Tuning for Intake?
Oct 16, 2006, 04:46 PM
#16
Originally Posted by nj1266
Here are the AFRs that you asked for Eric. As you can see the low boost/torque AFRs are not that much different on botth cars. The AFR is different above 4500-5000 rpm. I still suspect it is the filter element that is causing the load to spike so high. I guess I will know when I log his car with a stock filter element next time.
Evo w/ apexi filter system
My evo w/stock box.
Evo w/ apexi filter system
My evo w/stock box.
Looking at the AFR data at 3500 RPM, most of your counts hit the 11.77 (if the (11) means that it was from 11 samples) whereas his AFR at 3500RPM has most points falling at 10.77. So, it definitely looks like he is hitting the higher load cells for sure, producing richer AFRs.
But, I still can't definitively say that it was due to the filter altering the airflow reading or if it was due to a boost spike. I wanted to see the AFR data to see if he was running richer at the load spike, which is appears that he is. It really doesn't tell us why the load is higher, but it at least confirms that the load is hitting that number (without seeing his fuel table).
Maybe you can take his Apexi filter when he's not looking, install it in your car, and log the boost, too.
That would give us great data since it would be data from the same car with just the filter change.Other than that, we won't know since we can't log his boost.
Eric
Oct 16, 2006, 04:50 PM
#17
Originally Posted by jordo
If looking at that.. It looks like the air filter caused it to run richer, which means it is a restriction.. meaning its not making as much power unless it is leaned out.
We don't have the before and after for the Apexi car to see if it got leaner or richer. But, as I mentioned previously, I would expect the Apexi to perform pretty well, without leaning out the airflow like other cone filters would.
This is actually a good thing, not a bad thing. It doesn't mean it's a restriction....it just means it accurately measuring the airflow.
Eric
Oct 16, 2006, 09:10 PM
#18
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so, the best filter to go with would probably be the Apexi? Is there another filter that provides the most stable MAF reading or is the apexi the best way to go?
Also im wondering the Apexi filter will cause your car to run a little richer? or did i not understand right.
Also im wondering the Apexi filter will cause your car to run a little richer? or did i not understand right.
Oct 16, 2006, 11:09 PM
#19
Originally Posted by coolguycooz
so, the best filter to go with would probably be the Apexi? Is there another filter that provides the most stable MAF reading or is the apexi the best way to go?
Also im wondering the Apexi filter will cause your car to run a little richer? or did i not understand right.
Also im wondering the Apexi filter will cause your car to run a little richer? or did i not understand right.
Oct 16, 2006, 11:38 PM
#20
Originally Posted by jcsbanks
The elegant/"correct" to do it would be to adjust the airflow meter scaling. However, because the exact processing of the airflow signal is relatively poorly understood, many will just scale the fuel and timing maps to suit.
Closed loop stuff will give away the changes from the fuel trims.
Open loop stuff from your wideband.
Timing from your knock sum/octane number/knowledge of sensible timing on these engines/your setup.
The stock airbox is limited. At 7000 RPM at 21 PSI on pump fuel on a IX with exhaust, pump and HKS hard pipes I was getting a 1.5 PSI depression from atmospheric pressure at the airflow meter. This was halved by removing the airbox lid and securing the filter - you've just gained 5% air density before the compressor which will either allow more boost and airflow, or allow the turbo to run at a slower speed by opening the wastegate (so improved compressor efficiency and lower exhaust manifold pressure, less pollution of the fresh air charge from the end gases etc). Some have had similar results by cutting a hole like the one for the snorkel in the lid of the airbox on the opposite side to the snorkel. This is away from most of the hot air. Doesn't seem to upset MAF readings, looks stealth, still increases induction noise a bit. FWIW with the airbox lid off you can record gains in acceleration and on the dyno.
Closed loop stuff will give away the changes from the fuel trims.
Open loop stuff from your wideband.
Timing from your knock sum/octane number/knowledge of sensible timing on these engines/your setup.
The stock airbox is limited. At 7000 RPM at 21 PSI on pump fuel on a IX with exhaust, pump and HKS hard pipes I was getting a 1.5 PSI depression from atmospheric pressure at the airflow meter. This was halved by removing the airbox lid and securing the filter - you've just gained 5% air density before the compressor which will either allow more boost and airflow, or allow the turbo to run at a slower speed by opening the wastegate (so improved compressor efficiency and lower exhaust manifold pressure, less pollution of the fresh air charge from the end gases etc). Some have had similar results by cutting a hole like the one for the snorkel in the lid of the airbox on the opposite side to the snorkel. This is away from most of the hot air. Doesn't seem to upset MAF readings, looks stealth, still increases induction noise a bit. FWIW with the airbox lid off you can record gains in acceleration and on the dyno.
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