Max Karman Frequency to send to computer?

[mas]

Just wondering if anyone knows around what Karman frequency will cause fuel cut? at full load. I have seen 2256 sent to the computer so far at 6988 RPM. I would rather know i have a few hundred Hz to go as a safe gaurd. fuel cut at 15PSI singing at 7K rpm's would be bad.

I KNOW the numbers are set in stone and are related to other engine aspects. what have you seen on your logs. what numbers have you seen send you into fuel cut.

is there a magic threshold.. a "getting close" number to avoid.

What is the highest you have logged?
Full load. full temp. Ambient air and no knock?

[Forest Gump]

look in the emange ultimate thread, there is a post about where to put the maf ceiling per rpm.

I've hit fuel cut at high boost and rpm plenty of times and never hurt anything. The engine doesn't go lean when this happens, combustion stops completely. The factory would've have designed it this way if it would hurt the motor. It is designed to save the engine from leaning out.

[stupidvr4]

I'm curious about this too since the maft gen2 has a max hz number you can input so the ecu doesnt cut fuel.

[mas]

i guess im use to my old turbo dodges form the 80's fuel cut under boost = cracked piston lands.

anyone wanna chime in with Hz levels they have seen? just would like to know if im close. or at least be able to tune my FP up and down to give my self 200Hz or so leaveway.

[stupidvr4]

Ive seen 1500hz at 13psi with stock turbos, and I was getting fuel cut at 16.5psi at around 4000rpms but i didnt log hz at that time.

[2Nol]

Sorry for digging out an old thread. I just logged my MAF signal with e-manage blue and it gave me a readout of ~2200Hz@5500rpm@12psi. I couldn't go higher as I've run out of a road :P.
I've been recently experiencing random fuel-cuts and I'm suspecting some leaks in the intake. Is it possible that a leak is responsible for such high karman values? I assume, that the leak is somewhere between turbos and the throttle (turbos are pumping the best they can - this is why the MAF reads so high - but it goes out into the atmosphere).

Am I thinking right?

[RealMcCoy]

Originally Posted by 2Nol

Sorry for digging out an old thread. I just logged my MAF signal with e-manage blue and it gave me a readout of ~2200Hz@5500rpm@12psi. I couldn't go higher as I've run out of a road :P.
I've been recently experiencing random fuel-cuts and I'm suspecting some leaks in the intake. Is it possible that a leak is responsible for such high karman values? I assume, that the leak is somewhere between turbos and the throttle (turbos are pumping the best they can - this is why the MAF reads so high - but it goes out into the atmosphere).

Am I thinking right?

Yes, that's exactly what a boost leak does... It's air that gets metered by the sensor, but never makes it to the motor.

Makes you run rich as hell too...

[keithmac]

You`re on the brink at 2200hz!. Plus it alters with RPM, the lower the RPM the lower the threshold (I`ve hit it at 3000 rpm while tuning my output map..).

I have my Karman Hz output table set to 2000hz peak at 7000rpm.

[Forest Gump]

Originally Posted by keithmac

You`re on the brink at 2200hz!. Plus it alters with RPM, the lower the RPM the lower the threshold (I`ve hit it at 3000 rpm while tuning my output map..).

I have my Karman Hz output table set to 2000hz peak at 7000rpm.

Stock Fuel Cut table: (99 ROM)

RPM: 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000

LOAD: 162.5 162.5 167.5 172.5 192.5 210 205 202.5 197.5 197.5 197.5 197.5

Greg will have to chime in with what the load relates to HZ readings, I don't want to tell you guys incorrect info.

[2Nol]

Yeah, that's what i suspected. I will have my intake disassembled and reassembled on friday night.
And yes, it runs rich as hell. AFR never comes over 12 while idling (which is shitty also btw) It is so rich I need to open my windows while in traffic. Fuel fumes are nice, but only on a gas station. They give me headache while I'm driving.

Thanks Forrest for the table.