Once you grasp the job of a coolant you recognize that the traditional anti-freeze mix with water is very poor at the task of cooling the cylinder head. Straight water is even worse, but many still falsely think that it is a good choice. If you want to limit detonation then a better coolant needs to be used.
The Hysterisis of Knock
When an engine knocks, even when no damage occurs, the piston crown and combustion chamber become super-heated. The calibration of the ESC system recognizes this and when evoked pulls out a large amount of ignition lead so these components can cool down. After a programmed amount of time it then adds the ignition timing back. Thus, if the engine experiences abnormal combustion the performance will be severely compromised to cool the piston and combustion chamber. This kills horsepower and ET. The purpose of this exercise between GMHTP, IDA Automotive and the owner of our subject 1987 Buick GN, Anthony Petridis, is to not evoke the hysterisis of knock, or in simpler terms, the ESC circuit.
The car we used was a completely stock Buick with only 71,000 miles. The plan was to chassis dyno the engine at an elevated coolant temperature of 193 degrees F and record the power and knock retard being issued, using a scan tool. The coolant temperature was not the ideal for a dyno pull but would represent a real driving scenario on a summer day. We did not want a false test protocol. Most dyno sessions are performed with the engine cool, hood open and a huge fan in front of the radiator. That only tells you the power the engine will produce under ideal conditions not what it will do in actual street driving.
Our approach would be to properly tune the engine, chemically remove the IVD and CCD and upgrade the cooling system with the advanced Evans NPG+ coolant.
Evans Cooling Systems, Inc. has developed a coolant that has a lower surface tension than water and traditional anti-freeze, boils at 369 degrees F at atmospheric pressure allowing the coolant to remove more heat from the cylinder head and eliminates all water and the possibility of corrosion.
C.A.T. Products, Inc. has created an ingenious tool that accurately and safely administers its proprietary carbon removal chemical into any spark ignition engine. The tool drips the chemical into a vacuum hose as the engine is run at a fast idle of approximately 1,400 rpm.
After performing the services, we would then bring the coolant up to temperature and dyno test again. So follow along and see what we find.
 Efficient intercooler performance...  Efficient intercooler performance is paramount to controlling knock. We removed the intercooler and washed out any oil residue deposited from the valve cover breather with Simple Green and water. |  The Evans coolant requires...  The Evans coolant requires a Prep Fluid to pull any water from the traditional coolant that is left over in the block after draining. We introduced two gallons of Prep Fluid and ran the engine until it got hot. |  A refractometer is used to...  A refractometer is used to determine the amount of moisture left in the coolant. This step only needs to be done if the engine is already in service with traditional anti-freeze. |
 A BRIX scale is read on the...  A BRIX scale is read on the refractometer. A maximum of 5 percent water is allowed for the NPG+ to work effectively. |  Once the water content is...  Once the water content is below 5 percent, the Evans NPG+ is a simple pour in. We filled the system and bled out all of the air. |  After the procedures we tested...  After the procedures we tested again. This time the coolant was at 198 degrees F and the Buick responded by picking up 23.43 horsepower and 38.88 lb-ft of torque at the tires. The engine had no knock retard and this was accomplished without changing any parts! These procedures would be just as effective on a normally-aspirated engine. |