Gain 5 Horsepower This Weekend, For Practically Nothing

What if I told you that you can gain 5 horsepower this weekend, for less than $100? Or, what if I told you that you could gain 5 horsepower this weekend, for less than $20?
I bet you'd be interested eh?
Well, the good news is, I'm going to tell you how to gain 5 horsepower this weekend for $0-15 spent. Sound too good to be true? Well, read on!
1) Increase the H2O ratio in your coolant - if it weren't for corrosion and freezing concerns, automotive makers would use pure water. Water cools much better than coolant any day of the week, and a cooler engine is a better performer.
Instead of half and half, try 40/60. DO NOT use pure water, As this may cause premature corrosion and that can be no fun at all to clean up. You may also try water wetter to further enhance this effect.
2) Index your spark plugs - this is an age old trick that is good for about 1 extra pony. The idea here is to "aim" the open end of the spark plug terminal (the gap) towards the intake side of the head. In order to accomplish this, simply mark on the plug a small line to indicate where this gap is, and install the plug as normal.
Try to line up the line with the intake side as best as you can. It may require buying 2 sets of spark plugs in order to do this, but hopefully you'll be able to do this the first time. Be careful with aluminum heads not to over tighten, as that could lead to a costly repair.
3) Relocate IAT Sensor - This is a very simple modification that will work on a great deal of fuel injected vehicles. The IAT sensor ("Intake Air Temperature") tells the computer how hot or cold the incoming air is. The computer will then adjust the amount of fuel being injected, as well as make minor adjustments to timing based on that reading.
The problem is that in many vehicles, the IAT sensor is located in the intake manifold, near the cylinder head. Therefore the air that the IAT sensor "reads" is much hotter than the air, say, in the intake arm. The idea with this mod, is to relocate the sensor to the intake arm. Use JB Weld or similar to patch up the old port for the sensor.
This will cause the computer to believe that incoming air is slightly cooler, causing it to inject more fuel and advance the timing a tad.
4) Synthetic Oil - This is guaranteed to pick up 1-2 horsepower, as multiple dynos over the years have proved this fact. Simply by switching to a true synthetic oil this weekend you can reduce the friction in your engine, improving efficiency, and therefore going faster.
5) Insulate Fuel Lines - When your fuel lines travel through the engine bay they heat up. However, cooler fuel produces more power for more reasons than just cooling down the intake charge--although that certainly helps things! So, to improve power output, simply purchase some refrigerator/air conditioning insulation and wrap the fuel lines with the insulation. While you're at it, you may wish to go ahead and do this to the intake arm as well for even more power.