2" or 2.5" IC pipes?
#1
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Everyone keeps yelling at me about my starion IC, so I'm going to replace it with a big son of a bitch( more money, more weight, pointless) well I really don't care, I like them big
<~~~ that was for the next comment you guys will say. Anyways the question is should I go with 2" or 2.5" IC pipes? Is there an avantage? Let me know your opinions
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Your Dad
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Your Dad
#2
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2" hot side, 2.5" cold side is the norm.
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#4
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... nothing I say here will be clever enough to make it worth it... I'll leave this one to someone else
I'm not an engineer, but its my understanding that smaller pipes = less volume = faster boost response. However, being able to flow less volume, you sacrifice top end power. It is also *slightly* tougher to route 2.5" pipes on the hot side depending on which way you go, whether you still have ac/ps, and how your compressor housing is oriented. I went with 2.5", but my engine bay is super gutted. I've also seen guys do 2" on the hot side, and 2.5" on the cold side. It's really about personal preference and what you have to work with.
ps. sorry if this wasn't much help.
Originally Posted by miataspeed2005
Anyways the question is should I go with 2" or 2.5" IC pipes? Is there an avantage? Let me know your opinions
Thanks
Your Dad
Thanks
Your Dad
ps. sorry if this wasn't much help.
#7
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No, it's the same as the flow rate through your turbine.
We run larger exhaust to maximize the pressure differential across the turbine.
EDIT:
My BEGi kit uses 1.75" hot and cold side, which I'm sure gives me quite a bit of velocity. Since upgrading to COPS and 2.5" exhaust I haven't seen any drop in power at the big end. I'm only flowing ~80% what you're flowing though.
We run larger exhaust to maximize the pressure differential across the turbine.
EDIT:
My BEGi kit uses 1.75" hot and cold side, which I'm sure gives me quite a bit of velocity. Since upgrading to COPS and 2.5" exhaust I haven't seen any drop in power at the big end. I'm only flowing ~80% what you're flowing though.
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Well my biggest consern was my top end power and torque. If you saw my dyno graph you could see my topend. One I'm leaning out the fuel from 6k on, two I'm upgrading my wastegate and re routing it to my IC cold side, and three 2.5" IC pipes(well maybe that's why I mad a thread)
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You'd be surprised how much a little tuning and simple upgrades can really make some pull at the top end.
I had a thread not too long ago about how to augment the big end since I'm boost limited with this turbo. A few posts in my build thread explain how that problem went away...basically the two mods I mentioned above.
I seriously doubt that 2" piping would limit you...but I haven't done the math. I can tell you that the difference in flow capacity between 2" and 2.5" inch will be significant (~60%) if you want to plan ahead for future upgrades or just be sure now. The trade offs are probably unnoticeable to the butt dyno at your current power level.
I do know that I wouldn't hook up a 2.5" adapter to any compressor outlet less than 2" in diameter. You want to keep pressure drop to a minimum pre-intercooler. This is why 2" hot/2.5" cold is commonly accepted like levnubbin said. Once the air is cooled you can expand it with minimal deltaT, and you have to step up to 2.5" sometime before you hit the throttle body anyhow.
I had a thread not too long ago about how to augment the big end since I'm boost limited with this turbo. A few posts in my build thread explain how that problem went away...basically the two mods I mentioned above.
I seriously doubt that 2" piping would limit you...but I haven't done the math. I can tell you that the difference in flow capacity between 2" and 2.5" inch will be significant (~60%) if you want to plan ahead for future upgrades or just be sure now. The trade offs are probably unnoticeable to the butt dyno at your current power level.
I do know that I wouldn't hook up a 2.5" adapter to any compressor outlet less than 2" in diameter. You want to keep pressure drop to a minimum pre-intercooler. This is why 2" hot/2.5" cold is commonly accepted like levnubbin said. Once the air is cooled you can expand it with minimal deltaT, and you have to step up to 2.5" sometime before you hit the throttle body anyhow.
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But that mass going into your cylinders gets heated up a whole bunch during combustion, causing it to expand. Ideal gas law says PV=nRT. The increase in temp causes the increase in volume that requires your exhaust piping to be bigger than your intake to flow the same mass without creating a restriction.
#13
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A better waste gate and tune will get you there. Unless you're IAT's are high I wouldn't mess with the IC setup at all. Unless you're doing it for aesthetics.
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#15