intercoolers changing turbo efficiency?!

[Formz]

I got this idiot kid trying to tell me that intercoolers effect a turbo's efficiency level. So apparently, if I buy a turbocharger that is 70% efficient, and thrown an IC on it, I could have (in theory) a turbo that is now at 74%! Wow!

What could I say that may get through his thick skull that that's impossible, and the ONLY thing IC's do is decrease inlet temps, which will NOT effect what the turbo does.

 

[InferiorWang]

don't i/c's sometimes have a pressure drop which would decrease the efficiency?

 

[Formz]

no that doesnt effect the turbo itself

 

[dyezak]

Actually they decrease turbo effiency. Let me explain so you can set him straight. Lets say you have a turbo on your car and boosting at 14.7psi without an intercooler on it. The turbo is in it's max effiency island at, say, 74%. At 74% effiency at 14.7psi (guage pressure) you are going to see (didn't actually do the calcs, just a random number) fairly high outlet temps...like 200F. Because this outlet temp is so high it would hurt performance (less dense air, and possibility of detonation), so you put a FMIC on it. Now we got our temps down to, say, 110F...awesome performance potential. BUT, due to pressure drop through the core we are only seeing 12.9psi at the intake manifold now...so what do we do? TURN THE BOOST UP!! We are now back to 14.7psi at the intake mani...outlet temps are still a managable 115F...BUT WAIT. We now have a turbo running 16psi+ at the turbo outlet (to make up for FMIC pressure drop) and it moved our turbo to a lower efficency island (like 70%)....so effectively to run the same boost with the intercooler we have decreased the effiency of a turbo.

This is actually a VERY simplistic description of what is going on, and if this thread gets out of control or I get flamed (or asked)...I'll go into full detail and explain this...I will also explain how it actually COULD increase turbo effiency if you picked your parts correctly. Anyhoo, hope you can set him straight.

Basicly...simply stated...the intercooler does NOTHING to turbo effiency...only air charge density.

 

[Formz]

very good info, keep it coming!

 

[jdmawd]

dyezak:

good points, this topic was trolled over from another board. as an attempt to discredit a post i made. however i think its going to back fire. now we all know that in the compression process, the air is heated as the air molecules are compressed and boost is created. this is what the efficiency number is based on correct? now lets say you have a turbo that flows 750 cfm at 30 psi. this same turbo has an efficiency rating of lets say 70% for sh@ts and giggles. now we connect that turbo to a stock 1G side mount intercooler what happens to our efficiency rating and outlet temps after the turbo. the object it to keep the inlet temperature (pre intercooler) and outlet temperature (post intercooler as close to ambient as possible correct? because air density=HP higher charged air temps= less HP and a greater chance of preignition detonation. formz you still with me? OK good. it was not implied that an intercooler would increase a turbos efficiency, the quote was that the intercooler or more specifically an incorrect sized intrecooler, will effect the turbos ability to maintain that efficiency rating. because of intercooler flow chairicteristics, and heat soak. which is directly related to the intercoolers flow rate. other factors will effect this process like inlet temps(pre turbo), if the intercooler is artificially cooled..ect..ect

 

[DeezNutsForYou]

what is the psi drop of a stock 1g side mount, and wouldn't a fmic have a lower pressure drop.

 

[L2RTSiAWD]

Yes a good FMIC will have a lower pressure drop. Almost any FMIC will have lower pressure drop than a stock SMIC.

 

[diefwd]

if i were to put a fmic on a car with a 14b would it make the car any slower?

 

[Formz]

Originally posted by jdmawd
dyezak:

good points, this topic was trolled over from another board. as an attempt to discredit a post i made. however i think its going to back fire. now we all know that in the compression process, the air is heated as the air molecules are compressed and boost is created. this is what the efficiency number is based on correct? now lets say you have a turbo that flows 750 cfm at 30 psi. this same turbo has an efficiency rating of lets say 70% for sh@ts and giggles. now we connect that turbo to a stock 1G side mount intercooler what happens to our efficiency rating and outlet temps after the turbo. the object it to keep the inlet temperature (pre intercooler) and outlet temperature (post intercooler as close to ambient as possible correct? because air density=HP higher charged air temps= less HP and a greater chance of preignition detonation. formz you still with me? OK good. it was not implied that an intercooler would increase a turbos efficiency, the quote was that the intercooler or more specifically an incorrect sized intrecooler, will effect the turbos ability to maintain that efficiency rating. because of intercooler flow chairicteristics, and heat soak. which is directly related to the intercoolers flow rate. other factors will effect this process like inlet temps(pre turbo), if the intercooler is artificially cooled..ect..ect

good try, but WAY off base. the efficiency of a turbo has NOTHING to do with post intercooler temperatures. thats what the kid asked on the other board. He said "does an intercooler effect the efficiency of a TURBO?" the answer is NO. and an incorrect intercooler would not effect the "turbos ability to maintain that efficiency rating." the turbo has a set efficiency level, it doesn't care how big or small the intercooler is. you really are an idiot that's just trying to sound smart. who is the "copy paste" poster now?

bottom line: the kid asked if intercoolers changed the efficiency of a turbo, the answer is NO. which I answered correctly. some how, some where in your screwed up little mind, you found that to be incorrect. so uh.. back peddle much?

 

[jdmawd]

Originally posted by Formz


good try, but WAY off base. the efficiency of a turbo has NOTHING to do with post intercooler temperatures. thats what the kid asked on the other board. He said "does an intercooler effect the efficiency of a TURBO?" the answer is NO. and an incorrect intercooler would not effect the "turbos ability to maintain that efficiency rating." the turbo has a set efficiency level, it doesn't care how big or small the intercooler is. you really are an idiot that's just trying to sound smart. who is the "copy paste" poster now?

bottom line: the kid asked if intercoolers changed the efficiency of a turbo, the answer is NO. which I answered correctly. some how, some where in your screwed up little mind, you found that to be incorrect. so uh.. back peddle much?

:laugh:

lets recap and highlight on some points that most already know.

1)

Originally posted by dyezak
Actually they decrease turbo effiency.

2)

Originally posted by dyezak
.I will also explain how it actually COULD increase turbo effiency if you picked your parts correctly.

efficiency and air density go hand and hand.you can not have good efficiency if the turbo heats the air excessively during the compression process. this is why larger turbos are more efficient than small turbos at high boost levels. again i will state if you do not have a proper sized intercooling system, attached to the turbo. your turbo will loose its ability to maintain its outlet temperatures at a given boost level. which exuates to less effiency, at the outlet of the intercooler. sorry bro, after all your cute little insults, and attempt to sound intelligent. you are still wrong have a good day. but please contiune, you are very amusing.

 

[iwantawd]

turbo efficiency has nothing to do with intercoolers. the efficiency of a turbo is what some super math guy says the temp of the air coming out of the turbo should be divided by what it actually is so if im right on this (which im fairly confident of and ill check on it when i get the chance) then the intercooler has no effect on what comes out of the compressor