460 BBC Dyno Test

[Stan Weiss]

2 and half years ago I generated this HP / Torque curve and ran a simulation on a 3575 lb vehicle with a CD of 0.42 and a frontal area of 25.52 sq ft with no hood scoop. Local correction factor 1.015. This is what it produces.

60 Foot ET = 1.2705
330 Foot ET = 3.7348
1/8 Mile ET = 5.8680
1/8 Mile MPH = 114.1761
1000 Foot ET = 7.7363
1/4 Mile ET = 9.3230
1/4 Mile MPH = 142.3908

Stan

With or without traction control ?
What Launch RPM?
How much torque?
What gearing?
What tires width? Slicks ?

You can not calculate HP from just those inputs.
A 460ci engine that makes 700hp@6,000rpm will not have the same MPH in the 1/4, as a 460ci engine that makes 700hp at 7,000rpm, let alone all the other variables.

Mike,
I posted the full HP / Torque curve.

Here is some other information about what I used.
28" diameter tire
4.1:1 rear gear
T350 Auto trans 2.52:1, 1.52:1, 1.0:1
Launch 5000
Converter stall 5500
3.25% converter slip
shifted at 7900 rpm
track air density used for aero drag 29.92

Stan

[vortecpro]

I disagree.

Of course you do, but that doesn't change the facts. Since none of these cars are reaching terminal velocity in 1/4 mile, acceleration rate plays a huge part in the MPH they're running at the end of the 1/4 mile. HP and weight are just part of the equation, and they won't tell you how much power the engine is making.

Mike I understand your very frustrated but the facts are you didn't consider the "ME" in your math, that is fact. At this point you should just say you don't accept Super Flow data as your buddy did on the last page, just say it, your going to feel better

My next example:

[vortecpro]

2 and half years ago I generated this HP / Torque curve and ran a simulation on a 3575 lb vehicle with a CD of 0.42 and a frontal area of 25.52 sq ft with no hood scoop. Local correction factor 1.015. This is what it produces.

60 Foot ET = 1.2705
330 Foot ET = 3.7348
1/8 Mile ET = 5.8680
1/8 Mile MPH = 114.1761
1000 Foot ET = 7.7363
1/4 Mile ET = 9.3230
1/4 Mile MPH = 142.3908

Stan

With or without traction control ?
What Launch RPM?
How much torque?
What gearing?
What tires width? Slicks ?

You can not calculate HP from just those inputs.
A 460ci engine that makes 700hp@6,000rpm will not have the same MPH in the 1/4, as a 460ci engine that makes 700hp at 7,000rpm, let alone all the other variables.

Mike,
I posted the full HP / Torque curve.

Here is some other information about what I used.
28" diameter tire
4.1:1 rear gear
T350 Auto trans 2.52:1, 1.52:1, 1.0:1
Launch 5000
Converter stall 5500
3.25% converter slip
shifted at 7900 rpm
track air density used for aero drag 29.92

Stan

Stan, Larry Meaux also simulated the same pass (9.29 @ 142.29 @ 3580) and came up with 782 HP, and also had a comment to make about my dyno data, I might post them up as this progresses.

[CamKing]

Not frustrated at all. I know how to correct to an SAE standard. I just feel bad for those people out there, that don't. Your numbers do not reflect a true SAE correction factor. That's all that matters. When you give someone a corrected HP number, they assume it's an SAE corrected number. Your numbers are not. Does that mean, your engines aren't any good? No. Does it mean you don't do good work? No.
It just means the correction factor your using is off, and it's way off.

You seem to want to make this about you, and it's not. Study the math used for any SAE correction factor, and you will get an understanding of why your numbers are so high. It'll take some work, but in the end, you will have a much better understanding of what you're looking at.

I'm done.

[Stan Weiss]

Not frustrated at all. I know how to correct to an SAE standard. I just feel bad for those people out there, that don't. Your numbers do not reflect a true SAE correction factor. That's all that matters. When you give someone a corrected HP number, they assume it's an SAE corrected number. Your numbers are not. Does that mean, your engines aren't any good? No. Does it mean you don't do good work? No.
It just means the correction factor your using is off, and it's way off.

You seem to want to make this about you, and it's not. Study the math used for any SAE correction factor, and you will get an understanding of why your numbers are so high. It'll take some work, but in the end, you will have a much better understanding of what you're looking at.

I'm done.

Check out this thread where it is talked about the difference between the standard correction and the Super Flow correction which also includes ME%.

http://www.yellowbullet.com/forum/showt ... 70&page=29

Stan

Based on the way I believe it works. Let say we have a 1000 BHP

Just using the CF

1000 * 1.010 = 1010

1000 * 1.110 = 1110

1000 * 1.210 = 1210

===========

At 85% ME (1000 / .85) - 1000 = 176.47 FHP

((1000 + 176.47) * 1.010) - 176.47 = 1011.7647 diff 1.7647 HP

((1000 + 176.47) * 1.110) - 176.47 = 1129.4117 diff 19.4117 HP

((1000 + 176.47) * 1.210) - 176.47 = 1247.0587 diff 37.0587 HP

Stan

Mike,
A couple of pages ago I posted a link which showed this. Which is quote above.

Stan

[vortecpro]

Not frustrated at all. I know how to correct to an SAE standard. I just feel bad for those people out there, that don't. Your numbers do not reflect a true SAE correction factor. That's all that matters. When you give someone a corrected HP number, they assume it's an SAE corrected number. Your numbers are not. Does that mean, your engines aren't any good? No. Does it mean you don't do good work? No.
It just means the correction factor your using is off, and it's way off.

You seem to want to make this about you, and it's not. Study the math used for any SAE correction factor, and you will get an understanding of why your numbers are so high. It'll take some work, but in the end, you will have a much better understanding of what you're looking at.

I'm done.

The correction I use is exactly how SF designed it, you do not accept friction HP, I didn't design the software I just use it like every body else that has a SF dyno, the study is how MPH over 1320 feet translates into HP, that HP just happens to match my dyno testing. These calculations you use DO NOT INCLUDE "ME" you don't accept SF data, just say it, I've seen you go after other peoples SF data the same way, my only question right now is' did you run the hand crank, or did you read the meter and write the data down? LOL

[mohrperformance]

The simple fact is you cannot use any correction factor to adjust from your conditions at high altitude to sea level conditions, that is not what the correction factors are designed to do. There is a limit to any of the correction factors and you are way outside their limits. It would be better to standardize to your altitude and adjust for variations in your baro air temp and humidity.That way you would see what changes at your location due to your weather. In order to tune an engine for sea level you need to test at sea level. Just because SF does it does not make it correct, in fact just because the SAE does it also does not make it correct. The best results are obtained by controlling the atmospheric conditions in the test cell to what the operating conditions the engine will see. Way outside my budget but not for some. Forget trying to equate HP to speed or ET way too many variables. Take at look at Depac Daves site, look at how just incorrectly compensating for inertia skews the numbers.

[vortecpro]

The simple fact is you cannot use any correction factor to adjust from your conditions at high altitude to sea level conditions, that is not what the correction factors are designed to do. There is a limit to any of the correction factors and you are way outside their limits. It would be better to standardize to your altitude and adjust for variations in your baro air temp and humidity.That way you would see what changes at your location due to your weather. In order to tune an engine for sea level you need to test at sea level. Just because SF does it does not make it correct, in fact just because the SAE does it also does not make it correct. The best results are obtained by controlling the atmospheric conditions in the test cell to what the operating conditions the engine will see. Way outside my budget but not for some. Forget trying to equate HP to speed or ET way too many variables. Take at look at Depac Daves site, look at how just incorrectly compensating for inertia skews the numbers.

How do you explain this:

1. Westec my dyno 699 HP Westec 700 HP both dynos prepped by SF before the test.
2. Owens 902 Houston Tx my dyno 661 HP 33 degrees Owens 657 HP 31 degrees
3. Reher Morrison my dyno 699 HP Reher Morrison 717 HP


"Forget trying to equate HP to speed or ET way too many variables. "

Thats a ridiculous statement.

[vortecpro]

Postby MaxRaceSoftware » Sun Jan 11, 2009 6:46 pm

Additional Info on my SF-901 Dyno Calibration

December 19th, 2008
was Calibrated to 1/10ths of 1 Lbs Torque
by using a series a small Lead-weights in
better than 1/10th of 1 Gram accuracy.

the Strain Gauge's "Linearity" was verified
by Shreve Automotive and Dave "DEPAC" Manzolini
on Dec 19, 2008
The accuracy of the total weight hung on the calibration bar
was exactly what was computed from totaling all the
individual weights. Accuracy = dead-on, no error

Computed Weight(s) = 610.5 Lbs
SF-901 Dyno Digital readout = 610.5 Lbs Torque
as verified by DEPAC and Shreve on Dec 19, 2008

i will hang more Weight as necessary for Calibration
of higher TQ output Engines like near 1000 + TQ

that Day,
we ran a 498cid BBC Engine
with both DEPAC and SuperFlow WinDyn instrumentation
side-by-side at the same time,
with dual Monitors and separate Computers/Softwares

Pics->

Image

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Image
MaxRace Software
Meaux Racing Heads
http://www.maxracesoftware.com/
MaxRaceSoftware

Posts: 127
Joined: Sat Jan 05, 2008 12:15 pm
Location: Abbeville , Louisiana

[Keith Morganstein]

I have no idea what this thread is really about, but I have conducted thousands of engine and chassis dyno tests using several manufactures of dyno equipment. Now most of this has been to OEM specifications. I have worked with superflow equipment, but OEM's do not use their software/correctional factors, just the data. The idea of of internal friction losses doesn't come into consideration. It's all about the fuel used for the power made.( when looking at power/BSFC) SAE correction factors are used, but this is so that data can be compared in different test conditions. The math is not difficult...

[Strange Magic]

What this thread is about, is that you will be guaranteed to have someone shoot your hp findings down, so if you want to play with figures on the internet, start low, let all, or whomever wants to shoot it down do so, and then post up the weight and et thereafter and not before.

The race track is the tool for really getting an understanding of how well you did. I've been dynoing for over 25 years, and the average in relation to the peak, over the rpm curve that it runs in down the race track, is what interests me. If you can keep your average over a nice curve, lets say 1400 rpms worth, to be within 18,20 or 22 from the peak, than you will have one bad azz player down the race track. You can give up average for a higher number if you operate in less of a curve.

[thedynoguy]

note to self, while dynoing 180-210 engines a year for the past 26 years on my SF dyno, don't ever post a sheet on this forum...

[77cruiser]

Glad mine was done on a DTS.

[MadBill]

.... The idea of of internal friction losses doesn't come into consideration....

The negative friction power is required to calculate a correction factor because it essentially doesn't vary with pressure/temperature/humidity and thus has to be subtracted from the observed power, then added back in after the correction is applied. With relatively small C.F.s it makes little difference but as they rise towards 10% or more, it becomes significant if the friction values used are incorrect for the specific engine.

In the early nineties I was involved in engine development with GM and I can report that the Superflow table values for the then-current LT1 350 Chev were out by as much as 20 HP from the meticulously derived factory data. I haven't checked lately, but my guess is that SF is still using the same friction formula, despite the move by O.E.M.s and the aftermarket to low friction coatings and ring packages. Improved bottom end oil control and crankcase vacuum systems would be in the same category. (In another thread, Big Joe reports up to a 50 HP gain with an optimum ring set up..)

[vortecpro]

.... The idea of of internal friction losses doesn't come into consideration....

The negative friction power is required to calculate a correction factor because it essentially doesn't vary with pressure/temperature/humidity and thus has to be subtracted from the observed power, then added back in after the correction is applied. With relatively small C.F.s it makes little difference but as they rise towards 10% or more, it becomes significant if the friction values used are incorrect for the specific engine.

In the early nineties I was involved in engine development with GM and I can report that the Superflow table values for the then-current LT1 350 Chev were out by as much as 20 HP from the meticulously derived factory data. I haven't checked lately, but my guess is that SF is still using the same friction formula, despite the move by O.E.M.s and the aftermarket to low friction coatings and ring packages. Improved bottom end oil control and crankcase vacuum systems would be in the same category. (In another thread, Big Joe reports up to a 50 HP gain with an optimum ring set up..)

Bill, how did I get these results 3 times back to back, the highest correction was 1.08 on the other peoples dyno? Not to mention my on track performance.



Westec......700 HP...........My dyno 699
Owens.......657...............My dyno 661..........SF 902........Owens 31 degrees........My dyno 33 degrees
Reher Morrison......717...........My dyno 699