Hallo,

i often see dyno sheets where the a/f ratio is exaclty 12:1 (i.e.) under boost over the full rpm range...

when i floor my car and look at the wideband, it goes up to 12:1 at the moment when i hit boost, then get leaner to 13:1 and then stabalize at aprox 12.5:1 when i reach full boost... it seems that the wideband needs a small amount of time to realize the change in a/f ratio or the ecu feeds a bit more and then leans out the mixutre a bit...

my maps are very smooth, so there are no bit changes in fuel amount so normaly the mixture must be very smooth but it isn't...

what do you guys do to stabalize your a/f so much...

here take a look at my maps, maybe somone has an idea ...

LowCam Fuel Map:


HighCam Fuel Map:


Greets
Malte.

 

good tuning and good engine managment

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gritsak &raquo;</TD></TR><TR><TD CLASS="quote">good tuning and good engine managment</TD></TR></TABLE>

That is has something to do with tuning is clear... but i asked a way to do this...
the engine management is quite good enough i think and the meassurement equipment is also ok but it is impossible to stabalize the a/f ratio...

so what steps do you make to stabalize it?
only full throttle runs in high gears or part throttle (closed loop is disabled) to hold a certain condition for a few seconds so that the wideband can recognize it.

Greets
Malte.

 

Could you list your fuel system mods please? It might be related to your fuel system itself and not the actual tuning.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Finest &raquo;</TD></TR><TR><TD CLASS="quote">Could you list your fuel system mods please? It might be related to your fuel system itself and not the actual tuning. </TD></TR></TABLE>

Ok, here is the List:

- 280ccm insted of 240ccm injectors (fuelmap's are lowwerd by factor 0,857)
- stock fuel pressure regulator so i think fuel pressure is stock
- high flow in line fuel pump (i think it is a bosch but not the exact model no.)
- stock fuelrail
- stock b16a1 cams
- stock block, stock compression ratio, stock head

so nothing special i think...

my second problem is that i think that my wideband (tech edge wbo2 with the 6 066 Bosch Sensor) needs some time to realize the exact new mixture, so when i make a full throttle acceleration the mixture seems to jump because the wb has not enough time. When i make the same with part throttle and i.e. hold 5psi for aprox. 5-10 sek. on the same rpm then i have a different a/f mixture which is more smooth when i make this over all load points (columns) of my fuelmap.

so maybe my problem is only a displaying one, not a true a/f mixture failure... what do you think? is this possible?

therfor my question, how do the pro's here measure the a/f mixture, is it under full throttle accel. or did you let the wideband a bit of time to read the mixture?

Greets
Malte.

 

Maybe someone with a smooth a/f mixture can post one of his maps so i can see if it is totaly differnet from mine... i don't want to copy it, because every engine needs differen tuning, its only to see if i'am on the right way or it the map look completly different...

Thanks
Malte.