3" UIC Piping - Overkill?

[97gstnick]

you guys are just polluting this thread with b.s. if anyone has questions about 3 inch piping, send me a pm. i have it done, and it works. it works well. nobody could answer my questions, so i made the damn thing myself. now i am here to answer other peoples questions. send me a pm and ill do my best to clear up rumors.

 

[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.

Yep, youre right, but. 650 cubic feet per minute you get with full spooled turbo. To have your turbo full spooled you need couple of seconds. i said in higher rms you could benefit but not that much.

 

[Slippi84]

Turbocharged I didn't even realise it but you responded to a post that wasn't for you my post was directed toward mirkoelek. This guy is def talkin with no first hand experience and if he is he doesn't knwo what he's doing anyway. Both me and 97gstnick have first hand experience with this and are saying the same thing but nope we're wrong and he's a wiseman

 

[mirkoelek]

Turbocharged I didn't even realise it but you responded to a post that wasn't for you my post was directed toward mirkoelek. This guy is def talkin with no first hand experience and if he is he doesn't knwo what he's doing anyway. Both me and 97gstnick have first hand experience with this and are saying the same thing but nope we're wrong and he's a wiseman

you both have bigger turbo than 16g, where i said that size of the pipe is proportional to the size of the turbo. The guy who started this tread has 16g. I'm not saying your car is gonna make no power. I'm on the topic and you guys pulled me to go little furthe.... i dont have experience with 3" piping, i admit. But i do have 16g and little more logic than you guys

 

[Turbocharged]

you both have bigger turbo than 16g, where i said that size of the pipe is proportional to the size of the turbo. The guy who started this tread has 16g. I'm not saying your car is gonna make no power. I'm on the topic and you guys pulled me to go little furthe.... i dont have experience with 3" piping, i admit. But i do have 16g and little more logic than you guys

There is no ideal proportionality that exists between turbo size and pipe diameter. Can you please back up your logic?

Imagine you have a series of straws with increasing diameters. You take these straws and blow into them at a constant volumetric flow rate. Which staw would you expect to have the greatest resistance (remember this is at constant flow rate). The larger the diameter, the less resistance the you will have.

Now consider a turbo, where you need to spool the turbine to increase flow rate. A larger diameter pipe will take longer to pressurize (not by much). However, since when is power created from pressure? Power increases with increasing flow rate, not increasing pressure. The less resistance to flow you have, the greater the flow rate will be. It doesnt matter how much you are flowing (however higher flowing systems will benefit more).

This discussion is too funny. People are arguing over 0.5" differences in intake pipe diameters.

 

[mirkoelek]

There is no ideal proportionality that exists between turbo size and pipe diameter. Can you please back up your logic?

Imagine you have a series of straws with increasing diameters. You take these straws and blow into them at a constant volumetric flow rate. Which staw would you expect to have the greatest resistance (remember this is at constant flow rate). The larger the diameter, the less resistance the you will have.

Now consider a turbo, where you need to spool the turbine to increase flow rate. A larger diameter pipe will take longer to pressurize (not by much). However, since when is power created from pressure? Power increases with increasing flow rate, not increasing pressure. The less resistance to flow you have, the greater the flow rate will be. It doesnt matter how much you are flowing (however higher flowing systems will benefit more).

This discussion is too funny. People are arguing over 0.5" differences in intake pipe diameters.

i kinda agree what you said. but there is tb elbow and tb that are less than 3".
So add the last straw to you straw setup that is the same as the first one, and tell me what you got. Is it gonna flow better with the last straw or without it.?
I'm not arguing, i just dont have nothing else to do....

 

[Turbocharged]

i kinda agree what you said. but there is tb elbow and tb that are less than 3".
So add the last straw to you straw setup that is the same as the first one, and tell me what you got. Is it gonna flow better with the last straw or without it.?
I'm not arguing, i just dont have nothing else to do....

You are correct. However, imagine you have a straw that is 4 ft long and 2 inches in diameter. Now you add 1 ft of straw that is 1 inch in diameter to the end of that. The resistance will increase but the resistance will still be less than if you had a 5 ft straw with a constant 1 inch diameter. A larger pressure gradient (larger pressure drop) is required to for the smaller diameter sections. Pressure drop is simply a way to quantify the resistance to flow and loss of kinetic energy (look at the first equation... looks a little like kinetic energy term doesnt it).

In otherwords, any increase in diameter is going to help flow. Many people like to argue against this but they have no experience or education on the matter. Ive noticed that a good number of people on these forums are highschool students or have no higher education. Im not calling these people stupid nor am I saying Im better than them in any way but I certainly didnt learn fluid dynamics in highschool.

 

[Turbocharged]

mirkoelek,

Im wondering about your hood. Is that just the way the light is hitting it or is there something else going on?

 

[mirkoelek]

mirkoelek,

Im wondering about your hood. Is that just the way the light is hitting it or is there something else going on?

A lot of people asked me for it. It is custom made. The Regular factory hood that has been modified. Very professionaly done, perfect cut.....

 

[mirkoelek]

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[Turbocharged]

To the original poster:

What size piping did you go with?

 

[Maglin]

I didn't see any mention of MAF placement???? IF you are running 3" piping and still using a draw thru (pre trubo) MAF then 3" piping with hurt you for a brief sec as you will run rich. It is going to put that extra air that is needed to create the "boost" pressue and use that for fueling calcs. That will be a noticalbe difference in mainly 60 ft. times. It is also something that is going to make for a very hard tuning processes as it will be very very hard to turn that out.

If running blow through then next to no negitive effect at all. Once the TB is taken to 75mm and you are using the whole 3" pipe to it's potential you should be able to see noticalbe gains on the top end. Noticalbe meaning maybe 7 hp. It's BIG TURBO cars running 35 PSI+ that will see the most benifit from running 3" pipes. Then again these cars might be almost pure track cars and could ditch the FMIC and run Meth injection to cool the charge.

And people thinking a 50trim is a big turbo and needs 3" piping is crazy. I have what I consider maybe a upper mid sized turbo and it dwarfs the 50trim's. Guys with big turbo's are not going to ask "Will this hurt spool up" cause they are already spooling at 5K+.

So full benifit is this. 3" IC piping from UPIC pipe to 75mm TB attached to either a extrude honed Manifold or SMIM. If your running a 75mm tb you better be runnign a SMIM cause you can't bore out the stocker to 75mm.