2 1/4'' Intercooler piping (hotside) - Potential Restrictions...

[EVO85]

I was wondering...who is using 2 1/4" intercooler piping for the hotside and what power are you making? What would the maximum power output (roughly) before this setup becomes restrictive?

I have just had aluminium intercooler piping made...2 1/4" hotside into a genuine Evo 5 intercooler with 2 1/4" inlet and outlet. From the intercooler outlet, it joins onto 2 1/2'' on the coldside into the 63mm throttle body elbow. I have all the power parts and the plan was to wring the little Evo3/20g's neck but I fear that i'm going to fall short of my goal. Can 400hp be within reach with this piping setup?

Cheers.

 

[Jonson]

Techincally speaking I think you could have 3" hot side piping and it wont make a difference seeing the turbo outlet on the 16g's are so tiny. I recently had new cooler piping made also, I was looking at having a new 'j' pipe made for the turbo outlet and the exhaust place said they can do it no worries, but it wont make a difference.

Although I've heard stories of people replacing the J pipe and noticing massive gains. So I'm not much help to you, but in my mind I don't see it making any difference for the hot side.

 

[SIVART]

I would keep it 2&half inch all the way and heap wrap the pipe over the manifold

2&quater is better for around 200hp and under

 

[olly]

i run 2 1/4 piping.. it's alright but if you're aiming 400hp you would need to upgrade the piping

 

[EVO85]

I was looking at having a new 'j' pipe made for the turbo outlet and the exhaust place said they can do it no worries, but it wont make a difference.

I have replaced the standard 'J' pipe so now it is 'matched'...should make a minor gain I would have thought...

If the turbo outlets on the 16g are 'so tiny', the 2 1/4" piping shouldn't be a restricting factor, would it? Isn't the big 16g rated @ 380hp and the 16/20g capped at ~ 400?

2&quater is better for around 200hp and under

I was actually after an honest and realistic response from people that had past experience!

 

[SIVART]

I have replaced the standard 'J' pipe so now it is 'matched'...should make a minor gain I would have thought...

If the turbo outlets on the 16g are 'so tiny', the 2 1/4" piping shouldn't be a restricting factor, would it? Isn't the big 16g rated @ 380hp and the 16/20g capped at ~ 400?



I was actually after an honest and realistic response from people that had past experience!

I see what you mean this was my last engine bay

 

[Jonson]

Thats what I was saying Brad, that the piping 'shouldnt' be a restriction because the oultet is just as small if not smaller.

If you have a larger J pipe made then I think thats a good start. Have you had the piping made alreay? Might be worth it just ging to 2.5" for the future maybe, the last thing you want to so is pay to get it made and then have to get it re-made cos it is holding you back.

I can recommend Exhaust Technology on Goodwood Rd, they recently did my cooler piping and it left D&T's work for dead. Decent prices too.

 

[D3bb4]

smallest point is meant to be where restriction occurs, and considering the housing are small as Jon has said; flow wise shouldn't make a difference. Means is constant velocity through the pipe, until reaches the intercooler, where can expand, then restrict again.

So yep... theoretically, shouldn't make a difference. If wanna be even more technical; means is less wall space for the air to experience friction against

 

[mattrat]

can i just ask a question, sort of on the subject, when we have our boost gauges coming from the intake, at the turbo and inside the cooler pipes it must be much higher psi right, like coming out of the turbo would be more like 20 psi if its only set on 10, not a true scale but just saying?
when people say they pressure test their intake for say 20 psi, and their boost is set on 16 psi inside* the intake mani where air will expand after the TB, most likely it will be way above that in the cooler pipes yeh?

 

[EVO85]

Thats what I was saying Brad, that the piping 'shouldnt' be a restriction because the oultet is just as small if not smaller.

If you have a larger J pipe made then I think thats a good start. Have you had the piping made alreay? Might be worth it just ging to 2.5" for the future maybe, the last thing you want to so is pay to get it made and then have to get it re-made cos it is holding you back.

I can recommend Exhaust Technology on Goodwood Rd, they recently did my cooler piping and it left D&T's work for dead. Decent prices too.

The piping's all made mate. I can't go 2.5'' all the way due to to way the intercooler in positioned (taking into consideration the inlets and outlets). There is only enough room for 2 1/4'' next to the headlight or i'll have to start cutting the body (big no no) but having said that, the pipes are incredibly short. It should be fine but when it's back on the road and run in, the first thing i'll be doing is a power run!!!

Thanks boys for you're help!

 

[GVR40]

can i just ask a question, sort of on the subject, when we have our boost gauges coming from the intake, at the turbo and inside the cooler pipes it must be much higher psi right, like coming out of the turbo would be more like 20 psi if its only set on 10, not a true scale but just saying?
when people say they pressure test their intake for say 20 psi, and their boost is set on 16 psi inside* the intake mani where air will expand after the TB, most likely it will be way above that in the cooler pipes yeh?

20psi is 20psi, size has nothing to do with it, the actual amount of air will vary with different size pipes, but the pressure will remain a constant. look at it this way

a turbo putting out 20psi on 3" piping hasa to work a lot harder than a turbo putting out 20psi on 2" piping.

 

[rob323]

Pressure will naturally try to equalise itself everywhere, but you do get pressure losses and flow losses where there are restrictions. It is common to read a slightly lower pressure after an intercooler as opposed to before an intercooler. A similar but smaller loss would also be at the throttle body.

Measure your boost at the intake plenum, as that is where it matters. But to answer your question, yes the boost pressure would be slightly higher in the J pipe than it would be in the plenum.