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Would running larger cams with more boost bleed also help put less pressure on the blower?

As mention with the bigger headers. Boost is a restriction. Less restriction = more efficient use of boost = less straight on blower???
 

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Yep conditions there were poor without meth or nos. It 80+ and da +2000. Was a great time enjoyed talking with everyone. I drove my car there ran and drove home. Car has 76,000 miles and runs great. Iat2 did get up to 145 or so.
 

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Would running larger cams with more boost bleed also help put less pressure on the blower?

As mention with the bigger headers. Boost is a restriction. Less restriction = more efficient use of boost = less straight on blower???
Larger cam, more overlap, less boost, less heat, all can't hurt.

BUT, what are the stresses that spinning the mass (rotors) have on the bearings, and the bores that the bearings reside in? What about the heat?

I wonder (I don't know) if this is more of the issue than the actual boost that the blower is seeing.
 

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At the risk of injecting some simple math into this discussion, stock blower speed (8.0/[email protected]) is 16,800 rpm, so even at 'only' double that, it would be spinning 33,600 rpm...so with a 2.5" upper you'd need about a 13.5" lower to attain that speed!!!

So getting back to real numbers, even with a 9.5/2.5 and 6800 rpm you're 'only' doing 25,800 rpm or roughly 54% faster than stock, not "double or triple". I'm NOT saying maintenance of the blower is unnecessary, just saying some perspective on the real numbers might be a reasonable thing to consider.

Cheers, Paul.
"Fuzzy math"

For CNC ported blowers and more, visit:
Dynamicflowconcepts.net
My guess would be that Jokerz was speaking in rough terms simply to make a point. The actuality is most likely that the relationship between blower RPM and the life of it's internal components is not a linear one. For example, increasing the blower RPM by only 15% may reduce the total life of the assembly/internals by 30% or more. Without some data collection nobody, could really say with any accuracy what that RPM vs. Life Expectancy curve would look like. It'd certainly be an interesting thing to see though!
This. Theres no way its linear.
I thought I'd throw a bit more fuel on the fire. Well, actually - I want to provide a little physics context to the discussion.

Here's a simple example to get the ball rolling. The kinetic energy of an object moving in a straight line changes with the square of the change in velocity. In mathematical terms, Ek = 1/2mV^2. Or .5 times the mass times the velocity squared.

Ok, ok - some academic stuff. But what does that mean? It means a car going 60mph has FOUR TIMES the energy of a car going 30. And a car going 120mph has SIXTEEN times the energy of our 30mph car. So the 3rd car is going 4 times faster, but has 16 times as much kinetic energy.

In our blower scenario, even though it is rotating and not going in a straight line, the same force relationships are at play. A blower spinning twice as fast endures forces four times greater in certain places within the blower. If the blower were - hypothetically - slightly imbalanced, the lateral forces on bearings and other components will increase with the square of the change in blower speed. All across the mechanical parts, forces related to the speed of moving parts follow these basic laws of physics. The same thing happens with piston speeds - as the piston goes up and down, it has to change direction at each end. The forces on a piston in an engine spinning at 6000 rpm are MUCH higher than one spinning 3000 rpm. And not twice as much - often times four times as much due to the physics involved.

For those that are more engineering inclined, I have used the term velocity as opposed to speed because it's a vector, and not scalar quantity. That is - both direction and magnitude matter. As such, spinning components are constantly changing direction, and hence are subject to similar issues.

So to kinda back up some of the assertions on here about how fast components wear, and to perhaps validate that all parties have valid observations...I'll claim that spinning the blower faster could easily double the forces involved - and due to the physics involved it's not hard to imagine a scenario where the blower and it's respective parts wear MUCH faster even though the blower speed hasn't dramatically increased.

I'm not gonna take the time to examine all the parts and do the math here, Duck style. But it's worth noting that the issue you guys are debating IS governed by some basic laws of motion that we can use to draw some conclusions and make some basic speculations.

I think even if you COULD get the parts to wear and hold up, the heat monster will quickly become the overwhelming concern.

As many have noted, the generally accepted peak blower speed is about a 3.6 to 3.7 ratio. Much faster and the efficiency drops rapidly. Further, the heat generated goes beyond what the currently available intercoolers can deal with. I suppose if you had a radically re-designed intercooler and could chill the compressed charge down in a way that substantially outperformed the stock or ZL1 lids, I bet you could get away with higher ratios.

That's Tri's $0.03 - I hope you find this info useful and gives you additional perspective on things.
 

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Yep conditions there were poor without meth or nos. It 80+ and da +2000. Was a great time enjoyed talking with everyone. I drove my car there ran and drove home. Car has 76,000 miles and runs great. Iat2 did get up to 145 or so.
Thats not bad at all for iats there. Im just suprised your boost isnt through the roof.

Maybe your bypass valve is leaking slightly? Lol

If it works, it works I guess.

Will atleast get some 10.30s in better air i
 

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Thanks. I think 30's are there I have had some trans issues. I have had a few 1.46&7 60' just haven't gotten everything to work in combination. Looking forward to spring.
 

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Tri,

Don't harmonics play into this as well? Even 2nd, 3rd, 4th, etc?



For CNC ported blowers and more, visit:
Dynamicflowconcepts.net
 

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Do you guys in the states have interchillers? There is a mob in aust that makes them and they are seeing IAT's of 0-5degres Celcius.
 

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I thought I'd throw a bit more fuel on the fire. Well, actually - I want to provide a little physics context to the discussion.

Here's a simple example to get the ball rolling. The kinetic energy of an object moving in a straight line changes with the square of the change in velocity. In mathematical terms, Ek = 1/2mV^2. Or .5 times the mass times the velocity squared.

Ok, ok - some academic stuff. But what does that mean? It means a car going 60mph has FOUR TIMES the energy of a car going 30. And a car going 120mph has SIXTEEN times the energy of our 30mph car. So the 3rd car is going 4 times faster, but has 16 times as much kinetic energy.

In our blower scenario, even though it is rotating and not going in a straight line, the same force relationships are at play. A blower spinning twice as fast endures forces four times greater in certain places within the blower. If the blower were - hypothetically - slightly imbalanced, the lateral forces on bearings and other components will increase with the square of the change in blower speed. All across the mechanical parts, forces related to the speed of moving parts follow these basic laws of physics. The same thing happens with piston speeds - as the piston goes up and down, it has to change direction at each end. The forces on a piston in an engine spinning at 6000 rpm are MUCH higher than one spinning 3000 rpm. And not twice as much - often times four times as much due to the physics involved.

For those that are more engineering inclined, I have used the term velocity as opposed to speed because it's a vector, and not scalar quantity. That is - both direction and magnitude matter. As such, spinning components are constantly changing direction, and hence are subject to similar issues.

So to kinda back up some of the assertions on here about how fast components wear, and to perhaps validate that all parties have valid observations...I'll claim that spinning the blower faster could easily double the forces involved - and due to the physics involved it's not hard to imagine a scenario where the blower and it's respective parts wear MUCH faster even though the blower speed hasn't dramatically increased.

I'm not gonna take the time to examine all the parts and do the math here, Duck style. But it's worth noting that the issue you guys are debating IS governed by some basic laws of motion that we can use to draw some conclusions and make some basic speculations.

I think even if you COULD get the parts to wear and hold up, the heat monster will quickly become the overwhelming concern.

As many have noted, the generally accepted peak blower speed is about a 3.6 to 3.7 ratio. Much faster and the efficiency drops rapidly. Further, the heat generated goes beyond what the currently available intercoolers can deal with. I suppose if you had a radically re-designed intercooler and could chill the compressed charge down in a way that substantially outperformed the stock or ZL1 lids, I bet you could get away with higher ratios.

That's Tri's $0.03 - I hope you find this info useful and gives you additional perspective on things.
Similar analogy..

When Tri types twice as many words, people's heads hurt 4 times as much after trying to understand them..
 

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This is not actually a bearing chart, but it's very similar to how a bearing behaves. Increase the load, shorten the life. Increase the speed, shorten the life. Our application is unfortunate in that the only way to increase the speed is to increase the load, so the two compound each other.
 

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Tri,

Don't harmonics play into this as well? Even 2nd, 3rd, 4th, etc?



For CNC ported blowers and more, visit:
Dynamicflowconcepts.net
Yes. Some parts way more than others. I think with the SC the belt harmonics are huge. The lobes I bet not so much. Honestly the fact that the SC input shaft sees such huge forces during shifts and changes in RPM is a big factor. That's a big reason the Hellcat has a clutch at the input. At least "braking" forces in the shaft are reduced that way. And boost isn't lost as much during a shift.
Do you guys in the states have interchillers? There is a mob in aust that makes them and they are seeing IAT's of 0-5degres Celcius.
Yes, much discussed option. Great for cooling down a large volume of fluid for a 1/4 mile run, but will actually add heat over the long run so NOT a good choice for a track car or anything that sees ongoing demand from the engine. It's basically a substitute for dumping ice into a big trunk tank...
 

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Yes. Some parts way more than others. I think with the SC the belt harmonics are huge. The lobes I bet not so much. Honestly the fact that the SC input shaft sees such huge forces during shifts and changes in RPM is a big factor. That's a big reason the Hellcat has a clutch at the input. At least "braking" forces in the shaft are reduced that way. And boost isn't lost as much during a shift.

Yes, much discussed option. Great for cooling down a large volume of fluid for a 1/4 mile run, but will actually add heat over the long run so NOT a good choice for a track car or anything that sees ongoing demand from the engine. It's basically a substitute for dumping ice into a big trunk tank...

All good posts Eric..;)

The formula that you gave gives the Kinetic Energy.

Actually, that same formula is used by some
to generate the 'Flow Energy' in Inertia Tuned
Intake Systems.

That is matched with the IVC or the Intake Valve Closing event.

-note-
I know you are interested in that so I decided to throw it in 'Just For You'..:p

------------------------------------------

Karch / Steve's question surrounds Harmonics.

As an example;
In music the Fundamental note, also called the 'Tonic'
is F1. That is what many also call the 'Pitch'.

F1 then is the 'First Harmonic'!

-------------------------------------------


All Harmonics are Linear Integer Values of F1.

So if the Tonic / F1 is 100 Hz., then F2 would be 200 Hz.
and F3 would be 300 Hz, etc.

It takes three (3) Harmonics to generate a recognizable
tone in music.

No, I am not talking about a three note 'Triad / Chord' here--<Big Wink>

-------------------------------------------

However,
Everything has what is called a 'Natural Frequency'.

So if a 'Blower' is spun 'To' it's Natural Frequency
it would 'Oscillate' and that Oscillation would tend
to cause the blower to 'Shake' at that frequency.

If that goes on long enough, then depending on the 'Q'
or the 'Freedom of Movement' of the Oscillation,
the blower could conceivably self destruct.

FFT's or Fast Fourier Transforms (Test & Measurement Equipment) are
used to capture such oscillations.

Finally,
As we move up from F1, to F2 and maybe to F5 we must
also understand that at each harmonic the 'Magnitude'
of the Harmonic is reduced significantly.

In what is called 'High End' Sound Reproduction, we measure
beyond the three (3) Harmonic Tone and measure out
to the 7th Harmonic.

Both the rise times and decay times, as well as the
magnitudes of the seven harmonics are quantified.

Cheers,
The Duck
 
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All good posts Eric..;)

The formula that you gave gives the Kinetic Energy.

Actually, that same formula is used by some
to generate the 'Flow Energy' in Inertia Tuned
Intake Systems.

That is matched with the IVC or the Intake Valve Closing event.

-note-
I know you are interested in that so I decided to throw it in 'Just For You'..:p

------------------------------------------

Karch / Steve's question surrounds Harmonics.

As an example;
In music the Fundamental note, also called the 'Tonic'
is F1. That is what many also call the 'Pitch'.

F1 then is the 'First Harmonic'!

-------------------------------------------


All Harmonics are Linear Integer Values of F1.

So if the Tonic / F1 is 100 Hz., then F2 would be 200 Hz.
and F3 would be 300 Hz, etc.

It takes three (3) Harmonics to generate a recognizable
tone in music.

No, I am not talking about a three note 'Triad / Chord' here--<Big Wink>

-------------------------------------------

However,
Everything has what is called a 'Natural Frequency'.

So if a 'Blower' is spun 'To' it's Natural Frequency
it would 'Oscillate' and that Oscillation would tend
to cause the blower to 'Shake' at that frequency.

If that goes on long enough, then depending on the 'Q'
or the Freedom of Movement of the Oscillation,
the blower could conceivably self destruct.

FFT's or Fast Fourier Transforms (Test & Measurement Equipment) are
used to capture such oscillations.

Finally,
As we move up from F1, to F2 and maybe to F5 we must
also understand that at each harmonic the 'Magnitude'
of the Harmonic is reduced significantly.

In what is called 'High End' Sound Reproduction, we measure
beyond the 3-note tone and measure out to the 7th Harmonic.

Both the rise times and decay, as well as the magnitudes
of the seven harmonics are quantified.

Cheers,
The Duck
Is this engineering class or a message board. Stop making me and 99.9% of the people on this board feel like the slow kids in the back of the class. Tell me how to make my car go faster and do it in English, please!!!!! [Joke]
 

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Is this engineering class or a message board. Stop making me and 99.9% of the people on this board feel like the slow kids in the back of the class. Tell me how to make my car go faster and do it in English, please!!!!! [Joke]
Actually you are going to have to 'Damn' Tri / Eric for this,
as well as Karch / Steve, as they started it all..:p

Cheers,
Bruce
 

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We did...and sorry for that. But we want your car to go faster reliably!
 

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Yes, much discussed option. Great for cooling down a large volume of fluid for a 1/4 mile run, but will actually add heat over the long run so NOT a good choice for a track car or anything that sees ongoing demand from the engine. It's basically a substitute for dumping ice into a big trunk tank...
interesting. I spoke at length with the manufacturer and he said there is no issues to run it all day every day. Hmm
 

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We did...and sorry for that. But we want your car to go faster reliably!

Some don't desire to deal with the engineering / physics side and some do Eric.

I felt that your post dealing with the formula for Kinetic Energy was a
very well written post filled with valuable information (JMHO)!

Karch / Steve brought up Harmonics which I also
felt was informative, but Steve posed the Harmonic
issue as a question to which I responded to.

-------------------------------------------

The issue of 'Flow Energy' which is quantifiable via the Kinetic Energy
equation you posted is something that many should consider when
using considering a Camshaft for a SC or Inertia Tuned Induction
System.

Harmonics / Helmholtz Equations are also used to 'Tune' Induction Systems,
so even though I used 'Music' to illustrate from (as everyone has a basic
understanding of music) the Physics surrounding Kinetic Energy and Harmonics
are valuable 'Tuning Tools' regarding High Performance IC-Engines.

Besides that Earl H. stated that his post was a Joke / Humor anyway.

Keep on Posting Eric..:cool:

Cheers,
Bruce
 
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I actually don't know much about harmonics, except for that they exist, and that if not considered, disastrous results can occur:

Tacoma Narrows Bridge Disaster

Excellent example Steve..:eek:

However, some have stated that the collapse of the bridge was due to
'Harmonics' while others consider it to be due to 'Resonance'.

Link==>> https://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)

I always thought that the 'Primary' cause was related to a 'Resonance'
coupled with a High 'Q', or a 'High Freedom Of Movement'.

Take care Steve..:p

Bruce
 
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