Doesn't a turbo effectively increase the engine discplacement?

[MattAvino]

"...Nitrous is fun, but we've also been toying with turbos. The fashionable motto is that adding one atmosphere, or 14.7 pounds of boost, essentially doubles the size of the engine. Now your 745 hp is 1490 hp..."
-Douglas R. Glad, Car Craft
"The High School Chevelle"

[Mr. Tasty]

In for this...conveyor belt is going "-" displacement when plain is going "+" displacement. It should equal to 0 net displacement. However, the jet engines push on air not the conveyor belt. The air still is in "0" displacement and the jet turbine is pushing air in the "-" direction causing, by laws of physics, to push in the opposite "+" direction. Think of the conveyor belt as a useless piece of information in a story problem back in school that doesn't matter in the calculation you have to do.

technically, neither are moving therefore 0 displacement.

[Exodus_2pt0]

So how would the displacement of 2 2.5's compare to say.....

[atmobenzin]

I'm just sayin` that total displacement is irrelevant, it all comes down to dimensions of each cylinder.

[slaterd]

even if the 5l is made out of two 2.5l engines? (m20+m20=m70)

[ATTACH]54460[/ATTACH]

[slammin.e28]

Even if the 5l is made out of two 2.5l engines? (m20+m20=m70)

But they were run as two separate 2.5l engines.

[atmobenzin]

second, a head that can flow well for a 2.5l engine would look way different than a 5l engine. apples/oranges.

Even if the 5l is made out of two 2.5l engines? (m20+m20=m70)

[FunfGan]

[Junior2552]

This thread is my favorite.

[slaterd]

I think you guys are missing the TRUE argument here:

In for this...conveyor belt is going "-" displacement when plain is going "+" displacement. It should equal to 0 net displacement. However, the jet engines push on air not the conveyor belt. The air still is in "0" displacement and the jet turbine is pushing air in the "-" direction causing, by laws of physics, to push in the opposite "+" direction. Think of the conveyor belt as a useless piece of information in a story problem back in school that doesn't matter in the calculation you have to do.

[5Toes]

He is talking about the E23 745i. A car with an m30, but marketed as a 4.5 liter because it was turbocharged

BMW named it the 745 because they felt the power output was that of a 4.5 liter engine

[nando]

Would it be fair to say; if all other factors remained constant, an engine running at 1 bar is effectively operating how the same engine would if it were double the capacity?

For instance; 2.5 1JZ + 1 bar = effectively operating how a 5.0 1JZ would at atmospheric pressure?

no.

for one, a turbo isn't 100% efficient so it doesn't double the efficiency/output of the engine.

second, a head that can flow well for a 2.5l engine would look way different than a 5l engine. apples/oranges.

[Jables]

Would it be fair to say; if all other factors remained constant, an engine running at 1 bar is effectively operating how the same engine would if it were double the capacity?

For instance; 2.5 1JZ + 1 bar = effectively operating how a 5.0 1JZ would at atmospheric pressure?

You would have to know the mass of air at atmospheric pressure in the cylinders for both and, if they are the same, then sure.

[OniKyan]

Would it be fair to say; if all other factors remained constant, an engine running at 1 bar is effectively operating how the same engine would if it were double the capacity?

For instance; 2.5 1JZ + 1 bar = effectively operating how a 5.0 1JZ would at atmospheric pressure?

[Jables]

Waahh..? Your argument is that more air is going through the engine THEREFORE it's effectively increasing displacement, which is an illogical and irrelevent statement in itself which is quite impressive.

For example, my dad's n/a e30 M3 has a bigger throttle body/intake/exhaust, which, by your logic of "getting more air in" (which is the logic behind ANY power gains), I could say "THEREFORE it's increasing the effective boost of the effective garrett turbocharger hanging off the side".

It's the same thing. Same logic. And, as you can see, same level of kid-susceptible bashing.

You got owned by a kid, trololool

EDIT: for the betterment of society I should probably say why you are wrong... Basically your argument is revolving around the fact that the turbo adds power and so can be classed with another type of car, which IS true, but not in the way that you've implied, simply because its so broad. That's why my silly argument I portrayed has just as much sense as yours. All you're saying is that a turbo car might have the same amount of power as a car with more displacement. There's no such thing as "effective displacement". All the "effective displacement" is, is a measurement of power. So you would be right in saying that a turbo decreases the relative air mass difference between a lower displacement car and a higher displacement car, but the displacement in both cannot change.

Hope that makes some sort of sense..