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Discussion Starter · #1 ·
I have been reading and performing the calculations as listed in Corky Bell's Maximum Boost.

I thought some of you might enjoy following along with me as I perform the necessary calculations to Borg-ify my MKII Supra and hit the 200mph mark (someday). Or if you're just curious about WTF is going on inside your engine, or curious about engine efficiency and other curious facts.

I will post the pictures of my calculations so that you too can understand what actually happens on the inside. I will eventually follow up and edit this post so that it contains all the complete calculations (and the post below this one will have them as I go along).

I will ALSO post up AMAZINGLY AWESOME gumdrops of info-tainment wisdom. (Ok, so it's really hard facts as put out by Corky, I just happen to find them AMAZINGLY insightful AND entertaining.)

Let the madness begin.

**Some of these calculations are using MY VARIABLES... like 18psi (as a working pressure) etc etc. You CAN use your own... figure it out or GTFO.

Also you'll see stock figures in the center-ish, and my upped-redline numbers off to the left...(margins)

CLICK PICTURES FOR HUGE VERSION



Pressure Ratio, Flow Rates/Airflow


Flow Rate by RPM chart I made up (NA Airflow is the tiny number above).
*This Chart WILL CHANGE depending on your turbocharger's compressor map, and the slew of no less than FOUR variables. That is why the Middle Section is INCOMPLETE (right now) I need to consult the Borg-Warner compressor maps... (compressor & turbine housing AR's, compressor and turbine wheel AR's, Spool Valve, Timing, AFR, Fuel, Temperature, Exhaust size etc etc.)


S472 Compressor Flow Map.... needed to figure out if it will fit my needs.

I have learned this. Figure out your Application/NEED (where you want power), Do the Math, then pick the Turbo. Sounds straightforward, because it is. So... this S472 May NOT be the right one for me... it's for example... and what I'm comparing against for now.



Turbo Flow Rate Calculations... and the beginnings of calculating the volume of a radius'd cylinder... (Can Anyone Help with this shit? like calculating the volume of a cylinder (u-bend) given a certain radius?)


blueprint, calculate, boost, maximum, engine, math, formula, pressure
 

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Vcyl = 3.14 X Radius squared X height
 

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Interesting reading Rusty. The first information that I have seen to trigger an interest in understanding turbo design. Seeing the equations puts it in a form I can understand. Will follow the thread with interest.
 

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Discussion Starter · #7 ·
A properly enclosed & ducted radiator/intercooler will see about a 20% increase in efficiency over a non-enclosed unit.

Air inlet to a properly enclosed and ducted radiator/intercooler only needs to be 25% of the total frontal surface area of the radiator/intercooler. This is true because only about 25% of the airflow would actually go through an open air radiator/intercooler.

Ceramic coated exhaust components will provide up to 50% more thermal heat rejection/containment.
 

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Discussion Starter · #10 ·
The first half of a radiator/IC does 3/4ths of the work. The last half of a radiator/IC only does 25% of the work.

It is always preferred to add more cores to a radiator/IC (provide more short paths) than to make the cores longer (which results in more unwanted resistance, back pressure, and pressure drop across the radiator/IC. More cores=better Longer cores=worse.

An IC that is thinner will outperform an IC that is thicker, but has the same internal volume. More frontal surface area=better

Copper transfers heat faster/more efficiently than aluminum. So a slightly smaller yet slightly heavier copper radiator could outperform a larger lighter aluminum one. Additionally a CRAZY copper IC will outperform an Aluminum one of the same size.

I need to compare the gains on air-to-air, and air-to-water of aluminum and copper to find the cost-benefit analysis.
 

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Discussion Starter · #13 ·
ha ha it took me 3 times longer to read this than it did for us to talk about it, think i need a nap
We'll blame it on the heat. It was ridiculous here in Louisville. 87 before factoring humidity into the heat index.
 

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Discussion Starter · #15 ·
Turbo flow rates as it concerns us must be calculated in respect to the turbine/housing as well.

--billyM
Are you saying that we must account for the NA flow rate, and choose a Turbine Housing based off of that?

I've not yet seen in Maximum Boost an explicit explanation on choosing a turbine housing AR.

I don't know the sequence in choosing the housing. Do you first figure out NA flow rate, then figure out how much additional flow the Turbo will add, then choose a housing based on the combined NA + Turbo flow rates... altogether confusing actually.
 

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Most people avoid it due to the complexity of a variable exhaust-pressure affect on available combustion volume calculation.

I try to pretend it doesn't exist... *covers ears* "lalalala I can't hear you"

--billyM
 

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This stuff makes my brain hurt anymore too. I build everything, from ass pulls, and call upon a few key people if I need to. Age, and time in grade, have given me enough -- I know what I want -- to get by ;)
 

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I was the guy in school you all hated who understood math. More, please, Rusty. Trying to grok (look it up) flow /inlet relationship right now, as it pertains to "power adders".
 

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I was the guy in school you all hated who understood math. More, please, Rusty. Trying to grok (look it up) flow /inlet relationship right now, as it pertains to "power adders".
:mfinger: I loved math also, and was very good at it .... key word -- was ;)

I've just flat forgotten a lot of the stuff that was second nature, and have to actualy think or look up to much now. I don't want to tax the brain that much anymore, if I don't have to.


That said ... Damn good info, and ood reading Rusty. Keep it up. Look back and find some of Kenny's old ramblings also, that will make your head hurt some more.
 
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