Out of curiousity why does everyone use 2.5" on the crossover pipe
#65
2.5 will tuck nicely in the tunnel 3 inch duals however will not. My car has dual tail pipe exits and wanted to use them so if 2.5 pipes will work and not restrict then o want to use them. Just am not sure on that yet.
#67
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I guess the reason I used 2.5 was becaust the vette manifolds I used had 2.5" outlet and the t6 turbo was just about perfect for a 2.5" pipe to either side of the flange. I honestly saw no reason to neck it down to 2.25" coming out of the manifold only to increase it again going into the turbo. I figured keeping it the same throughout would work better. Is this incorrect thinking?
#68
I guess the reason I used 2.5 was becaust the vette manifolds I used had 2.5" outlet and the t6 turbo was just about perfect for a 2.5" pipe to either side of the flange. I honestly saw no reason to neck it down to 2.25" coming out of the manifold only to increase it again going into the turbo. I figured keeping it the same throughout would work better. Is this incorrect thinking?
#69
If the T6 flange is a divided flange, two 2.25" pipes fit snug after a little hammering.
Looking at the area needed to feed a T6 flange, two 2.5" pipes equates to the open area.
That little divider will make a difference if a 2.25" or 2.5" crossover should be used (if you are basing your piping on matching the cross-sectional areas).
Looking at the area needed to feed a T6 flange, two 2.5" pipes equates to the open area.
That little divider will make a difference if a 2.25" or 2.5" crossover should be used (if you are basing your piping on matching the cross-sectional areas).
#70
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Donno, maybe my divider was a little on the slim size, but after hammering the pipe to a rectangular shape that pretty much matched the flange it was almost perfect. I tested with a 2.25" and it was pretty loose. So I decided to step up to 2.5" since that was what fit the c6 manifolds I was using. The flange matched the gasket and the turbo well though. Ideally something in between 2.25 and 2.5 would have been perfect.
But does necking down from the collector to a smaller size have any advantages?
But does necking down from the collector to a smaller size have any advantages?
#71
Donno, maybe my divider was a little on the slim size, but after hammering the pipe to a rectangular shape that pretty much matched the flange it was almost perfect. I tested with a 2.25" and it was pretty loose. So I decided to step up to 2.5" since that was what fit the c6 manifolds I was using. The flange matched the gasket and the turbo well though. Ideally something in between 2.25 and 2.5 would have been perfect.
But does necking down from the collector to a smaller size have any advantages?
But does necking down from the collector to a smaller size have any advantages?
You run your ***** off for the first 200'(intake valve)
then you slow down to speed walk for alittle(header)
you transisition into a slowwww jog(crossover)2.5"
then you run at a good pace(merge)3"
then for the last 200' you run your ***** off again(turbine housing)
Or
run your ***** off for the first 200'(intake)
then you slow down to speed walk for alittle(header)
then run with a very good pace (crossover)2.0
transiition into a short sprint(merge)2.5
and run your ***** off at the end(turbine housing)
#72
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iTrader: (6)
But slow and steady wins the race right? J/k.
So assuming you are not merging the two together (in my case divided housing), it seems like it would be a flow restriction going from a 2.5" collector to a 2.25" pipe only to widen back out to 2.5" again at the turbo. Am I missing something? I am sure I could rework my hot side piping later if need be, I just would like to know your thoughts on necking down then back up like that.
So assuming you are not merging the two together (in my case divided housing), it seems like it would be a flow restriction going from a 2.5" collector to a 2.25" pipe only to widen back out to 2.5" again at the turbo. Am I missing something? I am sure I could rework my hot side piping later if need be, I just would like to know your thoughts on necking down then back up like that.
#74
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iTrader: (12)
But slow and steady wins the race right? J/k.
So assuming you are not merging the two together (in my case divided housing), it seems like it would be a flow restriction going from a 2.5" collector to a 2.25" pipe only to widen back out to 2.5" again at the turbo. Am I missing something? I am sure I could rework my hot side piping later if need be, I just would like to know your thoughts on necking down then back up like that.
So assuming you are not merging the two together (in my case divided housing), it seems like it would be a flow restriction going from a 2.5" collector to a 2.25" pipe only to widen back out to 2.5" again at the turbo. Am I missing something? I am sure I could rework my hot side piping later if need be, I just would like to know your thoughts on necking down then back up like that.
#75
But slow and steady wins the race right? J/k.
So assuming you are not merging the two together (in my case divided housing), it seems like it would be a flow restriction going from a 2.5" collector to a 2.25" pipe only to widen back out to 2.5" again at the turbo. Am I missing something? I am sure I could rework my hot side piping later if need be, I just would like to know your thoughts on necking down then back up like that.
So assuming you are not merging the two together (in my case divided housing), it seems like it would be a flow restriction going from a 2.5" collector to a 2.25" pipe only to widen back out to 2.5" again at the turbo. Am I missing something? I am sure I could rework my hot side piping later if need be, I just would like to know your thoughts on necking down then back up like that.
header tube sees 1/8 of the total airflow
Crossover tube sees 1/2 of the total airflow
merge at the turbo sees the entire engine airflow.
#80
These calculations are based on gasoline combos that have worked well, methanol or an ethanol based fuel would be slightly different. I am using the same sized pipes from C16 and have changed over to methanol, you can tell there is more exhaust velocity/mass based on the additional fuel in the exhaust. The air is still the same just have more of a fuel mass.