Applying the DV 128 formula on a Supercharged engine

[CamKing]

IMO, Any accurate formula should work for NA, Supercharged, or restricted inlet.
The engine only knows the pressure of the air, not what's causing the pressure.
If the formula is accurate, it should be able to calculate for an NA engine, with 29.92" of pressure, or a supercharged engine with 110" of pressure, or a restricted inlet engine with 23" of pressure.
That's how my formula works, and that's what I use to design all my cams.
Although my formula isn't for sale, I'm presently working with one of the top engineers in the industry, to make it possible for customers to buy profiles designed specifically for their application, then send them to any cam company with a CNC grinder, to have produced. For those companies that don't have a small wheel grinder, we can adjust the shape for any grinding wheel radius. Hopefully, we will have it done, before the PRI show.

Does your formula use empirical data ?

No.
We now have decades of empirical data to back up it's validity, but it's a formula based on the mathematical relationships of an engine's parameters, effective atmosphere, and operating range. It's accurate for a 1cid engine, or a 1,000cid engine. It's accurate for a 1,000rpm engine, or 20,000rpm engine. Normally Aspirated, Supercharged, or Restricted Inlet, it's the same formula.

[BobbyB]

IMO, Any accurate formula should work for NA, Supercharged, or restricted inlet.
The engine only knows the pressure of the air, not what's causing the pressure.
If the formula is accurate, it should be able to calculate for an NA engine, with 29.92" of pressure, or a supercharged engine with 110" of pressure, or a restricted inlet engine with 23" of pressure.
That's how my formula works, and that's what I use to design all my cams.
Although my formula isn't for sale, I'm presently working with one of the top engineers in the industry, to make it possible for customers to buy profiles designed specifically for their application, then send them to any cam company with a CNC grinder, to have produced. For those companies that don't have a small wheel grinder, we can adjust the shape for any grinding wheel radius. Hopefully, we will have it done, before the PRI show.

Does your formula use empirical data ?

No.
We now have decades of empirical data to back up it's validity, but it's a formula based on the mathematical relationships of an engine's parameters, effective atmosphere, and operating range. It's accurate for a 1cid engine, or a 1,000cid engine. It's accurate for a 1,000rpm engine, or 20,000rpm engine. Normally Aspirated, Supercharged, or Restricted Inlet, it's the same formula.

Mike, So what cam would you suggest for Fbirds supercharged SBC? What if it was normally aspirated?

[CamKing]

Mike, So what cam would you suggest for Fbirds supercharged SBC? What if it was normally aspirated?

He would need to fill out my cam recommendation form, and submit it.

[bigfoot584]

What about using this formula and back tracking into DV 128 idea then.

http://www.wallaceracing.com/boost-comp ... o-calc.php

5 lbs= 9.9 CR
10lbs=12.4CR
15lbs=15.0CR

I sure SMW won't agree, but then I don't give a _____ what he thinks.

[superpursuit]

What about using this formula and back tracking into DV 128 idea then.

http://www.wallaceracing.com/boost-comp ... o-calc.php

5 lbs= 9.9 CR
10lbs=12.4CR
15lbs=15.0CR

I sure SMW won't agree, but then I don't give a _____ what he thinks.

bigfoot584. That is an interesting idea. What static compression ratio are you starting with for these numbers?

Thanks, Allan.

[F-BIRD'88]

Interesting calculators.

[bigfoot584]

What about using this formula and back tracking into DV 128 idea then.

http://www.wallaceracing.com/boost-comp ... o-calc.php

5 lbs= 9.9 CR
10lbs=12.4CR
15lbs=15.0CR

I sure SMW won't agree, but then I don't give a _____ what he thinks.

bigfoot584. That is an interesting idea. What static compression ratio are you starting with for these numbers?

Thanks, Allan.

7.5 CR it was in the 1 post.

[SchmidtMotorWorks]

What about using this formula and back tracking into DV 128 idea then.

http://www.wallaceracing.com/boost-comp ... o-calc.php

5 lbs= 9.9 CR
10lbs=12.4CR
15lbs=15.0CR

I sure SMW won't agree, but then I don't give a _____ what he thinks.

You have presented a hypotheses, one does not agree or disagree with a hypotheses, the next step is to examine evidence.
You have not presented any data that agrees or disagrees with your hypotheses.

[RevTheory]

I'm pretty sure he just basically said, "hey, what about this?"

[SchmidtMotorWorks]

I'm pretty sure he just basically said, "hey, what about this?"

noun
plural noun: hypotheses
a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.

[GARY C]

What about using this formula and back tracking into DV 128 idea then.

http://www.wallaceracing.com/boost-comp ... o-calc.php

5 lbs= 9.9 CR
10lbs=12.4CR
15lbs=15.0CR

I sure SMW won't agree, but then I don't give a _____ what he thinks.

No doubt the best idea given in context of the thread.

[GARY C]

I'm pretty sure he just basically said, "hey, what about this?"

noun
plural noun: hypotheses
a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.

Kind of like this?
Computer model definition
A computer model is a computer program that "attempts" to simulate a real-life system. In other words, it is a ‘ virtual ’ version of something in the real-world.
https://www.igcseict.info/theory/7_1/model/

[Stan Weiss]

What about using this formula and back tracking into DV 128 idea then.

http://www.wallaceracing.com/boost-comp ... o-calc.php

5 lbs= 9.9 CR
10lbs=12.4CR
15lbs=15.0CR

I sure SMW won't agree, but then I don't give a _____ what he thinks.

No doubt the best idea given in context of the thread.

My post from a thread in the advanced section

David,
Maybe you can help me out here. If I have 10:1 cr with 14.696 psi blower pressure I get 20:1 effective CR.

If I have 10:1 cr and 14.696 * 2. I do not get the same results as 20:1 and 14.696. Is this all just because of the difference in final volume between 10:1 and 20:1?

Stan

From John Wallace's calculator

The first is the standard equation used by many,
The second may be the more reliable one

The Boosted Compression Ratio from your Boost of 14.696 psi is 20.00 : 1
The Effective Boosted Compression Ratio from your Boost of 14.696 psi is 14.14 : 1

Stan

[SchmidtMotorWorks]

I'm pretty sure he just basically said, "hey, what about this?"

noun
plural noun: hypotheses
a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.

Kind of like this?
Computer model definition
A computer model is a computer program that "attempts" to simulate a real-life system. In other words, it is a ‘ virtual ’ version of something in the real-world.
https://www.igcseict.info/theory/7_1/model/

That would depend on the computer model, some are better than others.
If you imagine that computer simulations are all in the same class, you have a major misunderstanding.

To give an example related to engine simulations.

Some engine simulation software is based on the elementary principles of physics and have very rigorous validation of their accuracy. Sophisticated programs are made by building upon those elementary physics to model complex problems.

Other approaches that try to fit measured data from the results of testing a systems are not simulations, they are just approximations.

One big difference is that if you want to know "what if" I change a variable? The physics based simulation is far more likely to return a valuable answer.

It is the physics based simulation that enables the amazing things we do today that were impossible in the past.
Things like Spacex landing rockets are made possible by this way of thinking.

[digger]

All simulations need to be validated in some way to be truly valid it doesn’t matter what the underlying equations are based on.