air makes it FEEL like you're making more power sooner, but all you're REALY doing is running lean for a few seconds.

4: An AFC can't tell the ECU what kind/size/style injector you're running.
The ECU is programmed for one particlar injector size and style. The one that CAME in your car from the factory. If you change the injectors to a larger size, the ECU MUST be reprogrammed in order to realize this, and take awayor add some injector duration. If .013 seconds is the time an injector needs to be open to add fuel at 4600 rpm's at wide open throttle with a 240 cc injector, then how much MORE fuel is added with a 440 cc injector held open for the same amount of time?? Correct. Nearly double. That means you've added 2 times MORE fuel than the ECU thought it added. "Hi, it's me again, Check Engine. Yeah.... Ummm, What the ****."

 

The only time you need a vafc is if you add a SC - a vafc won't help with headers, cia, spark plugs etc etc...

there are plenty more 04s on the dyno - just check Giles site

actually some mods will rob you of HP - some exhuasts will loss hp

unlike other cars the S does not repond / gain too well with some mods

 

^^^^ you are really ignornat and don't know what your talking about. If you think the gains wont be there in 2 weeks then reset the ecu and your set.

I want you to explain to every one how on the same dyno same day I picked up around 10 rwhp at peek rpm and how I picked about 20 rwhp at 8,900 rpm??? Yes that right, 20 rwhp at 8,900. The 01 ecu runs way too rich and I picked up a ton of power after peek rpm. Please explain how I didn't see those gains.

You can think all you want, but reading a bunch of crap off honda tech isnt anythign creditable.

 

Many people have gotten VAFC, tuned them, and gotten like 7-10hp. So it has to do something. Even if it does correct itself over time. At that time, it is addind hp. So, can't you just reset your ecu whenever it corrects itself?

 

You guys are terrible... How is one s2000 at our bay area dyno day coming in at 202 rhwp (01') and then another 01' with intake, exhaust (vielside), intake and TB coming in at 224 rwhp??? Is that because those mods dont add power?