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link g4+ accel enrichment rb25

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hello, i am tuning my rb25 right now and have tuned the fuelmap correctly.

now i was trying to tune the accel enrichtment, have watched the webinair for linkg4 accel enrichment twice but i think i am doing something wrong.

my problem, i can increase the clamp table till the engine responses crisp to throttle input but i am at like 200% enrichment i dont think its supposed to be that much but okay, then when give full throttle and let the engine fallback in rpm to that particular cell and push the throttle quickly again it doesnt react crisp to the throttle even though the first time from that particular cell it responses crisp.

in the webinair Andre says if you have to make alot of changes to the default settings theres probably something not right, ive checked every cell in the fuel map several times and these are tuned correctly.

could anyone help me learn a little more about what i am doing wrong?

thanks in advance.

Hi Kenny,

Can you post a copy of your map and a log of the transient enrichment being applied?

heres the log with accel enrichment at 200% at idle then it has good response from idle.

Attached Files

heres my map.

Attached Files

Just quickly looking at the log i notice that your lambda values after the first accel event remain at fully lean. Your decel cut is active after the first accel event and could be the reason for this. I notice that your decel cut delay time is 0, i would try turning off the decel cut entirely and retesting to see if it makes a difference. If it does then just a bit of tweaking to the decel cut times and activation points should help.

See attached time plot.

Attached Files

Thank you for your response, i have tryd what you sayd with no succes.

what i notice is it only does it when the rpms are falling, when i shift gear and normaly get back on the throttle it gives 2 spikes of lean and the car bogs realy bad and then carrys on, same with when i rev the engine from idle and then let it fall and rev it again on the log it gives 2 spikes of very lean.

stil havent figured out what i am doing wrong so any help very much appreciated.

Andre, heres the log and mapping with decel cut turnt off, and 300% accel enrich in the clamp table. first hit of the throttle the engine responses and the second hit it bogs down.

Attached Files

My first thought is that your clamp value is way too high at 300%. As I've discussed in a couple of the webinars on accel enrichment, it can't be tuned strictly on the lambda reading, but rather as a combination of looking at your lambda and physically noting how cleanly the engine responds. in a well tuned accel situation I'll almost always see a lean spike still remain, however that doesn't bother me at all provided the engine is crisp to respond. A common mistake is to chase a perfect flat lambda curve and you typically end up with way too much fuel. Now I could be off track here but I think this may be part of your issue and I'd start here. Try pulling the clamp back to around 30-40 instead of the 300 you currently have and see how this affects your response. 30-40 may not be right for your particular application but I'd almost guarantee it's closer than what you have now.

Also, I notice your "accel hold" is set to 3 inj events. Since you have 6 cylinders running sequentially that means only the first 3 cylinders are going to get the full accel enrichment. Set this to 6 events or possibly 12 if you need it to be active for more than 1 engine cycle.

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