I see tons of threads on tuning for maximum power or full boost. I know for forced induction motors or NO2 motors, you want to be around 12.5 (give or take).

But what are we supposed to tune for in partial boost? Most of us are in partial boost in our daily driving. I know it's not supposed to be as rich as 12.5:1 and nor is it supposed to be aroudn 14.7:1

When i drive my car, in partial boost, it gets around 14.0:1 and it richens up as boost builds.

Does anyone have tips or ideas on this?

Danny

 

The ECU assuming its a honda, will compensate for partial throttle (closed loop) operation. Unless your map is way too rich or way too lean it will adjust itself to as close to stoichiometric (14.7). Given that, you would want to tune your maps to as close to 14.7:1.

 

so you are saying that if my throttle position is around 50%, and i'm boosting say 5psi, I'd want to be at 14.7:1?

Just trying to clarify. Thanks

Danny

 

wrong answer dude.........14.7 at WOT even in N/A conditions can cause damage..........at five psi I'd be somewhere around 12.8 or so minimum.........

you are a perfect candidate for EFI UNIVERSITY..............checkout http://www.efi101.com

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by R6Elmo &raquo;</TD></TR><TR><TD CLASS="quote">so you are saying that if my throttle position is around 50%, and i'm boosting say 5psi, I'd want to be at 14.7:1?

Just trying to clarify. Thanks

Danny</TD></TR></TABLE>

At 5lbs you would want to be atleast at 12.5:1.

 

Thanks for the info guys. But again, i know that maxium boost is you want to tune for roughly 12.5:1 or so.

So, would it be safe to say that at around 1psi you want 13.5:1, 3psi 13:1, and at 5psi onwards you want 12.5:1? Thanks

Danny

 

partial boost/partial throttle lol, guess I got confused . With partial throttle normally would mean your in closed loop to me. I didn't see you were talking about partial throttle with partial boost hehe. With 50% throttle I dont see how you can be building 5lbs of boost, in any case if the voltage goes over 3.1volts (1lb of boost) on a stock map sensor or 80% throttle from the TPS, the ECU will switch into OPEN LOOP. You SHOULD defenitely be atleast at 12.5:1 a/f.

 

12.5:1 on anything over 1lb and up. The lower the safer in some cases, I wouldn't go any lower than 11.5:1. Try to aim for something lower maybe 12.0:1 just to be on the safe side to compensate for anything that might throw off the readings, i.e (mileage on the wideband sensor, placement of the sensor, etc.)

 

12.5 is pretty rich............remember that the air/fuel ratio is just that.........a ratio.

The trick is to have enough fuel "quantity" in the combustion event to sucessfully burn all of the oxygen and absorb enough heat from the chamber to keep things together........increasing the ratio of fuel to air simply increases the overall mass of fuel in the chamber. Too much fuel in the chmber will hurt power and efficiency.

At only 5 psi there isn't a significant mass of air in the engine to warrant such rich mixtures............consider the fact that I run the Laskey's low nine second B18 engine at 32 psi with A/F's only in the 12.2 range........32 psi moves a lot more air and heat than 5 psi, and 12.2 is sufficient for that.......kinda makes 12.5 seem a bit excessive, huh?

 

im a noob, and all this is very interesting... more info i say!

 

with a Hondata and P28 chipped ECU, the ecu will no longer compensate for AF will it? UNLESS... you can run the hondata in closed loop for part throttle and open loop for WOT... is there such a thing? When people tune for partial throttle what do they do? it seems to me that the ECU would have to switch from open to closed, or run open and tune for part.. i DONT KNOW! help me.

 

BEN i hvae im'ed u about something regarding a tuning class in Australia and some help with autronic on my car.

Hvae u got the Im's? should i im u again?

 

i just tune it to where it drives right... then i make sure that the afr's are way off in left field and hte gas mileage is good.. driving right is far more important that making it stay at the so-called perfect 14.7:1. most hondas we do with the ems will run happily as lean as 16:1 under part throttle and cruise conditions... the down side to that is you have to do a little more work on the accel fuel, but it makes for a smoother driving car.

its all about the car driving like it should.

 

From http://www.boosted-hybrid.com

At very light load (first three columns) I have the target lambda at 15:1. At slightly heavier load (next three columns) I have the target lambda at 14:1. At the next heavier load (next three columns) I have the target lambda at 13:1, and at the boost transition column I have the target lambda set at 12.5:1. Then in boost the columns are set for 12:1.

 

bump so i can get a hand from ben