We Design Water And Oil Cooling Systems To Support A High-Stress Race Environment. In anticipation of the increased power output and consequent increase in heat that comes with turbocharging an engine, we've fitted a slew of cooling upgrades to ensure engine oil and water temperatures are kept in check in our time attack S2000. First off, we started with an all-aluminum Mishimoto radiator. The conventional S2000 radiator is mounted vertically, which is difficult to duct and has a higher center of gravity (CG) than a lay-down radiator setup.
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Honda S2000 Tuning - Project S2000
By removing the rad filler neck, changing the angle on the lower rad hose fitting and installing an AN -20 fitting for the upper rad hose, the radiator would now suit our application perfectly. All the unused ports were capped with 0.065 sheet aluminum and TIG-welded. We then fabricated a new lower radiator support that fastened to the front subframe, as well as new upper radiator mounts. With the rad secured in the lay-down position, a lower CG has been achieved and a clear path is available to duct the radiator outlet up through the hood (look for more on this in an upcoming installment).
Plumbing of the radiator required some special pieces, but the lower radiator hose was a straightforward affair. With the modified fitting on the rad, it was simply a matter of trimming the T1R silicone hose and clamping it down. The upper rad hose was more involved.
With the radiator filler neck/cap deleted from the radiator, it was necessary to mount a remote filler neck/cap. We turned to CSR racing, which offers an inline radiator neck with an array of fittings available. We used the standard S2000 1.25-inch-diameter push-on from the engine side and AN -20 to the radiator. Unfortunately, there are no mounting provisions on the CSR part, so a custom bracket welded to the housing was required. With the neck mounted to the shock tower, a trimmed T1R S2000 upper rad hose handles the fluid transfer to the engine.
BAT Inc. supplied all of our lines and fittings and we used the Aeroquip Startlite -20 hose to go from the neck to the radiator. The Startlite hose features a Kevlar braid and is much lighter than a conventional stainless steel braided hose. It's also much easier to assemble because the Kevlar braid doesn't poke holes in your fingers like a stainless braided line. Be sure when assembling the AN reusable fittings that the hose is cut square and pushed all the way into where the threads begin (a sharp utility knife works very well). Use some clean engine oil to lubricate the threads and hose prior to assembly. BAT's black/nickel-colored AN fittings look great and offer a secure connection. With the radiator system complete and sealed up, a pressure test was performed to ensure there were no leaks at any fitting/weld areas.
The turbocharger and higher power output, as well as prolonged high-engine rpm, will add heat to the engine coolant and oil. By maximizing the radiator's efficiency, it will be possible for a heat exchanger to use the reserve capacity of the radiator to lower the engine oil temperature, critical to prolonging engine life, turbocharger life and achieving maximum performance. This offers several benefits when compared to using a front-mount, air-to-oil cooler setup. A front-mount cooler increases the exit air temperature while reducing the pressure differential across the radiator, reducing the cooling system's efficiency. The air-to-oil cooler is typically mounted forward of the radiator and requires longer plumbing, which causes increased pressure drop in the oiling system, increased weight and a greater risk of damage from debris/incidents on track.
Conventional heat exchangers have been available for many years, however, and the Laminova oil cooler, available from Mocal, has improved efficiency substantially. The cooler uses a proprietary manufacturing process to achieve substantial surface area in a very small package. We opted to use the 43-330 (single-core) model fitted with AN -10 oil fittings and 16mm water fittings, which we converted to AN -8 by cutting off the push-on portion and welding on a AN -8 weld-on fitting. We fabricated brackets that use the four-bolt pattern at each end of the cooler and secure to the S2000 cross beam in the engine bay. Dual-core versions are available if additional cooling capacity is required.
Once again, we turned to BAT Inc. for the remaining Mocal pieces and fittings needed to plumb the oil system. We fitted a Mocal low-profile block adapter, which is a great option compared to the typical spin-on block adapters. The low-profile adapter features a two-piece construction that allows the fittings to be clocked at any orientation and offers increased clearance - a must for most turbocharged setups and cramped engine bays. The adapter also accommodates the factory heat exchanger, further helping to reduce oil temperatures. Be sure to label the inlet and outlet ports so there's no confusion when assembling either now or in future. From the block adapter, use the outlet port to feed to the remote filter housing (-10 Startlite line). We opted to use a cast-aluminum, four-port-type filter mount (two inlets and two outlets) and fitted it with a K&N HP3001 Gold filter.
It is critical to use the correct ports on the remote filter housing to ensure there are no restrictions to oil flow. Use the following hookup to ensure any debris/contaminants are removed by the filter before feeding the oil cooler. The first inlet port is the output from the block adapter, the first outlet is the feed to the Laminova cooler, the second outlet is used for the -4 feed line to the turbocharger and the second inlet is currently plugged/unused. With the remote filter mount plumbed, simply run the final -10 line from the Laminova to the block adapter inlet and the oil system is complete. BAT Inc. was also able to supply the 1/8BSPT (British Standard Pipe Taper) fitting needed to thread into the factory oil pressure port, allowing for remote mounting of an oil pressure sensor for the Motec Advanced Dash Logger. It can be difficult when ordering to know how many 90s, straights, 45s and so on that you'll need, so the chart on the left is a complete list of all fittings and components used to assemble the S2000 system.
