what does reseting the ECU do? should you do it if you have installed some aftermarket parts? if so how do you reset it? and my last question is what do pulleys do? thanks

Resetting your ECU just forces it to re-adjust itself to changes that you've made to things like intake or exhaust & such. I believe it would do this over time anyway (like adjust fuel to suit a new CAI) but resetting it will force it to re-learn much quicker.

You should reset your ECU every time you add/change something (performance-wise, not like if you add a new GT-wing or vinyls or whatever).

There are different ways to do this but I personally just disconnect the battery, then pump the brakes for a little while until it's drained all the power out of it (maybe best to leave it for a couple of minutes), then reconnect the battery.

During the first 30mins or so of driving the ECU will adjust itself to the way you are driving & will also add fuel to compensate for any breathing mods you have done, for example. Drive like a granny & it will be more economical. Drive it a lil' harder & it will implement a more aggressive fuel curve to the detriment of economy.

Over time, it'll just kinda even out anyway, so it's always good to reset it every once in a while.

As for the pulleys, there are different types...

A lightweight crank pulley, for example, will enable the engine to rev faster due to the reduced amount of rotating mass. Downside I suppose, is that revs will also drop quicker. Nevertheless, I want one of these.

Underdrive pulleys, I believe, reduce the amount of power allocated to ancilliaries such as A/C, water pump & alternator (I could be wrong here). They enable more of the power that your engine is already making to go to the wheels instead.

that sums it up very well...

I don't see what the downside is with the revs dropping FASTER. The engine speed (RPMs) in the Tiburon are always held so readily which makes it hard to cruise comfortably. This can be considered good in some cars, but not a sporty/performance car.

There are several other threads on both of these topics. Try searching; you'll find A LOT of info mang.

The DIY thread for resetting the ECU has all the answers my mang.

<div class='quotetop'>QUOTE (2kShark @ Jul 19 2005, 02:04 PM)</div><div class='quotemain'>I don't see what the downside is with the revs dropping FASTER.</div>

It is my experience that, with the few cars I have driven that had lightweight crank pulleys fitted, I found the revs to drop off sometimes too quickly, which actually meant a bit more driver input was required for basic daily driving. The cars would not carry speed as well, going up slight inclines for example. Nothing major but worth pointing out.

A underdrive pulley, isn't that supposedly to 'free' up hp

But how is it able that things like water pump, a/c and stuff are getting less power that they can still work properly ?

^ Which is why they are not for everyone... It's my understanding that they are no good for peeps with big, high-drain audio installs.

I have found at idle with my Unorthodoz underdrive crank pulley that the alternator does not put out much in the way of amps and that on the few occasions that I have had the air on, it starts to get pretty warm inside.

Now, anything above an idle and all is fine. The waterpump still works because it is designed to work from idle all the way to above redline. If anything it works better because at higher speeds it can cavitate and start pulling air out of the coolantr instead of pushing it through the block and head.