1HDT intercooler pros and cons

[Druepy]

I just bought a HDJ81 a few weeks ago and it came with an intercooler installed. I recently had someone that knows about these engines recommend taking it off to return the intake system to stock. Does anyone with more knowledge then me have an option on this topic? The way I see it is that the intercooler cools intake air temperature. On the flip side I've read that an intercooler can decrease power (by way of increasing the distance the air has to travel to reach the engine). The other question is: does air fuel ratio need to be adjusted when an intercooler is added if so was this done when mine was added? Let me know!

 

[chelo]

I just bought a HDJ81 a few weeks ago and it came with an intercooler installed. I recently had someone that knows about these engines recommend taking it off to return the intake system to stock. Does anyone with more knowledge then me have an option on this topic? The way I see it is that the intercooler cools intake air temperature. On the flip side I've read that an intercooler can decrease power (by way of increasing the distance the air has to travel to reach the engine). The other question is: does air fuel ratio need to be adjusted when an intercooler is added if so was this done when mine was added? Let me know!

Unless there is damage or something wrong with the intercooler, not sure why you would want to take it off.
Does it have an upgraded turbo? How much boost are you running? Remember cooler air means that you can up the boost.

 

[Druepy]

Unless there is damage or something wrong with the intercooler, not sure why you would want to take it off.
Does it have an upgraded turbo? How much boost are you running? Remember cooler air means that you can up the boost.

I haven't seen damage but I haven't looked too closely. I don't believe the turbo is updated and I don't have a boost gauge so I am not sure what it is currently running. my response is not too helpful ha

 

[chelo]

I haven't seen damage but I haven't looked too closely. I don't believe the turbo is updated and I don't have a boost gauge so I am not sure what it is currently running. my response is not too helpful ha

Can you snap a picture of the current Intercooler setup.

 

[lelandEOD]

Yeah, unless it's like an Igloo cooler plumbed in there, I'm not sure why you'd want to remove it.

 

[lelandEOD]

....and Congrats on the HDJ81 purchase!

 

[NLXTACY]

Maybe he works on scummins engines? I’ve never heard of any Toyota diesel owner itching to actually remove their IC. In fact I’ve been busy adding them for local JDM81 folks

 

[Druepy]

Can you snap a picture of the current Intercooler setup.

Not the best photo but it is one I found in my phone. I can snap some more with the intention of capturing the intercooler set up a little later

 

[Druepy]

....and Congrats on the HDJ81 purchase!

Thank you sir, I’m loving it

 

[Druepy]

Maybe he works on scummins engines? I’ve never heard of any Toyota diesel owner itching to actually remove their IC. In fact I’ve been busy adding them for local JDM81 folks

This was LC specific mechanic. I should have just asked why he said that instead of just wondering about it after the fact

 

[scottryana]

This was LC specific mechanic. I should have just asked why he said that instead of just wondering about it after the fact

An intercooler by its specific nature does introduce a restriction to the intake. Some intercoolers will drop the manifold absolute pressure a psi or two. If you have a turbo big enough to make up for that pressure drop it is not a big deal if the turbo is already maxed out you will be down a couple psi. But you will have a cooler charge temp so it is kind of a wash. Not knowing why he recommended it, there might be more to the story (i.e. he saw something you didn't relay to us). I would keep it if everything works the way it should.

 

[Rigpig]

If you decide to pull it off, I have an HDJ81 that would love to have it and would gladly take it off your hands!

 

[NLXTACY]

If you decide to pull it off, I have an HDJ81 that would love to have it and would gladly take it off your hands!

X2

 

[cody c]

There is literally almost no reason to remove an intercooler that isn't damaged, way too small or way too big.

Cooler air charge is easier on your motor, and with that you can crank the fuel up a touch for more power. It also will run cooler when pulling on hills slightly. Unless there's something we don't know, it sounds like you got bad advice.

 

[Dusten]

I just bought a HDJ81 a few weeks ago and it came with an intercooler installed. I recently had someone that knows about these engines recommend taking it off to return the intake system to stock. Does anyone with more knowledge then me have an option on this topic? The way I see it is that the intercooler cools intake air temperature. On the flip side I've read that an intercooler can decrease power (by way of increasing the distance the air has to travel to reach the engine). The other question is: does air fuel ratio need to be adjusted when an intercooler is added if so was this done when mine was added? Let me know!

The topic of lag has been discussed ad nauseam. Your engine is 4.2L, it moves 4.2L of air per revolution. At idle 1 revolution is complete every .075 seconds.
That's 13 revolutions per second or 56 liters of air. The amount of tubing to accommodate this is massive.

If you can notice the added time to fill the extra 1 or 2 liters added by the Intercooler, you're better at this than me.

 

[cody c]

The topic of lag has been discussed ad nauseam. Your engine is 4.2L, it moves 4.2L of air per revolution. At idle 1 revolution is complete every .075 seconds.
That's 13 revolutions per second or 56 liters of air. The amount of tubing to accommodate this is massive.

If you can notice the added time to fill the extra 1 or 2 liters added by the Intercooler, you're better at this than me.

You mean 1 cycle of the engine not 1 revolution I believe.

But, I can also attest to the addition of an intercooler (albeit top mount) having no noticeable lag on the 6BT or the 3B(T)

 

[Dusten]

You mean 1 cycle of the engine not 1 revolution I believe.

But, I can also attest to the addition of an intercooler (albeit top mount) having no noticeable lag on the 6BT or the 3B(T)

Correct. My bad. Point still stands though.

There are tons of articles related to piping and lag.

 

[cody c]

Correct. My bad. Point still stands though.

There are tons of articles related to piping and lag.

Ya, I’m splitting hairs, but it’s almost indistinguishable and the benefits of a cooler air charge in hot weather far outweigh any lag. Ported and polished heads also make the difference

 

[OffRoadScott]

There is no reason to remove the intercooler as mentioned earlier it will keep the temperatures down and allow you to raise the boost as well.

If you are not getting any type of heat sink, radiant heat absorbed into the intercooler keep the intercooler. A prime example of intercoolers that are subject to heat sink are Subaru's stock configuration.

I am going to open a whole new can of worms, what about a turbo timer. An electronic device that will idle the car after turning the car off and allowing it to cool down so you do not cook the oil in the turbo due it not cycling through the system.

Are the turbos on these LC air/water cooled? If so a turbo timer is not as important but I would take every step possible to protect my investment.

 

[cody c]

Scott those are a kind of different questions.

For heat soak, and in my situation (top mount intercooler) that is both an issue and not an issue. Why? Because my rig is only running hard on long hills on the highway where it is flowing air through it so fast that heat soak isn’t a problem. At slower speeds I’m not running hard, mostly just on trails. Heat soak would be an issue if I was running the engine hard at slow speeds, outside of the occasional run up to a hill or mud hole, it doesn’t matter. Furthermore, I’d rather keep the IC up high for mudholes.

The turbo timer is as you say, just for allowing turbo to cool before shut off. You can also let it idle for a bit, if I come off a freeway hot, I’ll drop it in neutral and let it cost on the off ramp and coast or idle a bit to drop the heat down a bit before landing at my destination. Also my electric fan will continue to run if I leave the ignition in while fueling up or whatever. Turbo timer is for cooling engine down to prevent coking oil in turbo bearings, not much related to intercooler other than IC helps keep temps down too.

Allowing the engine to engine brake or idle at zero boost does pull more cool air through it and helps it to cool fairly well. Gearing down to slow speed without throttle pulls air through with less fuel, and less dense (cooler) and can help with temp before shutting off. Well I’m Calgary summers it’s ok, maybe different in other places with higher temps.