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Discussion Starter #1
So I got this buddy Jeremy that guess by Heavychevy on the forums. He's got a pretty badass Silverado Crew Cab with a 408ish cube motor and a 94mm turbo on E85. So he's racing this CTS-V with a 150-175 shot. Here's the video. CTS-V gets the hit.


Looks like a nice clean pull. With the scramble and everything, that's about 1200 rwhp at like 4500 lbs. Well, what you can't see is that at about 1.5 secs into the run his fuel pressure went from 70 psi to 42-43 psi within the next .75 seconds (pink line). As this is happening, you can see the Holley spring into action with the closed loop correction (green dashes) and the injector duty cycle follow along with it (maroon line). He's not yet sure what happened but I suspect that the diaphragm in the boost reference fuel pressure regulator broke.



This is the 4th vehicle in our crew that has lived thru a 1000+ rwhp pump issue or failure in a multipump setup.

Have faith gentlemen. The shit works! :supz:
 

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Discussion Starter #4
Yeah, I was thinking that maybe a 150% duty cycle spike should light a bulb or pull all the timing or something. I don't know that I want it to activate at 100% (maximum value the Holley will allow me to input as a trigger). I hate false positives and would hate for someone to lose because of one.
 

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Yes, their wideband does work great. I would also advise to setup some internal safeties.
Then I might have lost the race. I'm just kidding. I am going to turn on some of the safties back on. And find the fueling issue. This is second time the holley saved my motor. First time was similar, but was do to alternator failing during pass and massive loss of voltage.
 

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Then I might have lost the race. I'm just kidding. I am going to turn on some of the safties back on. And find the fueling issue. This is second time the holley saved my motor. First time was similar, but was do to alternator failing during pass and massive loss of voltage.
Me to, I lost my alternator on a race against an f1 motorcycle. Car ran perfect but during the race the innovate wideband had an error and as we slowed down the lights were dull. Reviewed the data log and injector duty cycle went form the normal 70% range to 125% due to low voltage/fuel pump pressure. Holley Wideband control FTW!!!!!!
 

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That's awesome my Holley did the same thing in my race car. Car went 150% duty cycle and the Holley added 70lbs and hr to my setup. Found out mine was my weldon 2025 was down 50 gallons an hr and diaphragm in my regulator broke also so had them upgraded while out. Everything since has been perfect glad your motor is ok
 

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Make a safety output based on sensors...
then (even if you are not using it) add the boost config
then you can use the "Boost safety" and trigger it by the output you set up as a "safety output"
you can then set it to kick on the "Boost safety" if its triggered for more than a specified amount of time (1 second, 2 seconds)
this way you can filter out transient spikes set in the safety output...which can also light a bulb at the same time so you get a visual and it will cut the ignition if it comes on for more than the time specified.
 

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Doesnt FAST XFI 2.0 does the same thing? i run mine in closed loop with 25% positive correction which is the max.
 

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Had the same thing happen to me.. didn't know the pump was not keeping up... pressure at 4100 rpm was 61psi.... At 6300rpm it was down to 37psi. Holley Dominator never let it go leaner than 12.0... Injector DC went way up to compensate... Engine never flinched. Amazing!
~Scott
 

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Doesnt FAST XFI 2.0 does the same thing? i run mine in closed loop with 25% positive correction which is the max.

holley can correct up to 999%, and can also have a learn amount of up to 999% on top of that.....

not that it would be practical to do so....but it exists..
 

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Holley can correct up to 999%, and can also have a learn amount of up to 999% on top of that...

Not that it would be practical to do so....but it exists.
Yep, and if the Learned Compensation Limits % are significantly decreased (as they should be after the engine is tuned), the Closed Loop will save the engine without skewing the Base Fuel Table. So you can fix a temporary fuel system fault without necessarily having to fix the "tune".
 
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