[radz28]

Hmm. I've watched Mike's video, but wasn't really trying too hard to let it sink in, because I knew I was going to come back to it.

I think I recall him saying the idea of it was to polish the tune, but didn't really remember if leaving in CL was okay/not okay/bad idea/etc. Also - have you tried running HPTuners at the same time? I've been dubious of this because it seems like I'm already at the channel-limit in my SCANNER, but didn't know if running the REFLEX in CL, while datalogging, would work.

Also - have you been monitoring your LOW SIDE pressures and such? I THINK I'm finally turning a corner with mine. I can't see why I'd be running out of fuel, and I'm probably overlooking/misinterpreting something, but after seeming like I was getting large pressure swings, after the DSX kicked-in, largely smoothed out, I'm still dealing with LOW SIDE pressure dropping off at the high-end. Maybe fueling still needs to be added, but I could make more than a few hits, and have most look good, then have one that seems like it's going a few percent lean, and that's when it seems like LOW SIDE pressure drops; so it appears when LOW SIDE pressure drops up there, I start going slightly lean. I can see pressure fall as low as upper 50s to lower 60s in these cases. My last tune, yesterday, kept pressures in the mid-to-upper 60s, for all the hits, but I had to crank up pressures to near 80-psi, and ramp the OEM LPFP in a little more. I'm only running 60-pounders, but, while I don't believe I SHOULD be near their limit, the way I'm interpreting the data seems to suggest that. I'm probably wrong.

I as just curious if you've noticed anything with your pressures after your last batch of changes.

[cjperformance]

My understanding of the continued/long-term use of the lambda feedback is that it's fine. What I recall from the video is that initially you may allow +/- 20% lambda correction. My interpretation is that it's used in this way initially as a safety factor for initial shakeout.

Then the idea is that you use the correction values to adjust the tune. The intent would not to be to continue allowing massive amounts of correction, but rather get the base tune closer. Once the base tune is not requiring a large amount of correction, then you would reduce the amount of allowed correction to whatever you are comfortable with like +/- 2%, 5%, etc...

You can run HPT scanner and reflex logging at the same time. That's what I've been doing. You'll have two connections to your laptop, one from the MPVI, and one from the reflex box. Then you just open HPT scanner and TunerPro at the same time and log individually. On my tuning laptop it seems to require quite a bit of drain on the battery when both are open, but the laptop I'm using is an older one.

My low side pressure is rock solid, but I'm not pushing it hard yet. I've only done a couple of sub 6k rpm runs on E50 with the 4.13 pulley, but it is stable so far.

I doubt you are at the limit of any low side pressure. I've got the crappy LT1 low side pump + DSX and things are fine so far, but we'll see after I pulley down and raise E content.

I would think there is some kind of fuel pressure compensation with the reflex???? but I don't know for sure, maybe a question for Mike? But if there isn't then I could see why low low-side pressure could cause a lean condition.... I just haven't experienced that since I've been super-conservative. Once I go full E85, pulley up, and raise shift points... then maybe I'll see something.

I'd wager your in-tank low-side pump is trailing off too much and sabotaging the DSX efforts.

In any case, I'd def enable the lambda compensation, no matter what method of tuning you are using.

I'll post a few things from HPT logs later. I don't have them on my current comp.

[cjperformance]

Sorry for the delay, here's the screencapture of the log. Just LMK if you want to see anything else.

[radz28]

Thanks for all of your comments! That screenshot supports how effective the CL is.

I think I'm convinced I'll probably see about activating it this weekend. I just watched Mike's video again, paying attention this time, and it is not complicated at all. It looks like it'll take me tens of minutes to set up, and seems like it will add to fine-tuning.

I think my fueling is more of a challenge because I'm just using more of it, because I'm running 15-16psi. I think I'm moving in the right direction at least with a little more adjustment to the OEM LOW SIDE pressure limits and pump. It seemed to improve from the last run where there was little to no more OEM pump duty cycling, and slightly lower pressure limits.

That's all great stuff, and I'm learning a lot!

[cjperformance]

Swapped to the 3.7" pulley today, but need a smaller belt.

Also... when I pulled the original pulley off there was NO key in the keyway

I didn't drop it or lose it or anything... just absent. I noticed right after I loosened up the pulley bolt that the pulley was spinning. Didn't even require heat or anything to pull the pulley off.



Guess they figured a basic p1x with a 4.13 pulley didn't need it. I mean... I guess they were right, there was no indication of slippage. The keyway was machined into both the shaft and the 4.13 pulley. Why not use one?

In any case, I went out and bought a 3/16 key and stuck it in with the new pulley.

I tried to get away with a quick pull with the old belt, but it was slipping too much. Not enough tension. So will order a new belt. Maybe more fun times next weekend.

[toohighpsi]

Continued use of lambda is expected, I don't know of any reason to ever turn it off.

Some level of fuel pressure correction is already in the Reflex+ but not being used unless you add a FP sensor (or we have enough time to find the fuel pressure PID) On my 2015 C7 the fuel pressure on the CAN bus is quite intermittent (as per HP Tuners) so I simply installed a fuel pressure sensor at the fuel rail feed using the components below.

https://toohighpsi.com/products/refl...ensor-0-150psi

https://www.amazon.com/EVIL-ENERGY-P...2s9dHJ1ZQ&th=1

The sensor plugs directly into INPUT 2 on the Reflex+ and will let you log / correct based off port rail pressure. There is a "Fuel Pressure Factor" table and I am working with MOTIV to verify/rewrite this to be differential pressure (FP - MAP) that way we can simply input the flow data from the injector manufacturer directly.

I don't currently do any injector correction based off fuel pressure - I primarily use the fuel pressure sensor to set the duty cycle of my aux pump to maintain the commanded pressure in the E92.



Lots going on in this plot, but I'm commanding 55psi fuel pressure in the E92 and its maintained fairly close by the stock pump plus the Reflex+ PWM control of the secondary pump. The PWM allows the system the avoid the spike of turn on like is normally seen with simple secondary pump control systems.

[laynlo15]

Mike's is slightly different than mine, he has mine set up for 30 percent port. My fuel pressures are a little higher at 64 psi of low side.

[toohighpsi]

Originally Posted by toohighpsi

Continued use of lambda is expected, I don't know of any reason to ever turn it off. Remember that the % limits are based off the port % being used, so 20% limit is 20% of the amount of port being used (in my case 35% port). So in reality 20% is pretty small.

Correcting my previous post, when you allow 20% correction - it IS 20% of full required fuel flow (DI + PI), when you apply the correction to the fueling to reduce your error you need to add fuel to either delivery system or both in the amount need to achieve the error.

So for example if you're running say 40% port and the Lambda Correction % you're trying to fix is 5% you need 5% more total fuel at that point.

If you have enough margin in your DI to add 5%, then you can just add 5% to BOTH your DI and PI flows values at that point.

If you want to add it with PORT only, you'll need to add:
5% + (5% x 60% / 40%) or whatever your DI/PI ratio is = 12.5% fueling to PORT ONLY to fix your Lambda error.

Actual calculation is 0.05 + (0.05 * 60/40) = 0.125

Sorry for that incorrect statement on my previous post (which I'll edit out), sometimes just too many numbers rattling around in my head...

[cjperformance]

Originally Posted by toohighpsi

Correcting my previous post, when you allow 20% correction - it IS 20% of full required fuel flow (DI + PI), when you apply the correction to the fueling to reduce your error you need to add fuel to either delivery system or both in the amount need to achieve the error.

So for example if you're running say 40% port and the Lambda Correction % you're trying to fix is 5% you need 5% more total fuel at that point.

If you have enough margin in your DI to add 5%, then you can just add 5% to BOTH your DI and PI flows values at that point.

If you want to add it with PORT only, you'll need to add:
5% +5% x (60%/40% or whatever your DI/PI ratio is) = 12.5% fueling to PORT ONLY to fix your Lambda error.

Actual calculation is - .05 + (.05 * 60/40) = 0.125

Sorry for that incorrect statement on my previous post (which I'll edit out), sometimes just too many numbers rattling around in my head...

Got it Very good info!

[cjperformance]

New belt on. Filled up with E85 (prob more like E70-something right now)... mixed with my half tank of E50 worked out to be E64.

I'm still intentionally running rich for addl safety, but things are looking good!

I'll probably take about 2% out of both ECU and Reflex MAF and start bumping up the shift points until I feel "good" about things.

At 6000 RPM getting about 9.5 PSI now with the 3.7" pulley, where before it was around 7 PSI with the 4.13" pulley. Procharger ramps up the PSI real quick above 6K engine RPM, so going to make fairly small shift point bumps at a time.

I think I'm seeing the low side fuel pressure dips that radz28 mentioned too now that I've pulleyed down and running more E. Nothing too concerning to me at the moment, but will keep an eye on it.

The pulley REALLY is making a difference earlier in the RPMs too. I can feel it SOTP.

[toohighpsi]

Nice work - looks like you have a good handle on it now!
Time for more E and more boost!

[laynlo15]

Chris is getting his shit together on this build. When you finally get there you'll enjoy that addition power and those track times are going to take a big dip. Get out there before the weather gets hot. Congrats.

[cjperformance]

Originally Posted by toohighpsi

Nice work - looks like you have a good handle on it now!
Time for more E and more boost!

Thanks! I could use a refresher course on the Lambda P/I/D values. It was very lightly touched in your video, but I'd like a deeper insight into what those values do.

I'll take my educated guesses here for fun and public humiliation:

If I recall correctly, the P (Proportional) value has to do with the amount of correction applied and can be tweaked based on the % of PI. You had said that when on 30% port, the theoretical ideal value is 2.0, but that setting to 2.2-2.5 allows more (or maybe more precise) correction. If % of PI were higher, 40-50% etc... then that value should be lower, no doubt because a lesser amount of correction needs to be factored in when PI is a greater % of total fueling. Not being on a dyno makes it difficult to make, test, and analyze a bunch of changes to see the real-world impact of changing these values.

The "I" being the integral, I assume as described by Integral Calculus having to do with finding the area under curves, but it isn't my strong suit, and I'm not clear how it is being used in the calculations, or what the real-world impact of changing that would be. Based on the formula in TunerPro:

ITerm = ITerm + (ki * error)

I could surmise that this factors into a carryover effect to ipw calculations from moment to moment by the Reflex to the injectors at run-time. I have observed that the final inj pulse width by the Reflex is not always what it says in the "after lamba correction" value... In other words, there appears to be a smoothing effect based on prior lambda correction values for ipw...

No clue how the derivative term would be used.

[cjperformance]

Originally Posted by laynlo15

Chris is getting his shit together on this build. When you finally get there you'll enjoy that addition power and those track times are going to take a big dip. Get out there before the weather gets hot. Congrats.

Thanks! It's definitely running stronger. Just hoping I don't make the engine go splody all over the place