Braineack

iTrader: (62)

the exhaust flow of the same motor, at the same sea level with 1bar of boost will still be the same. compressor flow goals, is not the same thing as exhaust flow, a factor of the displacement of your engine.



so lets say i want to make 400BHP, how would you pick your turbine?

lets say i want to flow 44 lb/min out of the turbo, how would you pick your turbine?

opek

Explain to me how an 800whp 1.8liter honda flows the same mass/time as the same 1.8liter honda with the boost turned down to 200whp.

opek

I would look at real world examples of people who have my same displacement engine and a similar flowing head, and see at what power level the turbine combination chokes and dies.

Seriously man, if what you were saying is correct ALL 1.8liter engines would use the same turbine/wheel combination regardless if they were making 200whp or 800whp.

Braineack

iTrader: (62)

because it's still a 1.8L. turbos don't increase the displacement of your motor. The VE will increase.....the ratio of the volume of outside air to the engine displacement. Since I assume 100% VE to make life simple, I leave it out of the equation....if you wanna add it back in, do so. so lets say a N/A motor at 80% VE makes 160 CFM (based off our 198 number) and the same turboed motor may make 120% VE, so 236 CFM. Either way, take that number and look at a turbine map.

opek

dude, more CFM is more lb/min. ESPECIALLY when you are not only increasing CFM, but density.

Braineack

iTrader: (62)

yep, youtube videos for all your turbo information. There are plenty of hondas making 650rwhp with a Stage I .63 A/R T3 turbine.

no. because the a/r has a lot to do with ultimate power output, like i posted the graph of previously. If i wanted to make **** tons of power, I'd choose a larger A/R and possible go with a stage higher turbine wheel. This lessens the overlap of the blades on the wheel to further reduce backpressure and increase the velocity. It's all a compromise. Since I chose overall performance me T3 utilizes a .48 A/R, if I want top end only for that 2000RPM powerband, I'd go with a .63 and make more power per psi. If I went with a larger turbine and a larger a/r, chances are it may not spool at all.

patsmx5

iTrader: (16)

Sure. Conservation of mass comes to mind.

Does that make sense? It clearly goes against your statement you made above. Do you agree with the Law of Conservation of Mass? It doesn't list any exceptions to the rule. I've read this in many science and physics text books and it seems to be generally accepted, so much that it's called a "Law" rather than a rule. My guess is it's impossible break the Law. If we could build a mechanism that put out less, or much more desirably, more, of a given substance, there would be no oil crisis or shortages in the world.

You can't put 40 lbs of something in and get 15 out. 40 pounds of something has to come back out. If you were forcing air, water, liquid gold, or protons through the intake, you will not always get 15 pounds out. You will get out what you put in.

Opek had several points I agreed with, do I need to quote them all? I agree with his point that exhaust flow is dependent on boost. Conservation of Mass at work here. I also with most of his statements so far. I don't agree with all of yours. It seems every one of your post your talking about displacement. Yea, I understand that. It's constant. Mass in and out of the engine is not constant. It's proportional to HP.

Braineack

iTrader: (62)

15psi of boost does not mean 15psi of boost inside the chamber.

the same amount of volume is always entering the chamber. the same mixture gets compressed further and ignited. This creates your torque, the exhaust volume is still the same. the pressure has increased, the power has increased, the amount of exhaust has increased, but the volume will remain the same. when you add boost does it it bore out your cylinder walls?

exhaust flow is not dependent on boost. Boost is dependent on the exhaust flow to spin the turbine. the faster engine spins, the faster the turbine spins, the faster the compressor spins, the more air you can stuff into the engine and burn, the more power you make; the volume is still not increasing.


again for the 17th time: the 15 lb/min number was a conversion from 198 CFM assuming 545ºR and 28.4 in. Hg Absolute (0.0691 lb/cf Density Ratio).

patsmx5

iTrader: (16)

Brain, the above post makes sense. Earlier, you stated that MASS is not conserved. This started a huge debate. Now, you acknowledge that it's conserved. Pounds of air per time, the time rate of mass, is conserved. Earlier you said it was not, and that was the reason all this started. So why don't you go and unban the guy you banned that correctly pointed out your mistake? You apparently got volume and mass per unit time mixed up 2 pages ago. Now, you have corrected this misunderstanding.

Braineack

iTrader: (62)

WTF read post number 26.

patsmx5

iTrader: (16)

Post 26 you state that poundage varies. Correct.
Post 28 you state it's constant. Wrong.

MX_Eva

I'm pretty sure I agree with Scott. (braineack)

Were this not true turbo's would not spool based solely on RPM. They'd spool based on some function of how much boost per RPM.

Braineack

iTrader: (62)

i'm stating the exhaust volume displaced is the same, yes. be it n/a or 15psi of boost. give or take the amount of change in VE and the atmospheric conditions.

Atlanta93LE

iTrader: (5)

I believe the confusion stems from the fact that Scott is using lb/min to indicate a volumetric flow rate, which it is not. Converting a volumetric flow rate, i.e. CFM to lb/min using a conversion factor derived for a specific physical state is not meaningful, and worse, is misleading.

Braineack

iTrader: (62)

yes, i wonder what this thread would look like if Garrett simply used CFM as thier air flow rate of their turbines as opposed to CFM. I wonder if anyone read the 10 times I posted this information and even posted the turbine air flow map to validate my point. It's also good that garrett flow everything at the same atomsphereic conditions....again: 545°R and 28.4 ~Hg.


But let's keep arguing a minute point...the whole point that everyone keeps forgetting is that turbos don't increase displacement, therefore the same volume is displaced. that's my entire point. thats it.

Ben

iTrader: (33)

I think everyone agrees that the engine (air pump) displaces the same volume of air per stroke, regardless of pressure.

Braineack

iTrader: (62)

if that were the case, then why have i been arguing that all day.

im spent, im going home to get laid. and yes my wife is hot. **** all you.

Atlanta93LE

iTrader: (5)

Atlanta93LE

iTrader: (5)

See you in 2 minutes.

Ben

iTrader: (33)

in for video stream