Replacing intercooler piping

Was under the bonnet the other day after driving & noticed the intercooler-engine rubber pipe thing (not a mechanic) was bloody hot, not surprising seeing as it sits atop the engine.
Anyway, it got me thinking its kind of defeating the object of the intercooler (which baffles me enough), and maybe replacing it would be a good idea, maybe even a pipe within a pipe with some sort of insulation between would be a good idea.
Then I thought I might be pissing in the breeze though as the air will be flying through that pipe so quick that it won't have time to heat up.
Perhaps a hard pipe would be less restrictive too? I don't know.
Any opinions would be good, i'm not a mechanic so a fair bit of my ideas have been formulated after a few bevvies.

Hard pipe is the way to go for sure. Probably wont help with cooling but sure makes a difference to throttle response, my standard hose expanded like a balloon on boost.

Have you done it in hard pipe? Where would I get the stuff?

There's another advantage to using a hard pipe. A plastic pipe under heat will soften and a restriction in the air intake could cause the pipe to contract.

I also doubt that the heat will have a lot of effect on the air, but do think that replacing the straight sections of pipe with metal will probably serve to remove any concerns about the pipe causing a constriction.

I'm sure some auto performance shops would sell the stuff, failing that you'd surely get some from someone that manufactures intercoolers.

justdrinkbeer said:

Have you done it in hard pipe? Where would I get the stuff?

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Yep done mine! Ebay of course.

08KINGCAB said:

Yep done mine! Ebay of course.

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Got a pic or two? Pipework and intercooler are the next OE on the list to be replaced by some decent equipment.

Gus

Is there anything that isn't on ebay?
Now then, is there any advantage in getting piping that is bigger than the rubber stuff i've got? And do i get it welded or are the silicone joiners ok?

If you use mostly metal pipe and have like a 50mm section of silicon hose that joins the two together, it's just about impossible for that silicon section to collapse, so it shouldn't cause you any grief at all. It's how I'd do it!

So I just went and had a poke about, not sure how it all works but what i see is:
1. Air into snorkel
2.Air into filter
3. Air into Turbo
4. Air gets speeded up and sent to intercooler.
5. Chilly air get sent into a silver thing that must be something to do with injectors.

So, I see a couple of problems along the way.
Pipe from air cleaner to turbo is about 3inch
Pipe from turbo past motor is soft rubber stuff, which comes out of a flanged metal pipe which looks about 40mm dia (heaps smaller).
From this metal pipe (also has a pretty tight bend) it goes into a weird looking metal pipe thing and pipe is about 60mm dia.
From metal pipe thing it curls around the motor, drops down behind/beside the radiator (soft rubber) at 60mm dia.
Here it joins a piece of steel pipe about 50mm dia, which connects via rubber joiner thing to intercooler.
Now, on the other side of the intercooler it connects to the silver thing (i'll call it the injectors) via a rubber hose about 90mm dia.

My point is, before I crack out the hacksaw and a 6pack, would it make sense to make the pipe all the size of the largest pipe (90ish mm)?
And could the metal pipe that bolts to the flange on the turbo be made less restrictive cos at the moment it looks a bit ordinary.

Sorry for the long post, just a bit interested in getting it to pick up its heels a bit quicker.
Also how nissan have pinched a bit more power from it

good call justdrinkbeer......on the 6 pack that is..

I'm no turbo expert but, the way I see it is the larger pipe on the air filter size is to allow the volume of air into the turbo, from there the air is compressed, so the pipe doesn't need to be as large, the stainless steel silencer isn't really that restrictive nor are the bends, it's the intercooler itself that's represents the largest bottle neck. But this will only effect the lag, once on boost, the shape, size, materials of construction would become irrelevant, on this size motor and type.
The advantage of changing to the hard pipe is to get better throttle response off idle, as there is a lag time of boosting up, then the expansion of the hoses.

There's also the added benefit of the hard pipe not being able to collapse when hot. Plastic is, well, plastic.

Measured up everything, will put this on my "to do one day list".
Thinking of doing the bit between the Air Box & the Turbo too but there is a sensor or something plugged in it, anyone know what it is?

justdrinkbeer said:

Measured up everything, will put this on my "to do one day list".
Thinking of doing the bit between the Air Box & the Turbo too but there is a sensor or something plugged in it, anyone know what it is?

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Not sure if I have any senors in mine, but I was hesitant about changing that one because of the amount of movement between the motor and body, due to engine torque and vibration. My concern was the joins between the filter box and the snorkel could possibly get pulled apart.
That particular hose on mine is ribbed and quite stiff, it didn't appear to collapse at all when I was reving it up to boost.
I took my hard piping and chip off before my 40K service, there is a noticeable difference in throttle response.
I'll put them back on this weekend!

Do you reckon you could replace the hard pipes before the chip and take it for a spin,and let us know if just the pipes make a difference?

navarian said:

Do you reckon you could replace the hard pipes before the chip and take it for a spin,and let us know if just the pipes make a difference?

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Will do.
Ian I remember your hose felt a lot stiffer than mine anyway. So I don't think it would have as much an effect on your truck.

That sounds bad, I was referring to the turbo/intercooler hose everyone!

No worries,when they eventually need replacing i will probably go the hard pipes.
The hard pipes looks great as well.

08KINGCAB said:

Not sure if I have any senors in mine, but I was hesitant about changing that one because of the amount of movement between the motor and body, due to engine torque and vibration. My concern was the joins between the filter box and the snorkel could possibly get pulled apart.
That particular hose on mine is ribbed and quite stiff, it didn't appear to collapse at all when I was reving it up to boost.
I took my hard piping and chip off before my 40K service, there is a noticeable difference in throttle response.
I'll put them back on this weekend!

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I see that one has a concertina type arrangement which I assume is for that movement, although a couple of silicone joiners might be ok.
Will get a picture of sensor jobbie, whatever it is definitely aint waterproof cos it just pushes in which is a bit of a worry.
that hose on mine is also ribbed bus is soft as, especially when engine is hot.
How bout from Intercooler to Injector throttle jobbie, did you do that? Looks tricky, with a few bends close together, but is pretty soft.
Did you consider changing the intercooler as it looks like it may be a bit restrictive itself?

justdrinkbeer said:

I see that one has a concertina type arrangement which I assume is for that movement, although a couple of silicone joiners might be ok.
Will get a picture of sensor jobbie, whatever it is definitely aint waterproof cos it just pushes in which is a bit of a worry.
that hose on mine is also ribbed bus is soft as, especially when engine is hot.
How bout from Intercooler to Injector throttle jobbie, did you do that? Looks tricky, with a few bends close together, but is pretty soft.
Did you consider changing the intercooler as it looks like it may be a bit restrictive itself?

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I have only done the long hose from the turbo to intercooler, Your right about the other hose, it would require some cutting and welding of the bends to get the right fitment.
I think 4.8GU has a complete intercooler and hard pipe upgrade kits, That's the way I would prefer to go, something that I can just bolt in.

Time is precious at the moment.

I have been looking at this mod for a bit now and was thinking. (shut lookout here im thinking)

Putting aside the expansion / shrinkage of rubber hoses and the cooling ability of an upgraded intercooler. which has there own results.

With a diesel having no throttle butterfly and not that large intake of air as its only a 2.5Lt.
If you install larger piping from the airbox to the "injector thingy" does it provide any benifet as the turbo can only breathe so much air if you derestrict this passage of air by making the volume larger wont you lose boost slightly and reduce the air speed within the piping resulting in......well....nothing but a few skinned knuckles??!!?!

im no turbo expert may I add.