What Size Exhaust Tubing for how much boost? (1.8)
12-21-2012, 11:52 AM
#1
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What Size Exhaust Tubing for how much boost? (1.8)
I'm not sure if I can't find it our theres not sticky post?
Is there like a common knowledge for a certain amount of boost/hp for a certain size exhaust. Like Oh a slapon greddy kit is fine with 2.5".
A begi pushing doubled that HP needs 3".. etc..
Is there like a common knowledge for a certain amount of boost/hp for a certain size exhaust. Like Oh a slapon greddy kit is fine with 2.5".
A begi pushing doubled that HP needs 3".. etc..
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12-21-2012, 12:01 PM
#3
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3" with large free flow muffler- non turbo.
3" with large free flow muffler- low boost turbo/super charger 5-10lbs
3" with large free flow muffler- higher boost levels 12-xxlbs
These are rules to live by.
3" with large free flow muffler- low boost turbo/super charger 5-10lbs
3" with large free flow muffler- higher boost levels 12-xxlbs
These are rules to live by.
Last edited by Braineack; 12-21-2012 at 12:20 PM.
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12-21-2012, 12:50 PM
#10
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bullshit.
my BEGI 2.25" to 2.5" DP, to 2.25" cat, to 2.25" borla exhaust
to the same Begi 2.25" to 2.5" DP, 3" cat, and 3" catback:
same dyno. same boost*.
*was getting creep, so i lifted.
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12-21-2012, 01:46 PM
#15
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The only reason to not do a 3" exhaust on a turbo car is because you can't afford it AND you're too lazy to build one yourself.
N/A cars should get 2.25" straight-through systems.
N/A cars should get 2.25" straight-through systems.
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12-21-2012, 02:03 PM
#16
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Lol, don't hate at me bro! Its not my data and its the only comparison I could quickly find.
Your results are obviously better. I believe Curly has something similar going from his Frankenstein exhaust to a 3" ARTech? Couldn't find it quickly.
Ironically, I'm using Cordus old catted 2.5" FM turbo exhaust on my NB with the Rotrex and an BP6D exhaust manifold and factory downpipe. It's less than ideal, but it works for now. I will eventually be replacing manifold with a RB unit and the muffler with a 2.5" Magnaflow 5x11x22 because the ancient FM muffler has definitely seen better days. It's actually significantly quieter than expected, but it rasps on throttle stomps.
Your results are obviously better. I believe Curly has something similar going from his Frankenstein exhaust to a 3" ARTech? Couldn't find it quickly.
Ironically, I'm using Cordus old catted 2.5" FM turbo exhaust on my NB with the Rotrex and an BP6D exhaust manifold and factory downpipe. It's less than ideal, but it works for now. I will eventually be replacing manifold with a RB unit and the muffler with a 2.5" Magnaflow 5x11x22 because the ancient FM muffler has definitely seen better days. It's actually significantly quieter than expected, but it rasps on throttle stomps.
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12-21-2012, 03:04 PM
#17
The considerations for a SC car are different and more like doing the exhaust for an NA car (taking into consideration some additional flow). Things like sizing the pipe diameter and length to promote scavenging become important. Bottom line, on an SC car run a good header and an exhaust system matched to the header. That will likely be smaller than a 3".
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12-21-2012, 03:15 PM
#18
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Turbo cars are much more sensitive to the exhaust size because the turbine acts as a backpressure multiplier.
The considerations for a SC car are different and more like doing the exhaust for an NA car (taking into consideration some additional flow). Things like sizing the pipe diameter and length to promote scavenging become important. Bottom line, on an SC car run a good header and an exhaust system matched to the header. That will likely be smaller than a 3".
The considerations for a SC car are different and more like doing the exhaust for an NA car (taking into consideration some additional flow). Things like sizing the pipe diameter and length to promote scavenging become important. Bottom line, on an SC car run a good header and an exhaust system matched to the header. That will likely be smaller than a 3".
Ok, back to the trubo stuff. Who has more apples to apples comparison data for exhaust upgrades?
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