Pre and post intercooler inlet pressures

[johnR]

I have been told the inlet air pressure on an intercooled 4.2T diesel is 2-3 psi lower behind the intercooler than before the intercooler. That is of course supposed to be denser air but due to the restriction of the intercooler it is actually lower than is the case before the intercooler - pissy thing it is.

Has anyone tested the pressures before and after the intercooler or reconnected the point at which the exhaust relief valve is controlled from?

[John H]

Just fitted a largish (600x300x76) front-mount intercooler. I used to have 12psi at the manifold, now with all of the plumbing it has dropped to 10 or 10.5psi at the same point (the wastegate actuator is turbo mounted).
So my front mount has lost me 1.5 to 2psi — not bad really. I would guess that a Nissan top mount with less pipework would have less pressure drop (but less cooling as well).
Have to say that the difference in torque after fitting the IC is VERY noticeable.

[johnR]

Thanks for the response. I am keen to know also whether it would be ok to get the actuation pressure for the waste gate from the manifold side of the intercooler or would it have a detrimental effect on the turbo. Would it slow down the actuation too much ? By rights you would think it should just lift the turbo boost pressure to the level of the current pressure before the intercooler.

Problem with the Nissan on top intercooler is is a bit small and restrictive and I would have thought should do with a boost.

[blackmav]

Just fitted a largish (600x300x76) front-mount intercooler. I used to have 12psi at the manifold, now with all of the plumbing it has dropped to 10 or 10.5psi at the same point (the wastegate actuator is turbo mounted).
So my front mount has lost me 1.5 to 2psi — not bad really. I would guess that a Nissan top mount with less pipework would have less pressure drop (but less cooling as well).
Have to say that the difference in torque after fitting the IC is VERY noticeable.

Can you show us some pics? Pipe work mainly.

I have to jamb this in

[bilby]

whats wrong with were it is

[blackmav]

whats wrong with were it is

Dont worry, it has been suggested

needs to be a bit bigger for a true top mount

[vn15]

Just fitted a largish (600x300x76) front-mount intercooler. I used to have 12psi at the manifold, now with all of the plumbing it has dropped to 10 or 10.5psi at the same point (the wastegate actuator is turbo mounted).
So my front mount has lost me 1.5 to 2psi — not bad really. I would guess that a Nissan top mount with less pipework would have less pressure drop (but less cooling as well).
Have to say that the difference in torque after fitting the IC is VERY noticeable.

Can you show us some pics? Pipe work mainly.

I have to jamb this in

My new IC looks just the same, was told it was a Spearco unit???

[John H]

Just fitted a largish (600x300x76) front-mount intercooler. I used to have 12psi at the manifold, now with all of the plumbing it has dropped to 10 or 10.5psi at the same point (the wastegate actuator is turbo mounted).
So my front mount has lost me 1.5 to 2psi — not bad really. I would guess that a Nissan top mount with less pipework would have less pressure drop (but less cooling as well).
Have to say that the difference in torque after fitting the IC is VERY noticeable.

Can you show us some pics? Pipe work mainly.

I have to jamb this in

My new IC looks just the same, was told it was a Spearco unit???

I don't have a digi camera so pic's are a bit tricky.
It is basically the same as the one above — pipes are at the top with a hole cut for the plumbing to go through. Had to cut the grill to bits to get it to fit.
Mine is a gineric one from China — cost $175 from the Skylines forum. All of the plumbing cost $350.

[blackmav]

Just fitted a largish (600x300x76) front-mount intercooler. I used to have 12psi at the manifold, now with all of the plumbing it has dropped to 10 or 10.5psi at the same point (the wastegate actuator is turbo mounted).
So my front mount has lost me 1.5 to 2psi — not bad really. I would guess that a Nissan top mount with less pipework would have less pressure drop (but less cooling as well).
Have to say that the difference in torque after fitting the IC is VERY noticeable.

Can you show us some pics? Pipe work mainly.

I have to jamb this in

My new IC looks just the same, was told it was a Spearco unit???

What did you end up with for where it enters the inlet manifold. Instead of the cross-over pipe?

[John H]

<<What did you end up with for where it enters the inlet manifold. Instead of the cross-over pipe?>>

The cross over pipe from my aftermarket turbo kit was a two-piece affair so I just used the manifold end and turned it around to suit the new intercooler plumbing.