Quote:
Originally Posted by steve99
That's rearly weird that just a drop in filter could cause the engine to run lean especially 14:1 lean. and don't understand why that would happen as your not altering the position or the size of the maf sensor housing, unless it created large amounts of turbulence or something, then with drop in and elbow or dropin elbow and modded snorkel is much better. Or it was an oiled filter and its contaminated maf ?
just not experienced or seen that issue with just a drop in filter
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And we saw it repeatedly. When we did testing that day we did 3 pulls in 3rd gear, and 3 more in 4th gear. Every single one was consistently lean like that. All 6 pulls.
DIF and modded snorkel didn't make it much better, about a quarter point.
And Silicone elbow, DIF, and modded snorkel wasn't much better than that either, still very lean.
And yes, the K&N is an oiled filter. But no, this is not an example MAF contamination. These were some of the first pulls of the day, and if we had a contaminated MAF we would have seen the same poor results on all of the other intake combinations were did.
I do agree that it is really weird for the reasons that you mentioned, but it also certainly is not the first time we or other people have seen this effect with drop in filters.
Also that post is right here:
http://www.ft86club.com/forums/showp...&postcount=200
It's a good one because it shows stuff that people usually never see like power gain from the silicone elbow, modified snorkel, and combinations of everything.
Quote:
Originally Posted by Wayno
There's no way a dry drop in filter will make you run lean, unless you do something ridiculously stupid like reset the ECU before putting it on the dyno like some vendors like to do.
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Do you have any data on that, or is that just speculation? If you're insisting that based on the idea that the oil from the filter is contaminating the MAF, then that idea is already unfounded from what I posted above.
And I do agree with you, there are lots of vendors that do "stupid things" like reset the ecu before a dyno run. Usually before the dyno run that they want to look "bad." We reset the ECU before every single intake combination (so 23 times), but we were also using an OFT with stock tune, but that forced the IAM to 1.0 upon reset. This was done for consistency between all combinations, and to clear any sort of learned values.
So while I've seen a ton of dyno charts from people from all sorts of intakes and drop in filters, but they almost never have AFRs. We did extensive testing, and provided tons of data including all kinds of dynos with AFRs for competitor's products. And even better, we don't have a dyno, so 100% of it is 3rd party testing. The only thing we did was change the intakes on the car. There is no reason to think that this data isn't accurate, especially with the extremely large data sample that we have, and how consistent the results are.
Chase
Engineering