The only useful search I found in the archives was one started by Black R. The only thing I got out of it is that it helps but there was no process on how to do it. I'm running Kenji's P28 right now and althought it gave me a significant boost in power throughout the powerband with the help of the VAFC, it runs awfully rich. I'm trying to prevent any longrun ill-effects of running rich so I want to tune partial throttle settings since that's how I acquire most of my miles. So here come the questions.

- Can I get on the dyno and make adjustments to my fuel curve while running through the whole rev range at 10% throttle work? I've experimented with partial throttle settings putting mine at -3 from 2000-4500rpms - with VTEC is set at 5000rpms - and I've seen 20-mile increase per each tank of gas.

- I read the Tech section of the Hondata site and it states that during partial load, the aim is to get close to stoichemtric which is 14.7:1 ratio. What's a safe A/F ratio to shoot for with partial throttle tuning?

 

it runs rich because it runs in open loop.

best way to tune part throttle is with a wide band on the street.
It will also be very important to set your lo-hi throttle points properly

You may or may not be able to do anything about it though.

 

Hey, the friendly sGT showed up in my thread today. I was going to hit you up on AIM but decided to post my questions here instead to share the knowledge that I hope you will drop.


1.) Since Kenji's P28 is running open loop 24/7, is it still subjected to the short and long term adjustment described here... http://www.hondata.com/techclosed.html My understanding is that the ECU can make it's own adjustments only when running in closed loop.

2.) If an ECU that runs in open loop all the time is not subjected to the short and long term adjustments, doesn't this give the tuner more control of the tuning since the he/she doesn't have to worry about the ECU applying the long term adjustments during idle time between dyno runs?

3.) How are the HI/LO settings on the VAFC set "correctly?" I think I read somewhere that the HI setting should be at a point where if you run it at the throttle that the HI setting is set at, the A/F curve should be close to or the same as the A/F curve at WOT. I haven't read anything about how to set the LO setting correctly. Any insight?

 

i want to learn too, so bump up.

 

.....basically, the vafc's partial throttle settings were how I was able to get 300-340 miles per tank with spec b's and ATS final drive.

But what sgT said is 100% true - you need to street tune with a wideband o2... or you could do some tuning on the dyno as well for "fuel trim." I was using the stock p73 though on my car... and I set the WOT maps for 60% throttle. Anything less, and it was using the partial throttle maps for me.

 

partial throttle adjustments are what makes 34+mpg possible with Toda C's

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Black R &raquo;</TD></TR><TR><TD CLASS="quote">.....basically, the vafc's partial throttle settings were how I was able to get 300-340 miles per tank with spec b's and ATS final drive.

But what sgT said is 100% true - you need to street tune with a wideband o2... or you could do some tuning on the dyno as well for "fuel trim." I was using the stock p73 though on my car... and I set the WOT maps for 60% throttle. Anything less, and it was using the partial throttle maps for me. </TD></TR></TABLE>


damn, really. i tried that once, i mean, playing with my the partial throttle setting but never really got to increase my gas mileage. then again, i havn't mess with it since.

 

i dug this thread up coz i need info on this. can anybody add information? specially on where to set the lo and hi throttle position

 

lo = 10%
hi = 60%

If you're obd2, then the ecu will need to be reset periodically because it will constantly be second-guessing your partial throttle vafc settings.

If you have an open loop obd1 ecu, then you have fewer worries about such.

Go as lean as you can without getting super high egt's and no pinging... 14.7:1 is a good starting point. I've gone as lean as 20:1 with no load (idle), and each car is different in what it likes (depending on mods/ cr/ cams/ etc...). Play with it a bit. Leaner = less gas = better mileage. PARTIAL THROTTLE ONLY THOUGH.

 

I like to keep it at or near GANGSTA LEAN nah mean?

Ryan, who didnt think you could tune VAFC partial throttle. Or so he's been told.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RTW &raquo;</TD></TR><TR><TD CLASS="quote">Ryan, who didnt think you could tune VAFC partial throttle. Or so he's been told. </TD></TR></TABLE>

thats bc j00 is obd2 foo

 

OK I missed that part

 

I'm interested also. Could someone post up some examples of setting that they use on there R.

 

anybody

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gents97civ &raquo;</TD></TR><TR><TD CLASS="quote">I'm interested also. Could someone post up some examples of setting that they use on there R. </TD></TR></TABLE>


Someone has already posted this in the thread on how to do partial throttle, set it lo at 10% and 60 for high. Set your rpm points, and start out rich use a wideband and keep leaning it out till you get good numbers.