Cannot get rid of TMA occurring when going from cruising to WOT

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Originally Posted by GHuggins

Back the rail pressure down. I've seen that problem with the LT4 injectors a few times. I'm bad to jack rail pressure up near borderline for them too, which is how I know the problem exist :) You're going to want it to cap around 21 MPa or less then retest. There may even be a designed in pulsewidth timer of some sort since extending the spray time made it do it that we can't see?

On a side note - how are you calculating power and torque or is torque just what's being reported from the model?

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I am using this formula for HP calculations I retrieved from Goat Rope garage.

[50070.56] * [50108.127]/5252
Engine Speed Sensor x Engine TQ Sensor / 5252 hp/tq cross point

The TQ is form Engine torque which is not matching what is in the channel which is higher. We all know these numbers are not accurate by far! While N/A it said I was producing near 600 crank HP which is a lie!!

If you look a the attached screen snip, you see the Engine TQ @ 1,032 but the graph only shows only 836. So not sure which sensor the HP is calculated from on this one, the 1036 in the channel or the 836 in the chart but either way, no way I am at that power with that boost. 836 TQ seems more close to reality at 11.5 psi. but looks as though the math may be using the engine TQ in the channel.

I know however that I must be at least making over 750 bhp at 9 psi as I had a BMW X6M competition try me while tuning and I walked away from him, by looking at power to weight calculations, I'd had to be at 750 at the crank. They are 617 bhp and about 600lbs lighter. The fueling is way better now and runs much stronger compared to then.

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Originally Posted by GHuggins

Back the rail pressure down. ... around 21 MPa or less then retest. ...

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Is that under the Desired Fuel Pressure table?

Yes to the rail pressure. A very accurate HP calc is maf g/s x 1.25. Usually within 5 or 10 HP. Its just if I try to back calc torque from that it gets screwy

Just updated my scanner with that math and going to test it. I believe I have it dialed in as close as I can get it so it's time for a light acceleration test to see how these new springs work on wastgate. I pray I have enough fuel!

Everything was appearing to be fine with the tune but no matter what I did with the controller, ma boost was capping out around 11.2psi. Then I realized I was having boost go through my catch can and into the engine. Installed a PCV check valve and it was giving 12.5 as shown in the first screen snip which was off to a good start but thought maybe the PCV wasn't fully sealing off when it seen boost so I removed it and disconnected the catch can entirely so the vacuum block is just manifold pressure only.

Herein lies the problem, now when I get on it I am loosing fuel at an area I have not had issues with previously. No fuel changes have been made since the last update and it has done this twice. I am totally lost with the low boost on a 14 psi spring and the fuel which just started to occur... Seems to only happen with the cut out is open.

WOT pull with the cutout closed seems to work fine and has plenty of fuel, when the cutout is open, fuel starts to disappear @ 5,900 RPMs. Can anyone figure out what is causing this all of a sudden? Once it cools down, I'm going to check every line and fitting for leaks to figure out the boost issue.

Put high flow low side pump setting and O-ring protection back like it was previously and recheck.

I swapped the factory pump back in and it did the same thing so as I was swapping at the second time I noticed the grommet was broken on the fuel pressure sensor on top of the tank so I just put a new sensor in and I'm going to see if that might fix it but I will adjust those settings. I didn't realize they were changed but I'll put them as you said and see if that makes a difference as well

I swapped the factory pump back in and it did the same thing so as I was swapping at the second time I noticed the grommet was broken on the fuel pressure sensor on top of the tank so I just put a new sensor in and I'm going to see if that might fix it but I will adjust those settings. I didn't realize they were changed but I'll put them as you said and see if that makes a difference as well

Quick lil update before bed...

All is good, no fuel drop however I did see an over rev once. The fuel rail is at 21mpa. What else could cause this or is that the definite reason for the over rev? This is so exhausting. Also, still need to figure out the low boost as well...

Did a leak test on my wastegates and found a tear in the passenger side due to a set screw coming loose and bouncing around inside the housing.

Is there any possibility this could cause the over rev I've been or am experiencing?

Change rev limit to Auto and let it use spark and throttle for the rev limiter. You need the boost controllers fixed and that combined with the rev limit it's using could keep it going I guess.

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Originally Posted by GHuggins

Change rev limit to Auto and let it use spark and throttle for the rev limiter...

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Having a hard time finding where those parameters are located...I believe this is the rev limit change to auto you mentioned, must have changed it without realizing when I was comparing the LT4 fuel settings.

That's it. Accel Based - Filter Coefficient - change that to 1 too.

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Originally Posted by GHuggins

...Accel Based - Filter Coefficient - change that to 1 too.

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Done! Thanks Man, just hoping I can find a replacement diaphragm for my wastegate tomorrow. Cannot wait to get full boost.

Any one know what would cause the fuel pressure to pulse like this? Is this normal or is there a setting that causes this? Would rather it stay a steady pressure but not sure if this is supposed to be this way.

The fuel rail pressure is staying steady for the most part but the fuel pressure is going up and down constantly.

Mostly normal, but you can change min DC to help - increase 10% usually helps with dips and things like that. Also highly possible that your check valve at the engine not flowing enough is causing issues. Lingenfelter and another company make bigger higher flowing ones.

I've replaced the fuel line going to the high pressure fuel pump with an lt4 fuel line. Is that why you mean by the check valve or is there something different I need to look into? I will try adding 10% to the min DC to see if that smooths it out.

***EDIT*** I found the Lingenfelter check valve you were referencing. So this will eliminate the pulse and steady the pressure?

Won't eliminate it, but should help smooth the flow out.

So I am still waiting on the fuel check valve to arrive...did have to swap out a new fuel pressure sensor as it went bad so that could of been some of my issues...

Currently seeing 10 psi on wastegate (cutout closed) with a 14psi spring. One thing I am noticing is when I use the boost controller to increase duty cycle, it is raising the boost but it drops back to wastegate pressure. Called AEM and they said this is normal as I shift gears it should drop. This doesn't drop at all when I am on wastegate however. Attaching a screen snip of HP tuners log showing this. Shouldn't is stay at the 14.5 psi the entire time? Going to do another bleed test to see if I have vacuum loss but with the consistent wastegate pressure I don't think so as I have new wastegates now.

If I can just get the pressure to stay steady, I'd be very happy with the current set-up. Adjusting the crack pressure lowers the spike but doesn't add any additional boost throughout the RPM range even when I shift to other gears.

***edit***added a snip on wastegate for reference and never mind my intake temps, got a meth kit I will be installing soon...lol At the start of that run it was only 117. climbs quick!

I hooked up my compressor to the vacuum lines and discovered a fitting the bottom of my passenger wastegate that was leaking. I repaired but still getting the same results with the boost dropping off with the boost controller. Will be installing a new solenoid when it arrives to see if that is the culprit. At least now I know that it is no longer leaking boost.