Had our '13 SL in for maintenance today and took some pics of the Hayden 512 Cooler and Derale bypass valve. This was an easy installation by any standards. Ours was the first Altie to get this treatment in the shop and there's one small thing we've done differently in a couple of customer installations since, but I'll touch on that as we go along. The job takes about an hour with a lift, probably two in a driveway with jacks, and there's no disassembly necessary except to remove the engine splash cover. Here's a diagram of the installation:

On the 2.5 Altie, the radiator lines are long enough that only one fresh piece of hose is needed to place the Derale between the beehive and radiator. The Derale has four handy 6mm mounting holes, and two of them can be used to mount it at the front left corner of the subframe by drilling two clearance holes in the subframe flange as shown here:

The second pic shows the location relative to the beehive, which is at the top of the image. The Derale fittings are all pipe-thread and some teflon tape is in order, but be cautious about how you wrap it. Leave the bottom 1-2 threads untaped so no shreds get into the lines. Don't tape all the way to the bottom like you would with a plumbing joint.

The Derale is mounted 45 degrees across the inside corner of the subframe, spaced upward on a pair of 8mm nuts used as standoffs (this keeps the subframe from interfering with the hose nipples). Drilling the clearance holes in the flange is the toughest part of the job, you'll want a sharp 9/32" drill bit and keep it lubed. The flange isn't hardened steel but it's pretty thick. It's also uneven from the flange welds, so your standoff nuts may look a little cockeyed even though they're tight. Don't over-tighten, the Derale's body is aluminum and you could strip the holes with too much torque. Use Loctite instead of muscles.

Note also that the orientation of the Derale is critical. The side with the black cap has the thermostat, so the inlet on that side must be the outflow from the beehive. The valve won't cycle properly if it's backwards or upside-down.

Once the Derale is mounted, mount the cooler to front of the condenser:

The through-fin restraints that come with the Hayden kit work great, and there's enough hand room to work three of them through the fan, radiator and condenser without removing anything. Make sure to use the foam squares that come with the kit in between the cooler and condenser, you don't want them rubbing on one another. After you get three of them through past the condenser, hold the cooler in place and push them all through. The one thing that was poorly planned on this installation was placing the cooler too low. Because the restraints are 1-way fasteners like zip ties, I ended up cutting channels into the ribbing on the engine splash cover to make enough room for the hoses to right-angle without kinking. You'll want yours mounted an inch or two higher than shown, or get right-angle flares in place of the straight ones that come in the kit (that's what we're doing for customer installations).

Once the cooler is mounted, it's time to route the hoses. The order in which you do it is important, because once the hoses from the cooler are in place, you won't be able to reach the bottom nipple on the radiator. So do the 5/16" side of the system first, then the 3/8" lines to and from the cooler. The top line from the radiator (the return to the beehive) won't be touched, it's left in place as-is. The line from the beehive to the bottom of the radiator is simply detached at the radiator nipple and reattached to the Derale's inlet. That's hose A with the corbin clamp in the pic below, hose B with the band clamp is a new piece of hot-oil rated 5/16" hose connecting the radiator to the Derale's bypass outlet:

There's generally very little drippage when you take the hose off the bottom fitting on the radiator, so you'll really only need a pig-pad and not a drain pan. It's a good idea to lube the inside of the hoses before pushing them onto the nipples, do that by dipping the end in a can of NS3 or whatever CVT fluid you use. Don't use other lubricants, CVT's can be very sensitive to certain types of contaminants, especially regular ATF.

The cooler hoses get routed next. There's a hole at the base of the radiator core support big enough for two 3/8" hoses to pass through as shown here. The arrow in the pic is a piece of self-stick foam pad, have some on hand and use them anyplace the hoses might chafe on a hard surface or corner:

The bottom pic shows the routing on the other side of the radiator core support. You can see why the 5/16" hose to the radiator needs to be done first, it's barely even visible once the cooler hoses are routed. Reaching the corbin clamp would be impossible. Before the cooler hoses are in, the lower nipple can be reached easily with a needle-nose by working your arm between the inner fender cover and the subframe. The arrow in the bottom pic points to the lower radiator coolant hose, the 3/8" cooler hoses will loop up and over it in a corkscrew to reach the Derale:

The cooler hoses won't care about orientation. The cooler doesn't have directional flow, so either one can go to top or bottom.

Once you're done, fire it up and check for leaks before putting the splash shield back in place. Chances are you won't have any, the pressure in the cooling loop is actually quite low, 10~15 psi. There's also very little fluid volume in the added cooling, so you won't need to top the fluid immediately and you won't be adding much when you do. However, you do need to make sure the bypass is working correctly, and that means getting the fluid temperature to top 180F. The best way to do that is hold the RPM around 1500 with the car in Drive and your foot on the brake. That generates heat in the Torque Converter without involving the belt and pulleys, so it's harmless to the latter but drives the fluid temperature up very quickly. Even if the car was dead cold, you'll probably see the bypass crack open in well under 5 minutes. Once it cracks you'll feel the cooler lines get hot immediately. Having an assistant is a better idea than watching a scanner, because you'll only see the temperature drop on a scanner if the radiator fan is running. If it isn't, you could drive the temperature up dangerously before thermal lag allows the scanner to detect it. Let off the gas as soon as the valve cracks and let it cool down again. Then level the car and top off the fluid using the usual leveling-plug procedure. You won't need more than a few ounces unless you were low to begin with.

Once you know the bypass is working and she's topped-off, button her up and run cool. In conclusion, I'll just add that this setup will also work as-is on gen4.5 Alties with 4-port beehives, and the basic parts will work on any Nissan with a 4-port and a side-tank radiator. That's most of the Nissan product line.

Hope you find this useful. Happy motoring!