FAQ:

How Do I Increase Horsepower and Throttle Response?

Information:

Whenever you want to increase horsepower and throttle response it is key to note that if you want to increase your horsepower over the stock you must start with stock figures. The common problem these days are people just slap exhausts, headers, and intake on their 2nd hand cars and expect to go beat the rest of us on the track, but end up screaming when their grocery "gitter" just wont perform. Well, lets help you take your car, do it right, and actually increase over stock numbers. So this is what needs to be done before we get to the goodies of tuning and creating power.

You need to do a proper tune-up on your car.

This includes the following must be done (*Note some may not apply to your car due to advancements in technology):

1. Replace the spark plugs

2. Replace the fuel filter

3. Replace the PCV valve

4. Replace distributor cap & rotor

5. Replace the spark plug wiring

6. Replace the air filter only if you don't plan on buying an intake

7. Flush the radiator

8. Drain and Refill the transmission fluid

9. Flush the brake fluid

10. Flush the Power Steering fluid

11. Oil Change

12. I also recommend a seafoam treatment

13. Ensure proper alignment and tire balance

14. O2 Sensor if over 100,000 Miles

Once you have completed all this you may now start to tune and increase your horsepower and throttle response.

The proper starting point for increasing horsepower is generally increasing air into the engine by removing restriction and allowing the engine to breathe more by reducing restriciton in the exhale of the engine, known as exhaust.

Lets talk about intakes. Intakes weather it be a SRI (Short Ram Intake) or CAI (Cold Air Intake), both use the theory of low restriction life-time filters as their main use of increase. You can also now buy OEM replacement filters for stock applications from K&N. Their site provides a conversion list for your application. The claim is you will receive the same benefits from their filters as you would from a performance intake.

1. Save at the pump by increasing gas milage

2. Increase horsepower

3. Save money by never needing replacing

4. Washable and Reusable

OEM Replacement:

Short Ram Intake System:

Cold Air Intake System:

So, now you're asking yourself what is the difference between the SRI and the CAI? Well, besides the price not all that much. Some argue that the CAI system reaches lower to the ground where the less dense air resides and since its less dense it is colder reducing the engine temperature and ultimately increasing horsepower and throttle response, but is it worth the extra money to get the CAI?

The answer... Not even close... The CAI intake system, however extra you may get, is easily out weighed by the risk of hydrolock (water sucked in by the engine) in wet weather driving. Granted they do come with a by-pass valve to prevent this from happening but sometimes it still happens. This problem is almost entirerly eliminated with the SRI and OEM replacement filter application. Keep in mind if you remove the intake resonator and install a K&N replacement filter you for the most part have a SRI. So give it a try, remove the intake resonator and install a OEM replacement filter and see how you like it. Should save you some money and produce very close performance.

Next lets discuss exhaust systems. Your basic exhaust systems consits of headers, catylitic converter, center pipe, and muffler. This has a number of possibilities just by the fact you can change almost every piece of the exhaust system and produce more throttle reponse and horsepower only if its done right however. I'm sure all around town you have noticed Honda Civics, Dodge Neons and Mitsubishi Eclipses with loud massive exhausts. What does this mean though? Very little in the way of performance. I would like to think since aftermarket costs less their original exhaust fell off and they just replaced it with that type of exhaust because they couldn't afford anything else, but the fact of the matter is people, mostly kids, think this is more powerful and makes a difference. The fact points else where and their theory couldn't be further from the truth. Yes, it does free up a lot of what hangs up the exhaust exiting, but when you factor in back pressure it equats the wrong answer. The very first part of your exhaust is the header(s) system. As shown below.

This is the very very first place a tuner should start when considering exhaust. I assure you that if you start at the beginning of the exhaust you will acquire more horsepower and throttle reponse from a header system than from a cat-back system alone. A header system opens up the collectors allowing for less hangup and giving it a higher flow for the start of the exhaust. Once you have a header system installed you can look at replacing the rest of the exhaust. Aftermarket shown below. You can see the difference in design.

A high-flow cat is good for a racing enviroment only because it will hinder your smog elimination and possibly increase the possibility of you failing emission testing. Especially good to be noted if you live in California. I don't recomend replacing these unless you want a track only car. Shown below is a stock (left) compared to a performance (right) Cat.

Last we can talk about a cat-back system for your exhaust. cat-back exhaust systems are exsactly what they sound like. It is the exhaust from the catylitic converter back towards the rear of the car. Generally you'll have a resonator, muffler, and exhaust tip. The resonator reduces the noise of the exhaust exiting the car by colliding exhaust sound waves hopefully canceling out the sound. The muffler collides the sound waves even more with internal parts reducing the sound of the exhaust. So what does it mean when I install a cat-back system?

Well, simply you're taking out or reducing the function of what I just described. Cat-back systems often remove the resonator completely or have a false resonator in place to give the appearance of a resonator soley for inspection purposes. When you install a cat-back system you're mostly purchasing wider diamater piping with a high flow muffler and a larger exhaust tip. The purpose is to open the exhaust from the cat back to increase flow and ultimately increase horsepower and throttle reponse. Stock verses Aftermarket is shown below.

Note the wider piping, straighter piping and no resonator.

Stay tuned for the next series!