With forced induction and big-cube motors, it gets increasingly difficult to keep your late model GM EFI a cool customer. Even with stock motors, improvements to the cooling system can do wonders for the performance and reliability of your TBI, TPI, LT1, LS1, LS2, or LC2. The increased efficiency and decreased weight associated with aftermarket aluminum radiators may be just the ticket for your dragster, road race warrior, or streetcar. Obviously hours of hotlapping your whip on the road course can boil the coolant necessitating a more efficient radiator, however, few are aware that they may already be exceeding the horsepower capacity of the stock radiator in their streetcar or weekend dragster.
If you want to take it a step further, some manufacturers even have oil and tranny coolers that tie in to the radiator. High-flow fans are crucial to drawing fresh air through the radiator, so upgrading these bad boys is never a bad idea either (especially on older vehicles). Catch cans are also key for forced induction or road racing, as they will prevent you from spilling coolant all over the track when temps and cylinder pressure rise.
Three things every motor could benefit from are high-performance fluids, a high-flow thermostat and water pump. Technology has come a long way since the generic anti-freeze cocktail that became standard in most cars decades ago. Today there are a handful of companies that seek not only to make your coolant last longer, but to better dissipate heat as well. A high-flow pump will also more efficiently move coolant through the engine to increase its effectiveness. Best of all, most aftermarket pumps are made of aluminum for reduced weight. Those wishing to steal back a few horsepower lost in parasitic drag can elect for an electric water pump. Most tuners and experts also recommend a thermostat (usually 160*F) that will open at a lower temperature to reduce operating temperature, which is said to be good for at least a few horsepower in even a stock motor.
COOLANT & ADDITIVES
DEI
Design Engineering Radiator Relief has been created to reduced engine operating temperature by a whopping 30 degrees and cut warm-up time in half. In doing so, DEI hopes to reduce the wear caused by extreme heat as well as cold start-ups, and extend engine life. This additive is compatible with all types of coolant as well as water, safe for all alloys, non-toxic, non-corrosive, and 100 percent biodegradable.
Evans Waterless Engine Coolants
Evans revolutionary coolant is the only 100 percent waterless fluid on the market, which enables a far superior boiling point to prevent boil over, cavitation, and detonation. Meanwhile this coolant will also become thick at extremely cold temperatures instead of becoming solid and expanding like antifreeze containing water. Since there is no water, corrosion and electrolysis is also eliminated. High performance applications would be best suited for the NPG+ coolant as its boiling point is 375*F with a freezing point of -40*F. NPGR is Evans Race Fluid, which is designed to tolerate the intense heat created in racing. It has an increased boiling point of 400*F, however it has a shorter life span and freezes at only -10*F. The original NPG formula is also available with a -79*F freezing point and 369*F boiling point.
Quaker State
Quaker State has been stepping up its game for high performance enthusiasts with its Q Power line, which now includes Super Coolant to combat the elevated temperatures that lead to overheating and knock. Surface tension is reduced significantly with the Radiator Quench treatment additive for outstanding overall engine cooling, including the cylinder heads. Quaker State's blend of inhibitors also prevents corrosion and creates a temperature range between -34*F and 265*F. Life expectancy is around 5 years or 150,000 miles.
Red Line Synthetic Fluids
Red Line Water Wetter is one of the cheapest (at $8.95 a bottle) yet most effective coolant additives on the market. Through extensive testing and development, Red Line has managed to produce an additive that even stands up to ASTM D2570 and D4340 heat/corrosion tests upheld by the OEMs (to ensure that the additive will not corrode your cooling system). Water Wetter promotes better heat transfer properties than plain water or antifreeze mix, as well as superior rust and corrosion protection, making it ideal for not only racecars but even plain streetcars that don't have the coolant flushed as often as needed. Most likely a change in daily operating temperature will not occur, however, when pushed in extreme conditions, up to 20-degree drops have been seen. Water Wetter combats vaporization and bubbling that would otherwise keep water from removing heat from the engine by changing the surface tension of water.
Royal Purple
Royal Purple Purple Ice is another coolant additive, which acts as a surface active or wetting agent. Royal Purple says that in changing the surface tension of water, it can increase heat transfer and reduce operating temperatures by as much as 10 percent. However, in 50/50 antifreeze mixes, 5 percent is more likely due to the difference in surface tension in coolant. Purple Ice is also a corrosion preventative, and contains MolybdateR to prevent erosion and electrolysis from flowing liquid through dissimilar metals. One ounce per quart is the recommended dosage for antifreeze mixes, and 1.5 ounces for straight water. However, Royal Purple recommends streetcars stay with the antifreeze mix if exposed to cold weather since Purple Ice does not affect the freezing point.
THERMOSTATS
Scoggin-Dickey
In addition to carrying a full catalog of aftermarket water pumps, radiators, fans and expansion tanks for your late model GM, Scoggin-Dickey also produces a few of its own products including a Gen III/IV thermostat. Lower your LS1, LS2, or LS6 operating temperature to a more manageable 160 degrees, whether 4.8, 5.3, 5.7, or 6.0 liters for just under $25.
SLP Performance Parts
SLP carries a variety of thermostats for many late model GM applications including LS1 F-bodies, Corvettes, and full-size trucks (4.8, 5.3, and 6.0 liter). In reducing the temperature in which the engine runs SLP says its 160-degree thermostats will help your engine make more power through better thermal and volumetric efficiency. In replacing the factory 195-degree stat, coolant will circulate at a lower engine temperature to keep the engine cooler, which racers know equals a better-performing engine. LS1 F-body thermostats (PN 100223) don't exactly break the bank at $54.95, while all other Gen III/IVs (PN 100228) are a drop in bucket at $19.95. Best of all they are made by the same manufacturer that produces the OEM units and include a new O-ring seal.