SuperCoupe Intercooler Installation

After selling my Spearco Air/Water 2-252 IC core, I decided to run without an intercooler and see how far I could push the car with only water/alcohol injection.  Really, it was an economic decision...  I had sold my Spearco Air/Water IC core to help pay for the big Turbonetics T3/T04E turbo that I wanted to purchas.  My original intention was to purchase another Air/Water IC core (perhaps the bigger 2-231) from Spearco when money allowed.  Because the price of this IC core was high, it was going to be a while before I would be able to make the purchase.  In the meanwhile, I focused on tweaking my "ICless" setup and seeing how much power I could extract with only the water/alcohol injection.  In a short time, I was able to get around 250HP at the rear wheels without much tuning.  I could have tweaked and tuned further to try and get more power without an IC, but a window of opportunity opened up for me to work on a bigger project, so I decided to jump on it and install an IC system.

Our 3rd Little One was due to be born at the end of October, and I was planning to be home for 2 weeks after the birth helping my wife with the Little Ones while she was recovering.  During that time, I knew that I would get stir crazy being stuck in the house so much, so I decided to pursue a budget, good performing intercooler project.  Since I was going to be home for 2 weeks, I wouldn't have to drive the XR on a daily basis and would have a nice block of time to complete the project.  I planned to do all my work at night, because I wanted to make sure that I was available to help out with the family during the day.  That was the whole point of taking 2 weeks out of the office in the first place!  Anyway, as it turns out, it took me about 7 "all-nighters" to complete this project.  I'd go for 2 all-nighters in a row and then sleep for a night or two.  Then, I'd pull some more all-nighters.  Some days, I'd only nap for 45 minutes.  It was worth it.  I was able to accomplish a lot at night and was still able to help with my family (MOST important thing) during the day.

I chose the Ford SuperCoupe intercooler because it is a good size OEM intercooler that can be purchased used at a reasonable price.  I paid around $100 for mine.  People have gotten them cheaper, but that's the best I could find in the timeframe I had.  The Thunderbird SuperCoupe has a 3.8L supercharged V6 engine, so the SC IC core is a decent size.  The SC IC core measures 3" thick, 8" wide, 12" long.  The overall length is around 20" - including the cast aluminum end tanks.  Below is a photo showing the front side of the SuperCoupe Intercooler.

SuperCoupe Intercooler - Front View

The SuperCoupe intercooler has 2 bolt flanges on the inlet and outlet.  See the photo of the back view to see the inlet/outlet configuration.  By the way, the IC shown in the Front and Back View photos is not the one I actually used.  The one in these 2 photos actually had a leak.  The IC came off a wrecked SC.  Apparently, the front end of the car (including the IC) was pushed back into the engine.  It appears the engine was still running and the power steering pulley kissed the back side of this IC and rubbed off some of the aluminum.  There were 2 charge air tubes actually perforated and leaking.  The fella who sold me this IC didn't realize that the core was leaking.  He quickly sent me another IC core to replace this one and I sent the leaking one back.  Actually, at one point I had 3 SC IC cores sitting in my garage!  I only wanted to buy ONE!  Anyway, that's a whole nother story I won't get into here!!

SuperCoupe Intercooler - Back View

As mentioned, the SC IC comes with 2 bolt flanges on both the inlet and outlet.  This is not very good for the do-it-yourselfer at home.  Of course, you could go to a muffler shop and have them make up some pipe with 2 bolt flanges with expanded/tapered ends to match the SC IC flanges.  After considering my options, I decided upon a different route.  The inside diameter of the SC IC inlet/outlet was almost exactly 2-3/8".  I had a piece of  2-3/8" OD mandrel bend lying around so I tried to see how it would fit in the openings.  I was glad to discover that the pipe was a VERY nice, snug fit.  I ordered some additional 2-3/8" OD mandrel bends from Summit Racing, and I started to lay out my IC plumbing.  What I finally did was mock up the installation and figure out exactly what I needed in terms of angle and position of the inlet/outlet pipes.  I then throughly cleaned the pipe and IC openings.  I roughed up the inside of the IC inlet/outlet openings, and I did the same on the mandrel bend piping.  After this, I cleaned both VERY carefully with carburetor cleaner.  I then applied JB Weld to the outside surface of each pipe and pressed them into the IC.  Even without the epoxy, the pipes were a "press fit" and very snug.  It was hard to get them pressed in and harder to get them out when I was testing out my idea.  The epoxy mostly served as a sealant and extra insurance to make sure that the pipe stayed solidly in place.  In terms of force loading, the pipe to IC snug fit takes most of the stress.  I would not have done this except that the pipe was such a snug fit that I wasn't worried about the JB Weld taking too much force and cracking.  In addition, I have had good experiences with the JB Weld on both my upper and lower intake manifolds.  Also, I've used it to bound some tubing in my big 60mm throttle body.  Over the past couple years, the JB Weld has proven itself to be durable and reliable on my engine.  Obviously, it would be better to get some aluminum mandrel bends and weld the inlet/oulet tubes in place, but I think what I've done will serve the purpose just fine.  Time will tell.  As extra insurance, afterwards I took some steel reinforced epoxy putty and created a "cold weld fillet" around each pipe/IC interface.  The photo below is after the JB Weld was applied, pipes pressed in, and excess epoxy wiped off - but before I applied the additional epoxy putty.

SuperCoupe Intercooler with added Inlet/Outlet Tubes

  After choosing the SC IC, I then needed to decide the mounting position.  I considered several options, but felt that a front mount next to the radiator (Cosworth style) would be best for intercooler efficiency.  As a result, I needed to find a smaller radiator.  At first, I thought I might mount the IC vertically next to a narrower radiator.  This ideas was discarded when I realized that I would probably have major clearance issues with the A/C compressor.  Since I live in Florida, I was not about to give up the A/C on my daily driver!  So, I decided to pursue a horizontal mounted IC above the radiator.  Next step was to locate a shorter radiator.  Because of the low price, I ended up choosing a Scirocco style universal drag racing radiator from Summit (SUM-380648).  It has an aluminum core and is 1.125" thick X 12.75" wide (vertical height) X about 21" long.  The overall radiator dimensions including plastic end tanks and radiator cap are about 13.5" tall X 27" long.  Inlet/Oulet hose barbs are 1.25" diameter.   The low cost of $109 was hard to resist.  Below is a photo of the Summit radiator.

Scirocco Style Summit Universal Drag Racing Radiator

There are bosses molded into the plastic end tanks which are intended to be used to mount an electric cooling fan.  I tapped these holes for that purpose - as well as I used these bosses to carry the load of mounting the radiator in the car.  I used 1/8" thick X 1" wide steel stock to make some simple brackets to hang the radiator and intercooler from the "radiator cross support".  You can see what I mean in later photos.  In addition, I attached the bottom of the radiator to the lower bumper cover to provide some light support in the fore-aft direction.  The weight of the radiator and intercooler are supported by the simple steel brackets I made, and attaching the lower radiator mounting points to the lower bumper cover simply helps keep things a little more stable.  The radiator is EXTREMELY lightweight.  In some ways, it's a little more of a "lightweight" than I'd prefer.  The aluminum fins are very thin and easily damaged.  The densely packed, thin fins should be good for heat transfer, but it makes the core a bit more fragile.

In terms of whether or not the lightweight Summit radiator is up to the task of handling the cooling needs of the 2.3L Turbo engine....  it's too early to tell right now, but I think it will work just fine.  Getting good airflow through the radiator is a key factor, and if this is accomplished I believe it will work just fine.  Right now, in Florida it is extremely "cold" compared to our typical summer weather.  I've driven the car in the 50's and 60's lately and the water temp gauge has stayed very low - even lower than with the stock XR radiator.  That may just be because the ambient air temps have dropped about 10-15 F versus the last time I drove the XR with the stock radiator.  Regardless of how it works now, the true test will be in the middle of a "pressure cooker" Florida summer with temps in the 90's and the A/C turned up to the max - with condenser rejecting maximum heat in front of the radiator.

To help ensure good airflow through the radiator at lower speeds, I installed a 14" Summit Adjustable Electric Fan (SUM-320714).  This fan is supposed to be able to move up to about 2000 CFM of air, so it should be up to the task.  The fan is available in 14", 16", and 18" diameters.  The 14" was the smallest offered of this type of fan, but it was still too big for my installation.  To make it work, I carefully trimmed off about 0.5" off the end of each of the aluminum blades.  This reduced the overall diameter to around 13" and resulted in a much better fit.  I made up some aluminum plate adapters to mount the fan to the radiator as well as provide mounting points for my radiator support brackets.  The photo below shows the fan mounted on the radiator (after the blades were trimmed).  By the way, the stock XR cooling fan is way too large to get it to work with this radiator.  Even if it could be fit somehow, in my opinion it's way too heavy to be mounted on such a lightweight radiator.

Summit Adjustable Electric Fan Mounted on Radiator

In hind sight, I'd recommend anyone else trying to do a SC IC installation like I did to consider getting a custom aluminum radiator made - similar to the one David Godfrey had made for his KurTwo project.  It may need to be a little shorter than David's radiator since the SC IC is 8" wide.  The Scirocco style radiator is a little too tall for an easy installation in the XR.  Because the Summit radiator was a little too tall (maybe 2 inches), I needed to mount my IC up higher and as a result needed to mount it further back than ideal because of a step in the stamped sheet metal radiator support area (see photo below).  This made it a real pain to get the IC outlet plumbing to clear the engine belts.  After much work, tweaking, and frustration... I got it to fit and clear the belts.  Another reason why my final IC mounting location is less than ideal is because it is further back from the back side of the condenser core.  Because of air flow dynamics, it would be more desirable to keep the front of the IC closer to the condenser core.  In my case, because the radiator forced my IC installation upwards and farther back, I needed to live with the extra air gap.  Even though it is less than ideal, the setup still works just fine - as will be discussed later when I share my final results.  All this to say... I'd recommend a custom short radiator to make the installation much easier and the IC placement more ideal.

Ford SuperCoupe Intercooler Mounting Location

I ended up mounting a small 12V electric fan (approx 5" diameter) to the backside of the Supercoupe IC on the "hot" side of the core (see above photo).  I wired it in with the engine cooling fans, and I have a dash mounted switch which I can use to manually turn on the fans.  This way, when I am driving around town or sitting in traffic, I can manually override the stock fan switch and get some airflow through the radiator and IC.  This should help keep the engine coolant temps down in traffic as well as keep the IC "chilled" are ready for a WOT, high boost opportunity.  Obviously, once vehicle speeds are up, the electric fans are not necessary anymore.  In fact, the fans become more of an obstruction to air flow at higher speeds, but this is a reasonable trade off to the benefits they offer at lower vehicle speeds.  That's why I decided to mount one small fan to the backside of the IC.  Also related to air flow, I plan to cut my stock XR nose piece to create a budget Cossie style open grill.  Until I do this, I am running with the front grill removed.

Intercooler and Radiator Plumbing - Top View

The intercooler plumbing is setup as follows...
Out of the turbo I have a Spearco 2"-2.25" silicone adapter/coupler.  This attaches to a section of 2-3/8" OD mandrel bent tubing.  This section has about a 120 degree or so bend at which point a section of 2.25" heavy duty truck radiator hose goes down to the SC IC inlet tube (which is angled upward approximately 60 degrees or so).  Air flows through the IC core toward the drivers' side and exits the IC core through the 2-3/8" OD mandrel bent pipe outlet.  The outlet pipe has about a 100 degree bend in it - this was to help direct the subsequent plumbing away from the belts.  After the outlet pipe, the air goes into a section of 2.25" radiator hose with a nice molded 90 degree bend.  This gets the air flow pointing back across the car (toward the passenger side) where it goes through a straight section of 2-3/8" pipe.  From here, the air takes a 90 degree turn upward through a mandrel bend, and then through another section of straight 2.25" radiator hose.  Air flow turns 90 degree again through another mandrel bend pointing towards the back.  Then the air goes through one final 90 mandrel bend where it expands up to 3" OD using a big industrial copper pipe fitting.  At that point, it's a straight shot into the 60mm throttle body.  As can be seen in the photo, I also have a Bosch Bypass Valve installed with the necessary plumbing and adapters to hook this up.  By the way, I got the straight truck 2.25" diameter coolant hose at NAPA.  Cost around $12/foot and is normally sold in 3' sticks.

Speaking of plumbing, the new radiator has both inlet and outlet on the same side (passenger).  The stock XR radiator has the top inlet on the passenger side but the lower radiator outlet is on the driver's side.  I ended up using some 1.25" and 1.5" industrial copper fittings and adapters along with sections of the stock preformed radiator hose to form the lower coolant line.  This was a bit tricky and was definitely a puzzle that needed to be figured out, but it worked out just fine after a bit of work.  I used a copper fitting tee with 1.5" ends and a 0.5" tee to hook up my radiator fill line from the coolant tank into the lower radiator hose.  A custom radiator could have all the proper hose barbs needed for much easier fitting in the car... another reason why a custom short radiator would be a good idea!  Anyway, on the top radiator hose, I spliced 2 sections of a stock formed upper radiator hose (I had used ones lying around), and I used two Victor hose repair connectors (can be purchased at auto parts stores) to piece it together.  The top radiator hose was EASY compared to the much more complex lower hose.  I cut off the top barb on the coolant tank and epoxied the hole shut, since the intercooler plumbing had clearance issues with this barb.  I capped off the 3/8" metal hose barb on the metal line along the valve cover.  When I filled the system, I removed this cap and ran a 3/8" hose from here into the top opening of the coolant tank (obviously with cap the off).  I ran the engine until it was warm and the thermostat opened up.  This way, any air trapped in the system could be bled out during this initial filling and warm up.  Afterwards, I re-capped the 3/8" metal hose barb.  I only plan to use this fitting initially to bleed air from the cooling system when re-filling.  On the pressure cap that came with the Summit radiator, I drilled out the relief valve so that the 1/4" hose barb on the cap was open to cooling system pressure at all times.  I then ran a 1/4" hose along the front of the car and adapted it into the 3/8" line coming of the coolant tank.  This is the 2nd (from the top) hose barb on the side of the tank.  That about rounds up the cooling system modifications I did for this project.  Lots of gory details!

Finally, on to the results... where the rubber meets the road...

I do all my performance testing using the G-Tech meter.  I know that some people don't believe in it and prefer dyno results.   I agree that a dyno run would be ideal and is best for measuring horsepower to the wheels.  However, I also think it is cost prohibitive (for me) to pay for lots of dyno runs.  If I ran on a dyno everytime I have done a G-Tech test though the years, I'd probably have spent more money in dyno testing than the car is worth!  The G-Tech is a useful device because it's cheap and gives accurate peak HP results (as well as other acceleration related data).  As to the accuracy of the G-Tech meter, I've read a magazine article that did back to back tests with the G-Tech and the very accurate 5th wheel measurement method.  Surprisingly, the tests showed that the G-Tech numbers were extremely close to the 5th wheel measurement method.  The article confirmed the accuracy of the G-Tech.

With that said, I'll admit the G-Tech is limited in it's power reading abilities as it only gives you a PEAK measurement of power to the rear wheels.  Even so, the readings are useful for BEFORE/AFTER comparisons.  Once I do some additional tuning and testing with the G-Tech meter, I plan to get some dyno time to confirm my G-Tech results.  In addition, I am eager to see how the HP and TORQUE curves look throughout the engine RPM range.

I knew by seat of the pants that the SC  intercooler installation had made a BIG difference, but I didn't know how much of an increase in peak HP I had gained.  Right before doing this project, I did some "BEFORE" G-Tech testing and got an average reading of about 250HP to the rear wheels.  This was with NO IC, 20psi boost, and only water/alcohol injection providing evaporative intercooling.

After installing the SuperCoupe IC - without touching any of the other variables (boost, timing, etc...) - I took it out for some runs.  The boost gage showed that I still had 20psi.  There was no noticeable pressure drop after installing the SC IC system.  I know that there should be some pressure drop, and I know that this would have to be measured with more precise methods to get exact values.... but because my factory boost gage didn't show any noticeable drop in boost, that tells me that I don't need to worry much about the pressure loss through my intercooler system at my current power levels.

Speaking of power levels...  On my first G-Tech run, I saw 301HP flashing on the display!  In subsequent runs, I also got 300HP, 302HP,... multiple runs above the 300 rear wheel HP mark.  It was very satisfying to see that the SC IC installation had gained me around 50HP without even touching the boost knob.  It was also fun to crack the 300 rear wheel HP barrier.  When I first started testing with my G-Tech meter, I had some mild modifications (air/water IC, mildly upgraded turbo).  Even so, back then I was only getting about 170HP to the rear wheels as measured by the G-Tech meter.  The old 110,000 mile 2.3L Turbo engine has come a long way since then.  With some additional  tuning and a turn of the boost knob, I will see how far I can really take this 110K+ mile stock shortblock....

After installing the Ford SuperCoupe IC, I wanted to get some additional airfow through the front of the grille.  The actual Cossie grille has the opening down lower, but since my SuperCoupe intercooler was mounted very high, I decided to make the opening much "taller" to try and gain some additional airflow.  I wasn't trying to fool anyone into thinking this was a real Cossie grille anyway.  I was mostly interested in function.

I used a scrap of some coarse screen that I picked up on a junk pile at a construction site.  The screen is normally attached to wood faces on buildings that will have stucco applied.  It's just a mesh material to help anchor the stucco to the wood.  The same stuff can be purchased at Home Depot here locally.  Anyway, there's nothing special about this screen.  I used it because it was free and looked OK.  I cut the opening using a Dremel with a cut off wheel for the straight sections.  On the curves, I used a red hot knife (heated with a torch). For the edges of the opening, I used some rubber molding that I picked up at a local electronics surplus store here in Orlando called Skycraft.  They sell all sorts of used parts and materials.

Poor man's "cossie" style grille

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