Merkur XR4ti Intercooler Fabrication Ideas 

I've installed lots of custom intercoolers on my XRs. Hopefully this information will help you to do the same. It isn't hard and you will feel good about yourself and your car, when you are done. And you stand to save a pile of money, better spent on other stuff.

You'll need to fabricate the tubing, hoses, and mounting details of your installation. But it's easier than you think. eBay is an excellent source for various intercooler cores. Just keep in mind that plenty of people are looking for good ICs and you will be bidding against them, possibly even me.

Hoses - use radiator hose for big trucks, available in any size you need and some really handy ones that change from one commonly used size to another, some even have 90 degree elbows made into them. Go to the "Big Truck Store" and ask to look thru the book, or their stock.

Piping - use mandrel bent exhaust piping available almost anywhere. Ask to see the Walker exhaust parts book at your local store. They may not have it in stock, but they can get it quickly. If you don't have a wholesale account with your local shop, then ordering it from J.C. Whitney might be cheaper. You can also get mandrel piping used for electrical conduit at an industrial supply store.

Clamps - use Constant Torque hose clamps, also found at the "Big Truck Store". They look like this. Don't buy anything else. These work. I have almost $100 worth of clamps on the Ranger, but they have NEVER blown off.

Blow off & Bypass Valves - There is a difference. You want a bypass valve. That said, I've never used one, but I don't have my engine combos together very long before I'm changing something else. And I'm lazy. And I have LOTS of cars. You want one. It will keep the turbo spooled up between shifts and make the car faster and easier to drive. You want it plumbed between the outlet of the turbo, and the inlet of the turbo. When vacuum is present, it allows air to pass, when pressure is present you want it block air. They all work like this, don't sweat it. The Bosch valve is approximately $25. Don't spend much more. Bosch Part Number  is 0280142103

Intercooler Positioning - There is room to install an IC in an XR. It looks tight, but I've put them in several different places.

1) Flip the radiator fan over, and move it all the way to one side fo the radiator. Then install the IC next to it behind the radiator. This makes for a clean installation and it works well. Sure it would be better if it wasn't behind the rad, but life is full of compromises and this works well, from experience.

2) There is a big empty space under the VAF meter outside the fender. The IC actually winds up being in the wheelhouse between the inner fender liner and the sheetemetal. A bonus of putting it here, is that it doesn't take up engine compartment space, and that nifty hole in the lower bumper cover feeds air to the IC. I usually cut a hole in the inner fender liner and epoxy mesh screening in the hole. This is to allow air after it leaves the IC to vent out into the wheelwell. I installed Spearco's smallest core in this position, and it worked very well, from experience.

3) A bottom breather installation between the front of the steering rack and the bottom of the radiator. This is the location for the Modern Performance IC, and it works well, from experience.

4) In front of the radiator with a different radiator, or the stock one moved downwards. I haven't done this, but I've seen it, and several people have done it with sucess.

Here are some photos of various intercoolers, listing the experiences I've had with them.

Intercooler Cores - There are many intercooler cores available. Junkyards typically charge low prices for them, so have at it. Several various car types are shown below.

This is the intercooler from an Isuzu Impulse Turbo. It is a nice compact, efficient design. Larry Davis has one of these jacketed to convert it to water to air, and it works very well. I've owned a few but never used one. It should be an easy installation, and I believe it flows well enough to not be a hindrance to performance.

This is the intercooler from a Probe Turbo. It is a nice compact, efficient design. The fins are smaller than the Impulse so it might not flow all that much but it still looks like it would work well. I've owned a few but never used one. The inlet and outlet are 2" OD.

This is the smallest core from Spearco with the simplest end tanks. This assembly is about $350 retail. I bought one used for $100 with some piping. This is the intercooler I had installed in the 88XR that I wrecked, in position number 2 above. This picture is actually from a magazine article on Mike Abbey's car. He went 12s with it. Obviously, it flows well. It is a nice compact, efficient design.  The inlet and outlet are 2.25" OD.

here's the pic of the one I had on my car. Picture was taken after the wreck :(

This is from a Ford Powerstroke Diesel truck. It will NOT fit in your XR. I have one in my Ranger though, and it works EXCELLENT. Duh, it should, it's HUGE. the inlet and outlet are 3" ID.

This is an 87-88 Thunderbird Turbo Coupe intercooler modified by Richard Thompson to bolt right on to the stock Merkur turbo compressor outlet. It is an EASY installation. A hole should be cut in the hood, or air ducted to the IC, but it is still an improvement without doing any of that.

This is an unmodified 87-88 Thunderbird Turbo Coupe intercooler.   In my experience I have found the limits of the Turbo Coupe intercooler, with exhaust, a stock head and one of my camshafts. All I know is the car was faster WITHOUT the TC-IC than with it. You may ask, well how can John Huber go 10s with a Turbo Coupe IC? Because he is using nitrous and he has additional air being injected into the throttle body in the form of N2O. That's how.

This is a custom intercooler and radiator combination that used to be available from RS Consultants (Howie Rayburn, I think) I don't think they are stil in business, and it was very expensive when it was available. Hopefully, just seeing it can help you with your fabrication ideas.

This is the intercooler from a Saab 900 Turbo. It is a nice compact, efficient, dual pass design. I have one of these in my car, in the most ridiculous place, and it stil works very well. It is an easy installation, and integrates well in to the car if installed according to position 1 above. Dave Planakis has done a couple of cars this way, and it works well. It is my opinion that this IC flows better than anything else available, that is comparable in size, from my experience. Look at the pass tubes. It's about the same size as the MP IC, just doubled over. This IC is available with metal or plastic end tanks. It doesn't seem to matter which one you get.

This is the intercooler from a Saab 9000 Turbo. It is big. These pics or of one that Peter Nefdt modified, but died before he could install it. RIP. It would not be easy but it should work very well.

This is what it looks like stock, as in the Saab 9000.

Peter cut the inlet and outlet at an angle.

and this is what it looked like after modification

This is the intercooler from a Conquest TSI or Starion. I personally think it's a POS, but you wouldn't know it by the stupid prices they fetch on eBay. It's to much work to reconfigure the inlet and oulet piping, and they don't have enough or large enough pass tubes size to flow well. I recommend you stay away from them at almost any price.

Keep in mind that if you are going to be doing extensive mods, exhaust, cam head porting etc, you will need a bigger intercooler than you will for a stock car.

Take your time, roll the intercooler around in your hands, placing it in several spots before deciding on where it will be permanently. That is how I found some of the oddball places to mount them.

My favorite is Position 1 above, because it takes two pipes and two special hoses that we have already tried and used. Piece of cake.

Good Luck!