In this part two of the front mount turbo build I will go over making the radiator efficient enough to cool the engine in all conditions.
Some information about the car:
1997 Maxima
VQ35DE
Automatic
Turbo (initially rear mount turbo)
DIY Fan Shroud
I used a generic brand radiator from eBay. It is a two core aluminum radiator for a Honda del Sol. The fan used is a Spal 12″ Curved Blade Puller Fan. With a pullIng fan it is important to use a shroud so that the air is pulled from all sections of the radiator. Having no shroud the fan will only pull air through the area where the fan is mounted too; limiting the cooling area to that diameter.
I created the Shroud using two cookie baking trays. I cut both of them in half then I overlaid the ends together so that I can have a specific width to cover the whole area needed. The tray is about a quarter inch to half an inch deep which means this is how far the trays floor will be away from the radiator; you want this distance or greater to help pull air from the corners of the radiator.
I then riveted the trays together to make a sturdy. I cut a hexagonal shape in the center with the same diameter as the fan (12″). To support it all, I used the brackets that came with the fan and bolted them to the radiator; I fastened the shroud to the radiator with through bolts.
Dealing with exhaust Heat
For the radiator hoses I visited a local parts store and asked to get access to all the hoses. The tricky part was the bottom hose, so I found several bends that worked out great. I used a connector to merge the hoses together to make one final piece that would go across the radiator support, to the passenger side, and up like the usual stock hose path. This bottom hose passes directly in front of the feed and down pipes so wrapping them in header wrap was necessary in my opinion to protect the rubber from direct heat.
After driving around it was clear that I needed to wrap the down pipe and feed pipe to keep it from starting to over heat; this is when I thought I should have purchased a three core radiator. With a few modifications I have had success with the two core. I created a shield to block the down pipe from radiating heat directly onto the radiators side which helped a lot.
As you can see in the video, I had the transmission cooler mounted on the grill in front of the turbo. This was an issue because the heat coming off the turbo and exhaust piping would warm up the cooler in traffic. I had to relocate the cooler and at the same time upgraded to a larger unit; more on this in its own blog post.
The next test was sitting in traffic or in a staging line. The engine would start to warm up after a long while. I realized that the reason for this was because the passenger side of the grill area was opened exposing the turbo and exhaust piping. This means that when the car is at a stop, heat comes out of the front of the grill area then gets pulled back in through the radiator; basically the radiator was pulling air that was already hot. The solution was to make a plate from thin aluminum which blocked the left side of the grill completely. I then cut a triangle on the hood above the turbo so that it could be an escape for the heat. The end result gave me a reliable setup for cooling.
Finally, since the car is now more focused for racing, I created a short exhaust pipe that exits out of the hood. This is used for the track or weekends. Alternately I can attach the catback to the original turbo outlet I created when I want a quiet ride. will go into details in the next post.
In the next post I will go over how I created the rear side exhaust while still keeping a muffler.
