HP Tuner Math Channel Help

[gtstorey]

You do realize that HPT only shows you a portion of the tables actually used in the ECM. Probably more than most of the vehicles, but still a lot of tables they never touch.

It's not my car so tweak away at your formula and try and tune it to some high boost level using it. It should be very close in closed loop mode, where the wideband isn't needed. I will weigh in on any post that portends to say how great it works as a warning to those who don't know better.

[gtstorey]

Originally Posted by topgzl1

Hey guys! I’m a new member but have been on the forums since 2013 (if that makes any sense)
I had a 2014 V6 Camaro that had a ton of SLP parts on the car. Now in a 6th gen ZL1. However. I’m looking to get another 5th gen and looking to put SLP parts on the car they are now discontinued and i’m now stuck looking for one specific part the SLP hood scoop for SS1LE hoods (heat extractor is what they called it lol)
Does anyone have one and willing to sell PLEASE. I live in Cali but will pay for part and shipping for this item.
Thank you guys!!

Don't just pop in at random on some thread for something like this. Either classifieds or at least start your own thread.

[acammer]

Originally Posted by Dark Sun

See that’s a great response with useful information. I know it’s not perfect and was asking for the comparison so I can understand and tune the math. ...

You saw that I did your test above, right? It works, kinda, but isn't reliable. At the end of the day, calculating AFR is a calculation on what you're delivering to the engine. You can get it more or less accurate depending on how much you measure, and how many variables you account for, but ultimately, it's what you gave it. Just because you gave measured the air and fuel going in at a 12:1 ratio doesn't mean that's how it actually worked out - there are a lot more variables going on in the fuel, the air, and inside the combustion process that can alter that further. What it actually burned, and the resulting AFR, are always going to be a bit different, and that's why tuning with the wideband makes so much more sense - you need to check your result, and adjust to it.

This is what the OEMs do - they calculate what they need for fuel based on a given amount of air, and then they provide that to the engine. But they know it won't always be spot on for all sorts of reasons, and so there is a constant feedback loop of monitoring the result, and continuing to adjust the fueling accordingly. Tuning on a calculated AFR alone is never going to be a good idea.

[gtstorey]

Originally Posted by acammer

Tuning on a calculated AFR alone is never going to be a good idea.

Isn't that what it basically is doing in OL? With the adjustment in LTFT from closed loop?

[acammer]

Originally Posted by gtstorey

Isn't that what it basically is doing in OL? With the adjustment in LTFT from closed loop?

That's exactly what it does in open loop - it fires in a given amount of fuel based on a calibration against airflow, with no feedback loop. It does consider the LTFT, and adds fuel if the LTFTs were also doing so. Its not, however, how the initial calibration would be setup, and it's not how it would be modified after the fact.

Tuning for WOT is critically dependent on using an external sensor to properly calibrate the air-fuel ratio. It's also why when I tune I will tend to defer slightly towards the safe side of the AFR, in order to allow for some unforeseen variables coming into play that would alter the AFR in a negative way. The power to be gained or lost in a half a point of AFR is fairly minimal. For a race application, sure, you get all you can. Those cars also typically have the best fuels and maintenance routines, and are kept under high levels of oversight. For a street driven car, I will absolutely roll 2-3% of WOT fueling back in the calibration once it's finished as a buffer, it might cost a couple horsepower, but it also gives the engine a better shot at a long happy life with a less involved operator that might neglect a fuel filter, run some less than top tier fuel, etc. I'll do the same with the spark - we'll get that maximized, and then take just a small step back for a bit of a safety margin.

It's also worth noting that we're talking about 5th gen Camaro's here. There are plenty of other vehicles on the road that utilize closed loop fueling in all modes of engine operation, including WOT/power enrichment. It's a better strategy - you'd have to ask GM why they went with their scheme. It's usually related to money...

[gtstorey]

Somehow I interrupted "Tuning on a calculated AFR alone is never going to be a good idea" to mean "fueling based upon desired AFR". Not sure how I did that, but that is really what you answered to anyway.

[Shodown]

Originally Posted by Dark Sun

So how much PSI are you at with all the mods you listed? I know there’s recipes out there and everyone is a cook, but nothing tastes the same when all the cooks follow the same recipe.
So as I stated before that you mentioned, I raised the boost with my first trick from stock to 9.25 psi and everyone is scolding my recipe, I did some research and math, and put a 10% lower pulley on two days ago, now I’m making 13.2 psi hitting the torque management boost disable, injectors are 112% and my cat temps are good. My MAF is just a few percent off at WOT, my calculated AFR for my stock ECM is within 1% of commanded lambda AND the PE table. I am getting a wide band soon, injectors, cam, springs, etc. So take your standard chicken soup recipe like the other 10 thousand have done, I personally don’t follow others with anything and revel with others telling me it can’t be done, you are wrong, or it’s impossible, then doing it. Can you personally design parts in AutoCad, have them made, cut weld and fabricate it all in stainless, build a rear differential, transmission, a twin turbo draw through carburetor system on a LS engine making 20 psi on stock pistons, get that ground up design and build to pass DOT regulations, get it titled, registered, and tagged without ANY help from others because there is no RECIPE for it and run it to 219 mph? Everyone said I couldn’t use hydraulic steering on a motorcycle, did it, everyone said I couldn’t use that transmission and differential setup, did it, everyone said the turbo system wouldn’t work, did it, everyone said you can use a single sided hub centric front wheel on swing arms for a motorcycle, did it. Do you know the exact PSI factory GM hypereutectic pistons will break ring lands no matter the AFR and .060” ring gaps? I do. Thanks for input.

Seems I hit a nerve here. Relax, boomer lol.

Yes I have access and the knowledge to do all those things. It's not overly difficult. I'm not here for a dick measuring contest. If you have relevant questions I'm happy to help.

To answer your question my car makes 15 psi. I hope that helps with your wild endeavors