although i concur....there wasn't a need for that....keep this one on topic so it doesnt get locked

 

how the hell can u compare a ps2 to a pully??? lol.. w/e

i really dont see anything bad with a pulley upgrade. hotrodders and imports have been using them for years. and maybe back then they might do some damage. but i dont understand if some of us stay n/a, why would a pulley hurt us, even in the long run. or am i just missing something?? why would companies produce something that would hurt your engine as people say when they know thats the main reason someone would not buy it in the first place.

i mean is it really that bad especially for us n/a guys to do this upgrade with out sacrificing the longevity of our motors??

can anyone really answer that?

 

The ZPI pulley V2 seems great and all, but ZPI never seems to have any in stock (anodized). Just wondering if any of you know when they'll be getting any more in.

*Sorry, tried to email them, but not sure if it ever got through.

 

if you want an answer to that, check out the locked pulley threads.......i'm really interested in hearing from the guys who have the ZPI V2 Pulleys and this thread will get locked, just like all the other threads, if it resorts to opinions. Keep it on topic.

 

They sell before they even enter the shop. That's why they run out fast. So, you have to catch them at the right time. These things fly off the shelves.

 

Yeah I think I ordered mine the day they came in and they were all gone in just a few days. They should be getting more in really soon so look everyday.

 

Diluvium & tcPete if you want to talk about the effects of the ZPI pulley check out yoursciontc.com, there is a thread going on about this same issue and they are far less "lock-happy" then scionlife.

This thread is for experiences with the pulley, that is all.

 

Can you explain how a lighter belt pulley increases horsepower?

 

The same way a lightweight flywheel or lighter wheels do. It reduces parasitic loss by lightening up the rotating mass. The engine can rev faster which is displayed as increased HP on an inertia dyno.

 

I can't wait to get mine installed as soon as I get my tax return. Im going with a ZPI crank pulley and NST water pulley to stay 100% oem size/no belt change/no under or over-driving.

 

That means the engine makes the same horsepower sooner by revving faster. Or put another way, at any point in time during acceleration, the engine is making more power because it is revving faster. But the engine does not make more top horsepower. Its max hp is still 108.

It is like lightening the flywheels of my old BMW motorcycles, which have 20 lb flywheels. The high rotational mass keeps the engine from stalling on takeoff when lugging a sidecar, but the the engine revs slowly when the throttle is blipped, and the rpms hang up between shifts. For better solo performance, some people replace the flywheels with lighter drilled aluminum flywheels. They get better throttle response and faster acceleration, but since nothing has changed regarding combustion, the horsepower and top speed is not affected.

Lightening pulleys and flywheels increases acceleration by lightening the load on the engine, not increasing horsepower.

 

Yes, but where your explanation is misleading is that because it's lighter, and less rotational mass, the engine, INSTEAD of using the alotted HP to turn things, it now can put that to the wheels. Therefore, on a dyno, decreasing the rotational mass of objects..will reflect in higher WHP #'s on a dyno. Therefore, it increases horsepower being transfered to the wheels, not actually ADDING hp to the car, like a turbo would.

 

This mod makes your car faster, who cares if it actually gives it "real" horsepower or not..

It makes the car faster, and that's the main reason anyone would add this pulley anyways.

 

Its a classic internet debate but the fact is the HP isnt being increased...only the dyno displays a power increase since it measures the ability of a car to turn the drums. The Dyno thinks that if the drums are spun up at faster rate then more HP is being produced when it may not be true. Changing the gearing can have the same effect. Its more of an issue of how the dyno measures power but in the end your performance will increase so who cares what the dyno says right?

 

Yes, a lighter pulley diverts the HP that would go to turning the pulley into moving the car. But when the engine reaches its max RPM at each upshift, the engine is making the same 108 HP.

Carbon fiber panels and lightened pulleys and flywheels all reduce the amount of work needed to accelerate the car. But the work that an engine is doing does not change the power that it is capable of. An engine having less work to do will do it faster, but not because the lesser amount of work has given it more power.

 

Exactly..

Personally, I don't know much about dynos but I know the dyno this was done on was not a dynojet, it was a "Dyno Dynamics".

 

And You sir Are Correct!

 

this forum has been a big learning experience for me

 

i ordered mine w/o being anodized... oops will it make THAT much of a diffrence? or can i expect some problems later? they still havent shipped out darn it..=/

 

I ordered mine without anodizing also.. I saw this thread and did a little more research about anodizing, so sent them an email about 4 days later and they switched the order for me before it shipped out.