HDJ81 - HP Diesel Series 2 Intercooler Install & Review

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I recently purchased and installed the HP Diesel series 2 intercooler (from Austrailia) into my 1991 HDJ81 (JDM spec). I decided to do a thread to share my results and add some additional pics and info on intallation not detailed in the instruction manual. Their is a couple slight differences between the Aus and JDM spec 80 series

Shipping was not cheap but it arrived quickly and was very well packaged. Also they were able to combine shipping and fit one of their oil catch cans into the box. My initial reaction is very positive. All the pieces appear very high quality.
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Step 1 strip everything off the front end
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Step 2 is replacing the center hood latch support. Unfortuanetly somebody in the assembly plant was having an off day and made the bracket backwards. I have not contacted the company about it yet but will will update with their response.
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I simply cut the bracket in half turned it around and welded it back together adding a backing plate to the joint. (A/C condenser get replaced after test fitting)
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Step 3 is to cut the top off the original hood latch / grill support and bolt it together. This determines the position of the intercooler and the upper mounting brackets are drilled and attached
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Step 4 is installing the lower mounting brackets. Be bery careful here as the radiator is behind this crossmember and clearance is very tight. Keep the holes as low as possible and install the supplied inserts
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With the lower brackets installed the intercooler is tightened down in its final position and helps to determine where to cut the holes for the piping
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Step 5 is drilling the holes in rad support panel. This is where the pictures in the instruction manual make it a little dificult to determine precise location. I used the intercooler and piping as a reference while using the recomended 70mm (2 3/4") holesaw blade backwards as my marking template
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The passenger side (RHD) hole in the rad support panel is a bit more difficult. Their is also differences here in regards to the A/C drier mounting locations and related piping between the Aus vs JDM spec trucks. Possibly differences in the rad support panel as well but very dificult to determine from the pics in the instruction manual. They call for a 80mm hole on this side but in North America you"ll have to choose between 79mm (3 1/8") or 83mm (3 1/4"). I chose the first one but in the end it doesnt really matter as its very dificult yo use a holesaw over an existing cut out and the hole ended up getting enlarged and altered as required
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Final hole and of course dont forget to paint the cut edges
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The passenger side (RHD) piping is very tight. The first piece of piping off the intercooler will fit either direction and it took several test fits to determine the proper orientation. Use the welded seam on the pipe and clearance on the hole as a reference in these pics
Wrong
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Right
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Step 6 routing the piping through the engine bay. Again I'll say how tight the fit is, particularly under the battery boxes. It took many adjustments to get things right.
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However no matter what I tried a rib on the bottom of the batery box would touch so I choose to cut it out
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On the turbo side of the motor my issue was with the A/C line coming off the top of the compressor. Another spot the Aus and JDM trucks appear to differ. The pics in the instruction manual show this line staying lower to the compressor and routing farther over between the air box and air intake hose. I used a flat piece of steel with a couple deep sockets bolted to it, to bend the A/C line closer to the motor and out of my way
Excuse the crappy pic
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Final routing and everything secured. I should note that the kit comes with regular banded style hose clamps (assuming to keep the cost down), I replaced them with the more expensive spring loaded constant torque variety (needed 2 more at time of pic)
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Also worth mentioning is the alluminum billet intake adapter. Very nice piece!! It comes with a new bracket to reposition your throttle cable over the top. You'll also fiind one allen head bolt in the kit. This replaces the front lower bolt on the intake. Very little clearance to get a wrench in there on the new adapter
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Step 7 reasseble the front end. Only a couple minor issues here. The body piece that goes below the grill has a bracket that sticks out to far and needs cut down to clear the intercooler. I didnt remove it completly because it allows the hose for the JDM headlight washers to route in front of it (previosely through it).
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Again its a tight fit
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Coming together
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The only other minor issue I had was the lower center grill mount needs to be trimmed off of the inside. I didnt take a pic but pretty straight forward and not needed.
Grill in place
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Overall impression: I am very happy with my purchase. This kit is really good quality and the fit and finish is excellent. Yes its a very tight routing it through the rad support panel and under the batteries but it makes for shorter piping which should mean less turbo lag.

Initial testing: Ive been running the same 1 mile stretch of 6+% grade hill since rebuilding the motor and IP and struggled with propper tuning and high EGT's. After a fair bit of playing around this is where I was at:
Running @ForealBoreal turbo upgrade with stock wastegate (14psi) and stock 2LT fuel pin
Topping hill under full load at 100kmh 3rd gear on 35's with 4.11's
(Guages: AFR, Boost, EGT)

Before Intercooler
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After intercooled
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Not sure what caused the 2psi variation in boost pressure reading and assosiated change to AFR's? Perhaps I previousely had a slight boost leak? Or the boost descrepancy could be because the Aubern boost gauge gives absolute zero readings so it is effected by the barometric pressure and the AFR's were effected by the cooler intake air? I dont really know but I do know that my EGT's are down over 200F right out of the gate.

I have sense upped the boost to 20psi, turned the main fuel screw up 1/2 a turn and rotated fuel pin to a slightly more aggressive profile

Currently topping the hill in drive at 110kmh and actually have to let off before the top. I have not been able to reach 1200F no matter how hard I've tried
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This intercooler has really allowed me to wake this motor up!! The difference driving it now is night and day. So much more enjoyable. I highly recomend this kit
 
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IanB

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Great writeup and excellent pics! I'm only hoping your 8th installment will include before/after EGT readings! Fingers crossed!
 
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awesome Great post. nice detailed pictures this is defiantly on the list...

can someone host a group buy on these products?
oh lala i wanna see your catch can install too!!!
 
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oh lala i wanna see your catch can install too!!!
As requsted:
A little pricey but very blingy and worth the money IMO to protect my investments. No point letting a new intercooler get gummed up with oil. Super easy install. Takes about 15 minutes. Comes with nice bracket, hoses, clamps and fittings.
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Has a handy little dipstick for checking oil level
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Plus the bottom unscrews making it very easy to empty
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IanB

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That is hands down the nicest catch can for this application I've been able to find. Just can't bring myself to spend the $$ on it.
 

GTSSportCoupe

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Not sure what caused the 2psi variation in boost pressure reading and assosiated change to AFR's? Perhaps I previousely had a slight boost leak? Or the boost descrepancy could be because the Aubern boost gauge gives absolute zero readings so it is effected by the barometric pressure and the AFR's were effected by the cooler intake air? I dont really know but I do know that my EGT's are down over 200F right out of the gate.
Nice kit and nice install. I really like this design.

Are you reading boost after the intercooler? If so, the 2psi variation is pressure drop across your intercooler. Measuring before the intercooler would give you the same boost before and after the install.

Change in AFR's is due to more dense cooler air entering the combustion chambers. More oxygen molecules means a higher AFR. This is why you can safely add more fuel for the same boost after an intercooler installation.
 

IanB

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Are you reading boost after the intercooler? If so, the 2psi variation is pressure drop across your intercooler. Measuring before the intercooler would give you the same boost before and after the install.

Change in AFR's is due to more dense cooler air entering the combustion chambers. More oxygen molecules means a higher AFR. This is why you can safely add more fuel for the same boost after an intercooler installation.
Agreed, as the boost charge cools through the intercooler, its volume is decreased, which leads to the pressure drop you're seeing, assuming you are measuring post-intercooler.
 
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I would agree with you guys if that was what he's seeing, but based on what the OP has posted he's seeing 2 PSI higher after the intercooler install. I would expect to see 2 PSI less after the intercooler install if boost is being read post-intercooler.
 

IanB

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I would agree with you guys if that was what he's seeing, but based on what the OP has posted he's seeing 2 PSI higher after the intercooler install. I would expect to see 2 PSI less after the intercooler install if boost is being read post-intercooler.
Yup, I missed that, and thought he was seeing less boost after the IC install. Good catch.
 
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