tsitalon1

iTrader: (3)

Has anyone else seen fluctuations like this before at high rpm?:



We thought it might be the K&N dropin I have, so I switched to an open cone filter with no change in issue.

Does this look like high rpm BOV flutter?

BTW, in the graph MAF= maf grams/sec

UT_EvoX

I started having MAF/load fluctuations when my MAF was on its way out... mainly due to the over-oiled filter that came with my Cobb intake.

UT_EvoX

Just so you can compare, this is what it looked like when I had a bad MAF:



You could be seeing the onset of the same symptoms, it's hard to tell. I do know they are very finicky because after cleaning my air filter and very lightly oiling it, then swapping in a new MAF, it still would muck up after several hundred miles and start giving me crap readings.

But honestly, I think what you're seeing is normal. Mine is a definite example of a "bad" MAF.

tsitalon1

iTrader: (3)

That does seem more extreme then mine. Do you still have this issue?

UT_EvoX

Yes. It ended up looking something like your graph even with a new MAF and a lighter-oiled filter. I continuously cleaned the MAF with electrical contact cleaner to get it back to behaving normally. Eventually, it ended up looking just like my previous datalogs again.

tsitalon1

iTrader: (3)

Thanks for responding.

I will have to try to swap my maf with a buddies and see what happens. The car feels normal. Even though the fluctuations in load are clearly there you cannot feel them.

tsitalon1

iTrader: (3)

I cleaned the MAf with some high quality electronics cleaning spray. This however, did not resolve the issue.


Run1


Run 2


Run 3

UT_EvoX

Oh, definitely not the MAF spiking.

Though, your load does seem really low for your modifications. Have you logged MAF voltage?

tsitalon1

iTrader: (3)

Yep...hit 4.85 at redline.

UT_EvoX

Is your load graph scaled really funny? Cause 240-ish load is a little low for that kind of airflow and boost. I'm thinking more like it spikes to 285 or so and tapers to 265. That would make more sense.

But otherwise, I think everything looks good on your end. I would worry if you start to get IDC spikes. That's the indicator or something being horribly wrong.

tsitalon1

iTrader: (3)

Load peaks about 280-290 and tapers to 240-250.

I do get IDC fluctuations consistent with the fluctuations I am seeing in load. The car drives fine and accelerates smoothly, there is no feeling that something weird is happening. The only reason I even started a thread on this is because i also get some slight knock in this area that is proving difficult to resolve. I believe the fluctuations may be causing the knock.

fostytou

iTrader: (15)

It looks like it stays pretty in-line with the boost... Personally I wouldn't be too worried.

tsitalon1

iTrader: (3)

It's just kinda weird. I haven't seen this in anyone else's logs....

While I don't consider myself a perfectionist, I like things to be in-line with the expected norm.

Guru

iTrader: (6)

Is your ignition timing advance bouncing around due to the load fluctuations? This can induce knock possibly.

tsitalon1

iTrader: (3)

Nope, timing is stable.

I really can't find a root cause.