mrx

Hallo,

i have a strange problem when tuning my fuel maps for my car.
when i try to tune it to the correct AF Ratio under boost (12.5:1 is my goal) for full throttle this is possible.

Procedure is the following: taking a long straight road, putting the car in 3rd gear and floor it from 2000rpm to 7000rpm and look at the AF Ratio... then i correct the specific columns where he runs to lean or to rich to get my 12.5:1 ... until now everything works fine.

yesterday i realized when i drive with part throttle (3/4 throttle pos i.e.) on the hightway in 4th or 5th gear and in an rpm band where it is possible to build full boost (8psi) with this throtle position. The car leans out extreamly (nearly 14:1, sometimes 15:1 or 15.8:1 UNDER BOOST!!!) when i retry this with full throttle i have an exact mixture of 12.5:1

What can that be? did i make anything wrong?

i think the ecu make something like a full throttle enrichment... this can explain this phenomen, but how do i have to tune my fuelmap then

Thanks
Malte.

tranceminister

Nope, thats normal for a higher gear.. I wouldn't do any 5th gear pulls at all unless you can get that thing tuned out real good. 4th gear should be fine to boost in though as long as your AF is straight . Theres alot more load on the engine in 5th gear plus your trying to spool the turbo which will cause your air fuel readint to be much leaner than you want under boost. Be careful... this has been the cause of alot of blown motors. But it all comes down to tuning. It can be tuned for 5th gear pulls, but I'd see if a shop or someone local to you who has done that before can help you out.
What are you using to tune with?

scttydb411

also, if you do a wot pull from 2k-7k you will need to tune columns for lower psi since you are pulling through those columns to build full boost. i'm assuming you get full boost somewhere at 3.5k-4krpm. do you have closed loop disabled? if not part throttle boosting the ecu may be trying to get stoich afr. if you do have it disabled you may not have fully tuned each column based on rpms while in part throttle boost. you can also change the throttle enrich too.

this is based on if you are running uberdata, but probably similar to other standalone as well.

if you are running the hack...well, that's just what the ecu does...you'll need to make sure you are over the throttle position for you ecu to switch to open loop and not try and run stoich.

mrx

Hi,

CL is disabled... take a look at my fuelmaps here:




i think they are smooth... the problem is that i have both times full boost so i'am in the last column, but with WOT i have a good mixtrue and with 1/4 throttle i have a bad mixture... how can that be its the same column in both situations... and with cl disabled he must use the same values.

Values in my maps are the same as hondata used them... so you can interpret them like hondata 2d maps.

Greets
Malte.

mrx

Hallo,

i have a small update, i guess my errors come from the fast throttle enrichment that the ecu does when you quickly open the throttle.

i made a testdrive a few min. ago and it seems to me that when i make a full throttle run then my mixture is ok, becuase of the throttle enrichment, if i make the same run with i.e. 1/2 throttle then the ecu don't make an enrichment because i don't open the throttle quick and wide enough.

so i think my maps are generaly to lean in this area.

But there i one last question, if the throttle enrichment makes a difference from 15:1 (without) and 13:1 (with enrichment) what is my mixture when i tune my maps for 12,5:1 without enrichment? then i can expect 10:1 or more or what?

does anyone realized this behavior on other hondas during tuning? or do you tune your cars only for full throttle? and ignore the mixture when dirivng with part throttle?

Greets
Malte.

leed

What size injectors you running?

My experience on 900cc/B16 on both Uber and Hondata is that the acceleration fueling (depending on what I set the TPS enrichment at) will affect the A/F for only about 1-2 sec after going WOT. The A/F always seems to stablalize within 500rpm of a large TP change.
I have never run a map w/ stock accelerating fueling on the 900's, but I cant see it adding enough fuel at WOT to affect A/F through the whole RPM range to such a large extent.

This is on a Honda right? Or is this on a MAF car?
Whats your setup? What software?

Edit:
ok looking at your other posts, Im gonna guess your boosting on a PR3/PW0, and scaling the MAP voltage down for larger injectors. Dunno, but at part throttle, there is a chance that your switching back into closed loop thus causing the 14-15's A/F....

Chris Harris

Sounds totally like the ECU is going into closed loop when you are boosting part throttle.

I am assuming you disabled closed loop for tuning...but when you aren't tuning, and you are noticing these lean mixtures...did you burn the chip with CL Disabled?

mrx

i know what CL can do in part throttle but i have CL DISABLED and have the problem anyway. So CL is definitiv not my problem... maybe if i enable it but not at the moment and not with the current problem and setup.

Injecotrs are 300ccm

i have made a chip which is richer in the area between 1000mbar till 1400mbar ... because i notices yesterday that i have the problem not under full boost, also in part throttle not... maybe my map is only a bit to lean in this area. i will see.

Greets
Malte.