Front wideband accuracy
Just an FYI for you self-tuners out there.
Our initial base maps were done with a wideband in the tailpipe, and generally we see the stock sensor pegged at 11 while our wideband indicates 12-11 or so. This is with expanded scaling using hypothetical numbers. Stock mapping is good only for 12.17 at the richest end.
So lately we took a few cars on the dyno that have less traditional maps. Innovate with small pulley e85, NA but with the 3" MAF, and a few remote folks utilizing the new rear o2 functionality of ProECU. This way we can directly see the AFRs imported into the datalogs. Results?
Well, lets just say this. We won't remote tune your FI FT86 unless it is equipped with a proper wideband or you're willing to eat the motor, or it is 100% stock and similar to the OTS mapping. We're seeing pegged rich stock meters while widebands are showing 13. Last year we might see this a handful of times on local cars, but we'd figure it's post cat or just an unusual one. But now we're having folks put these into the rear o2 port on non-catted setups, and we see the same things. Dyno numbers confirm that we lose power being too lean in those cases.
If you have experience with this please post so we can get a better idea of how off they really are. But we're not going to use the stock wideband for anything except NA setups. We may even do a rental wideband you can clip into the rear harness from now on.
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