Hi,

I've been doing some canscans of my computer, in order to do some canzoomer tuning in the few next weeks (as soon as I receive my midpipe).

I'm seeing something very disturbing (for me): the second and third gear pulls AFR results are very different, being too rich on second gear. See:

2 GEAR PULLS:



(this one with the last flash)


3 GEAR PULL:



The last second gear pull and the third gear pull were done in the same day. With these second gear AFRs I'm a little scared of tuning my AFRs using the third gear pull data as a base and then blowing my motor on second gear.

Is this difference among gears normal? What do you think about the AFR tuning I can do?

Thanks!

 

yep - a first gear pull will be even leaner .
I think it is more to do with the load on the engine than the ECU . I do most of my tuning in 3rd gear & don't worry too much about what is happening in the lower gears .
The higher the load on the engine the greater the chance of detonation .

The timing advance in that second run looks strange - 31 deg @ 4000 rpm ? I would recheck that .
what type of piggyback are you using ?

 

Ok, so it's normal. I plan to tune from 6300 to 8500 (only open loop) to about 13-13,2 and let the higher revs stock, only AFR for the moment because I don't understand timing very well at this point and I'll let this stock for the moment.

 

I got most gains from timing changes (contrary to what others here have found) . The chages are all retarding the timing which is pretty safe to try . Let me know if you would like some details.

You should be OK to tune anywhere in open loop which varies depending on load but you are safe over 4000 rpm & 30% throttle .

 

The OEM timing is extremely aggressive. This is why it is so difficult to tune for FI using a piggyback.
Log the MAF with your RPM and A/F in both gears and look for the relationship.

 

MM, I sent you a p.m. regarding the factory ignition coils and the problems we seem to be having. Would you like to reply when you have a chance? Thanks, Man.