ignition tip in options

hello everyone,

i am experiencing lean spike at small throttle changes in some of my tuned cars. as for now i tested all the fueling options in the software, but nothing helps (enrichment in the main tables dosnt help. and increasing tip in fueling dosnt help,)

so now im looking at the ignition tip in options,

can you guys take a look at my ignition tip in options and maby tell me if somthing there is skewing off the fueling?

thanks alot!

In general I find very few applications where I need to use tip-in retard. I can only think of about 2-3 cars in my career where I actually used this function. Typically I'll use it if I'm finding the engine suffers from knock during sharp throttle applications but the actual main ignition table is correctly tuned.

Having a look at your settings it appears you're removing a very large amount of ignition on tip in (assuming I'm reading the settings correctly). This wouldn't affect the AFR being measured but it will make the engine feel flat and unresponsive on a throttle tip-in. I'm just wondering if this is the problem you're noticing? While you obviously need to have your tip in fuel settings correct, even when they are correct you'll often see a small lean spike on tip-in. I use the lambda as a guide when tuning tip-in enrichment, however I focus more on the way the engine responds - Is it crisp and clean, or does it hesitate and lag?

HELLO ANDRE AND THANKS FOR THE REPLY,

the tuning platform is NEPTUNE (chipped honda obd1 code) which is a great software,MORE or less like hondata s300,

the tip in retard settings i provided are stock ecu settings (for a NA engine with a distributor)

this ecu code also has a built in constant rpm based dwell correction: that i can turn off, but i always keep it on, and tune for mbt,

0deg@850rpm / 2.25deg@2800 / 5.75deg@4900 / 9.25deg@7300 / 14.75 @ 11.000rpm, so i'm not sure if the tip in retard applies on top on the rpm based correction (i guess it should,)

i have a clean engine response with no bog or hesitation,

for example: lets say i cruise at 250mbar at 7% throttle, if i increase the throttle to 15% 600mbar its get to about 1.06 lambda for a split of a second and then goes back to my tuned afr. it even does that sometimes from 0% tps (deceleration) to 9%tps

i know that this is not related to fueling tip in since i can get the car to a point that i get a rich bog at full throttle tip in. and even if i keep the settings that it bogs at wot i still get the lean spike at lower throttle, (my fuel tip in correction is not a table just a general raw value adder)

all the electronics and the fuel system in the car are sound

i will upload some datalog screen shots tomorrow since my current ones are not tuned enough, and maybe a video clip,

sorry for the long reading :) and thanks!!!

As Andre mentioned, I also rarely pay attention to lambda when on throttle tip in. You will always get a lean spike, if the engine tips in ok and doesn't hesitate or bog when it has the slight lean spike I would be more than happy with that and wouldn't worry.

Its more about giving the engine what it wants to operate correctly and feel smooth than making it do something it doesn't want to.