alittle info from AEM

[Bigg Tim]

Nope.

Here is the deal....

You have turbo #1 (T3/T4), and turbo #2 (T30/40)

Yes, the air from turbo #1 is flowing as fast as turbo #2 at the same PSI, say, 10 PSI.

Even though they are flowing at the same rate, there will be more air molecules put into the same space.

Here is a decent analogy (although this one deals with momentum versus cfm and turbos, but you get the idea)....

I punch you in the face with my fist at 40 mph versus Bob Sapp (400 pound Pride Fighter) hitting you in the face at 40 mph.

Which one will hurt more? I would like to say me, but hell no.

That's more like what I remember being told.

 

[kyle's protege5]

Kyle- you're comparing 2 items with the same pressure and the same flow rate, that's why you think this way. The stock T25 and, say a 30R or any other turbo for that matter will have comletely different flow rates regardless of pressure... The T-25 @15psi will flow much less than the T28/T30 @15psi because of the difference in cfm. Theres no two ways about it- bigger turbo w/better flow=>more airflow=>more fuel burned=> bigger bang.


Your argument makes sense in theory, but you're comparison is way off...

you are correct, i got sidetracked a little. a bigger turbo does make more power like you said because more flow, does mean more air which does require more fuel which is what this was all about.

But i stand by my original post 15 psi is 15 psi! LOL

 

[stomper65]

Purdue by the way.

I won't be going to Purdue

 

[kyle's protege5]

I'm tired, I'm going to bed. I believe we are all right just with different points.

And I graduated in '98

 

[kyle's protege5]

I won't be going to Purdue

and if you are so smart get your $1000 and prove me wrong

 

[65racecoupe]

and if you are so smart get your $1000 and prove me wrong

If an engine inhales and exhales (exchanges air) faster, there is more power.

Your $1000 bet is not quite on. An engine is not a container. An engine is constantly taking in air and taking out air.

 

[yesiownaskyline]

Your $1000 bet is not quite on. An engine is not a container. An engine is constantly taking in air and taking out air.

Exactly, concepts that work for closed system engineering (Kyle) cannot be applied to open system situations. exactly what i said above.

 

[kyle's protege5]

ok, this is my last post on this thread then I'm unsubing it. Its giving me a headache.

At work today i made a call to an engineer friend of mine that i do business with and another engineering firm that does some calculations of tower sizing etc.

After explaining last nights conversation to them we discussed this from all angles and everbodys points. In a nut shell it comes down to this.

15 psi IS 15 psi no matter what the cfm is when referring to a closed space, say an intake tube, intake mani, intercooler, cylinder chamber, etc. No matter what the cfm is. No if ands or buts about it. Where the extra HP from the larger CFM comes into play is when the valve opens up and the volume of that air is pushed into the cylinder.

If for example the valve is open for say 2 milliseconds. The air being pushed into it by 1 turbo at 15 psi and 550 cfm can only manage to push in a certain amount of air. But a 2nd turbo at 15 psi and 750 cfm can push in more air in the 2 milliseconds. That more air as stated is what gives the extra horsepower. The entire intake system will only ever have 15 psi on it.

If you could put a pressure gauge on the cylinder chamber itself, the second turbo would have a lot higher psi there since its higher flow rate was able to push more air into the chamber in the time the valve was open, but again they will both have the same psi in their intake systems.

Again no one has proven me wrong, but now i've explained it more completely.

And thank you all for the bad feedback. Especially since like 4 of them were from people who lacked the brainpower to even make a comment on the thread at all. Especially the loser in the 41hp escort that collects Xmods and works at Radio Shack. Maybe you could hang out with my son he collects toys too.

I really could care less, in fact I like the red bars better than the green ones anyway!

 

[wicked]

wow,you guys took this farther then I planned on.

but yeah,the larger turbo will out flow the other ,and all though your running say 15 PSI on each turbo,the one closet to it's efficientcy is the one thats going to make the most power at said PSI.

 

[ddogg777]

Kyle is right guys... If you take two blocks that flow the same and put different turbos on them that both can hold 15psi (neither flinch), then the flow is the same. HOWEVER! You guys are not taking into account temperatures and efficiencies (Wicked mentioned it). If one turbo is pushing in 15psi of hot air and the other is pushing in 15psi of cold air, guess which one gets more oxygen in the combustion chamber. You should also be thinking about which one makes that 15psi easier, the bigger ball bearing turbo or the smaller oil bushing turbo that has to spin like heck to keep up (which is where the higher air temps would be coming from). You need to invest a ton of energy into that smaller turbo to make it push 15psi, and that is where your robbing yourself of power...efficiency, good call Wicked, and nice job Kyle trying to explain your point.
BS in ME from BYU here.

 

[65racecoupe]

BYU....

JK - That is a very good college. I have actually been on that camups, it is nice.

I go to a community college. Yea for me.