Applying the DV 128 formula on a Supercharged engine

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SchmidtMotorWorks
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Re: Applying the DV 128 formula on a Supercharged engine

Post by SchmidtMotorWorks »

RevTheory wrote: Mon Jun 15, 2020 12:36 pm
SchmidtMotorWorks wrote: Mon Jun 15, 2020 11:37 am If you narrow down the range of engines that 128 is supposed to be applicable to.
What is the highest and lowest value that it returns?

Is it right for all exhaust systems?
Is it right for both automatic and manual?
Is it right for all driving environments?
Is it right for all driving abilities?

Of course not, because those parameters are not inputs to the formula.

Even when customers can see the measured dyno charts of engines, they never choose the one they like best when double-blind test-driving them.

Yeah, that makes complete sense because those are the exact parameters that were laid out in the initial post.

Nope: see the OP below.


The point is, that the 128 formula is incapable of considering those parameters.
How would you adjust -modify the LSA of the 128 formula when applying to a supercharged engine.
Eg: Roots supercharged (non intercooled)
Lowered compression for pump gas operation.

X? amount of added LSA per lb of boost?
Y? amount of subtracted LSA per full 1 compression ratio reduction?
Or???

Example engine: Typical 350 cid Sbc 23 deg head
2.02" intake valve.. 7.5:1 cr
5 psi boost....... 10 psi boost 15 psi boost.

What would the 128 formula LSA recommendation be for these boosted example engines be?
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Re: Applying the DV 128 formula on a Supercharged engine

Post by SchmidtMotorWorks »

F-BIRD'88 wrote: Mon Jun 15, 2020 12:41 pm This is why SMW is simply the wrong guy for the job.
He wants to turn a $300 problem on a $1200 engine
in A $3000-$4000 car into a $45 million project requiring NASA type analysis.
False ^^^^^

If you don't know what to do, call someone like Jones that does it for a living.

Jones will use a physics based software to determine the right cam for you.
And throw in a few decades experience in rationalizing your inputs.

Where you guys get off track is with the false belief that a simple formula can replace the tools and experience a professional has.
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Re: Applying the DV 128 formula on a Supercharged engine

Post by Warp Speed »

Everyone says they are here to learn, but that is pure BS!
Same reason I no longer post here, too much energy waisted, arguing truth to idiots that refuse to learn........
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Re: Applying the DV 128 formula on a Supercharged engine

Post by mt-engines »

SchmidtMotorWorks wrote: Mon Jun 15, 2020 12:50 pm
F-BIRD'88 wrote: Mon Jun 15, 2020 12:41 pm This is why SMW is simply the wrong guy for the job.
He wants to turn a $300 problem on a $1200 engine
in A $3000-$4000 car into a $45 million project requiring NASA type analysis.
False ^^^^^

If you don't know what to do, call someone like Jones that does it for a living.

Jones will use a physics based software to determine the right cam for you.
And throw in a few decades experience in rationalizing your inputs.

Where you guys get off track is with the false belief that a simple formula can replace the tools and experience a professional has.
128 is not a formula. nor is it fact or a rule. by definition it can not be a formula.
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Re: Applying the DV 128 formula on a Supercharged engine

Post by F-BIRD'88 »

SMW do you have an ounce of proof to support your claim

MT Engines same question?
Last edited by F-BIRD'88 on Mon Jun 15, 2020 1:07 pm, edited 1 time in total.
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Re: Applying the DV 128 formula on a Supercharged engine

Post by gmrocket »

F-BIRD'88 wrote: Mon Jun 15, 2020 12:41 pm This is why SMW is simply the wrong guy for the job.
He wants to turn a $300 problem on a $1200 engine
in A $3000-$4000 car into a $45 million project requiring NASA type analysis.
I don’t think he’s applied for the job....his advice has been free.

Have you purchased DV’s program ? If so, maybe you could input the compression ratio that a blower would produce into the program...see what happens. It does have comp ratio inputs

It might blow up right on the screen in front of your eyes
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Re: Applying the DV 128 formula on a Supercharged engine

Post by RevTheory »

SchmidtMotorWorks wrote: Mon Jun 15, 2020 12:50 pm
F-BIRD'88 wrote: Mon Jun 15, 2020 12:41 pm This is why SMW is simply the wrong guy for the job.
He wants to turn a $300 problem on a $1200 engine
in A $3000-$4000 car into a $45 million project requiring NASA type analysis.
False ^^^^^

If you don't know what to do, call someone like Jones that does it for a living.

Jones will use a physics based software to determine the right cam for you.
And throw in a few decades experience in rationalizing your inputs.

Where you guys get off track is with the false belief that a simple formula can replace the tools and experience a professional has.
I've been following Jones and Vizards 128 for years now and you'd be amazed at how often a simple one-liner ends up being in the same place. That's probably what bugs you the most. White coats can't stand it when someone with more actual experience than you can simulate narrows something down. I bet you can't sleep.

I can tell because, like I said, you'll disappear until someone mentions Vizard and then we're right back to green-flag racin' on the internet.
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Re: Applying the DV 128 formula on a Supercharged engine

Post by F-BIRD'88 »

GM Rocket I am not convinced that modeling a higher compression ratio will model a increase in Induction system applied absolute pressure.. (bolt a blower on it)
Yes cylinder pressure will be higher but mass air fliw in will be much higher.. (More stuff getting forced in VS just more squeeze on the stuff.)
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Re: Applying the DV 128 formula on a Supercharged engine

Post by mt-engines »

Warp Speed wrote: Mon Jun 15, 2020 12:59 pm Everyone says they are here to learn, but that is pure BS!
Same reason I no longer post here, too much energy waisted, arguing truth to idiots that refuse to learn........
its a shame that the same 15 people that will most likely not build anything in their lifetime, have so much negativity towards people that clock in for work to do this, come home and do this, and on weekends as their hobby or profession.

I have learned from people on here. but probably not in the last 8 years. because the quality of the posts are no longer there. I still talk a few times a week in the morning amongst a group of top level builders and machinists. And many of them miss how this site used to be. they refuse to post here for many reasons. and mostly because someone asks a question but only wants to hear their answer.
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Re: Applying the DV 128 formula on a Supercharged engine

Post by F-BIRD'88 »

In my case my engines all have low compression ratios.
One is going to be 7.25:1 cr.
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Re: Applying the DV 128 formula on a Supercharged engine

Post by mt-engines »

F-BIRD'88 wrote: Mon Jun 15, 2020 1:06 pm SMW do you have an ounce of proof to support your claim

MT Engines same question?
which claim? that the Theory is not a formula?

The FORMULA is a FACT or a RULE written with mathematical symbols. It usually connects two or more quantities with an equal to sign. When you know the value of one quantity, you can find the value of the other using the formula.

This therotical formula does not use enough inputs for it to be complete. Why must you try so hard to not understand.

How about this, open up a catalog and buy the cheapest blower cam that will get you in the rpm range you want. Now run it. I bet it will work as well as any other cam you decided not to use. Therefore it seemingly ran well. Would you know if you were 100hp off of a different cam? No! of course you wouldnt because you only tried one cam.

Now if you talked to someone who say has sold 100 different camshafts for the exact same build. do you think they would have no idea what they are doing because they didnt drink the Koolaid and jump on DVs D?

A camshaft is way more complex than just the LSA.

Asymmetrical lobes prove that LSA is JUST A NUMBER
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Re: Applying the DV 128 formula on a Supercharged engine

Post by mt-engines »

F-BIRD'88 wrote: Mon Jun 15, 2020 1:21 pm In my case my engines all have low compression ratios.
One is going to be 7.25:1 cr.
Why? so at 10lbs of boost it makes as much power as it would have with 11:1 NA

Its funny to see crap like this. But sad when i am the guy that has to explain to the customer why their engine was such a pooch and overheats.
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Re: Applying the DV 128 formula on a Supercharged engine

Post by F-BIRD'88 »

mt-engines wrote: Mon Jun 15, 2020 1:31 pm
F-BIRD'88 wrote: Mon Jun 15, 2020 1:06 pm SMW do you have an ounce of proof to support your claim

MT Engines same question?
which claim? that the Theory is not a formula?

The FORMULA is a FACT or a RULE written with mathematical symbols. It usually connects two or more quantities with an equal to sign. When you know the value of one quantity, you can find the value of the other using the formula.

This therotical formula does not use enough inputs for it to be complete. Why must you try so hard to not understand.

How about this, open up a catalog and buy the cheapest blower cam that will get you in the rpm range you want. Now run it. I bet it will work as well as any other cam you decided not to use. Therefore it seemingly ran well. Would you know if you were 100hp off of a different cam? No! of course you wouldnt because you only tried one cam.

Now if you talked to someone who say has sold 100 different camshafts for the exact same build. do you think they would have no idea what they are doing because they didnt drink the Koolaid and jump on DVs D?

A camshaft is way more complex than just the LSA.

Asymmetrical lobes prove that LSA is JUST A NUMBER
If I wanted a cam select opinion from a true expert on roots supercharged engines Believe me , I know who to ask for that.
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Re: Applying the DV 128 formula on a Supercharged engine

Post by mt-engines »

F-BIRD'88 wrote: Mon Jun 15, 2020 2:17 pm
mt-engines wrote: Mon Jun 15, 2020 1:31 pm
F-BIRD'88 wrote: Mon Jun 15, 2020 1:06 pm SMW do you have an ounce of proof to support your claim

MT Engines same question?
which claim? that the Theory is not a formula?

The FORMULA is a FACT or a RULE written with mathematical symbols. It usually connects two or more quantities with an equal to sign. When you know the value of one quantity, you can find the value of the other using the formula.

This therotical formula does not use enough inputs for it to be complete. Why must you try so hard to not understand.

How about this, open up a catalog and buy the cheapest blower cam that will get you in the rpm range you want. Now run it. I bet it will work as well as any other cam you decided not to use. Therefore it seemingly ran well. Would you know if you were 100hp off of a different cam? No! of course you wouldnt because you only tried one cam.

Now if you talked to someone who say has sold 100 different camshafts for the exact same build. do you think they would have no idea what they are doing because they didnt drink the Koolaid and jump on DVs D?

A camshaft is way more complex than just the LSA.

Asymmetrical lobes prove that LSA is JUST A NUMBER
If I wanted a cam select opinion from a true expert on roots supercharged engines Believe me , I know who to ask for that.
Then how about you do that. Ask him if he uses Dv128 and how he manipulated the formula to get to his LSA.

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Re: Applying the DV 128 formula on a Supercharged engine

Post by SchmidtMotorWorks »

RevTheory wrote: Mon Jun 15, 2020 1:06 pm
SchmidtMotorWorks wrote: Mon Jun 15, 2020 12:50 pm
F-BIRD'88 wrote: Mon Jun 15, 2020 12:41 pm This is why SMW is simply the wrong guy for the job.
He wants to turn a $300 problem on a $1200 engine
in A $3000-$4000 car into a $45 million project requiring NASA type analysis.
False ^^^^^

If you don't know what to do, call someone like Jones that does it for a living.

Jones will use a physics based software to determine the right cam for you.
And throw in a few decades experience in rationalizing your inputs.

Where you guys get off track is with the false belief that a simple formula can replace the tools and experience a professional has.
I've been following Jones and Vizards 128 for years now and you'd be amazed at how often a simple one-liner ends up being in the same place. That's probably what bugs you the most. White coats can't stand it when someone with more actual experience than you can simulate narrows something down. I bet you can't sleep.

I can tell because, like I said, you'll disappear until someone mentions Vizard and then we're right back to green-flag racin' on the internet.
I post in 128 threads because it is amusing to see people believe things that are false.
It is also amusing to test and see if there is any reason that will convince them that their belief is mistaken.
Kind of like flat earthers, or 911 conspiracy theorists, it's fun to poke them once in a while but not something to do every day.
It gets depressing to know that there are people that are so hopelessly lost.
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