Karmen reading?

[2fast4]

If you got pocket or data logger or AFC, what is your typical Karmen hertz number running
15psi or whatever psi you run? Is this your stock 14b or 16g or etc?
I run 12psi and Karmen reading is 1800-1950hz. Maf overrun, am I?
1G maf w/ lower h/c removed and screw taken off, s16g, 2.5" exhaust, uip, k&n, hacked air can, etc.

 

[MyBeatGSX]

I usually see around 1800-1900hz with an EVO 16G at 18psi. But that's with a 2G maf.

 

[2fast4]

I usually see around 1800-1900hz with an EVO 16G at 18psi. But that's with a 2G maf.

Do you know what the maf overrun is for 2g cars? Same as 1g - 1604hz?

 

[MyBeatGSX]

It can't possibly be that low. I'd be fuel cutting like crazy if the maf overrun limit was 300hz below what I'm seeing. And they're supposedly good to like 400whp I believe? I'm no where near that. Mine spikes as high as 2100hz when the BOV opens (that must be what that stock dump tube in the intake pipe is preventing), so it definately reads higher.

I seriously doubt you're overunning your's either. I believe 1G maf's are good to around 300whp?

 

[2fast4]

It can't possibly be that low. I'd be fuel cutting like crazy if the maf overrun limit was 300hz below what I'm seeing. And they're supposedly good to like 400whp I believe? I'm no where near that. Mine spikes as high as 2100hz when the BOV opens (that must be what that stock dump tube in the intake pipe is preventing), so it definately reads higher.

I seriously doubt you're overunning your's either. I believe 1G maf's are good to around 300whp?

I don't understand when you say "it can't possibly be that low". I get around similar numbers as you, but, I run at 12psi to get that similar number. And if I run 16psi, it would go up to 2150hz. I don't get the "fuel cut" shock. And during idle, it reads as low as 27hz to 32hz. Do you have lower h/c in place?

My theory is that smaller 1g maf reads higher than bigger 2g maf(trying not to sound like opening can of worms).

1g guys, please input your maf reading. If you got AFC or other devices, you know what you get! Put it up in here!!!

 

[CanadianTSi]

That high of a Karmen reading at that low of a boost level generally means that you have a boost leak.

And a 1g mas can read well into the 2000 hertz range, that 1604 number is just the highest number a logger can display (it has to do with the size of a byte).

I see 2500 hertz at 24psi on my unhacked 2g mas. (it was 2700 when i had a boost leak)

 

[MyBeatGSX]

Canadian, is it true that MAF readings can vary widely car to car? I thought I remember hearing somewhere on this site that you can't even compare MAF readings car to car because the Hz reading is meaningless and doesn't directly correspond to an airflow number and in most cases is car specific based on MAF age, conditions, calibration, etc. I could be wrong, but I swear I heard that somewhere.

And if I'm wrong, it looks like I have a lot more air to pull before I make the power I want.

 

[iiiwildfireiii]

I usually see around 1800-1900hz with an EVO 16G at 18psi. But that's with a 2G maf.

1800-1900 hz at 18 psi? Hm. I'm getting 1500 hz at 13 psi on my V-trim. Oooh, I bet its time for me to do another boost leak test...

 

[MyBeatGSX]

Just went for a ride.... high 1900's at 20psi

 

[iiiwildfireiii]

Just went for a ride.... high 1900's at 20psi

Is this the hz that you dyno'd on? I wish some more people would post their readings!

 

[MyBeatGSX]

I couldn't tell you exactly, I wasn't paying attention to that on the dyno. The peak/hold function on the AFC doesn't work because of the BOV vent spike I mentioned before, so I'd have to sit there and watch the numbers.

But I dyno'd on 18psi, so I'm assuming it was in the upper 1800's like I was getting before.

 

[CanadianTSi]

I'll post some numbers but you can't really compare them as hz readings change with temperature and alot of other factors.

With my 16g at 20psi I was around 1800-1900( trapping 110mph) I believe. With my 50 trim at 20psi I was right around the same 1900(trapping 112mph, Turned the boost up to 24psi and I was around 2200, added cams and the SMIM and that brought me up to around 2500(trapping 121mph).

 

[iiiwildfireiii]

Oh, I knew there would be differences due to temperature and barometric pressure. I was just curious about what flow readings others were getting.