Well, I've been on this planet for 21 years and there are lots of things I still don't understand. I'm not a gearhead, I'm no carpenter, my cooking is the shits, and I have to get my girlfriend to do my taxes.

I'm bad at a lot of things, which is why I have some basic car knowledge questions I would like to have answered. After you all laugh at me, I know I'll still have my dignity, because I had the courage to ask (I won't have my dignity).

So, the questions...

1) Headers - I know what they look like, but what do they do? How does changing your header affect performance? Numbers like 4-2-1? Huh?
2) Underdrive pulley - What the hell is this thing?
3) Cat-back exhaust - Ok now, catalyic converter... Does the cat-back just bypass it for less exhaust gas resistance?
4) CAI - What keeps it from getting plugged up with road garbage and water?

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Use search & all will be answered bigeyes2.gif

 

1)Headers flow better. Better flow = more power. 4-2-1 generally create more low end and mid range power, while 4-1 increase the top end.

2)Underdrive pulleys spin the the accessory pulleys slower. It takes engine power to power your accessories (power steering, etc). That frees up power. It is also lighter, so it takes less power to spin it the same amount.

3)Cat-Back means its new piping from the catalytic converter all the way to the muffler. Same as headers, more flow means more power. Stock exhausts and headers are restrictive for sound reasons and cost-saving.

4)Its called a filter. You put it on the end of a Cold air intake. LOL smile.gif

 

Thanks very much!

And I realise the CAI needs a filter, and I know some people build protective housings for them. What would be the best way of doing this? Just have a metal sheet protecting the underneath, or could you build half a box around the whole thing?

 

Just get a AEM CAI and you don't need a sheild. It'll be shielded by your car parts.

 

4-2-1 refers to how the runners come together. 4-2-1 means that they mesh from 4 runners into two runners, and then into 1 to the exhaust. 4-1 headers mean they go straight from collecting exhaust from the 4 cylinders into the exhaust.

www.howstuffworks.com.

go to the auto section there and start reading. you will learn a bunch.

 

An engine is similar to a big vacume cleaner. It has to suck air to work. A Cold Air Intake allows the engine to suck in cooler air more efficently giving it more power (you don't want to suck up more hot air as you will loose power). A header and exhaust basically allow the exhaust to flow out of the engine easier..giving it more power as well. These are just the very basics, there's more to it then this but hopefully this helps you out.