I'll also mention that having a sub-11 second car at the Friday night drags is semi pointless. If you are running slicks, the street tires mess up the starting line and the prep is not going to give you much info for 60 foot times and how the car reacts. It should be useful for down track spark and fuel curves, though. If one or more cars let go down track, it can be dangerous with a powerband that cranks up, too. I'd imagine you are well aware of these limitations. Be safe, Jim. We need you and your crazy fun builds around.
I need to sell the hood, so folks won't keep talking about it Also shipping and tax are not treated consistently. Mostly I left it out, except for stuff from ebay, where it's included in the amount I paid and is easier to deal with that way. No coolant in the engine, it's summer, and drag strips don't like it. Oh..I'm pretty careful on the strip, and around town, I don't like it getting very far out of shape before I let up.
I have always told people that its the little things that add up fast. That last couple of weeks push to get it running kills most budgets. I'm pretty surprised (and impressed) you got it on the road for that money. A couple years ago, 9G probably would have been an easier target. We will be waiting to see how close to the 9s your $11,476 got you.
thanks! I'm learning about computers now, it's fun. And I'm the computer guru among all my non-EFI friends oh...I had the date wrong on the race in Tucson, it's the following weekend, not this weekend. I'll probably plan to go to Phoenix friday night next week, and then see what happens (if the car is still in one piece, etc) This is the VE table after a bit of learning was transferred to it. I still don't understand a lot of this...but I'm starting to get a little bit... I wonder if my badass cam is why it's so red on the left side? and now I need to figure out how to make the table extend past where it learned, by extrapolating?
Its a colorful picture.... But its speaking a different language to me. I assume the area in red is not good. How do you tell its the left side that is in the red? Is the left side the farthest from the turbo? A bit of turbo lag? Most turbo issues from back in my day were until the turbo gets wound up. Its starting just off idle and getting better by 1600 rpm (at least that's what I see). My turbo knowledge is 25 years old, back then we didn't have pretty graphs to look at...
@gene-koning and others, this is a basic outline of what you are looking at. I am not an EFI tuner, but have looked at a few of these. Across the bottom is engine RPM. Simple, idle (500) to the left, up to 7000 RPM on the right. The left side is Manifold Absolute Pressure in kilopascals. What most old school recognize as vacuum in In.hg. It's actually low pressure, not vacuum. To convert kilopascals to inches of mercury (inHg) 1 kilopascal (kPa) = 0.29529983071445 inches of mercury (inHg). That's going to mess with your head, but that's the numbers. Here's a pic worth a thousand words. Zero is atmospheric pressure. -29.5 inHg. or -100 kPa is total vacuum or no pressure. So typical near stock engines develop around 18 inHg. at idle, no load. That's around -60 kPa. Look at the chart Jim posted. 500 and 600 RPM haven't changed. This probably means it's not idling that low. But look at 700. the red cells are all way under 50% VE from -42 to -70. Think about an engine idling at 700 RPM with a light load or big cam developing 13 inHG. to snapping the throttle closed (high vacuum) up to a bit over 20 inHg. That engine is CHOKED OFF, not efficiently pumping the air. So Volumetric Efficiency (VE) is low. The computer can do a basic calculation of 5.7L engine turning 700 RPM = this much air, but it needs to know how much the exact engine, the throttle and exhaust all affect this calculation. So it knows it's not 100% efficient, but needs a percentage for each amount of RPM and use the MAP sensor to judge load. That will allow it to calculate the actual amount of air entering, and using that Air volume to calculate the Fuel needed for proper Air/Fuel Ratio.
I can also display the pressure (vertical axis) as PSIG, so you'll recognize it. another way to look at the pressure is that 1 Bar is one atmosphere. And it's also 100 kPa. So the bottom row of the chart is full vacuum (zero absolute pressure), the middle row is 1 bar (atmospheric pressure), and the top is 2 bar (atmosphere plus one more of boost, or 14.7 psi boost). I'm getting the hang of that part. The base tune I'm using is one that comes with the software, it's for a mild cam turbo LS engine. It's way off from what my engine is, at low rpm, as my cam has a lot more overlap. This will all take a while to figure out. I'll get there, eventually.
I did a quick search and found this. Seems to have a good grasp but again, I'm NOT a tuner. I'd imagine there are hundreds of videos like this. www.youtube.com/watch?v=XiFnfpHdUeU
I usually can get one up running & driving , The VE tunning My self has me No ideal what key to push . I know in theory what the engine Needs or I want. Most knowledgeable / decent tuners are months out or have a select few they will tune for. Naturally aspirated No power adder is So much more Forgiving then Power Adder's , My self I am nervous in witch VE to change dealing with pistons around 150 a hole , Here is a Basic list , Of descriptions and Meaning EFI AE In Carburetion Terms: "AE vs TPS Rate of Change" = carburetor accelerator pump "AE Correction vs TPS" = carburetor accelerator pump cam (shape) "AE vs MAP Rate of Change" = carburetor power valve function "MAP AE Time vs Coolant" (Decay) = carburetor shooter size "AE TPS vs Coolant Temp" = carburetor choke effect (in terms of AE) "MAP AE vs Coolant Temp" = carburetor choke effect (in terms of AE) "AE vs TPS RoC Blanking" = carburetor accelerator pump lever adjustment (feeler gauge) "AE vs MAP RoC Blanking" = carburetor idle transfer slot/circuit exposure (idle & off idle) "Coolant Temperature Enrichment %" & "A/F Ratio Offset" = primary carburetor choke functions "Target Idle Speed" & "IAC Parked Position" = carburetor choke fast idle cam & idle kickdown functions
And most of those functions aren't very important for keeping the pistons intact, that's all in the base fuel VE table (which can be sort of self adjusting using Target A/F Ratio table) and the spark table. They say you learn best by doing, so I'm diving in and doing. I have a better understanding now of what's going on, after watching a few more videos, and trying some things. I learned that the base calibration included with the software is pretty far off from what I really want, and I found a few files on the internets that are closer to what I'm running. Using them, and some of the basics learned from some videos, I ended up making new tables for VE, target A/F ratio, and spark advance. I loaded it in and went for a drive. First thing I noticed is that it's idling better, since I added more advance and fuel at low rpm. And the learn table ended up making relatively small changes. Previously it was going -30 in some places. So I guess it's getting closer now. Time for more driving, and see what it does. I also swapped to a colder thermostat. It was running 200 degrees +/-3 all the time, so it should be a bit cooler now. Weather has been warm here, in the 90s.
This is another of those things that IF I wanted to dig into, I could probably understand this much better. Thanks guys, you have brought up my old mind to current standards. I don't full understand, nor would I know how to move forward with the current info, but at least now I can grasp what I'm looking at. You have reminded me of the old vacuum/pressure gauge we had in the Chrysler Dealership back in the mid 80s. We watched the needle on the gauge and compare it to the tachometer reading, looking for a problem. Now you get a color screen with the graphics, that you can print out and can pinpoint the problem area. Pretty cool! My reality is that at this point in my life, a full understanding of this would probably end up being more knowledge stuffed into my brain, that I will probably never use. Just more stuff to 1/2 remember, (or to 1/2 forget, depending on how you look at it). I've traveled through this life with probably only a dozen trips down the 1/4 mile drag strip, and that was nearly 20 years ago. My dirt track racing ended nearly 30 years ago. Now, I'm just an old man that likes to drive his modernized old car or old truck @ 65 mph down the highway, and enjoy a laid back life. Life is good, but I don't envision another build in my future, upkeep on what I already have will be fine with (and for) me. You guys keep after it, I'm living through you. If i was still in my 50s, I would have been right there in the trenches with you.
If u want to do a lot of reading on EFI - there is an online network of people using a DIY system Mega Squirt. Search it out, read the “educational” section. Can also find users & learn from them. Met a Holly rep selling there system, mentioned MS & he said “good system”. Give it a look
I'm with you, @gene-koning . I won't have a laptop stuck between me and the steering wheel, but admire the guys that do. Although I wonder why nobody hasn't designed a good holder, so they aren't always balanced precariously. It allows a great deal more fine tuning, but also requires a depth of knowledge to be able to look at transient stuff and 'know' what it is telling you and what to change to improve or avoid disaster. All of it is out there, you just have to want or need to educate yourself.
I built a MS unit about 25 years ago, then later installed it on my 55 temporarily to log data with the carbs. Interesting stuff. I still have it.
Ok, I was away for 3 weeks so I just had to read about 10 pages to catch up. Can someone explain the theory of TTY bolts. My only experience with them was on a VW diesel. A friend has a shop and they didn't know about TTY bolts when they had the engine out, reused the old bolts and a few thousand miles later the engine literally fell out. All the bolts fell off first and the last one broke a mounting ear off the head. I made a welded bracket to use other bolt holes to hold the engine in for him. I'm too old fashioned to understand. To me a bolt should be torqued to a specific specification. Not torqued then plus 1/4 turn. WHY?
Pretty amazing build so far! "CHEEP" is going to turn a lot of heads when it gets all of its little elements figured out! " C = Cheap " " H = High-Tech " " E = Excellent " " E = Engineering " " P = Perfected "
thanks! You know how steel work hardens, it gets stronger after it's bent? Well...engineers figured out how to use cheaper, softer, smaller bolts by having them work harden as you tighten them. But it only works once! then they get weaker. Also there are a lot of reusable bolts in modern cars that have a torque and angle spec, instead of just torque. The idea is that you can eliminate the variables of friction when tightening bolts, by telling you how many degrees to turn them, to get the bolt to stretch far enough to provide the necessary clamping load. Since the threads are at a specific angle, if you turn the bolt another 90 degrees, you'll get a certain number of thousandths of an inch of stretch, and since Young's Modulus tells us how much force it takes to stretch that amount of steel that far, you can control the clamping force precisely. Compared to the normal torquing method. TTY bolts generally are tightened to a small torque level (about 15 ft lbs), then tightened in stages about another half turn. Non-TTY bolts that are tightened by an angle usually only get about a quarter turn after the initial low torque. At least that's how it appears to ME, after assembling my first modern engine, according to the shop manual.
TTY bolts provide a very uniform clamping pressure. I was skeptical at first but have had good luck with TTY bolts. Dan
I've been exploring a few more things about the Holley system. I want to have the original idiot lights working, because it's much easier for me to notice a big red light, than a gauge. The battery light does work already, because I connected the alternator to it. But the oil and coolant lights were not connected to anything. It looks like I can use one of the electric fan controls to run the coolant light, by just connecting it's ground output and configuring it to turn on at a reasonable temperature, such as 220 or so. I can also test it by setting it to turn on at a lower temperature. I wired it in, but didn't test it yet. The light does come on briefly when the computer boots up after turning on the key. The oil pressure is a little more complicated, but there's a way to configure outputs to trigger based on one or several variables. I'm trying to get the oil light to turn on if the pressure drops below 20 psi. I connected it and tried it with the engine off, but did not work. I'll play with the configuration, and see if I can make it work. I expect it's something simple that I don't yet understand. I also mounted and connected the hoses to the EVAP can. This gives the gas tank vent a place to go. I did some research on how the Jeep system works, and that led me to take apart the vacuum valve on the top of the can, and remove the spring, and flip over the diaphragm. This will let the purge fitting stay open all the time, so I can connect it to the Chevy purge solenoid, and control it with the computer. It looks like I can use the TCC torque converter clutch output to run it, and set it to engage above a certain RPM, coolant temp, and manifold pressure, then turn it off when the manifold pressure gets too high (under boost). This will let it purge the gas vapors under normal cruising conditions, but not when it's not appropriate to be doing so. I expect to get a few funny looks when guys see the charcoal can connected...it's so out of place! but it's not there because I want to reduce HC emissions, it's there to keep my garage from getting stinky, and also to have a safe vent for the gas tank. I'm also working on the speedometer. After my exhaustive research, I discovered that the cruise control speed sensor that I want to use puts out the wrong type of signal for the digital speedo to understand. So I ordered an adapter box that turns a +/- 4 VAC sine wave into a 5 or 10 VDC square wave. Hopefully it will work. It looks like the number of pulses is right, at 8000 per mile. I and adjust the gearing to make it read properly, I think. One more thing I need to work on is the crankcase vent. Right now there's a 3/8 hose sticking out of the valve cover fitting, not connected to anything. This needs to go to a breather cap or catch can, or something. I expect it will be producing a bit more vapor under boost. It's pretty common to add larger holes to the valve covers and connect to a vapor separator/breather, there are some commercially available. It could also tie into the exhaust, using a check valve, like a header evac system. This might work OK since I do have a functioning tailpipe.
The Jalopy Journal
