2" or 2.5" tubing for DIY FMIC setup??
- Thread starter hotrodf1
- Start date
one would assume... an i know ass u me.. etc .. but assume.. lets say you have 8 paritcles of air in a 2.5 inch part... as temp decrease the particels will become closer no..?. .. not more air or less air... just more dense... so i would assume.. to keep presure you would want larger on hot side... cooler on cold.. i could be totaly wrong but... i dunno.. that make any sense..?
think about it... but then again... maybe im missing something.. wich would nto be a first... (enguard)
think about it... but then again... maybe im missing something.. wich would nto be a first... (enguard)
volcombro16
Banned
- :
- 03.5 titanium msp
Im running 2.5 on both sides at 8psi and i have great throttle response. Plus my charge pipe is ice cold all the time.
awsmp5 said:
all three of us are thinking the same, but it does not necessarily mean that we see all the angles of course.
I have been trying to think of why we might want the small pipe on the turbo side, but I can't quite get it.
Maybe a physics major could do some good. used to know one. Haven't spoken to him in years. nows probably not the time. . . .
I would like to see someone try the 2.5" tube from turbo to IC and then the 2" to the TB. maybe that someone is me. I dunno.
- :
- MAZDA 03.5 MSP
go to ur local home pot store or tool rental place and rent a metal chop saw..the one u pull down on (miter saw)..with a metal cutting blade on it...
khaosman said:
PlatinumMSP
Member
- :
- Blazing Yellow 03.5 MSP
hotrodf1 said:
use 2.25" piping like the Perrin kit
Right, right, Ideal gas law. That what was on my mind when I posted, because of the direct proportionality of what we were talking about, anyone else care to chime in on how this works in the real world?hotrodf1 said:
I said air contracted when cooled, not expanded and rose. The reason a hot-air balloon fills, is because the heated air expands and fills it out, no?505zoom said:If cool air was lighter and thinner than hot air, then we would use cold air in "hot-air baloons", no?
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hmmmmmm
let me add 2 cents in this issue, bc i too am about to make a decision to choose what size to make the diy FMIC.
As future engineer i'd say that bigger size 2.5 would be from sucktion side ( intake manifold) , and about hot side this is give or take but since there's two forces acting and drastic temp changing you could go 2.25 from hot side, this being smaller might help on pushing much faster the air as the main force there is toward ic and hot air is hard to controll on the other hand the cold side could be bigger than the hot on helping pulling/sucking the air acumulated in the ic at much faster rate.
there's laws that apply but as far as i remember in physic or chem there's no example on turbo situation that we are dealing with. They cover mostly general situation.
But for curiousity, this mech from a mazda deal in wayne (around my area) he build his 4" cold and 3.5 hot size but his running a huge turbo.
let me add 2 cents in this issue, bc i too am about to make a decision to choose what size to make the diy FMIC.
As future engineer i'd say that bigger size 2.5 would be from sucktion side ( intake manifold) , and about hot side this is give or take but since there's two forces acting and drastic temp changing you could go 2.25 from hot side, this being smaller might help on pushing much faster the air as the main force there is toward ic and hot air is hard to controll on the other hand the cold side could be bigger than the hot on helping pulling/sucking the air acumulated in the ic at much faster rate.
there's laws that apply but as far as i remember in physic or chem there's no example on turbo situation that we are dealing with. They cover mostly general situation.
But for curiousity, this mech from a mazda deal in wayne (around my area) he build his 4" cold and 3.5 hot size but his running a huge turbo.
I did spend some time looking at compressible gas fluid flow. There is a calculator type deal you can get on the net and it showed that the hotter the air was, the less mass you could flow through a pipe, which suggests that to get the same flow capability throughout the system, you would want a larger pipe to the IC and smaller to the TB.
USing the calculator, I looked at different lengths of piping, and that didn't change flow all that much. But, using a 2" pipe seriously inhibited flow as compared with a 2.5" pipe. I dont' know what the cfm requirements for the MSP engine is, but the 2" pipe seemed hardly sufficient, if you wanted to keep a 1 psi drop or less.
At this point, I can't see that limiting that flow (and possibly increasing the pressure drop through the system, making the turbo work harder) with the 2" pipe would be a good thing.
I wish someone could explain the actual reasoning behind using the 2" to the IC and then the 2.5" to the TB.
The notes on the site did say that the high pressure side of a system was less finicky about flow restrictions than the low pressure suction side (which would be the CAI, SRI, etc.) And that makes sense.
Any more input on this???
USing the calculator, I looked at different lengths of piping, and that didn't change flow all that much. But, using a 2" pipe seriously inhibited flow as compared with a 2.5" pipe. I dont' know what the cfm requirements for the MSP engine is, but the 2" pipe seemed hardly sufficient, if you wanted to keep a 1 psi drop or less.
At this point, I can't see that limiting that flow (and possibly increasing the pressure drop through the system, making the turbo work harder) with the 2" pipe would be a good thing.
I wish someone could explain the actual reasoning behind using the 2" to the IC and then the 2.5" to the TB.
The notes on the site did say that the high pressure side of a system was less finicky about flow restrictions than the low pressure suction side (which would be the CAI, SRI, etc.) And that makes sense.
Any more input on this???
GA_MZDASPEED
Member
- :
- 2003.5 Titanium Speed
Hot air is thinner (less mass/volume, very low viscosity) and can be forced through smaller openings using less energy (think: water through a straw vs milk shake) the milk shake IS less dense but more viscous. If fluid dynamics can be used for advanced aerodymanics it makes sense that the idea of viscosity can be used in this discussion. the opening that ALMOST ALL of exhaust gases exit the turbo through is very small. this is done on purpose the small opening creates the EXTREME velosities that are needed to spool up the turbo and compress the cooler denser air on the compressor side. between the exhaust pulses of the engine these high velocity gases will accually PULL the slower gases behind it. the gases that get compressed on the compessor side rise in tempeture by hundreds of degrees. these now hot gases must now exit the compressor housing and do so through a relatively small opening to maintain this velosity and take advantage of the scavenging effect the high velosity gas has on the gases behind it. this means that the velocity of the hot gas is most important.(hot charge air in this instance) equal volume of gas through smaller hole = higher velocities
these gases then pass through the intercooler (or interwarmer) and emerge out the other side cooler denser and harder to push through the same diameter piper. while you can do it if you want to it will compress the gases and reheat them some (SEE : ideal gas law). the larger diameter pipe will move the gases with minimal reheating of the charge air.
also the velocity of the intake charge it not as important as one would think (in the charge pipe). the intake manifolds on modern engines are HIGHLY engineered to take advantage of the intake stroke pulses and tuned to produce a compromise of volume and velocity through the length and shape of the intake runners in combination w/ the specific volume of the plenum feeding those runners....so the intake charge velocities are generated there and the charge pipe can be larger to keep the reheating to a minimum.....you know.........maybee?
(blah)(blah)(blah)(blah)
these gases then pass through the intercooler (or interwarmer) and emerge out the other side cooler denser and harder to push through the same diameter piper. while you can do it if you want to it will compress the gases and reheat them some (SEE : ideal gas law). the larger diameter pipe will move the gases with minimal reheating of the charge air.
also the velocity of the intake charge it not as important as one would think (in the charge pipe). the intake manifolds on modern engines are HIGHLY engineered to take advantage of the intake stroke pulses and tuned to produce a compromise of volume and velocity through the length and shape of the intake runners in combination w/ the specific volume of the plenum feeding those runners....so the intake charge velocities are generated there and the charge pipe can be larger to keep the reheating to a minimum.....you know.........maybee?
(blah)(blah)(blah)(blah)
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