3" UIC Piping - Overkill?

[DROOPY209]

All those calculations that some people have thrown out are actually not that accurate. Those calculations would be kind of accurate if your whole intercooler piping was ONE WHOLE complete piece, which it is not. There are various couplers, sometimes reducers, weird intercooler pipe angles, and the intercooler itself.

If you make the calculation based on piping diameter, material, blah blah blah, you still have to account for the various silicone couplers, reducers and other things that are going to restrict the air flow, change the direction of the air, cause turbulence, etc....

So, unless you plan on having (1) ONE solid exact diameter through-out intercooler piping, from turbo compressor outlet all the way to the intake manifold, your calculations are just that, calculations.

Anyone dare to prove me wrong and prove they can account for the differences that will occur within the intercooler piping amongst the silicone couplers, intercooler outlet-intercooler piping, intercooler piping to TB elbow, etc?

Honestly, I think 2.5" intercooler piping is already overkill for the majority of dsmtuner member's needs.

Hey its your money....If you wanna go out and buy titanium 4" intercooler piping, do what you want. Money that could be better spent, but whatever.

 

[Turbocharged]

All those calculations that some people have thrown out are actually not that accurate. Those calculations would be kind of accurate if your whole intercooler piping was ONE WHOLE complete piece, which it is not. There are various couplers, sometimes reducers, weird intercooler pipe angles, and the intercooler itself.

If you make the calculation based on piping diameter, material, blah blah blah, you still have to account for the various silicone couplers, reducers and other things that are going to restrict the air flow, change the direction of the air, cause turbulence, etc....

You need to take a fluid dynamics class at the very least before making this statement.

1. Different bends/reducers/expanders have "equivalents of length" that you add to the overall piping length "L".
2. The only thing that the different materials effects is the fanning friction factor "f" (f doesnt change much between various "smooth" materials).
3. The intercooler is a constant for a given setup. In other words, keeping all else constant, larger pipes WILL have a lower pressure drop.

That equation is accurate to within 15% and I have been using it in industry for years. I am a process engineer with a chemical engineering background.

 

[Turbocharged]

This is a pretty good site for those of you interested in learning about this:

http://www.engineeringpage.com/engineering/pressure_drop.html

And here is a calculator that will incorporate reducers, expanders, bends, and material of pipe into the above equation:

http://www.engineeringpage.com/calculators/pressure_drop/fittings_u.html

And heres another good site I just found on google:

http://www.cheresources.com/eqlength.shtml

 

[Slippi84]

All those calculations that some people have thrown out are actually not that accurate. Those calculations would be kind of accurate if your whole intercooler piping was ONE WHOLE complete piece, which it is not. There are various couplers, sometimes reducers, weird intercooler pipe angles, and the intercooler itself.

If you make the calculation based on piping diameter, material, blah blah blah, you still have to account for the various silicone couplers, reducers and other things that are going to restrict the air flow, change the direction of the air, cause turbulence, etc....

So, unless you plan on having (1) ONE solid exact diameter through-out intercooler piping, from turbo compressor outlet all the way to the intake manifold, your calculations are just that, calculations.

Anyone dare to prove me wrong and prove they can account for the differences that will occur within the intercooler piping amongst the silicone couplers, intercooler outlet-intercooler piping, intercooler piping to TB elbow, etc?

Honestly, I think 2.5" intercooler piping is already overkill for the majority of dsmtuner member's needs.

Hey its your money....If you wanna go out and buy titanium 4" intercooler piping, do what you want. Money that could be better spent, but whatever.

Who gives a rats ass about calculations I'm talkin from experience

 

[Turbocharged]

Who gives a rats ass about calculations I'm talkin from experience

I speak from experience that those calculation work

 

[Slippi84]

I speak from experience that those calculation work

If you want to go by 2 1/4" or 2" piping and think that your not shorting yourself knock yourself out that's money that could be better spent on.....bigger piping

 

[Turbocharged]

If you want to go by 2 1/4" or 2" piping and think that your not shorting yourself knock yourself out that's money that could be better spent on.....bigger piping

What? Im not sure what you are trying to say but I think anything smaller than 2.25" is going to hurt performance.

 

[Slippi84]

Oh ok just checkin cause you said 2.5 is overkill for most dsm guys.

 

[Turbocharged]

Oh ok just checkin cause you said 2.5 is overkill for most dsm guys.

Could you please show me where I said that? I have been pointing out the advantages of running larger diameter intakes.

 

[mirkoelek]

Could you please show me where I said that? I have been pointing out the advantages of running larger diameter intakes.

Why dont you put 10" or maybe 20" piping, run 16g and let me know how did it work?
There has to be perfect value for piping regarding the turbo size.

 

[Turbocharged]

Why dont you put 10" or maybe 20" piping, run 16g and let me know how did it work?
There has to be perfect value for piping regarding the turbo size.

Have some common sense... There is no "perfect size" for intake piping. In my line of work we use the term "optimum pipe diameter" which is really more of a cost saving principle; it calculates the largest diameter you can run without significant economic drawbacks.

My advise:
Run the largest intake pipes that you can run without having to make steps in pipe diameters. As long as everything is matched properly, bigger pipes will outperform smaller pipes. Lets see you find a 10" throttle body or route 10" pipes... lets be reasonable here.

 

[97gstnick]

let me help clear this up, i have not noticed any problems with bigger piping. i thought i had problems a while back, but it was due to a horrible tune. i have since got dsmlink and with 15-17 psi the car pulls hard! harder than i used to run 21. when i dyno and give you guys the specs, we'll get a good idea of its potential. i dont see my setup hurting my turbo, yet i dont see it really helping until i get the 75mm tb.

 

[larsrya8]

i dont see my setup hurting my turbo, yet i dont see it really helping until i get the 75mm tb.

That right there is the bottom line on the 3 inch piping issue. Thank you for that post.

 

[mirkoelek]

Have some common sense... There is no "perfect size" for intake piping. In my line of work we use the term "optimum pipe diameter" which is really more of a cost saving principle; it calculates the largest diameter you can run without significant economic drawbacks.

My advise:
Run the largest intake pipes that you can run without having to make steps in pipe diameters. As long as everything is matched properly, bigger pipes will outperform smaller pipes. Lets see you find a 10" throttle body or route 10" pipes... lets be reasonable here.

I have a question for you. Can air be compressed? your formulas would work if there is no pressure inside of the pipes. Under the pressure air compress and move slower. With big 3"pipes there is a lot more volume to compress before air starts to move. Thats why we have boost, you need more energy to boost bigger pipes. Turbo is your only energy source. Why would you spend turbo energy to make a pressure in those 3" piping, when you can make right ratio between "how much air you need" / "and what is the smallest piping that you can go with to get whole amount of that air". this is physic, not chemistry my friend. Happy boosting.

 

[97gstnick]

having 3 inch piping is not that much more volume to fill guys. you are highly over exaggerating. just sit there and think about it, its not that much more. it only takes probably a millisecond more to fill it. then minute you step on the gas it has filled the pipes and is working its way to pressurize it to your setting.

 

[mirkoelek]

having 3 inch piping is not that much more volume to fill guys. you are highly over exaggerating. just sit there and think about it, its not that much more. it only takes probably a millisecond more to fill it. then minute you step on the gas it has filled the pipes and is working its way to pressurize it to your setting.

Is it because you have 3" piping. you are so stubborn to accept it.
It is much my friend, 3 * 2pi * 120inch(piping lenght) = 2260 inch2 or , 2.5*2pi*120 =1884;
give or take: difference is about 380 square inches (depending of lenght of your piping).

That is 25 inches longer piping. We all want piping as short as we could. If you add traction of air with piping wall , where 3 inch has more that 2.5 inch.....

 

[larsrya8]

There are 1728 cubic inches in 1 cubic foot.

If a turbo flows 650 cubic feet per minute, that is almost 11 cubic feet per second.

Volume is PI * (radius^2) * length

2.5 Inch:
1.25^2 * PI * 120 = 589 cubic inches
589/(1728*11)=0.031 seconds

3 Inch:
1.5^2 * PI * 120 = 848 cubic inches
848/(1728*11)=0.045 seconds

Give or take depending on your piping length and your boost level. I'm not sure how much this would affect spool up though, but I'm sure the results would be similar. When you take into account the fact that the engine is sucking in a lot of air during spool up, the size of the intercooler piping doesn't really matter.

This is all a very very basic version of what I'm sure could become a much more complicated equation. It's just to show that any turbocharger from the Evo3 upwards could easily fill a 3 inch pipe in almost the same amount of time that it could fill a 2.5 inch pipe.

Relax.

edit: Sorry, I forgot to compare the equations.

 

[larsrya8]

I'm sure having the throttle body be smaller than the intercooler piping may cause some turbulence, but have you seen the outlet on SBR's and AGP's FMIC kits? Compressed air must act differently or something...

 

[mirkoelek]

There are 1728 cubic inches in 1 cubic foot.

If a turbo flows 650 cubic feet per minute, that is almost 11 cubic feet per second.

Whoa.. those volume calculations are way off... one second while I adjust here.

Give or take depending on your piping length and your boost level. I'm not sure how much this would affect spool up though, but I'm sure the results would be similar. When you take into account the fact that the engine is sucking in a lot of air during spool up, the size of the intercooler piping doesn't really matter.

Relax.

edit: Sorry, I forgot to compare the equations.

dude how did you figure that out?

 

[Turbocharged]

I have a question for you. Can air be compressed? your formulas would work if there is no pressure inside of the pipes. Under the pressure air compress and move slower. With big 3"pipes there is a lot more volume to compress before air starts to move. Thats why we have boost, you need more energy to boost bigger pipes. Turbo is your only energy source. Why would you spend turbo energy to make a pressure in those 3" piping, when you can make right ratio between "how much air you need" / "and what is the smallest piping that you can go with to get whole amount of that air". this is physic, not chemistry my friend. Happy boosting.

When the pressure drop is small compared to the gauge pressure, the fluid can be assumed to be incompressible. In the case of intake piping, where pressure drops are on the order of 1-2 psi and gauge pressure is on the order of 20 psi, this assumption is valid. Here is the equation for compressible flow if you are interested:

Q = cED^n * (Ts/Ps)*[(P1^2-P2^2)/(LTZs^x)]^y

Q = volumetric flow rate
c = constant (dependant on fluid type)
D = pipe inside diameter
E = efficiency factor - (similar to fanning friction factor)
L = pipe length
n = constant (dependant on fluid type)
P = Pressure
S = Specific gravity of gas
T = Absolute temperature
u = constant (dependant on fluid type)
x = constant (dependant on fluid type)
y = constant (dependant on fluid type)
*Z = Gas compressibility*

You can see why I used the simplified equation. Notice that this eqation is not a function of volume. From this equation, P1 and P2 are the pressures of the inlet and outlet, respectively (P1-P2 = pressure drop).

None of this really matters. The point is that larger pipes have smaller pressure drops; please stop trying to argue anything else. That was the only point I was tryin to make. I stand by my assertion that it is best to run the largest intake piping that your system is capable of handling without significant reductions/expansions.

I never said I was a chemist. I am a chemical engineer; there is a VERY big difference in what the two disciplines study. Chemical engineers are more concerned with thermodynamics and physical systems than batch reaction chemistry.

 

[Turbocharged]

Man, there is a TON of ill-informed posts on this thread. I give up... good luck and get what ever the hell diameter pipe you want.

 

[larsrya8]

dude how did you figure that out?

Your equations are still way off.

Man, there is a TON of ill-informed posts on this thread. I give up... good luck and get what ever the hell diameter pipe you want.

I never said my equation was accurate. It's a riduculously basic version of yours. Something that anyone who has passed high school can understand. I don't know the values to over half the variables you have in yours Turbocharged...

 

[97gstnick]

well you know what? my setup works. period. my car runs and it runs great. i get full boost of 17psi less than 4000 rpm. does anyone see a problem here?

 

[mirkoelek]

When the pressure drop is small compared to the gauge pressure, the fluid can be assumed to be incompressible. In the case of intake piping, where pressure drops are on the order of 1-2 psi and gauge pressure is on the order of 20 psi, this assumption is valid. Here is the equation for compressible flow if you are interested:

Q = cED^n * (Ts/Ps)*[(P1^2-P2^2)/(LTZs^x)]^y

Q = volumetric flow rate
c = constant (dependant on fluid type)
D = pipe inside diameter
E = efficiency factor - (similar to fanning friction factor)
L = pipe length
n = constant (dependant on fluid type)
P = Pressure
S = Specific gravity of gas
T = Absolute temperature
u = constant (dependant on fluid type)
x = constant (dependant on fluid type)
y = constant (dependant on fluid type)
*Z = Gas compressibility*

You can see why I used the simplified equation. Notice that this eqation is not a function of volume. From this equation, P1 and P2 are the pressures of the inlet and outlet, respectively (P1-P2 = pressure drop).

None of this really matters. The point is that larger pipes have smaller pressure drops; please stop trying to argue anything else. That was the only point I was tryin to make. I stand by my assertion that it is best to run the largest intake piping that your system is capable of handling without significant reductions/expansions.

I never said I was a chemist. I am a chemical engineer; there is a VERY big difference in what the two disciplines study. Chemical engineers are more concerned with thermodynamics and physical systems than batch reaction chemistry.

You dont expect from me to even check this formula, do you. just kidding...

 

[mirkoelek]

There are 1728 cubic inches in 1 cubic foot.

If a turbo flows 650 cubic feet per minute, that is almost 11 cubic feet per second.

Volume is PI * (radius^2) * length

2.5 Inch:
1.25^2 * PI * 120 = 589 cubic inches
589/(1728*11)=0.031 seconds

3 Inch:
1.5^2 * PI * 120 = 848 cubic inches
848/(1728*11)=0.045 seconds

Give or take depending on your piping length and your boost level. I'm not sure how much this would affect spool up though, but I'm sure the results would be similar. When you take into account the fact that the engine is sucking in a lot of air during spool up, the size of the intercooler piping doesn't really matter.

This is all a very very basic version of what I'm sure could become a much more complicated equation. It's just to show that any turbocharger from the Evo3 upwards could easily fill a 3 inch pipe in almost the same amount of time that it could fill a 2.5 inch pipe.

Relax.

edit: Sorry, I forgot to compare the equations.

you are right, i missed r squared but still it shows mine concern