Im curious if anyone has done any experimentation with different sizes of piping pre and post intercooler. What were your results?

 

The results are that 2.75 inch works very well and there's no real need to go smaller or larger on a street FD

You're better off playing around with turbo compressor and turbine sizing as well as components on the exhaust side like downpipe size and waste gate placement IMO.

 

bends in intercooler piping kill flow, try to smooth out all the bends and have cast end tanks that fan the air out well.

 

i have a curious question about this . I am in the process of swapping to a single turbo , and I wanted a very fast spooling turbo . so i got a .70 / 1.15 T61 .60 A/R obviously

And the turbo's flange for the intercooler piping is only 2 inches... i figured that flow is always going to be limited by the narrowest part of the system .

if that narrowest part is the turbo itself . Than is there a point to running a 2.75 system ???

This turbo will only be temporary so I'm not going to change my system because of it , but I was curious about weather the narrow turbo would hurt flow .

 

i figured that flow is always going to be limited by the narrowest part of the system .

if that narrowest part is the turbo itself . Than is there a point to running a 2.75 system ???

Not really kinda.
Yes, the narrowest part of a system does set the ultimate flow limit (this is why they use inlet restrictors in racing), but the narrowest section can flow much more than having the whole system that same narrow size.

On IC sytem/piping you have have losses to the intake energy from friction, turbulence and velocity decrease from volume increase.

When I did my piping I did slow, smooth transitions from the 2" turbo outlet to the 2.75" TB elbow inlet, kept the piping short and minimum # of bends.

On a standard IC core (non laminova) you still have to have a transition to turbulent flow when the intake enters/exits the IC end tanks for even/eased distribution of flow through the many IC core passages.

What I personally did was bell mouth my 2" turbo outlet > 2"to2.25" coupler > 2.25" pipe > 2.25"to2.5" coupler > 2.5" inlet pipe on IC > 2.75" pipe on IC outlet (flow is already slow & recovering from turbulence) > 2.75" all the way to the 2.75" inlet on the TB elbow.

Alternatively, I have seen several JDM race cars that used a continuously expanding volume pipe from turbo to IC and then just "big" from IC to TB.

I also flared and knife edged all pipe ends (instead of rolling beads) for less turbulence.

I kept the bends to One 90 deg as large a radius as possible (off the turbo) and one 15 deg bend (off the IC).

I kept the IC piping down to around 2ft total.

I polished everything internally.

My FC made 340rwhp on 10psi on a 57mm turbo (pretty good) and then later 420rwhp/420rwtq on a different 57mm turbo at high boost (26psi taper to 21psi).
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Since that set-up, I have been bothered by the requirement to trip the flow to turbulent to get through the IC core, so I have an idea on laminar flow inlet/outlet/core IC. Let me know if you want more info on that.

 

Absolutely this isnt somethign that would be very difficult to do as I dont have much IC piping , and it wouldnt be expensive in the least so I would love to know more , and i'm sure it would be beneficial to the community

 

Absolutely this isnt somethign that would be very difficult to do as I dont have much IC piping , and it wouldnt be expensive in the least so I would love to know more , and i'm sure it would be beneficial to the community

Well, it is expensive because it utilizes Laminova air to water cores and involves a lot of fabrication.

My idea is to put the Laminova cores in a circle and have the inlet pipe keep a constant volume while changing shape to wrap around the outside of the circle of Laminova cores decreasing as it passes each core by the volume on the individual core inlet area.

On the Laminova cores' outlets (on the inside of the circle) there is a lengthwise cone shaped piece that varies volume of the outlet to the maximum of the cores' outlet volume.

This internal cone is truncated on the small end at which attaches a 4150 style 4 barrel throttle body to the 4 intake runners.

In this system, I think it would be possible to trip the airflow to turbulent only at the junction of the truncated cone to the TB for best airflow distribution while possibly? maintaining laminar flow from the turbo outlet through the intercooler for low pressure drop/high velocity.

Not sure on that, it would take some computational flow modeling. It might end up creating a cyclonic flow on the surface of the truncated cone on to the TB that makes things get weird.

This A2W IC would sit transverse across the engine with the TB on the intake side and 135 deg arcing runners to the ports (on FD) or 180 deg on earlier straight port runner engines.

I will put up a sketch when I get some time.

edit- attach sketch

 

keep the piping as short and simple as possible