Posts by ARM

  • Fuel Pressure

    Quote from Dave@DDMWorks

    Is that a Yes to both questions?


    ARM with your tuning at ZZP, Kyle only has the fastest speed in the 1/2 mile for now, a great accomplish for sure. However, maybe you are not aware we have a faster speed recorded in the 1 mile and faster than even Kyle thought anyone would go before the event.

    You can drop the passive-agressive BS at any time, You've been that way to me from day one and it's pretty annoying.
    Anyone that looks at the results can easily tell you were only the fastest because kyle wasn't there. Your 1/2 speed wasn't even close.

    REGARDLESS....


    This thread is about a guy being fed false hope that he's going to make a true 500whp on pump 93. And somehow people have convinced him that he just needs enough pressure? It's absurd.
    There's a hundred different calculators online that convert mass fuel flow into approximate HP. Witchhunter is a good start. However, flowing 500hp worth of fuel does not mean you're going to make 500hp; those calculators are assuming you're NOT knock limited. It's disturbing that people would sit here leading him on, as if buying the right fuel system parts is somehow going to get around that.

  • Fuel Pressure

    Quote from Dave@DDMWorks

    From tuning experience at ZZP then, the fuel atomization on a boosted 2.4L engine running an EFR 7163 at 25psi of boost pressure using #80 fuel injectors with a 33# pressure delta is considered acceptable? You consider 33# of fuel pressure a usable pressure differential at the fuel injector?

    did you even read what I said? If it’s enough to get the required mass flow, then it’s enough.
    kyle is the fastest in the world with a ~33psi differential.
    Real world trumps keyboard thumping.

  • Fuel Pressure

    also, this talk of atomization at high boost is kind of silly when you're spraying on the back of a closed valve any time you're past 25%idc. the fuel mostly vaporizes from the heat of the valve and the remaining liquid is atomized as soon as the valve cracks open. Hell OEMs have been spraying on the back of the valve on PURPOSE for decades in a lot of cars.
    Yeah you need a usable pressure differential, but it's simply because you have to be able to hit your mass flow. These cars/bikes need a feed line upgrade long before a referenced regulator IME.

  • Fuel Pressure

    you're forgetting that required drive pressure on the turbine side increases as boost pressure goes up, and it does so at a faster rate than the boost is climbing. Your guesstimations are only accurate if you had a magic turbine that used the same drive pressure at any boost level.
    At 9psi it's likely you're near or even under under a 1:1 backpressure ratio. at 26 on a 7163 you're going to be well beyond 1:1, likely seeing backpressure in the mid 30's at high rpm.


    To make 500 wheel on a 7163 with pump 93, you're going to have to push to the ragged edge and STILL hunt for the happiest dyno you can find. I know that's not what you want to hear, but that's the reality.

  • The Truth About Natural Power - A Look At What Makes Power and How Much

    Quote from TravAZ

    Maybe clarifying the below two questions/points will help a lot of people out in this thread. It would be a bummer to see so much wasted effort on education if these certain details aren't addressed...


    Why should you dyno a vehicle in the 1-1 gear, and what happens to dyno power readings when you vary from this?


    What is the difference between Open Loop and Closed Loop tuning and how does the vehicles O2 sensor work to build fuel tables, timing, etc., etc.?

    The 1:1 gear idea comes from minimizing power loss through the transmission, that is all. This theoretically would give you the highest numbers, although there are other factors involved. In the cobalt world, I do not see much difference between 3rd and 4th gear pulls, aside from the intake temps climbing a little more in 4th (more time in boost, more heat in the intercooler). Sometimes you simply CAN'T use the 1:1 gear, due to traction or top end MPH. All dynos have a speed limit somewhere.

    Almost all stock style automotive ECUs only use closed loop for low load driving, when the ECU is commanding stoich (14.7afr on gas, 1.0 lambda). The common narrowband O2 sensor can only tell if you're above or below stoich, but not the actual lambda reading. This is where fuel trims come in. Basically the ECU says "hey we're over stoich, better add a few % fuel. Ok now we're under stoich, better pull a few %" and the cycle continues.


    WOT fueling is almost ALWAYS open loop, aside from a select few oem PCMs and most aftermarket standalone stuff. It's all pre-programmed numbers determining how much fuel is injected and when. This just means that you don't have any live feedack from the ECU, so you have to monitor the exhaust with a wideband O2 sensor and then make adjustments to the pre-programmed numbers after the pull is done.
    You CAN force the ECU to run open loop all of the time while tuning, and use your wideband feedback for adjusting the idle/cruise fueling, and this is a pretty common thing. However, for me personally, it is a lot more efficient to leave closed loop active when tuning. Once you learn an ECU/software combo, it's pretty easy to blend your open and closed loop adjustments together.

  • The Truth About Natural Power - A Look At What Makes Power and How Much

    Quote from Neosolidus

    kev This was said by Al earlier, which to me seems like he is advising people who run 91oct gas to skip his tune.


    I am just asking for clarification on this, I am not bad-mouthing ZZP,being ungrateful for their hard work or in any way trying to pick a fight for no reason but asking for one of them to explain that statement.


    I am thankful for them proving us with all the data but that statement from Al puts a lot of doubt on the tune until him or Kyle D clears what could be a simple misunderstanding.

    Sorry for the delayed response. What I meant was that the OEM calibration appears to be more than safe for running 91 fuel, and the limited power gains available from tuning make it not a very cost-effective power adder. But, the option is still there for someone who decides it's worth the cost to them.
    We're not here to suck up every penny we can from every customer, we're here to actually help you guys and provide solid advice. I would feel like a crook if I sat here and tried to talk you into buying a tune for 91.

    Quote from edwardaneal

    the fact he followed it with the wink face implies that he was joking with me


    At least thats how I took it

    No jokes, I just love boost!

  • The Truth About Natural Power - A Look At What Makes Power and How Much

    Quote from edwardaneal

    Hey Kyle D Thanks for all the work. Having real honest numbers is awesome. I do have a question if you don't mind. how strict are the fuel requirements with this tune. Is this something that requires 93 octane? I ask because here in California the best I could reliably get is 91. Also if it is safe with 91 could I expect the power gains to be the same or would they be lower?


    Thanks


    Ed

    This was done on 93. To answer your question definitively, it would really need to be done on a dyno. In reality, this was still at a fairly conservative level and i would not be surprised if it also ran well on 91. We were not at the knock limit of 93 with the final tune, and additional timing was not making significant changes signifying it was at/near MBT. That leads me to the conclusion that similar gains are probable on 91. It's still way better than 87. But, like I said, this would need to be verified on a dyno.
    In reality, I would advise you to stay on the stock tune with 91 and put the money towards boost ;)

  • Hello everybody!

    Hey there friends, just wanted to take a moment to introduce myself. My name is Al, and I'm the guy behind the computer here at ZZP for the slingshot PCM tuning. I have a 10 year background in ecotec tuning, specializing in the LSJ but tons of time spent on the 2.2/2.4 cars as well. I know these engines inside and out! My personal play car is a 2006 Saturn Ion Redline that makes somewhere around 700whp. Near useless power, but it sounds cool :D Throughout its life, it's been supercharged, NA, NA w/ nitrous, turbo, turbo w/ nitrous, and at one point had a sequential compound turbo setup.

    I'm also involved directly with R&D work here, so I love seeing feedback on parts and hearing what kinds of things the market needs. If you have any questions, feel free to tag me in a thread or shoot me a PM.

    I won't be able to be quite as active as Kyle D but I'll do my best!