Confused on what IC piping i should be using

[icapture]

I am running the SR20 and doing a custom front mount with an IC that has 3" end tanks. Throttle body outlet is 2 3/4" on the SR. Turbo outlet is 2".

 

My buddy an I were wondering what size piping we should be looking for.

 

im gonna be running anywhere from 7lbs - 14lbs on the stock turbo.

 

thanks,

 

adam

[jc052685]

2 1/4 to 2 1/2 would be more than fine

[kiwi303]

rule of thumb I've picked up from reading specs of shop-installed setups is the piping tends to be 1/2 the difference of the throttle body and the turbo outlet.

 

I.E. 2" turbo outlet + 2.5" TB/plenum entry = 2.25" intercooler piping connecting everything.

 

Dunno if there's any reasoning behind this, but it's just what I've seen reading magazine buildups and browsing car shows.

[evildky]

I run 2" hotside and 2.5" cold side on my cars, my logic is that anything bigger than the turbo outlet is an opening for pressure drop, and then i try to match cold side piping to the tb, 2.75 being an odd size

[ktm]

I run 2" hotside and 2.5" cold side on my cars, my logic is that anything bigger than the turbo outlet is an opening for pressure drop, and then i try to match cold side piping to the tb, 2.75 being an odd size

 

If your MAP and WG actuator are set to your manifold pressure, then you can have all of the pressure drops you like. Your MAP will still be your target value since it is referencing your manifold.

 

I am running 2.5-in. all the way. My IC ends are 2.5-in; turbo outlet is 2-in. and TB is 2.75. You have two reducers (2 to 2.5 and 2.5 to 2.75) which result in negligible pressure drops.

[Pyro]

I run 2 inch on the turbo output then 2.5 from the ic to the throttle body.

 

I'm using a T04B-h3 turbine and 12 to 14 psi of boost.

 

The main reason for selecting that size is because it was easy. However, I don't think you will need more than 2 inch from the turbo. The ID on your turbo output is most likely less than 1.5 inches.

[icapture]

cool, thanks alot guys.

[Clifton]

The only reason to go up in size is to keep the air speed down. Bell covers it in his book. With a stock SR turbo I don't think you'll ever outflow a 2" tube.

[AkumaNoZeta]

So what's proven to a better way to route IC piping? Using 2 different sizes for either side of the IC or using a single sized piping thats the medium between turbo outlet and TB?

[jc052685]

If your MAP and WG actuator are set to your manifold pressure, then you can have all of the pressure drops you like. Your MAP will still be your target value since it is referencing your manifold.

 

I am running 2.5-in. all the way. My IC ends are 2.5-in; turbo outlet is 2-in. and TB is 2.75. You have two reducers (2 to 2.5 and 2.5 to 2.75) which result in negligible pressure drops.

 

do not ever use your intake manifold as a referance point for a wastegate. If you do this will cause the turbo to "overboost". This will happen under patial throttle and cruising only. The reason is lets say you are just under 5psi on the boost gauge while merging onto the freeway. Well if you were to measure the boost pressure before the throttle body then it would be rediculous. Not only is this badd for the turbo but will heat soak your intercooler, poor fuel milage, not to mention the harm and unnecessary wear in other components. This is due to the wastegate not getting the proper boost referance. Wastgate needs to get its referance from anywhere before the TB.

 

end.

[mtnickel]

I think you raise some good points here. Unfortunately with my last turbo setup I somehow had a 2-3psi Pressure drop at HIGH RPM. Not so great for performance. Perhaps best solution would have been to fix pressure drop (better intercooler i think), but i just referenced IM instead. IN hindsight...a reference after the intercooler but before IM would have been better.

 

Mark

 

 

do not ever use your intake manifold as a referance point for a wastegate. If you do this will cause the turbo to "overboost". This will happen under patial throttle and cruising only. The reason is lets say you are just under 5psi on the boost gauge while merging onto the freeway. Well if you were to measure the boost pressure before the throttle body then it would be rediculous. Not only is this badd for the turbo but will heat soak your intercooler, poor fuel milage, not to mention the harm and unnecessary wear in other components. This is due to the wastegate not getting the proper boost referance. Wastgate needs to get its referance from anywhere before the TB.

 

end.