What Hp Gain Will I Get If I Put A Udp On

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Junior Member
Does anyone know what kind of power gain i will get if i put a under drive pulley on. And what will it help if i do install one. And what kind should i get? Thanks for the help....


Senior Member
I'm not sure what HP gains you'll get but i never did it because it makes everthing turn slower (alternator, water pump, and everthing else that runs from your belt). Just dont think that you'll gain enough from the pulley to make it worth everthing. Just my opinion. LOL


Member of the 20 nut club
the slight power gain will be far out weighed by the price of replacing the alternator every other oil change

id strongly suggest finding HP elsewhere


Senior Member
Very little gain, completely not worth the money unless you have already done everything else.


Senior Member
It just an oversized version of the regular crank pulley. Bigger pulley = less power needed to turn the belt so you gain back a few HP. Definetly not worth it.


Junior Member
Buying a crank pulley is definitely worth every penny. I have an Unorthodox crank pulley and I can actually FEEL a difference once I installed it. Considering the stock 1.6 sohc pulley weight of 6 lbs and the Unorthodox pulley's weight of 0.5 lbs!, you are saving 5.5 lbs of rotating mass off of the crank, which in turn helps the car rev faster and have a lot less load under acceleration. The gain in HP is not really from any under/overdrive of the pulley, but instead from the weight savings, when you're talking about the crank pulley. Other pulleys such as the alternator, and P/S pulley gains power thru underdriving, not weight. I have had Crank pulleys in two previous cars and everything ran perfect. No dead alternators. But only the Unorthodox pulleys are worth the money. Other ones are junk.


it just underdrives the accesorys, ie. ps pump, alternator, ac. The waterpump is timing belt driven, which will have to effect with the underive crank pulley. I had one on my d16 and did notice a difference, although the battery is never fully charged due to the slower turning of the alternator, ive since had to replace my 1 yr old bat. due to it always going dead.