Using lean spool tables to match AFR's
 

Hi Guys, been thinking and wanted so input from the more experienced guys.

As you know with scaling the injectors your fuel map AFr's more often dont match your Actual AFR's

SO Now can we not use the "lean spool AFR mapping" table to compensate the difference at various AFR's so that the numbers in the fuel table actually match the real afr's and the ecu then does the calc via lean spool to get the number its after.

or will this not work?

Mike

It wont totally work... it will be closer but it just depends on how you scaled the injectors and such. I have scaled my maf some to help get it closer but it is never perfect!

Just scale your injectors correctly and your airflow sensor as well. Lean spool was designed to screw your AFRs up, not fix em.

That doesn't necessarily mean it can't be used to do so. That said, I think it would be a poor bandaid at best. If your AFR's are off from the table and it really bothers you, just change the ecuflash formula and create a copy of that table adding or subtracting whatever you need to so that they match.

You don't want your ECU doing this, those AFR numbers are only a reference.

Disable lean spool through the periphery bits. Your actual AFRs should be damn close to the table values at that point. The values are right in the table.

The "lean spool AFR Map" table is what's causing the AFRs to not match the main fuel table under short burst of acceleration. Do some reading on the "lean spool" system. Pay attention to more recent threads as the overall understanding of the system has improved dramatically in the last year or so.

I think his probablem is the other way around, but it wasn't very clear.

The biggest change I found that works is rescaling the MAF, for me that got it very close.

My point is that if lean spool is disabled and the car is ran in open loop, it's very likely the MAP AFR values are very close to actual AFRs.

Trying to tune the lean spool AFR map to match the actual main fuel map is completely counter productive as that map is specifically meant to make the actual AFR NOT match the main map.

At what point is rescaling the MAF necessary?? Bigger turbo cams head stroker???

When using non-stock intakes and intake pipes.

I dont understand why people want to make it so the AFR in the fuel table are the same AFRs logged.

If you spent all the time to make the AFRs match, when you changed mods, you'll have to re-do it all anyways.

Hi,

thanks for all the replies,

My AFR's are very close (0.1) and it was more by luck on the injector scaling and latency than by trying to get it there

Was just a thought for those with ay off numbers to help bring it a bit more to reality.

Mike

Mods shouldn't matter much on a system that uses an airflow sensor, other than ones that throw the airflow sensor off a bit such as air pipes / filters.