Sweet, I emailed the Speedware guys and they already fixed their calculator to allow negative advance values! I've asked if they can also report negative overlap, instead of capping at 0.
Using that calculator, they are looking for valve lift. Are our rockers 2:1?
Cam-parked.jpg
Looks like it is 260 INT / 263 EXH, which would give you -0.5* overlap at 0 lift:
Ford Engine Spec.jpg
I've seen Intake advertised as 260 not 263. I don't trust a program that can't do negative values. I did real math and came up with -0.5 overlap @ 0" lift with a 260 Intake and 263 Exhaust Advertised.Originally Posted by CCS86
If we go with 263 / 263 then the overlap is 1 degree @ 0" lift, park.
lol I was writing and you were posting. I posted something before but wanted to revamp it to include 263/263 JUST IN CASE.
Wait we have forged pistons?!!!!?? EDIT: /cry I want forged pistons and rods in my 14 Gt engine :P
Last edited by blackbolt22; 10-31-2018 at 05:50 PM.
I guess it's an Aluminator build sheet, which may have different cams:
https://performanceparts.ford.com/do...6007-A50NA.pdf
That's up to you. Their math appears to be just fine. But they were only reporting positive overlap.
I reached out to them and they fixed that as well. Now it reports negative overlap as well.
I'm gearing up to run the tests I laid out in the OP. I think I can get them done tomorrow.
I've also been in touch with my former Combustion Engine Processes university course. He sent me some updates to his text book that include cam phasing information, and also some SAE papers to check out on the subject of optimizing performance with cam angles.
Mmmmm, data!
I did a series of 3rd gear WOT runs, from stable starting conditions, with different cam angles. I kept the same LSA (one that has 0* overlap @ 0" lift) and advanced/retarded them as a pair. This ensures that no compressed charge is lost to blow through. Each trendline represents a 10* cam phasing increment.
My theory was that minimum MAP (boost) would correlate to best cylinder filling and therefor MAF rate. This was shown to be true. I expected a fair amount of variation, in which cam angles performed best as RPMs changed. This is where I was surprised at the results. It seems that you can get max cylinder filling from 1500-6500 rpm with only a 10* total swing of the cams!
This is only the first part of the test. I will be moving into exhaust cam phasing now to see what the overlap tolerance is and maximize power extraction.
MAP Curves.jpg
that's a big difference. Could you label the lines with your angles/run #? What was your starting point/ending point in cam timing? Your test was keeping the 0 overlap the whole way right?
According to the spreadsheet I made: Bone stock the NA op angles overlap peak is around 3500 and trails the torque curve. I haven't plotted them against each other but I will...
No idea how boosted is but overlap is bad due to blow through, right? Depending on boost type and set up I imagine the tunes could be vastly different to find the optimal overlap settings...
Well, bad news. All that data I collected is garbage. Angles were changing, but not the way I defined them.
Because I don't have the pro interface, the only way I could collect MAP data, was by physically recording video of the mechanical boost gauge, next to my nGauge, and manually recording MAF, MAP, and RPM together. This meant I couldn't log with VCM Scanner at the same time.
Today, I decided to make sure the cams were responding correctly and found that they weren't. It's actually looking like the exhaust cam can only be retarded from parked. This could mean that the intake cam can only be advanced. If that is true, this whole protocol is pretty much inaccessible.
At zero overlap its kind of impossible but with overlap its possible:
Example: 20 overlap test (IVO/EVC): -20/0, -15/5, -10/10, -5/15, 0/20
Example: 50 overlap test (IVO/EVC): -50/0, -45/5, -40/10, -35/15, -30/20, -25/25, -20/30, -15/35, -10/40, -5/45, 0/50
Oh and data may not be garbage. It may be that you were limited however in essence you were actually testing overlap changes.
That is true. I'm planning to test some of those combos. It won't be as comprehensive as I hoped, but should still be worth looking at.
I think what I hit on these last tests was really -50/0, -40/0, -30/0, -20/0, -10/0, 0/0, 0/10, 0/20, 0/30.
I could use a little of that data, but would prefer to re run the tests so atmospheric conditions match.
I have been dynoing a 18 Procharged 5.0 here, finding power in cam angles. We had it pulleyed to around 7PSI, played with cam angles & found power, good bit actually a few weeks ago. Last Saturday, he came back with a smaller pulley, only added around 2PSI. After some tuning, I started playing with intake cam angles, I changed the intake 1? from 3000rpms up, and picked up power all the way. At 7000rpms, it came up 20rwhp. Keep in mind that this is after I had already got the best power at the lower boost. Seems like more boost makes it like different cam timing, at least the intake timing. I quit on Saturday evening, gonna get back on it later on today, still playing with intake timing, after that, I'll mess with exhaust, see what happens.
Anyone found any good gains on 18-19 na with long tubes and a jlt? Wondering a good starting point. It responds great to E85 for sure but I’m still on stock op cam angles.
Putting VCT angles in perspective. The world of TIVCT was and is a game changer for performance and the environment. We can have a custom cams from taps of a key board and control the tail pipe gasses introduced to the OZone. The tuning of angles vs overlap ended the external EGR system we no longer see hanging of the side of the intake all rusty and messing with our custom headers... Over lap is EGR. Scavenging is EGR. The dead fuels, the absence of oxygen, NOX, all the other inert gasses left over from the combustion cycle. DEAD AIR useless for balanced tuned combustion GREAT for the OZone. No one using HPTuner or any other tuner is trying to save gas money or protect the OZONE. We want HORSE POWER. Speaking of stock angles, they are defiantly set by FORD for emissions. Now throwing BOOST to the cylinder, the cycle is not EGR,ing or scavenging its BLOWING THRU, wasting boost or better said controlling boost. We can control separation and even compression in theory.
On a stock engine you may be able to see very small HP gains but mostly you are changing emissions. A stock TB intake... the engine will suck the same amount of are regardless BUT aftermarket intakes... will change the flow of air and has proven to increase HP. VCT tuning on stock is "picking fly shit out of pepper".
Now throwing Boost at it VCT tuning is much more complex not only controlling emissions also controlling Boost, VE, air fuel ratios, ignition timing...
So in theory controlling VCT overlap and opening and closing valve timing is doing a lot. LESS should be more. It all depends on all the other factors of the compression stroke. If we decrease overlap more boost probably need to change the fuel and timing, toque management tables speed density tables... "more like cutting fat off a steak"!
if your like me log data and make small changes and compare the results. "You can feel your car like no one else"
Any updates? Does anyone have CAM information for the 5.2 in the 350?
I've dyno'd cam changes twice now, once as NA and once as turbo at 15psi. When using a chassis dyno the answer is not black and white and you need to compare dyno power to MAF readings and other data to figure out what is working. Having said that my results are as follows: NA motors was, GT350 intake, SW headers. Turbo motor was, 5.2 bottom end stock GT head and cams, same GT350 intake and turbo headers with 6262 turbo's at 15psi:
NA Intake: 3000 to 3500 was -20, 4000 was -10, 5000 to 5500 was 0, 6500 was 5 and 7500 was 10.
Turbo Intake: 3000 to 4000 was -20, 5000 was -10, 5500 was 0, 6500 was 15 and 7500 was 10
So -20 still best setting for low range power, in both cases timing switched over at 5500rpm and then very similar retard above 5500. Turbo motor liking a little more retard at 6500 compared to NA
Exhaust cam changes are harder to evaluate with very little difference from timing changes. Either way this seemed to be best setting for me:
Exhaust NA: 3000 to 5500 was 15, 6500 and above was 20
Turbo Exhaust: 3500 was 15, 4000 to 4500 was 10, 5500 was 5, 6500 was 10 and then 7500 onward was 15
Making 20 or so back to back runs does not create a black and white answer, you need to blend power, MAF, timing, intake temp, etc to create your own fuzzy logic of what makes more power. Also other variables make huge power differences, for example the turbo car lost 18 horsepower with IAT going from 117degF to 126degF, all other variables were identical.
So what's my conclusion: the gen2 coyote intake seems to work best at -20 below 5500, it cross over to retarded timing at 5500, ending with timing 10 to 15 deg retarded. The exhaust cam is less critical, with anything around 10 to 15 working, less retarded at lower rpm and more at higher rpm
Last edited by Plimmer; 12-30-2020 at 03:23 PM.
Plimmer, thanks for the info. What was a typical range of torque and power gained and lost due to intake and exhaust cam timing changes? I’m not asking for your entire data set, it just an idea for how much is on the table when changing each.
I'm surprised you didn't lock timing to remove it from the equation.
Good info. -20 matches what some tuners I know have stated, the ford supercharged calibrations I have seen dont quite retard that much, but they do tend to retard less at higher RPM. I had figured it was also for safety and to lower cylinder pressure and fueling requirements up top. Keep the oem engines going until warranty
I do not have access to a Dyno, but I ultimately started to question this amount of intake retard when I noticed that two things were happening on my car during WOT runs and spirited driving under positive boost:
rolling from mapped points with less retard into more retard (same Ex) decreased the actual airmass per cyl / rpm, and the torque values for that mapped point needed to be lower to keep IPC errors down - eliminated. I could also see that when rolling into WOT at positive boost those torque values also resulted in TB angle reduction before it reached 90* which further supported that the values for that MP for the same rpm and load cell needed to be lower ie it wasn't making the power it thought it was - torque over reported.
I may be missing something and do plan on using ON3's dyno this spring. The highly scientific butt dyno also suggested to me the car felt slower once I went passed -10 or so. I have OEM gt350 cams so -10 for me might be different than -10 for you.
Mine is a Whipple with long tubes and no cats Borla 3inch all the way back to Atak mufflers. The only data point I have really thought to use was Measured (MAF) airflow to the cylinder, and a stand alone MAP sensor in the intake. Then watching how the logs behave moving from MP to MP. I basically created mapped points from others that were known good and then changed the cam values on the new points enabled them and assigned to the test calibrations and tried to interpret the results.
The car also seemed to tolerate more spark in that mapped point, I never went back to add however it registered less KR. MP with -10 would be pretty much zero to .1-.3, MP with -20 never registered any retard at all.
Superman07, I think you are right about the knock. If you look at the Predator borderline and mbt tables, you’ll see that the mbt is the lowest and borderline is the highest in the upper-left-most mapped point. It uses that mapped point in the midrange but then retards intake/advances exhaust up top.
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