Underdrive pulley recommendations?

[amondc]

I guess it depends on how sensitive your butt is. The pulley will add about 10hp.

[Jake Raby]

So far these pulleys have proven to give me the best improvements in real performance. They bolt on more than an ECU flash or a 3,000.00 exhaust system.

[pboard66]

I apologize in advance for the newbie question, but is there a noticeable increase in vibration? I threw an UDP on my 4 cylinder commuter and although I was happy with the small power gain, I do notice some resonance in the cabin.

[Boxster44]

Ques - when you say Underdrive Pulley and HP gains, are you assuming w/o A/C?... or still have A/C connected?

Would there be more HP gain w/o driving A/C?

thanks,

kj

[Lobo1186]

yes no A/C would "gain" you more HP, if you were to remove the whole system also some weight would be lost giving you even more...

however, its more along the lines that you will just have more HP that the car makes already available to you.


correct me if im wrong.

[amondc]

Correct. They pulley does not create horsepower it only reduces the factors that rob hp from the motor. Another way to think of it is that the motor is just an air pump. It sucks, bangs and blows. If you don't change the amount of air it sucks or how big the bang is or how it blows you do no "create" hp.

That said all we really care about is how much hp we have at the wheels not how we get it, and the pulley does work.

[Boxster44]

... sorry, I asked the question the wrong way. I know it doesn't create HP, I was just surprised at the estimate of 10 extra available to the drive train... that's pretty darn good for just an external pulley change.

I've been thinking about the pulley and instead of full A/C delete, just go with the shorter belt and eliminate the A/C drag from the equation. This pushes me a little farther along.

You're right about the weight, that compressor feels like it weighs 20 lbs. alone... the whole system ought to net 40ish?... no?


thanks,



kj