350ci 470HP Peak at 6000RPM

[Stan Weiss]

If I take fuel and divide by bsfc I get Uncorrected HP. ► 280.8 / .426 = 659.1549 If I take corrected HP and divide uncorrected HP I get correction factor which doesn't match what Super Flow says. ► 712.9 / 659.7 = 1.0806

Stan

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[Bigchief632]

If I take fuel and divide by bsfc I get Uncorrected HP. ► 280.8 / .426 = 659.1549 If I take corrected HP and divide uncorrected HP I get correction factor which doesn't match what Super Flow says. ► 712.9 / 659.7 = 1.0806

Stan

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Not sure. The dyno isn't calibrated correctly, playing games, weather data is off, many possibilities. Different software? I am referring to a 901, not a 902. The numbers jive on the dyno's around here. Maybe we are all doing it wrong. Either way, it shows less power then how we do it. Maybe that's why we've run 148.8 at 3000 lbs to the 1/8 with only 1380hp at 1500 corrected da. How much power is that? over 1500 according to the calculators.

[Bigchief632]

DYNOSHEET.jpgDYNOSHEET.jpgNot on my dyno you can't. Theres a formula that applies friction HP. Example: I used this formula, 500 HP X .30 = 150, 500 - 150 = 350 observed HP, so the correction would be 30 % and although the dyno would show that on a engine that produced HP at a certain RPM, I thought as you do. I would show this formula to Harold Bettes from SF and he would lose his mind "THATS NOT HOW IT WORKS" he would say. Lets look at another example from my dyno with track data:

SF 901 STP Corrected HP 820 @ 6700 RPM
SF 901 Measured HP @ 6400 feel elevation 570 HP @ 6500 RPM

You will notice on Wyndyn software the corrected HP will always have a higher RPM peak than the observed HP RPM peak, this is because friction HP is applied. Keep in mind I didn't design this I just know how it works.

820 X .28 = 229.6, 820 - 229.6 = 590.4 as you see the number don't line up, thats because as RPM rises friction HP changes.
Now to put this into performance, as you know STP correction is 29.92 60 degrees dry air, we would agree this is O DA conditions?
The above 820 HP engine, 570 observed @ 6400 feet ran 146.24 MPH @ 3440 in 615 feet positive air in ONE night of testing with limited runs. Now how much HP is that showing going down a 615 DA track?
https://youtu.be/E1Wz5qZDPAk

I am not questioning your abilities, or the quality of your engines. I respect them, and believe you do really good work for the record. But still, look at Stan's reply above, that engine showed about about 13hp more than what I would calculate using the numbers how I describe. On a 700hp engine, that's about 1.8%. So, at least me and Harrold are on the same page, what does he know. On the dyno I use, the numbers jive how I describe, not sure, maybe there's a setting, or the software is different, not sure. But the cars run the number and match the power.

Yeah, that car is showing the power. How much power is 148.8 at 3000 to the 1/8? And not in mind shaft air, like 1500 feet. Engine made 1380 on 2 different local dynos. According to the calculators, it takes over 1500 to run that mph at that weight, same calculator I used that shows your example makes 820.

[Stan Weiss]

1500 HP seen high for 3000# and 148.8 in the 1/8 mile.

I have had some of these simple calculators on my web site. But the faster one goes the more they are off. I always see what the calculator will do for a very well tuned engine car combination like Pro Stock. 2350# we know they make around 1500 HP and run around 6.55 @ 212.

What does your calculator show for this combination?

Stan

[vortecpro]

DYNOSHEET.jpgDYNOSHEET.jpgNot on my dyno you can't. Theres a formula that applies friction HP. Example: I used this formula, 500 HP X .30 = 150, 500 - 150 = 350 observed HP, so the correction would be 30 % and although the dyno would show that on a engine that produced HP at a certain RPM, I thought as you do. I would show this formula to Harold Bettes from SF and he would lose his mind "THATS NOT HOW IT WORKS" he would say. Lets look at another example from my dyno with track data:

SF 901 STP Corrected HP 820 @ 6700 RPM
SF 901 Measured HP @ 6400 feel elevation 570 HP @ 6500 RPM

You will notice on Wyndyn software the corrected HP will always have a higher RPM peak than the observed HP RPM peak, this is because friction HP is applied. Keep in mind I didn't design this I just know how it works.

820 X .28 = 229.6, 820 - 229.6 = 590.4 as you see the number don't line up, thats because as RPM rises friction HP changes.
Now to put this into performance, as you know STP correction is 29.92 60 degrees dry air, we would agree this is O DA conditions?
The above 820 HP engine, 570 observed @ 6400 feet ran 146.24 MPH @ 3440 in 615 feet positive air in ONE night of testing with limited runs. Now how much HP is that showing going down a 615 DA track?
https://youtu.be/E1Wz5qZDPAk

I am not questioning your abilities, or the quality of your engines. I respect them, and believe you do really good work for the record. But still, look at Stan's reply above, that engine showed about about 13hp more than what I would calculate using the numbers how I describe. On a 700hp engine, that's about 1.8%. So, at least me and Harrold are on the same page, what does he know. On the dyno I use, the numbers jive how I describe, not sure, maybe there's a setting, or the software is different, not sure. But the cars run the number and match the power.

Yeah, that car is showing the power. How much power is 148.8 at 3000 to the 1/8? And not in mind shaft air, like 1500 feet. Engine made 1380 on 2 different local dynos. According to the calculators, it takes over 1500 to run that mph at that weight, same calculator I used that shows your example makes 820.

All I can tell you is my dyno was always meticulously calibrated and checked often, when you drag race you would have be a jerk off to lie to yourself about dyno numbers. I don't use a 1/8 mile calculator, I use the Moroso, real data. Thanks for the nice comments!

[Stan Weiss]

DYNOSHEET.jpgDYNOSHEET.jpgNot on my dyno you can't. Theres a formula that applies friction HP. Example: I used this formula, 500 HP X .30 = 150, 500 - 150 = 350 observed HP, so the correction would be 30 % and although the dyno would show that on a engine that produced HP at a certain RPM, I thought as you do. I would show this formula to Harold Bettes from SF and he would lose his mind "THATS NOT HOW IT WORKS" he would say. Lets look at another example from my dyno with track data:

SF 901 STP Corrected HP 820 @ 6700 RPM
SF 901 Measured HP @ 6400 feel elevation 570 HP @ 6500 RPM

You will notice on Wyndyn software the corrected HP will always have a higher RPM peak than the observed HP RPM peak, this is because friction HP is applied. Keep in mind I didn't design this I just know how it works.

820 X .28 = 229.6, 820 - 229.6 = 590.4 as you see the number don't line up, thats because as RPM rises friction HP changes.
Now to put this into performance, as you know STP correction is 29.92 60 degrees dry air, we would agree this is O DA conditions?
The above 820 HP engine, 570 observed @ 6400 feet ran 146.24 MPH @ 3440 in 615 feet positive air in ONE night of testing with limited runs. Now how much HP is that showing going down a 615 DA track?
https://youtu.be/E1Wz5qZDPAk

I am not questioning your abilities, or the quality of your engines. I respect them, and believe you do really good work for the record. But still, look at Stan's reply above, that engine showed about about 13hp more than what I would calculate using the numbers how I describe. On a 700hp engine, that's about 1.8%. So, at least me and Harrold are on the same page, what does he know. On the dyno I use, the numbers jive how I describe, not sure, maybe there's a setting, or the software is different, not sure. But the cars run the number and match the power.

Yeah, that car is showing the power. How much power is 148.8 at 3000 to the 1/8? And not in mind shaft air, like 1500 feet. Engine made 1380 on 2 different local dynos. According to the calculators, it takes over 1500 to run that mph at that weight, same calculator I used that shows your example makes 820.

I just check a few more dyno files from some different dynos and they all show the same thing. The calculated correction factor does not agree with what Super Flow shows. Maybe next time you dyno an engine you have them show you what Super Flow says the correction factor is verses what you calculate.

Stan

[Bigchief632]

DYNOSHEET.jpgDYNOSHEET.jpgNot on my dyno you can't. Theres a formula that applies friction HP. Example: I used this formula, 500 HP X .30 = 150, 500 - 150 = 350 observed HP, so the correction would be 30 % and although the dyno would show that on a engine that produced HP at a certain RPM, I thought as you do. I would show this formula to Harold Bettes from SF and he would lose his mind "THATS NOT HOW IT WORKS" he would say. Lets look at another example from my dyno with track data:

SF 901 STP Corrected HP 820 @ 6700 RPM
SF 901 Measured HP @ 6400 feel elevation 570 HP @ 6500 RPM

You will notice on Wyndyn software the corrected HP will always have a higher RPM peak than the observed HP RPM peak, this is because friction HP is applied. Keep in mind I didn't design this I just know how it works.

820 X .28 = 229.6, 820 - 229.6 = 590.4 as you see the number don't line up, thats because as RPM rises friction HP changes.
Now to put this into performance, as you know STP correction is 29.92 60 degrees dry air, we would agree this is O DA conditions?
The above 820 HP engine, 570 observed @ 6400 feet ran 146.24 MPH @ 3440 in 615 feet positive air in ONE night of testing with limited runs. Now how much HP is that showing going down a 615 DA track?
https://youtu.be/E1Wz5qZDPAk

I am not questioning your abilities, or the quality of your engines. I respect them, and believe you do really good work for the record. But still, look at Stan's reply above, that engine showed about about 13hp more than what I would calculate using the numbers how I describe. On a 700hp engine, that's about 1.8%. So, at least me and Harrold are on the same page, what does he know. On the dyno I use, the numbers jive how I describe, not sure, maybe there's a setting, or the software is different, not sure. But the cars run the number and match the power.

Yeah, that car is showing the power. How much power is 148.8 at 3000 to the 1/8? And not in mind shaft air, like 1500 feet. Engine made 1380 on 2 different local dynos. According to the calculators, it takes over 1500 to run that mph at that weight, same calculator I used that shows your example makes 820.

I just check a few more dyno files from some different dynos and they all show the same thing. The calculated correction factor does not agree with what Super Flow shows. Maybe next time you dyno an engine you have them show you what Super Flow says the correction factor is verses what you calculate.

Stan

I definitely will. Might be there Friday. But, I've done it more times than I can count, calculated observed power from the fuel flow and bsfc's, then had Gary switch to the screen that shows the uncorrected data, it matches, then divide corrected by observed, get the correction factor, then switch to the screen that shows that data, and it's the same. Don't know what to tell you. I called him yesterday and asked him if I was losing it, he said no, that's how mine works, maybe there's a setting, or something different on those. I don't know.

[Stan Weiss]

You are missing the point. When you divide corrected HP by uncorrected HP you get a correction factor. If you look at the 3 pages I posted from the Super Flow software you see one of them shows what Super Flow says the correction Factor is. This will not be the same as what you got in your calculation. If you take the weather data and calculate the SAE J607 correction factor it will be the same as what Super Flow shows. At small correction factors this is very small but when you are in lets say Denver it be comes a much larger difference.

Stan

[Bigchief632]

You are missing the point. When you divide corrected HP by uncorrected HP you get a correction factor. If you look at the 3 pages I posted from the Super Flow software you see one of them shows what Super Flow says the correction Factor is. This will not be the same as what you got in your calculation. If you take the weather data and calculate the SAE J607 correction factor it will be the same as what Super Flow shows. At small correction factors this is very small but when you are in lets say Denver it be comes a much larger difference.

Stan

I get it Stan, I follow what you're saying, I did the math on your examples. . I'm telling you, the dyno I use, doesn't do that, the numbers work out. And it is a Superflow. I guess I have seen a very small difference, like it should be 1.061, but it's 1.062, or vice versa or something similar but that's a 1/2 a hp difference on 500 observed hp. But at that point, does it really matter? For us, no, if it's a bigger difference for Mark when he was at 6400 feet, then ok, I've never dynoed at 6400 feet to know. But then what was Harold talking about? He seems to agree with me, or, I should say, that's what he told Mark it should be? I don't know. If I'm wrong, I'm wrong. But what I've seen, there's a very tiny difference if there is. I've put the same engine back on 4-5 years later after a freshen up, and the numbers repeat like you made a photo copy of the original sheet.

[F-BIRD'88]

Does a 350 sbc have the same mechanical friction when dyno tested @ 6400' elevation as if tested @ sea level?

[F-BIRD'88]

Hard to run these 12:1 CR examples on pump gas.

"peaked around 6000"
Means it peaked at a higher rpm.

I built a very similar 12.5:1 cr 350 with ported 305 heads sane valve size. similar flow.. It really liked to rev up.
Its the nature of built 350's.
The whole o point is if you limit rpm to 6200 you leave much of the power to accelerate the #3600 car unused.
You need to gear these 350 engines up to make use of the engine power available. Otherwise the #3600 car is not going to be very fast in ¼ mi.

Dude.. what are you trying to prove? So what if it peaked at 6300.. of it made the power at 6000rpm.. it made it at 6000 rpm.

I've built engines for guys that peaked 800rpm higher than they shift at.. does that mean the engine didn't make the power that it did 800rpm sooner? Just STFU

No, it does mean the expected performance based on peak hp from your dyno, will not be fully realized.
Selling engines based on dyno corrected peak HP always provides you a convenient out when the car does not quite perform.

[1980RS]

Un. , it ran well into the 11's... Whats your point?

My point was that you were saying it needs to be geared right. My point was that small of a gear change makes no difference.

I bet the cam duration is short... Valvetrain becoming unstable. Try again with a longer duration on the higher reving geared version.

.600 lift 250duration@ .050 on a 108 LCA. Pulls to 7K effortlessly. Only time is studders on the big end is when I set my rev limiter to 7K and I can hear that at about 1200ft. Set it to 7200 and it's gone.

[vortecpro]

Does a 350 sbc have the same mechanical friction when dyno tested @ 6400' elevation as if tested @ sea level?

My understanding is: Stroke and bore and RPM affect friction HP.

[F-BIRD'88]

That would be logical but is there any more to the story?
EG: if the engine is loaded more by pumping more air mass at a lower denser altitude thus making more power output is the mechanical friction component the same or different?

[Tom68]

That would be logical but is there any more to the story?
EG: if the engine is loaded more by pumping more air mass at a lower denser altitude thus making more power output is the mechanical friction component the same or different?

More cylinder fill is more ring load on compression stroke, that's more drag, the other friction effects one would imagine would be miniscule.