Forum » General Tuning Discussion » CLL wideband auto mode link g4+

CLL wideband auto mode link g4+

General Tuning Discussion

Discuss all things tuning in this section. News, products, problems and results. 


Page 1
Author
64 Views

I have a question about using auto wideband cll mode for link g4+. Assuming I've created a solid open loop fuel table to work from, my question is if cll can keep up under wot conditions in 1st gear and 2nd gear.

My concern is if the engine ramps through the powerband so quickly, does ecu react fast enough to alter the signal to injectors in an effective manner?

Pretty much all of my wot loaded parts of fuel table were created on 3rd gear wot runs. Looking over logs, I noticed afr are quite a bit leaner in 1st gear particularly, (richer in 4th) and although I've read that this is normal, my question is if it's safe? And would it be better if I enable auto wideband CLL to operate at all times assuming my open loop map is solid.

I'd like to enable the CLL to operate in all conditions to hit the afr targets in all the gears, rather than just 3rd gear.

So far, I do have auto wideband mode on, but it's set to only operate up to 5k rpm and under 20 psi absolute manifold pressure. From what I can see in the logs, it has worked effectively in this region. I'm using a Bosch wideband sensor. Is it reliable enough to be safe for autowideband mode?

Pretty much all of my wot loaded parts of fuel table were created on 3rd gear wot runs. Looking over logs, I noticed afr are quite a bit leaner in 1st gear particularly, (richer in 4th) and although I've read that this is normal, my question is if it's safe? And would it be better if I enable auto wideband CLL to operate at all times assuming my open loop map is solid.

That is not normal. It sounds more like there is still not something right with your fuel table or one of the other compensations.

Once set up correctly CLL will be fast enough to take care of most deviations from target but you dont want it to be correcting a bad map. I would only recommend running CLL at full load if you had a Link CAN lambda so that the ecu has some means of knowing sensor status and can disable CLL if there is a sensor issue. Also, in recent firmwares the CLL trim can be set up as two seperate 3D tables so you can for instance allow the ecu less authority at higher load conditions to lower risk.

Your lower gears will be using a slightly different part of the fuel map. i.e. higher rpm to reach load. So maybe you need to have a look at the numbers to the right of where you tuned third gear

It's quite common to see a small variation in air fuel ratio in the lower gears due to the rate of change of rpm being so much higher than what you'll see in the likes of 4th gear. This is due to the way the volume of the fuel film changes as the engine rpm changes. In theory if you have an ECU that is modelling the fuel film correctly then you don't see this variation. In most cases it's not really a concern and instead I concentrate on making sure the fulling is on point in the higher gears where the engine is under high load and accelerating more slowly.