I have an 01 year s2k which I belive would benefit greatly with purchasing an vafc. I just have an intake on the car with 4.77 gears. I've read that you should not setup the vafc to work on low rpm since the ecu will reset the settings. What im trying to find out is if i normally don't go over 5k rpms in normal driving, should I or the tuner setup the vafc to start workign at that point. I've seen some put it as early as 3k rpm. If i leave it at 5k, then i shouldn't have any issues with having to reset the ecu every two weeks to clear the settings. Is this right..Thanks

 

I'm interested in this as well.
I have an 07 and I am interested in getting a VAFC as well.
I have gutted the stock airbox and dropped in a K&N along with the AUT cooling plate. I am planning on installing either the T1R 70R Sparrow with test pipe or the Mugen with TP.
I figured that I would need some tuning after the tp and exhaust install.
I have been seeing in several threads that the ecu can relearn and adjust making the VAFC settings not work.

Can someone clearify this for me. Is it just the partial throttle settings that don't work because the ecu relearns?

 

yeah, just partial throttle settings will be overridden by the OBDII system. Full throttle settings will work... this is due to open/closed loop operation during part/full throttle settings.

the AFC Neo on my '01 made 9 whp and about 6 ft/lbs.

get it properly dyno tuned, by a professional, and you'll be all set. dont have him waste time on part throttle settings though, as stated above. he should know that, but reiterate it to your tuner anyway.

There is no way to set up an AFC to 'start working' at a certain rpm, like 5K. you can switch VTEC points, and the AFC will make it steady through all throttle positions... but on our cars, the 100% full throttle air/fuel settings are the only ones that will work. Part throttle air/fuel settings will be overridden by the stock ECU.

 

It's just hthe partial thorttle setting that is relearned. To the OP, I think your confused between partial throttle and rpms. Just make sure the vafc is tuned for Wide open throttle and not just partial throttle.

 

so basically if its tuned for wide open throttel, it will only work when i floor the gas pedal. So even at 3k it will work and the ecu will not relearn this. would you be able to tell if the tuner leaned out the car to much on top or is it just on a dyno where you will be able to tel..

 

bump...

 

You can tell how rich or lean by using a wideband. Many dyno's have hook-ups for the wideband to display A/F along with the hp/tq numbers.

The partial throttle issue is easy to defeat. Before you have the car tuned, reset your ecu (instructions in the UTH FAQ sticky). Have the partial throttle settings tuned. Then each week or every 2hrs of drive time, reset the ecu. That will make the ecu 'unlearn' and put it back to where it was just before it was tuned.

 

I really dont want to deal with the partial throttle setting if I'm going to have to reset the ecu all the time. Ill prob just leave it at full throttle. Thanks for the info with the wideband information. Ill make sure they use it when its at a dyno. Do you think I will be able to tune it myself if I take into account all the other vafc users settings and when its put on a dyno change the settings if necessary..

 

From what I've read here VAFC isn't worth it because the car remaps itself pretty quickly, and although it only maps itself from partial throttle readings, those readings also reset full throttle. So, unless you reset your car right before you want the power, VAFC seems like a lot of trouble with the stock MAP....

 

Is this true, if you dont change any partial throttle setttings and just change the full throttle settings that the ecu will still reset itself. I thought if you dont change the partial throttle settings that the ecu wouldnt even know that you have the vafc installed. Once at full throttle, it then takes the settings out of the vafc for that short amount of time.. Is this right..