Crossover pipe sizing (600hp)
01-29-2016, 02:44 PM
#1
Crossover pipe sizing (600hp) I am in the middle of my turbo build and have seen this asked several times with differing suggestions. Yes I searched and still not satisfied!
My drivers side will have about 4'+ of tubing and the passenger side maybe about 1'.
I have a bunch of 2.5 mandrel bent tubing I could make it with but dont want to make it too large to affect when the turbo will come on line.
So is 2.5" too large for this application, or even as small as 2" in order to keep air speed higher into the turbo?
Its in a Tacoma with a long drivers side crossover that wraps underneath between the motor and trans.
Thoughts or suggestions?
My drivers side will have about 4'+ of tubing and the passenger side maybe about 1'.
I have a bunch of 2.5 mandrel bent tubing I could make it with but dont want to make it too large to affect when the turbo will come on line.
So is 2.5" too large for this application, or even as small as 2" in order to keep air speed higher into the turbo?
Its in a Tacoma with a long drivers side crossover that wraps underneath between the motor and trans.
Thoughts or suggestions?
01-29-2016, 03:20 PM
#4
Short answer: I would go with 2"
Long ramblings about pipe sizes and the price of tea in china:
I am running a log manifold so not apples to apples but I ran a 2.5" crossover and wish I had gone smaller. There are a lot of variables that you didn't provide info for but the bottom line is 2" is more than enough from each side and it is easier to package.
On the other hand, if you have 2.5" and don't want to spend money on 2" it will work and you should reach your power goal just fine (depending on motor and turbo) but you would probably be happier with the 2" performance wise.
Spool also has a lot to do with tune and converter as well. So while on one hand if I tell you that my setup doesn't cross into positive manifold pressure until 4200 rpm that sounds awful, but I am currently running a silly loose converter that flashes to 4500 on the hit. When I tell you that when I smash the throttle it goes from vacuum to 15 PSIG in about 1 second (and annihilates the tires on the street) it suddenly doesn't sound so bad.
Long ramblings about pipe sizes and the price of tea in china:
I am running a log manifold so not apples to apples but I ran a 2.5" crossover and wish I had gone smaller. There are a lot of variables that you didn't provide info for but the bottom line is 2" is more than enough from each side and it is easier to package.
On the other hand, if you have 2.5" and don't want to spend money on 2" it will work and you should reach your power goal just fine (depending on motor and turbo) but you would probably be happier with the 2" performance wise.
Spool also has a lot to do with tune and converter as well. So while on one hand if I tell you that my setup doesn't cross into positive manifold pressure until 4200 rpm that sounds awful, but I am currently running a silly loose converter that flashes to 4500 on the hit. When I tell you that when I smash the throttle it goes from vacuum to 15 PSIG in about 1 second (and annihilates the tires on the street) it suddenly doesn't sound so bad.
01-29-2016, 04:43 PM
#6
Short answer: I would go with 2"
Long ramblings about pipe sizes and the price of tea in china:
I am running a log manifold so not apples to apples but I ran a 2.5" crossover and wish I had gone smaller. There are a lot of variables that you didn't provide info for but the bottom line is 2" is more than enough from each side and it is easier to package.
On the other hand, if you have 2.5" and don't want to spend money on 2" it will work and you should reach your power goal just fine (depending on motor and turbo) but you would probably be happier with the 2" performance wise.
Spool also has a lot to do with tune and converter as well. So while on one hand if I tell you that my setup doesn't cross into positive manifold pressure until 4200 rpm that sounds awful, but I am currently running a silly loose converter that flashes to 4500 on the hit. When I tell you that when I smash the throttle it goes from vacuum to 15 PSIG in about 1 second (and annihilates the tires on the street) it suddenly doesn't sound so bad.
Long ramblings about pipe sizes and the price of tea in china:
I am running a log manifold so not apples to apples but I ran a 2.5" crossover and wish I had gone smaller. There are a lot of variables that you didn't provide info for but the bottom line is 2" is more than enough from each side and it is easier to package.
On the other hand, if you have 2.5" and don't want to spend money on 2" it will work and you should reach your power goal just fine (depending on motor and turbo) but you would probably be happier with the 2" performance wise.
Spool also has a lot to do with tune and converter as well. So while on one hand if I tell you that my setup doesn't cross into positive manifold pressure until 4200 rpm that sounds awful, but I am currently running a silly loose converter that flashes to 4500 on the hit. When I tell you that when I smash the throttle it goes from vacuum to 15 PSIG in about 1 second (and annihilates the tires on the street) it suddenly doesn't sound so bad.
They're definitely great for packaging.
01-29-2016, 05:53 PM
#7
I went with 2.5" Sched 40 MS. I have no complaints seemed to be what others used and I think its right for both sides into one. I personally like how clean it makes everything look and don't think it is holding me back much if at all. It probably isn't the most efficient design but seems to be doin work just fine and after almost a year it seems to be holding together just fine.
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02-01-2016, 01:20 PM
#9
Good to know, still trying to figure out how I am going to build my passenger manifold, I built a pair of headers and plan on using the drivers side since it snakes around the steering shaft, run the tubing to the passenger side, not sure if I want to go with a log type manifold where the other bank feeds into it or just another shorty tube type manifold that faces forward...
Such a pain in a Tacoma is it has the tightest engine bay in history!! Ugh I get so jealous and see everybody elses swaps have so much space!
My 90 degree intake elbow off of the TB actually hits the radiator/fan setup. its tight!
Such a pain in a Tacoma is it has the tightest engine bay in history!! Ugh I get so jealous and see everybody elses swaps have so much space!
My 90 degree intake elbow off of the TB actually hits the radiator/fan setup. its tight!
02-01-2016, 05:05 PM
#11
Staging Lane
When estimating sizes: with .059" (16 gauge) wall thickness, the area varies as the square of the ID.
2" = 2.78 in.2
2-1/4" = 3.57 in.2 (+28% of 2")
2-1/2" = 4.46 in.2 (+60% of 2")
2" = 2.78 in.2
2-1/4" = 3.57 in.2 (+28% of 2")
2-1/2" = 4.46 in.2 (+60% of 2")
02-02-2016, 12:50 PM
#12
Thank you for posting that!!
02-02-2016, 12:54 PM
#13
I think I am going to put it all back together with the NA setup for a day or two so I can tune it with the new Camshaft, 80# injectors, 243 heads (ported with hollow valves) with upgraded springs, and a 450lph fuel pump so I have a decent base tune for when the turbo goes on I dont have to start from scratch.
Just a thing I tend to do with all my turbo builds, I have found that it really helps save time on the tune since it gets you in the ballpark anyway..
BTW do you have any pics of that system installed complete from a few angles to give me some creative motivation?? Thx!
Last edited by Speed Freek; 02-02-2016 at 01:13 PM.
02-07-2016, 05:59 PM
#16
Good to know, still trying to figure out how I am going to build my passenger manifold, I built a pair of headers and plan on using the drivers side since it snakes around the steering shaft, run the tubing to the passenger side, not sure if I want to go with a log type manifold where the other bank feeds into it or just another shorty tube type manifold that faces forward...
Such a pain in a Tacoma is it has the tightest engine bay in history!! Ugh I get so jealous and see everybody elses swaps have so much space!
My 90 degree intake elbow off of the TB actually hits the radiator/fan setup. its tight!
Such a pain in a Tacoma is it has the tightest engine bay in history!! Ugh I get so jealous and see everybody elses swaps have so much space!
My 90 degree intake elbow off of the TB actually hits the radiator/fan setup. its tight!
02-08-2016, 02:35 PM
#18
I think there is a reason that LS swaps in Tacomas arent a common occurrence. As far as I know I am the first person to swap am LS motor into a 1st gen Tacoma successfully.
I did it back in late 2011. I had to cut the frame in the front and cut out the trans cross-member to make it removable.
I still havent seen another 1st gen Tacoma 5 lug since then, although I am sure others have been completed after seeing my build threads on other forums showing what was done to make it fit.
Me? I have a T56. Or was this for another poster??
I just pulled the motor/trans back out yesterday after the trans started making weird noises like it did during the initial failure...bummer. Now I gotta figure out what I missed since I apparently did'nt fix what was wrong, I simply replaced the broken parts thinking I WAS fixing it....
Since I pulled the whole drivetrain again I am just going to fab up the turbo now so its going back together with some BEWST!