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is 2 3/4 too big from the throttle body down to the end tank, and then use 2 1/4 for hot pipe???
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It doesn't really matter. Use whatever size is easiest to route, buy, weld, fit whatever. There was an engineer that did all the calculations on different size piping and found the difference in "lag" was in the milliseconds over the average distance of I/C piping.
Just some basics though:
Compress air, it gets hot, let it expand, it cools off. My theory is to run bigger piping out of the turbo ASAP to expand the air and cool it that little bit more. But my main consideration was my I/C and TB were both 2.5" so thats what I used.
Just some basics though:
Compress air, it gets hot, let it expand, it cools off. My theory is to run bigger piping out of the turbo ASAP to expand the air and cool it that little bit more. But my main consideration was my I/C and TB were both 2.5" so thats what I used.
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Cronic, read what I said above, its all negligable. And also like I said, pressure drop means cooler. How much cooler? Not much, but then again, it works both ways. How much pressure drop will there be? Not much.
Plus, many turbo's include this nifty device called a wastegate. What this does is run 10psi no matter how big the piping is (within limits of course) so again, we're worrying about trivial shit.
Just use whatever is easiest and stop worrying about it. You'll have much more to worry about than the extra pressure drop a .25" bigger pipe will allow.
Plus, many turbo's include this nifty device called a wastegate. What this does is run 10psi no matter how big the piping is (within limits of course) so again, we're worrying about trivial shit.
Just use whatever is easiest and stop worrying about it. You'll have much more to worry about than the extra pressure drop a .25" bigger pipe will allow.
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no, actually its not trivial. Boost is a relative term.
what you want to do is compare shaft speed at the boost that you are intending to run. cuz 70,000rpm @ 10 psi is giong to create less heat than 170,000rpm @ 10psi. its a matter of how much volume you are trying to push thru the pipe. you can have 20 lb/min of air at 10psi and 70000 rpm, and you can also have 32 lb/min of air at 10psi but be spinning at 170000 rpm.. boost is not the most important thing.
and the lag created by overly-large intercooler pipes and intercoolers does effect the operation of the engine...
for instance:
w/ stock intercooler and pipes, the engine expects the air counted by the MAF to reach the engine in, say, 4 seconds (for argument's sake). If you add a larger diameter pipes, longer pipes and/or a larger volume intercooler this will all add a delay in time from when the intake charge gets counted by the MAF and it actually passes thru the TB; this might take 5 seconds longer than the stock system did. now, the ECu thinks the influx of air is giong to be there in 4 seconds after being counted by the MAF, even though it Realy is still inside the intercooler... and now the ECU is going to add what it THINKS is the appropriate amount of fuel for that massive amount of air. all ths is going to do is cause the engine to load up and stumble and reduce the throttle response.
2.75" is going to be a little overkill for a litle T25, 2.25 would be a good size for it. but im sure you wont be keeping the little turbo. id go w/ 2.5" on both sides cuz its good all around size and will flow enough air for even a really mean ass setup... as long as you can live w/ the "negligible" amount lag.
i hope that helps
what you want to do is compare shaft speed at the boost that you are intending to run. cuz 70,000rpm @ 10 psi is giong to create less heat than 170,000rpm @ 10psi. its a matter of how much volume you are trying to push thru the pipe. you can have 20 lb/min of air at 10psi and 70000 rpm, and you can also have 32 lb/min of air at 10psi but be spinning at 170000 rpm.. boost is not the most important thing.
and the lag created by overly-large intercooler pipes and intercoolers does effect the operation of the engine...
for instance:
w/ stock intercooler and pipes, the engine expects the air counted by the MAF to reach the engine in, say, 4 seconds (for argument's sake). If you add a larger diameter pipes, longer pipes and/or a larger volume intercooler this will all add a delay in time from when the intake charge gets counted by the MAF and it actually passes thru the TB; this might take 5 seconds longer than the stock system did. now, the ECu thinks the influx of air is giong to be there in 4 seconds after being counted by the MAF, even though it Realy is still inside the intercooler... and now the ECU is going to add what it THINKS is the appropriate amount of fuel for that massive amount of air. all ths is going to do is cause the engine to load up and stumble and reduce the throttle response.
2.75" is going to be a little overkill for a litle T25, 2.25 would be a good size for it. but im sure you wont be keeping the little turbo. id go w/ 2.5" on both sides cuz its good all around size and will flow enough air for even a really mean ass setup... as long as you can live w/ the "negligible" amount lag.
i hope that helps
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ok i was thinking along the lines of....
turbo to end tank 2 1/4 and then towards the end weld on a little 2 inch piece for the silicone connectors because my end tanks are 2 inch
from throttle body to end tank... 2 3/4 about 1/4 of the way and then gradually make it to 2 inches...
2 3/4
2 1/2
2 1/4
ad then 2... because that is pretty much what the stock IC piping does so i would imagine doing so for a FMIC would make THAT much difference...
turbo to end tank 2 1/4 and then towards the end weld on a little 2 inch piece for the silicone connectors because my end tanks are 2 inch
from throttle body to end tank... 2 3/4 about 1/4 of the way and then gradually make it to 2 inches...
2 3/4
2 1/2
2 1/4
ad then 2... because that is pretty much what the stock IC piping does so i would imagine doing so for a FMIC would make THAT much difference...
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Jonas
2001 Nissan Maxima GLE FORSALE.
http://tampa.craigslist.org/pnl/cto/3952387467.html
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Jonas
2001 Nissan Maxima GLE FORSALE.
http://tampa.craigslist.org/pnl/cto/3952387467.html
For sale: tool cart, air tools, welding stuff, sata jet RP digital spray gun + more
http://tampa.craigslist.org/pnl/tls/3952277623.html
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bahh and actually along the lines of 11-12 psi...hopefully heh
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Jonas
2001 Nissan Maxima GLE FORSALE.
http://tampa.craigslist.org/pnl/cto/3952387467.html
For sale: tool cart, air tools, welding stuff, sata jet RP digital spray gun + more
http://tampa.craigslist.org/pnl/tls/3952277623.html
Jonas
2001 Nissan Maxima GLE FORSALE.
http://tampa.craigslist.org/pnl/cto/3952387467.html
For sale: tool cart, air tools, welding stuff, sata jet RP digital spray gun + more
http://tampa.craigslist.org/pnl/tls/3952277623.html
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Originally posted by flubyux2
no, actually its not trivial. Boost is a relative term.
what you want to do is compare shaft speed at the boost that you are intending to run. cuz 70,000rpm @ 10 psi is giong to create less heat than 170,000rpm @ 10psi. its a matter of how much volume you are trying to push thru the pipe. you can have 20 lb/min of air at 10psi and 70000 rpm, and you can also have 32 lb/min of air at 10psi but be spinning at 170000 rpm.. boost is not the most important thing.
and the lag created by overly-large intercooler pipes and intercoolers does effect the operation of the engine...
for instance:
w/ stock intercooler and pipes, the engine expects the air counted by the MAF to reach the engine in, say, 4 seconds (for argument's sake). If you add a larger diameter pipes, longer pipes and/or a larger volume intercooler this will all add a delay in time from when the intake charge gets counted by the MAF and it actually passes thru the TB; this might take 5 seconds longer than the stock system did. now, the ECu thinks the influx of air is giong to be there in 4 seconds after being counted by the MAF, even though it Realy is still inside the intercooler... and now the ECU is going to add what it THINKS is the appropriate amount of fuel for that massive amount of air. all ths is going to do is cause the engine to load up and stumble and reduce the throttle response.
2.75" is going to be a little overkill for a litle T25, 2.25 would be a good size for it. but im sure you wont be keeping the little turbo. id go w/ 2.5" on both sides cuz its good all around size and will flow enough air for even a really mean ass setup... as long as you can live w/ the "negligible" amount lag.
i hope that helps
no, actually its not trivial. Boost is a relative term.
what you want to do is compare shaft speed at the boost that you are intending to run. cuz 70,000rpm @ 10 psi is giong to create less heat than 170,000rpm @ 10psi. its a matter of how much volume you are trying to push thru the pipe. you can have 20 lb/min of air at 10psi and 70000 rpm, and you can also have 32 lb/min of air at 10psi but be spinning at 170000 rpm.. boost is not the most important thing.
and the lag created by overly-large intercooler pipes and intercoolers does effect the operation of the engine...
for instance:
w/ stock intercooler and pipes, the engine expects the air counted by the MAF to reach the engine in, say, 4 seconds (for argument's sake). If you add a larger diameter pipes, longer pipes and/or a larger volume intercooler this will all add a delay in time from when the intake charge gets counted by the MAF and it actually passes thru the TB; this might take 5 seconds longer than the stock system did. now, the ECu thinks the influx of air is giong to be there in 4 seconds after being counted by the MAF, even though it Realy is still inside the intercooler... and now the ECU is going to add what it THINKS is the appropriate amount of fuel for that massive amount of air. all ths is going to do is cause the engine to load up and stumble and reduce the throttle response.
2.75" is going to be a little overkill for a litle T25, 2.25 would be a good size for it. but im sure you wont be keeping the little turbo. id go w/ 2.5" on both sides cuz its good all around size and will flow enough air for even a really mean ass setup... as long as you can live w/ the "negligible" amount lag.
i hope that helps
) made very specific calculations and found differences in pipe diameter to affect spool in milliseconds. Can you count milliseconds? RUN WHATEVER IS EASIEST
