How closed loop can save a motor, holley
08-01-2015, 08:42 AM
#1
How closed loop can save a motor, holley Just wanted to share some cool info on what closed loop in power can do
Fuel pump is dying, didn't even realize until I looked at a log
Two files compared, same tune and boost
Middle brown lines are fuel pressures on both runs
Top red is rpm
Bottom purple is learn trim (I have base gain 100% yet so this is why the learn is up and CL isn't,)
blue towards bottom is AFRs
Yellow, target
Can see fuel pressure dropped off big, CL kept adding fuel and held target perfectly
I had no idea anything was going on lol
Fuel pump is dying, didn't even realize until I looked at a log
Two files compared, same tune and boost
Middle brown lines are fuel pressures on both runs
Top red is rpm
Bottom purple is learn trim (I have base gain 100% yet so this is why the learn is up and CL isn't,)
blue towards bottom is AFRs
Yellow, target
Can see fuel pressure dropped off big, CL kept adding fuel and held target perfectly
I had no idea anything was going on lol
08-01-2015, 04:09 PM
#4
9 Second Club
Also how easily reliance on closed loop could destroy a motor when there are no proper safeties in place for such things.
You're only aware afterwards from looking at logs there was a problem...with proper safeties in place you'd be alerted immediately and know there is a problem.
Closed loop adjustments are a good thing when used correctly.
You're only aware afterwards from looking at logs there was a problem...with proper safeties in place you'd be alerted immediately and know there is a problem.
Closed loop adjustments are a good thing when used correctly.
08-01-2015, 04:13 PM
#5
Pretty cool it compensated for a 20psi drop, however, I would not want it compensating with DC as you currently have it constructed. Too much fuel aeration that way potentially. If you have a dominator enable a ground output to trigger a ground activation on an available rev limiter.When you set up the ground output tie it to an available sensor input trigger of your choice (in this case fuel pressure) so that at WOT, between x rpm and y rpm, any deviation from x fuel pressure will cut fuel to the motor.
08-01-2015, 05:33 PM
#6
Datalog every pass at the track and review it back in the pits right after the run. Best way to keep an eye on things. It'd also work on the street. After a few spirited runs, pull in the garage, upload the logs, crack open your favorite beverage and review. Sounds like fun to me!
08-01-2015, 06:25 PM
#7
Shouldnt really be anything detrimental to engine life with CL being able to add alot of fuel, its when it takes it away you have to worry. I only allow a +100% and -10% WOT CL correction. But, I do have an ignition cut-off if fuel pressure dips too low. Nice to have as many layers of safeties possible with a FI deal.
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08-01-2015, 10:16 PM
#8
More on the story. Yes I have safeties in place. I just didn't hit them.... Although today I did lol
Here is how I am configured.
Anyway back on to my story... Pump is going out right can tell it has a dead winding or something or another
So today was in a rush as a friend wanted to go for a ride and I have a spare 4303 there, swap it in and take him out
Hit it one time and it shutdown. It hit my fuel pressure trigger and just about my DC. When it shuts down it shuts down like face to windshield fast lol
Anyway pull filters and the brush material paired with sticky E that I get sometimes plugged my post filter up. Could hardly blow through it
So yeah the CL and the shutdown work lol
It did go slightly lean. But it had hit the max CL correction. I allowed
Here is how I am configured.
Anyway back on to my story... Pump is going out right can tell it has a dead winding or something or another
So today was in a rush as a friend wanted to go for a ride and I have a spare 4303 there, swap it in and take him out
Hit it one time and it shutdown. It hit my fuel pressure trigger and just about my DC. When it shuts down it shuts down like face to windshield fast lol
Anyway pull filters and the brush material paired with sticky E that I get sometimes plugged my post filter up. Could hardly blow through it
So yeah the CL and the shutdown work lol
It did go slightly lean. But it had hit the max CL correction. I allowed
08-01-2015, 10:20 PM
#9
Also I have a standalone WB 02 gauge. I am always watching that vs the holley the computer to see they match before hitting it with healthy power
Here was tonight fixed. It's making some power when boost gets in. I arm the system at 70mph (4psi) and at 130 its in at 20psi. Can hear it rolling in easy
Here was tonight fixed. It's making some power when boost gets in. I arm the system at 70mph (4psi) and at 130 its in at 20psi. Can hear it rolling in easy
08-02-2015, 05:44 AM
#11
9 Second Club
If you're already pushing the pump/injectors hard, they may simply be no excess supply to allow extra fuel regardless of what CL tries to do. If you had a split fuel hose somewhere you may not throw a basic fuel pressure trip the ecu might go mad trying to increase injector output...but have no ability to do so.
People can see threads like this and think CL is a saviour and will save all modes of bad tuning or installation. For some it will, but they must be aware of the realities too.
Any fuel pressure trips must be relative to manifold pressure also, as fuel pressure alone gives a poor picture of how the system is performing as it is a large variable.
Fuel pressure relative to manifold pressure is almost a static value so by far the best information to use for a fuel supply system trip. Then you could run larger or smaller CL corrections with peace of mind that the pump setup is being closely monitored too.
08-02-2015, 08:28 AM
#12
There are many reasons that blindly allowing a lot of corrections is dangerous.
If you're already pushing the pump/injectors hard, they may simply be no excess supply to allow extra fuel regardless of what CL tries to do. If you had a split fuel hose somewhere you may not throw a basic fuel pressure trip the ecu might go mad trying to increase injector output...but have no ability to do so.
People can see threads like this and think CL is a saviour and will save all modes of bad tuning or installation. For some it will, but they must be aware of the realities too.
Any fuel pressure trips must be relative to manifold pressure also, as fuel pressure alone gives a poor picture of how the system is performing as it is a large variable.
Fuel pressure relative to manifold pressure is almost a static value so by far the best information to use for a fuel supply system trip. Then you could run larger or smaller CL corrections with peace of mind that the pump setup is being closely monitored too.
If you're already pushing the pump/injectors hard, they may simply be no excess supply to allow extra fuel regardless of what CL tries to do. If you had a split fuel hose somewhere you may not throw a basic fuel pressure trip the ecu might go mad trying to increase injector output...but have no ability to do so.
People can see threads like this and think CL is a saviour and will save all modes of bad tuning or installation. For some it will, but they must be aware of the realities too.
Any fuel pressure trips must be relative to manifold pressure also, as fuel pressure alone gives a poor picture of how the system is performing as it is a large variable.
Fuel pressure relative to manifold pressure is almost a static value so by far the best information to use for a fuel supply system trip. Then you could run larger or smaller CL corrections with peace of mind that the pump setup is being closely monitored too.
I agree with alot of what you say. I am just working with what I have.
The holley saftey incorporation is a joke compared to others out there, say proefi
If I had a table where I could set a fuel pressure shutdown based on a map pressure yeah it would be cake
I do disagree on the closer to the edge of injector the the worse, the closer to the edge the faster it will catch it
If I am running at 90%dc normally and something happens. I hit 100%DC with hardly any correction from the CL and the motor is shutdown
I don't allow CL to pull more than 10% above 150kpa once the base fuel is close.
08-02-2015, 08:43 AM
#14
9 Second Club
I agree with alot of what you say. I am just working with what I have.
The holley saftey incorporation is a joke compared to others out there, say proefi
If I had a table where I could set a fuel pressure shutdown based on a map pressure yeah it would be cake
I do disagree on the closer to the edge of injector the the worse, the closer to the edge the faster it will catch it
If I am running at 90%dc normally and something happens. I hit 100%DC with hardly any correction from the CL and the motor is shutdown
I don't allow CL to pull more than 10% above 150kpa once the base fuel is close.
The holley saftey incorporation is a joke compared to others out there, say proefi
If I had a table where I could set a fuel pressure shutdown based on a map pressure yeah it would be cake
I do disagree on the closer to the edge of injector the the worse, the closer to the edge the faster it will catch it
If I am running at 90%dc normally and something happens. I hit 100%DC with hardly any correction from the CL and the motor is shutdown
I don't allow CL to pull more than 10% above 150kpa once the base fuel is close.
That's my point...people blindly relying only on CL carries risks. You're backing it up with other safety items which in turn reduces risks.
08-02-2015, 03:40 PM
#16
Anyway take back about the pump dying. I am really impressed with what I see in the pump I took off for the run time it has on it
It perty much just comes down to shitty fuel..
The prefilter was all gummy too, and so was the pump all over, the commutator and brushes and board all sticky and gummed up. This is why the pump was acting goofy
Good pumps that is for sure. Fair amount of brush left
Can see how hard the fuel was on stuff, geara look very good though as do the wear plates
And can you believe it,...... An actual USA bearing lool
It perty much just comes down to shitty fuel..
The prefilter was all gummy too, and so was the pump all over, the commutator and brushes and board all sticky and gummed up. This is why the pump was acting goofy
Good pumps that is for sure. Fair amount of brush left
Can see how hard the fuel was on stuff, geara look very good though as do the wear plates
And can you believe it,...... An actual USA bearing lool
08-03-2015, 03:49 PM
#19
9 Second Club
Or on the other hand if your ecu cannot recognise any misfire events it could end up dumping in huge amounts of fuel because it wrongly thinks it is running lean.
There are a lot of reasons it is not sensible to always allow it large corrections