Opinions on this water to air intercooler for LJ78 / 2LTE?

Discussion in '70-Series Tech' started by digitalbuck, May 15, 2017.

  1. digitalbuck

    digitalbuck

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    I'm getting ready to install a water to air intercooler on El Troque and have been looking at all of the available options. It looks like the simplest / cleanest / most compact unit that has good capacity is this:

    Water to Air Intercoolers

    It is pretty good size and square with a straight through air flow, which is perfect. It fits right where the cross tube sits on top of the valve cover. I will put some insulation under it to reduce the ambient heat transfer from the top of the engine. I realize that one placed in a cooler spot may be slightly more efficient but also know that the extremely short distance and straight through design will gain a significant amount of efficiency compared to a couple of feet of bending air tubing, some of which is going to run right across the top of the engine anyways and pick up the same amount of heat or more.

    Any thoughts from you guys who have installed or studied water to air intercoolers on a Prado?

    Thanks!
     
  2. GTSSportCoupe

    GTSSportCoupe

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    I think most all of us so far have put it off to the side. The couple bends make virtually no difference in performance. On a turbo engine, post turbo piping has was less impact on performance than on a normally aspirated engine. Pre turbo is a different story. Freeing up flow there is a very good thing.

    I don't think the cooler you've linked to will fit. Make one out of cardboard that is exactly the same dimensions, and try placing it on top of your valve cover. I think you'll find that it covers your oil filler cap, might interfere with the throttle cable and hood. And the inlet/outlet are too high up.

    Does your A/C work and do you use it? If not, the best performance/simplicity/cost option is a front mount intercooler setup like this: How to Install a Intercooler on a '91 Prado EX5 (2L-TE)?

    On the highway (where you really need an intercooler to perform), an air/air system is just as good if not better than an air/water. Air/water is better around town though.... Only reason I went air/water is to retain the A/C (no room for pipes to the front of the truck there).
     
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  3. digitalbuck

    digitalbuck

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    Good advice, thanks. I'll make the mock up and see if it fits. I do use my A/C, I live in southeast Florida so it's an important part of my life! So I'm for sure needing to go with water to air.

    Also if I remember right you experimented with water / meth injection. Would you consider that a good alternative to intercooler?
     
  4. GTSSportCoupe

    GTSSportCoupe

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    No, I'd say the water/meth is not a replacement for an intercooler at all. An intercooler is basically the best modification you can do to improve this motor. Maybe the water/meth could have the same cooling ability, but you'd have to have a HUGE tank, and be injecting it all the time. Just not practical.

    I'm still running the water meth. Mostly for the extra boost in power. The 2LTE 10mm pump limits out pretty quick at the high boost levels actually. I have the fuel turned up all the way, and my EGTs are still low. So I use the methanol as an extra fuel source for more power. The water cools the air charge on compression stroke, and so helps keep things a bit cooler. I'm running 18psi post intercooler. Probably equivalent to around 23psi if there was no intercooler. So that is a lot of air. 10mm pump just can't put enough fuel in to match the air, so AFR's are pretty lean. Safe I suppose.... I'm making about 100hp to the wheels. A stock 2LTE puts around 40-45hp to the wheels.

    I did talk to a injection pump expert from NZ, and we figured there is a good chance the early 1KZTE injection pump would be a direct swap to a 2LTE. The 1KZTE pump is a 12mm pump, so has way more power potential. The calibration resistor values could be lowered to prevent over fueling at low rpm, and the spill valve fuel screw could be adjusted for the correct "in boost" fueling. With a turbo upgrade, a person could probably make 150hp to the wheels with the 1KZTE pump on a 2LTE. Tempting.... Anyhow, I digress, sorry.
     
  5. kbushnz

    kbushnz

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    I have a similar unit in my 1KZ powered Prado...
    One thing to watch is you have enough room when you close the bonnet !.
    I have a body lift and the hump has been cut off the rocker/tappet cover and it only just fits under.
    Intercooler.jpg
     
  6. AirheadNut

    AirheadNut

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    IIRC when I was measuring the space on top of the valve cover for an intercooler there is only about 2.5 inches between the valve cover and hood. Also, the turbo inlet is offset toward the front of the engine, meaning that the intercooler would have to be asymmetrical. I tried fabbing up a custom intercooler to fit that spot, but the inlet and outlet pipes were just a little off and it didn't fit.
     
  7. digitalbuck

    digitalbuck

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    Could you give me clear direction on bow to locate the spill control valve and turn up the fuel? My intercooler is functioning and I've increased boost now I wa t more fuel. Thanks!
     
  8. GTSSportCoupe

    GTSSportCoupe

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    I'll write a 'how-to' thread on tuning the 2LTE tomorrow (no time today, sorry). What type of intercooler did you end up going with? Pictures?
     
  9. GTSSportCoupe

    GTSSportCoupe

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    All right, here are a few points on tuning the 2LTE. I'll just put it here instead of starting a new thread.

    Before turning up fuel on a 2LTE, I think there are a few prerequisites. You should have the cooling system in top notch condition, larger exhaust, a good intercooler, and a pyrometer.

    You will need a manual boost controller ( Voodoo V MBC Black w/ Ceramic Ball Manual Turbo Boost Controller Made in USA | eBay ) installed on your turbo, and if you want to go over 14psi (which I do recommend), you will need a Pneumatic speed control valve (ASC-8 1/4" BSPT Pneumatic Air Flow Speed Control Throttle Valve CLEARANCE!! | eBay). The point of this valve is to bleed the air from the Boost Sensor in a very controlled manner (lower the boost curve).

    The reason an intercooler is the key to more power, is when the turbo boost pressure is increased beyond a certain point, it creates a huge amount of extra heat. This means higher EGTs and less dense air going into the motor (fewer oxygen atoms). Once an intercooler is installed, it solves this problem. Now you have dense air, and lots of it (lots of oxygen).

    The boost can be turned up a lot. I run 18psi max after the intercooler. This extra pressure has not worn my turbo in any discernible way over the past four years or so.

    Having a lot of boost, with cool air, means there is a lot of head room for safely adding more fuel and making more power. I've maxed out my pump and it seems a good match for the boost I'm running (EGT wise).

    Turning up the boost is simple, you just need any ebay manual boost controller. It goes on the boost line to the waste gate and increases the pressure at which the waste gate opens. Note it also takes a given amount of exhaust energy to drive the turbine to generate boost. You may think you've reached the boost limit of your turbo, but from what I've found, adding more fuel will solve this problem.

    Now adding fuel part is a little more tricky. First thing is dealing with the computer over boost fuel cut. This is not a sharp cut off. I've found it is a bit more of a progressive thing. Before the over boost light comes on, the computer is already limiting the fuel when the boost gets high. Seems to start happening around 13-14psi or so.

    The way to deal with this is the bleed valve that pradocruzer came up with. (Reducing 2lte egt's) It works really well, in that it shifts the whole boost curve down proportionally. So the idea is to trick the computer into thinking it is seeing a normal boost curve, where really you are running almost double the factory boost. The bleed valve just t's into the boost line to the boost sensor. It allows a certain amount of air leakage to reduce the pressure. It needs to be mounted after the little filter thing (which limits air flow a bit also). Tuning this valve is tricky. A 1/4 turn makes a difference. You want to be as high as possible before the computer starts limiting fuel. Only way to really tell is by seat of pants difference. Note, there is a product from a company called 'TurboSmart' called a pneumatic Fuel Cut Defender (FCD). DO NOT use this, because it leaves your boost curve as it is, and then abruptly clamps the boost at the maximum that you've set. This is impossible to tune to, as the computer will not add more fuel as the actual boost continues to rise past the clamp point.

    Once that is sorted out, you can progress to turning up the fuel at the injection pump. It is done on top of the spill control valve (solenoid sticking up from the pump head). (see picture below - for a 1KZTE pump, but it's the same for the 2LTE) There is a little cap there that has to be removed. Underneath is a lock nut and hex adjust screw. Mark and take a picture of the factory setting. Then release the lock nut, and turn the screw in a 1/4 turn at a time. DO NOT turn it in more than 3/4 turn, or the engine will go into run-away! (I experienced this at one full turn, and it is scary!). Run-away doesn't happen at idle, it only happens when the engine speed is increased by throttle, and then it revs really high and does not come down. So once you've adjusted the screw, rev your engine while not driving to make sure this doesn't happen. If it does happen, you need to turn the screw back out while the engine is revving like crazy. It sucks, trust me. I've learned that as you get close to the run-away situation, what you will notice is that when you rev the motor the motor will take longer to slow down when the throttle is realeased. This is a sign you are getting close to run-away. So turn the fuel down a bit, and rev the motor again checking that it returns to idle quickly as normal.

    Anyhow, 3/4 turn adds at least 30-50% more power. It's crazy. The extra fuel will likely increase the boost pressure, as more work will be done at the turbo with more exhaust gasses. So you'll have to go back and re-adjust the manual boost controller and air bleed valve accordingly.

    It took me a couple weeks of fiddling to get the perfect tune. Even with maximum fuel, I still run EGT's that are about 200F LESS than they were when the truck was stock!! All because of the extra boost and cold air.

    If you've had a pyro on for a while, you will know that you hit the highest EGT's when under sustained heavy load in hot ambient temps. So when you adjust your fueling, make sure you are tuning for safe EGT's under the worst circumstances. Around town and with normal highway driving my EFT's are pretty low, but under worst case conditions (towing up big hills in summer for example), they EGT's can end up much higher. My probe is post turbo, and worst case is 1000F. Normally I can never get it that high, and it maxes out closer to 800F. If your probe is pre turbo, shoot for 1200F worst case. With my tune, I never see black smoke at full boost. I can get black smoke before the turbo spools if I floor it, but I can control that with the right foot. I don't really floor it until the turbo has spooled up.

    Really makes the motor fun. When I add the methanol too and the weather is cold, the truck rips pretty good!

    These trucks make about 35-45 rear wheel hp when stock. Mine is making about 100 rear wheel hp right now (with meth/water on). Really transforms the truck. Doesn't seem like much, but it is about the same that my friends mildly tuned 1HDT is putting down to the wheels!! Not bad at all.



    [​IMG]
     
    Last edited: May 29, 2017
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  10. digitalbuck

    digitalbuck

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    20170529_143452.jpg Excellent. That's so helpful. I'm in the middle of a 2000 mile road trip right now so any adjustments and repairs I'm making along the way show quickly. It's also hard to do anything very expertly because everything feels like a trail repair. But here is my intercooler in a temporary / introductory setup. I k ow that I have to loosen a clamp and move it to add oil, but that is quite infrequently and is fast and easy so no worries. I have some more work to do on the cramped charge pipes...
     
  11. GTSSportCoupe

    GTSSportCoupe

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    Nice work! Cool to see a new approach to it. Doesn't have to look pretty; as long as it works!

    I didn't mention above, but if you stay under about 14psi, you can turn your fuel up maybe 1/4 to 3/8 turn or so, and not have to worry about the bleed valve thing (computer boost cut). 1/4turn seems to be about 12rwhp. Very noticeable increase.

    Nice thing is, diesel engines are a lot more forgiving to tune than a gasoline motor. Just keep those EGT's under control and everything will be fine.
     
  12. CRSWA

    CRSWA

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    Resurrecting this thread because I'm starting the planning stages of my own 2lte intercooler job. Does anyone know offhand what the size of the piping is leaving the turbo and entering the inlet? Eyeballing the tape measure, I'm guessing about 2.25", is that right?

    I'm considering this 4" by 6" canister style intercooler mounted on top of the valve cover. If I do it right, it should provide plenty of access to the oil filler.

    [​IMG]
     
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  13. Nas90tdi

    Nas90tdi

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    Leaving Turbo is 2"
    Intake inlet is 2.5"

    You can get a step down hose.

    For general info. Intake end of engine crosspipe is 2.25"
    Turbo end is 2"

    Not sure why they have the crosspipe inlet and exit different sizes.
     
  14. GTSSportCoupe

    GTSSportCoupe

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    Looking forward to seeing more intercooler setups! One very important thing, don't skimp out on the size of the front mount radiator. Bigger makes it much more efficient.

    Funny, I've been looking for the post I wrote a little way above on tuning the 2LTE for more power. Now I know where it is; thanks!

    Lots of potential for more power from these little motors guys. Just need to follow the recipe.
     
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  15. beno

    beno Gihee Arakawa Moderator Supporting Vendor GOLD Star

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    Do you have any experience with AXT intercooler kits from Australia?
     
  16. CRSWA

    CRSWA

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    What about the idea of putting a small fan on the front heat exchanger? Worthwhile? I could see that being a benefit in off-roading situations, but probably not necessary for highway or around town driving.
     
  17. richmason

    richmason

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    Taking a cue from Mitsubishi and some pics from down under that I've seen of intercooler setups on Surf with the 2L-T (non E), I ordered an intercooler and hood scoop from an L200 diesel pickup from Europe somewhere. I bought the scoop because there is no way this intercooler, which is air to air, will clear the bonnet. I haven't installed it yet and am keen to identify another off the shelf solution that doesn't require cutting a hole in the hood and that is already a proven design for this engine and vehicle with inside the engine compartment mounting. If anyone on this thread has installed something using off the shelf parts, besides obvious fabrication for bolting things on, I would really appreciate it if they could share part numbers and sources for the whole shebang.

    Thanks!
     
  18. beno

    beno Gihee Arakawa Moderator Supporting Vendor GOLD Star

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    Rich: Try AXT Turbo in Australia.

    Talk with Allan.
     
  19. richmason

    richmason

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    Cheers beno, I hope the new location is working out well for you.
     
  20. GTSSportCoupe

    GTSSportCoupe

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    No I have not.

    I put two 10" fans on my front heat exchanger. I don't need it while off-roading, because I'm basically not producing any significant boost or load on the engine while crawling along in the bush. I also don't need them while cruising on the highway (as I have good air flow to the exchanger). The reason I installed them is a little unique. When I go camping in summer 90F+ weather with my family, I tow a 3500lb camper trailer. We get stuck in about 45min of rush hour stop go traffic, and then hit a long 8% grade right after. I found the air water system would get heat soaked sitting in the rush hour traffic, and then it did not have time to cool down before I hit the long climb. This would impact performance on the climb. The fans solved that problem quite effectively.

    A top mount air/air intercooler will always be a compromise in my opinion. I had one on my MR2 Supercharged back in the day and detested it. It was so noticeable when that intercooler got warm from engine heat. Just killed the power. I called it an inter heater. An engine bay is full of heat, and it wants to rise. There is just no way around that.

    With a hood scoop, fan, and some smart ducting you can get around the heat soak a bit. But it will never be as optimal as a front mount intercooler setup (air/air or air/water). Of course it is an easier install and generally cheaper, so is an attractive option compared to no intercooler at all.
     
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