pulleys for the 2.0 liter forenza?

[Trubluwoo]

just wondering, is there a company that makes pulleys for the 2.0 liter motor found in the new forenza?

[get sideways]

I know a guy who builds custom sized pulleys all he needs is the
dimensions of your old ones and then how much bigger or smaller you
want them. a word of warning though if it causes your car to overheat
or alternator isn't producing enough power suzuki won't cover it under warranty cause its your own fault thats why i didn't do it.
by the way out of curiosity have you run your car bone stock
quarter mile yet if so what was your mph & e\t

[Trubluwoo]

nope, sorry man....havent run the car yet....i am interested though in what these things will do just as sort of a baseline for upcoming mods. i know the results wont be spectacular but i think they might be interesting.

[PrecisionBoost]

The Forenza motor is the same as the Nubira.... if you want an undersized pulley talk to Tom ( GsiTurbo )..... he has a post in the group buy section.

The alternator won't care about the pulley size.... it's not like the old style alternators that draw power all the time... technically it's called a generator....it will draw exactly the same amount of power no matter what pulley you have on it.

It's hard to explain.... it sucks power off the engine based upon a "duty cycle"

For example.... it will draw power for 20 milliseconds and then stop for 20 milliseconds ..... then it will turn on for 20 then off for 20 and so on.... so it's only drawing power half the time.

This is called a 50% duty cycle because the time on is exactly half of the total cycle ( which takes 40 milliseconds)

So what happens is if your pulley is running slower.... the gear ratio changes and the alternator/generator simply changes it's duty cycle to match the required amount of current.

So say your car was running 20mS on 20mS off at 1000RPM ( 50% ) duty cycle.

You change the pulley and the generator will change to a 70% duty cycle to make up for the difference. So a 70% duty cycle means that it would draw power for 28 milliseconds and then stay off for 12 milliseconds.

I hope you guys get this.... I tried to lay it out in simple terms.

Basicly this type of alternator/generator is widely used now because it saves on fuel economy and helps increase the engine horsepower.

The old alternators ran all the time.... sucking back power continuously.... which ends up using more gasoline.

So this pulley change will not affect your alternator unless the ratio of pulley you put on is so drastic that the generator can't put out enough power even at a 100% duty cycle (on all the time )

Where you will see a benifit in power due to changing the pulley is with the power steering system..... the wheel will be slightly harder to turn but this actually gives you more "feeling" compared to the stock setup.

One warning about aftermarket pullies is that they get rid of the stock harmonic balancer.... which could cause problems inside the engine at very specific RPM levels.

This is a very technical subject involving resonanace frequencies and harmonics so I won't get into it.

To me this lack of harmonic balancer is the only real thing that could affect your warranty.... if your crankshaft snaps because of harmonic resonance they will tell you where to shove your warranty.

On the other hand.... it would give you an excuse to drop in a high performance 2.0L turbo

Basicly everything you do to your car will risk something.... the car manufacturerers are pretty good at cutting corners to gain power and fuel economy.... if they feel they don't need harmonic balancers they won't put one on.... less cost to them and more power.

[Stefan]

Basicly this type of alternator/generator is widely used now because it saves on fuel economy and helps increase the engine horsepower.

Do you think these newer types of alternator/generator can be retrofitted to my 2.0L 8v? Will it need extra electronics to go with it?

One warning about aftermarket pullies is that they get rid of the stock harmonic balancer.... which could cause problems inside the engine at very specific RPM levels.

A point people often miss when buying these. I've designed an aluminium pulley for my engine which I'll be getting made soon. It'll be balanced with the crank and flywheel when the engine goes to the machine shop.

Stef

[PrecisionBoost]

I'm not sure if the controller is internal or external.... I don't see why it can't be retrofited to work with yours.

I can't guarantee that it won't "saturate" into a 100% duty cycle and give the same results as a plain old alternator (decrease in voltage)

I really don't know where the duty cycle cuts off.

Basicly you would have to graph the duty cycle vs RPM of alternator pulley while in it's stock configuration.

You could then see the point at which the duty cycle hits 100%.

Say for example the engineers decided to make it hit 100% duty cycle (with maximum standard load) at 600 RPM. (since the engine should never go this low)

Now lets say your new pulley decreases the RPM by 1.5 then all of a sudden your 100% duty cycle hits at 900 RPM instead of 600 RPM

This is to say that the generator will continue to work perfectly until the RPM's drop below 900RPM.....at which point the voltage starts dropping.

This is just an example.... I have no idea what the actual numbers are.

It's one of those try it out and see what happens things.

The alternative of testing the device would require a whole lot of time and effort as well as some specialized equipment to measure the duty cycle.